Slide 1

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 2

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 3

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 4

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 5

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 6

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 7

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 8

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 9

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 10

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 11

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 12

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 13

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 14

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 15

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 16

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 17

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 18

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 19

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 20

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 21

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 22

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 23

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 24

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 25

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 26

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 27

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 28

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 29

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 30

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 31

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 32

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 33

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 34

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 35

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 36

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 37

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 38

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 39

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 40

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 41

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 42

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.


Slide 43

The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the big bang.
This theory was born of the observation that other galaxies are moving away from our own at great speed, in all directions, as if they had all
been propelled by an ancient explosive force.

The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with
incomprehensible speed from its pebble-size origin to astronomical scope. Expansion has apparently continued, but much more slowly, over
the ensuing billions of years.

Galaxies are sprawling space systems composed of dust, gas, and countless
stars. The number of galaxies cannot be counted—the observable universe
alone may contain 100 billion. Some of these distant systems are similar to
our own Milky Way galaxy, while others are quite different.

Galileo Galilei was an Italian physicist and astronomer. He
was born in Pisa on February 15, 1564. Galileo's father,
Vincenzo Galilei, was a well-known musician. Vincenzo
decided that his son should become a doctor.
Galileo's observations strengthened his belief in Copernicus'
theory that Earth and all other planets revolve around the
Sun. Most people in Galileo's time believed that the Earth
was the center of the universe and that the Sun and planets
revolved around it.

Nicolaus Copernicus (19 February 1473 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology,
which displaced the Earth from the center of the universe. His heliocentric model, with the sun at the center of the universe,
demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the
universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often
referred to as the Copernican Revolution.

Neil Alden Armstrong (born on
August 5, 1930) is a former
American astronaut. He is the first
person to set foot on the Moon.
Armstrong is
a recipient of the Congressional
Space Medal of Honor.

Buzz Aldrin (born on January 20, 1930) is
an American aviator and astronaut who was
the Lunar Module pilot on Apollo 11, the
first lunar landing. He and mission
commander Neil Armstrong were the first
persons to land on the Moon; shortly
afterward he became the second man to set
foot on the Moon.

Yuri Alekseyevich Gagarin (9 March 1934 – 27
March 1968), Hero of the Soviet Union, was a
Soviet cosmonaut. On 12 April 1961, he became
the first human in outer space and the first to
orbit the Earth. He received medals from around
the world for his pioneering tour in space.

The star of our solar system is a huge Ball of hot, glowing gases. At about 333,000 times the mass of Earth, the
sun contains about 99.8 percent of all the mass in the solar system. Heat and light from this average-size star
travel a mean distance of 92.96 million miles (149.6 million kilometers) to reach Earth and support all life on our
planet.

Distance from Earth: 149,597,891 kilometers
Length of Day: 609 hours, 7 minutes
Surface Temp:5,538 C
Gravity:28 times Earth’s

Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around
it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and
generates space weather.
The sun is a big star. At about 1.4 million kilometers wide. How hot? The temperature is about 5,500 degrees Celsius on the surface and
more than 15.5 million Celsius at the core.
Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy.
The sun's surface, or atmosphere, is divided into three regions: the photosphere, the chromosphere, and the solar corona. The photosphere
is the visible surface of the sun and the lowest layer of the atmosphere. Just above the photosphere are the chromosphere and the corona,
which also emit visible light but are only seen during
a solar eclipse, when the moon passes between the Earth and sun.

Solar eclipses have been recorded as important events by humans for millennia. References have been found in
some of our earliest texts, including ancient Chinese academic documents and even a line from Homer's Odyssey
that declares, "The sun is blotted from the heavens."

It's easy to imagine how our earliest ancestors must have reacted to the sudden disappearance of the sun, and
over time the phenomenon has been seen as both fascinating and terrifying, a signal of the displeasure of the
gods, or an omen of bad things to come.

