Transcript Big Idea 5: Earth in Space and Time

By Mrs. Shaw
Chapter 1: Earth, Moon, Sun
 Learning Goals:
 Students will be able to
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explain the difference between revolution and rotation and
how these terms are related to time on Earth.
explain how the tilt of the Earth causes seasons on Earth.
explain what causes the phases of the moon and describe
them.
create a distance – time graph to show distances between
objects in space.
compare and contrast the geocentric and heliocentric models
of the solar system.
Lesson 1: Earth in Motion
What causes the
Earth to be heated
unevenly?
The Sun produces light
and thermal energy
through a process called
nuclear fusion.
 Light and heat from the sun is
more spread out at the poles
and more direct at the
equator due to the Earth’s
spherical shape.
Differentiate between
the terms – rotation and
revolution and explain
their relation to the
Earth’s motion.
 Earth rotates
counterclockwise (spins)
on it’s axis fully every 24
hours. The effect of this
is the day/ night cycle.
 Earth revolves around
the sun every 365.24
days.
What causes seasons?
 Seasons are caused by
the tilt of the Earth on
it’s axis (23.45 degrees)
 When the northern
hemisphere is
experiencing summer
the southern
hemisphere is
experiencing winter.
What is the difference
between the terms
solstice and equinox?
Solstices happen when the tilt of the Earth is either
towards or away from the Sun.
Equinoxes happen when the tilt of the Earth is NOT
towards or away from the sun . . . . .so both hemispheres
get equal sunlight.
Summer Solstice
in the Northern
hemisphere
happens when the
tilt of the Earth is
toward the Sun.
Winter Solstice in
the Northern
hemisphere
happens when the
tilt of the Earth is
away from the
Sun.
Lesson 2: Earth’s Moon
How do we see the
moon?
 We are only able to see the
What is the Moon?
 Our Moon is a satellite of
Moon because the sunlight is
reflected off of it.
Earth, made of a large hard
rock with no atmosphere, no
water, and no plate tectonics.
Earth, Moon, Sun Comparisons
•Distance from the Earth to the Sun - 149,597,890 km
,
•Distance from Earth to the Moon - 384,467 km
•Diameter
•Sun - 1,391,940 km
•Earth - 12,742 km
•Moon - 3,476 km
•The diameter of the Sun is about 100 times bigger than the Earth and 400 times
bigger than the Moon.
•If the Sun was as big as a soccer ball, the Earth would be about the size of a small
dried pea. The distance between them would be 2.3 m.
•You could fit 107 Suns between the Sun and the Earth
http://sciencenetlinks.com/interactives/messenger/psc/PlanetSize.html
How does the Moon
revolve around the
Earth?
 Gravity and inertia both act
on the Moon to cause it to
revolve around the Earth.
Review: Inertia
is the ability of
an object to
resist a change
in motion.
The Moon’s rotation and revolution
How long does it
take for the Moon to
revolve around the
Earth?
 The moon revolves around the
How often does the
Moon make one full
rotation?
 The moon rotates on its axis
How do we only see
one side of the
moon?
 Because the Moon rotates at the
Earth every 27.3 days.
every 27.3 days.
same rate it revolves, we always
see the same side of the Moon.
Why do we see different shapes of the moon?
Lunar phases are the result
of looking at the illuminated
half of the Moon from
different viewing angles.
Waxing phases are when the
moon appears to be getting
larger.
Waning phases are when the
moon appears to be getting
smaller
Lesson 3: Eclipses and Tides
 Lunar eclipse: when the moon
Differentiate
passes through Earth’s shadow and
between a solar and
it is either not visible or appears
a lunar eclipse.
orange.
 Solar eclipse: when the moon
passes between the Earth and the
Sun and causes the sun to be
blocked.
Why do we not have a solar and lunar eclipse somewhere
on Earth every month?
Because the moons orbit is
tilted about 5 degrees it
usually passes just above or
below the Earth’s shadow so
we only see a lunar eclipse
about every 6 months.
Solar eclipses can only be seen
when the umbra of the
Moon’s shadow sweeps across
Earth’s surface. The track
(Path of Totality) is usually
10,000 miles long but only 100
miles wide. It can only be seen
for a few minutes before it
moves.
What causes tides and how are they related to the phases
of the moon?
Tides are caused by
the gravitational
pull of the Moon on
the Earth’s oceans.
Tides are highest
when the moon,
earth, and sun line
up and the net force
is increased.
Review of
Universal Law of Gravitation
 Law states that “every
object with mass has a
gravitational pull on
every other object with
mass”.
 The amount of
gravitational pull
depends on two things:
mass and distance.
What are Spring and Neap Tides?
 Spring Tides happen
when the moon, earth,
and sun line up. (full
and new moon)
 Neap Tides happen
when the moon is at a
right angle to the sun (1st
and 3rd quarter moon).
Geocentric vs. Heliocentric
Chapter 2: The Solar System