Transcript Astronomy Chapter 1 Earth, Moon and Sun Earth in Space Section 1 Vocabulary       Astronomy: the study of the moon, stars and other objects in space Axis:

Astronomy Chapter 1
Earth, Moon and Sun
Earth in Space
Section 1
Vocabulary
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Astronomy: the study of the moon, stars and
other objects in space
Axis: The imaginary line that passes through
Earth’s center and the North and South poles
Rotation: Earth’s spinning on its axis
Revolution: The movement of one object around
another object
Orbit: Earth’s path around the sun
Latitude: the measurement of distance from the
equator expressed in degrees north or south
Vocabulary
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Solstice: The day when the noon sun is directly
overhead. (there is a winter and a summer
solstice)
Equinox: when nighttime and daytime are about
the same
Vernal equinox: the spring equinox that occurs
around March 21 and marks the beginning of
spring in the Northern Hemisphere
Autumnal equinox: the fall equinox that occurs
around September 23 and marks the beginning
of fall in the Northern Hemisphere
Main Ideas
Earth’s rotation on its axis causes day and
night
 Earth has seasons because its axis is
tilted as it moves around the sun
 Earth’s axis is tilted at an angle of 23.5
degrees
 It is warm near the equator because
sunlight hits Earth’s surface directly and is
less spread out
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Guiding Questions
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Why do the sun and moon seem to move each
day?
Explain the process that causes day and night
What two factors cause the cycle of the
seasons?
Compare rotation and revolution
What do the words solstice and equinox mean?
How are they related to the position of Earth’s
axis?
Phases, Eclipses, and Tides
Section 2
Vocabulary
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Phases: The different shapes of the moon you see from
Earth
Eclipse: occurs when an object in space comes between
the sun and a third object, and cases a shadow on that
object.
Solar eclipse: occurs when the moon passes between
Earth and the sun, blocking the sunlight from reaching
Earth
Lunar eclipse: occurs at a full moon when Earth is
directly between the moon and the sun.
Umbra: the darkest part of the moon’s shadow
Penumbra: the larger part of the shadow of the sun that
is visible from Earth
Vocabulary
Tides: the rise and fall of water very 12.5
hours or so
 Gravity: a natural force that pulls the moon
and earth toward each other.
 Spring tide: the combined forces produce
a tide with the greatest difference between
low and high tide
 Neap tide: a tide that is produced with the
least difference between low and high tide
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Main Ideas
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The positions of the moon, Earth, and the sun
cause the phases of the moon, eclipses, and
tides
The phase of the moon you see depends on how
much of the sunlit side of the moon faces Earth
When the moon’s shadow hits Earth or Earth’s
shadow hits the moon, an eclipse occurs
Tides occur mainly because of differences in how
much the moon pulls on different parts of Earth
Guiding Questions
How many days does it take the moon to
revolve once around Earth?
 Since the moon does not produce light,
how can you see it?
 Why are a day and a year on the moon the
same length?
 Why are there two high tides and two low
tides each day?
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Rockets and Satellites
Section 3
Vocabulary
Satellite: any natural or artificial object that
revolves around an object in space, just as
the moon revolves around Earth
 Geosynchronous orbits: orbits that revolve
around Earth at the same rate that Earth
rotates
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Main Ideas
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A rocket moves forward when gases expelled
from the rear of the rocket push it in the opposite
direction
Satellites and space stations are used for
communications, navigation, collecting weather
data, and research
Multistage rockets have three states or sections.
Each of the first two stages burns all its fuel and
then drops off. The next stage then takes over.
Only part of the third stage reaches the rocket’s
destination.
Guiding Questions
How does a rocket work?
 Describe three uses of satellites and
space stations
 Which stage of multistage rocket reaches
the final destination?
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Earth’s Moon
Section 4
Vocabulary
Telescope: a device built to study distant
objects by making them appear closer
 Crater: a round pit on the moon’s surface
 Maria: Dark, flat regions on the moon’s
surface
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Main Ideas
Features, on the moon’s surface include
craters, highlands, and maria
 Much of what scientists have learned
about the moon came from detailed study
of the moon rocks
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Guiding Questions
Name three kinds of features that Galileo
saw on the moon’s surface
 What did the Apollo astronauts do on the
moon?
 How did the craters form on the moon?
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