Mercury's elliptical orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million
kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear
almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 430 degrees Celsius. Because the planet has no atmosphere to retain that heat,
nighttime temperatures on the surface can drop to -170 degrees Celsius.
Because Mercury is so close to the sun, it is hard to directly observe from Earth except during twilight.
Scientists used to think that the same side of Mercury always faces the sun, but in 1965 astronomers discovered that the planet
rotates three times during every two orbits. Mercury speeds around the sun every 88 days.

Venus and Earth are similar in size, mass, density,
composition, and distance from the sun. There,
however, is where the similarities end.
Venus is covered by a thick, rapidly spinning
atmosphere, creating a scorched world with
temperatures hot enough to melt lead and a surface
pressure 90 times that of Earth. Because of its
proximity to Earth and the way its clouds reflect
sunlight, Venus appears to be the brightest planet in
the sky.

Earth, our home, is the only planet in our solar system known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of
complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to
create a constantly changing world that we are striving to understand.

Viewing Earth from the unique perspective of space provides the
opportunity to see Earth as a whole. Scientists around the world
have discovered many things about our planet by working together
and sharing their findings.

Some facts are well known. For instance, Earth is the third planet
from the sun and the fifth largest in the solar system. Earth's
diameter is just a few hundred kilometers larger than that of
Venus. The four seasons are a result of Earth's axis of rotation
being tilted more than 23 degrees.

The moon stabilizes Earth’s wobble, keeping
our climate steady over billions of years.
Rocks brought back from the moon date to
the beginning of our solar system (4.5
billion years ago). We have sent more than
70 spacecraft to the moon, and 12
astronauts have walked on its surface.

A lunar eclipse is an eclipse which occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur
only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, there is always a
full moon the night of a lunar eclipse. The type and length of an eclipse depend upon the Moon's location relative to its orbital
nodes. The next total lunar eclipse occurs on December 21, 2010. The next eclipse of the Moon is a penumbral eclipse on July 7,
2009.

The Red Planet
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and
Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric
effects such as dust storms. It has polar ice caps that grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has changed more than once, perhaps caused by a regular change
in the planet's orbit.

Scientists believe that 3.5 billion years ago, Mars experienced the largest known floods in
the solar system. This water may even have pooled into lakes or shallow oceans. But
where did the ancient floodwater come from, how long did it last, and where did it go?
At present, Mars is too cold and its atmosphere is too thin to allow liquid water to exist
at the surface for long. There's water ice close to the surface and more water frozen in
the polar ice caps, but the quantity of water required to carve Mars's great channels and
flood plains is not evident on—or near—the surface today.

The most massive planet in our solar
system, with four planet-size moons and
many smaller satellites, Jupiter forms a kind
of miniature solar system. Jupiter resembles
a star in composition. In fact, if it had been
about eighty times more massive, it would
have become a star rather than a planet.

Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first
to gaze at Saturn through
a telescope.

Like Jupiter, Saturn is made mostly of hydrogen and helium. Its volume is 755 times greater than that of Earth. Superfast
winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in the
atmosphere.
Saturn's ring system is the most extensive and complex in the solar system. In the early 1980s, NASA's two Voyager
spacecraft revealed that Saturn's rings are made mostly of water ice.

Unusual Uranus
Once considered one of the blander-looking planets, Uranus has been
revealed as
a dynamic world with some of the brightest clouds in the outer solar
system and 11 rings. The first planet found with the aid of
a telescope. The seventh planet from the sun is so distant that it takes 84
years to complete one orbit.
Uranus, with no solid surface, is one of the gas giant planet. Its
atmosphere is composed primarily of hydrogen and helium. Uranus gets
its blue-green color from methane gas.. As the reflected sunlight passes
back through the Uranus cloud tops layer, the methane gas absorbs the
red portion of the light, allowing the blue portion to pass through and
resulting in the blue-green color that we see.

Neptune was the first planet located
through mathematical predictions rather
than through regular observations of the
sky.
The magnetic field of Neptune is about 27
times more powerful than that of Earth.

The world was introduced to dwarf planets in 2006, when
petite Pluto was stripped of its planet status and reclassified as
a dwarf planet.
What differentiates a dwarf planet from a planet? For the most
part, they are identical, but there's one key difference: A dwarf
planet hasn't "cleared the neighborhood" around its orbit,
which means it has not become gravitationally dominant and it
shares its orbital space with other bodies of a similar size.
Pluto's surface is composed of a mixture of frozen nitrogen,
methane, and carbon monoxide ices. The dwarf planet also
has polar caps and regions of frozen methane and nitrogen.
In January 2006, NASA launched its New Horizons spacecraft
en route to Pluto and Charon. It is expected to arrive in 2015
and will be the first spacecraft to visit the distant dwarf planet.

Though too small to earn the distinction of planet, asteroids and comets strike
huge fear in the human mind. And for good reason: at some point in the future,
one of the chunky rocks or icy mud balls will slam into Earth and alter the
course of history. Such an impact 65 million years ago is widely believed to have
killed off the dinosaurs.

Asteroids are essentially chunks of rock that measure in size from a few feet to
several miles in diameter.

Ceres
At one-quarter the diameter of Earth’s moon, Ceres is the largest body in the asteroid belt.
Gaspra
Gaspra is probably made of a mixture of rocky and metallic minerals. Its surface is covered with impact craters.
Vesta
The third largest asteroid in the asteroid belt, Vesta has the most geologically diverse terrain of the large asteroids.

Eros
This odd-shaped body is a near-Earth asteroid found outside the main asteroid belt. Eros may be a chunk knocked off a
larger body, such as another asteroid. It is almost twice the size of Manhattan Island.

Comets are balls of rock and ice that grow tails as
they approach the sun in the course of their highly
elliptical orbits. The glowing trails are visible in the
night sky.
Halley’s Comet
This famous comet is named after the English
astronomer Edmond Halley, who first calculated its
orbit in 1705. The comet makes
a complete orbit around the sun every 75 to 76 years.

There are more than 8,000 artificial objects orbiting Earth. More than 2,500 of these are satellites,
working and dead. The remaining objects are space junk. That doesn’t include the millions of
objects smaller than 1 centimeter.

Hubble Space Telescope (HST)
This telescope is orbit around the Earth is named after astronomer Edwin Hubble and was launches in 1990. Since it is
outside the Earth’s Atmosphere, it has significant advantages over ground-based telescopes and can provide the clearest
space images possible.
Iridium satellites
Exactly 66 of there satellites orbit Earth, forming an active communications satellite network. This constellation of lowEarth orbiting satellites allows worldwide voice and data communication using handheld satellite phones.
GPS Satellites
There are 27 global positioning system satellites in orbit. There satellites transmit precise microwave signals, which GPS
devices. on the ground receive. Using signals from four satellites, these devices determine the precise position of a user.

GOES
Geostationary Operational Environmental Satellites (GOES) monitor weather pattern by orbiting Earth at a speed
matching Earth’s rotation and capturing imagery of cloud cover. GOES satellite images help meteorologists estimate
rain and snow accumulations, issue storm warnings, and monitor hurricanes as they develop in the ocean.
International Space Station (ISS)
The ISS is a research facility currently being assembles in space. The station is a join project funded and sponsored by
space agencies around the world. In November 2000, the station’s first residents began a four-month stay, and it now
has a permanent human presence.
Voyager Space Probes
In 1977 the Voyager 1 and 2 space probes were launched from Earth with primary mission of exploring Jupiter and
Saturn. After making several discoveries there, Voyager 2 was sent on to Neptune and Uranus while Voyager 1 headed
into deep space. Thirty years later, and each farther out than Pluto, the probes are still sending data back to Earth.

Orbital debris, the technical term for nonfunctional and human-made space junk, includes not only whole, abandoned
satellites, but also pieces of broken satellites, deployed rocket bodies, human waste, and other random objects, like the glove
lost by astronaut Ed White during his historic 1965 spacewalk. The oldest known piece of orbital debris is the 1958 Vanguard
1 research satellite, which ceased all functions in 1964. One of the newest is a refrigerator-size ammonia reservoir released
into its own orbit in July 2007, following a NASA decision that no other disposal options were feasible.

Black holes are the cold remnants of former stars, so dense that no matter—not even light—is able to escape their powerful gravitational
pull.
When giant stars reach the final stages of their lives they often detonate in cataclysms known as supernovae. Such an explosion scatters
most of a star into the void of space but leaves behind a large "cold" remnant on which fusion no longer takes place.

With no force to check gravity, a budding black hole shrinks to zero volume—at which point it is infinitely dense. Even the light from such a star is
unable to escape its immense gravitational pull. The star's own light becomes trapped in orbit, and the dark star becomes known as a black hole.
Planets, light, and other matter must pass close to a black hole in order to be pulled into its grasp. When they reach a point of no return they are said to
have entered the event horizon—the point from which any escape is impossible because it requires moving faster than the speed of light.

The National Aeronautics and Space Administration is an agency of the United States government, responsible for the
nation's public space program. NASA was established on July 29, 1958, by the National Aeronautics and Space Act.
In addition to the space program, it is also responsible for long-term civilian and military aerospace research. Since
February 2006 NASA's self-described mission statement is to "pioneer the future in space exploration, scientific
discovery, and aeronautics research."
NASA's motto is "For the benefit of all". The motto of NASA's Office of Education is: Shaping the Future: Launching
New Endeavors to Inspire the Next Generation of Explorers.

Laika was a Soviet space dog who became the first living mammal to
orbit the Earth and the first orbital casualty. Little was known about
the impact of space flight on living things at the time Laika's mission
was launched.
Laika died a few hours after launch, presumably from stress and
overheating, probably due to a malfunction in the thermal control
system. The true cause and time of her death was not made public
until 2002; instead, it was widely reported that she lived for several
days. On April 11, 2008, Russian officials unveiled a monument to
Laika.

Ham (July 1956 – January 19, 1983), also known as Ham the Chimp and Ham the Astrochimp, was the first hominid launched into outer
space. Ham's name is an acronym for the lab that prepared him for his historic mission — the Holloman Aerospace Medical Center,
located at Holloman Air Force Base in New Mexico.

NASA has an exciting new vision of future spaceflight—the return of humans to the moon by 2020 in preparation for visits to Mars
and possibly beyond.
Moon missions are essential to the exploration of more distant worlds. Extended lunar stays build the experience and expertise needed
for the long-term space missions required to visit other planets. The moon may also be used as a forward base of operations on which
humans learn how to replenish essential supplies, such as rocket fuel and oxygen, by creating them from local material.
Such skills are essential to the future expansion of human presence into deeper space.
Future human moon missions will be preceded by robotic reconnaissance launches, between 2008 and 2011, to scout landing sites that
may have the most resources available to astronauts. The moon's south pole is considered particularly promising because it is rich in
hydrogen and may be home to water ice as well.

These new NASA missions are being spearheaded by the development of
a state-of-the-art new spacecraft—but one with a retro feel.
The Orion crew exploration vehicle echoes the design of the original Apollo missions but updates its systems with modern
technology. The new capsules will also be larger, with three times the volume capacity and the ability to accommodate a
four-person crew. The new size has led NASA officials to describe the mission as "Apollo on steroids."
The Orion capsule, which launches attached to a solid rocket booster and Apollo-like upper stage, is seen as a safer and
more reliable design for future space exploration than the now-familiar space shuttle.
The Orion capsules, which may be reused up to ten times, will parachute to Earth like those of yesterday—though they
will arrive on dry land rather than via ocean splashdowns.
In the years beyond 2020, these spacecraft may aid in assembling Mars-bound vehicles in orbit to take the first humans to
the red planet.