1. Chapter 23
The Sun-Earth-Moon System
Section 2: The Moon-Earth’s
Satellite
Minersville Area School District
Mr. Motuk

2. Section 2: The Moon-Earth’s Satellite
A. Motions of the Moon
1. The Moon rotates on its axis.
2. The Moon’s rotation takes 27.3 days with the same side
always facing Earth.
3. The moon revolves around the Earth.
a. 1 Revolution takes 27.3 days
4. Because the moon revolves around Earth and Rotates at
the same rate, this is why we always see the same side
of the moon.
5. The moon seems to shine because it reflects sunlight.

3. Section 2: The Moon Earth’s Satellite
Moon Phases
New Moon Waxing Crescent 1st Quarter Waxing Gibbous
Waning
Full Moon 3rd Quarter Waning Crescent
Gibbous

4. Section 2: The Moon-Earth’s Satellite
B. Moon Phases are the different forms the Moon takes in its
appearance from Earth.
1. New Moon-when the moon is between the Earth and the
Sun and cannot be seen.
2. Waxing Phases-more of the illuminated half of the moon
can be seen each night after the new moon.
a. Waxing phases occur between the new moon and the
full moon.
3. Full Moon-when all of the Moon’s lighted side is visible
from Earth.
4. Waning Phases-Less of the illuminated half of the Moon is
visible after the full moon.

5. Section 2: The Moon-Earth’s Satellite
C. Eight Phases of the Moon
1. New Moon
2. Waxing Crescent
a. Right side of moon becomes visible, thin slice.
3. First Quarter
a. Right half of the Moon is visible, left half in
darkness.
4. Waxing Gibbous
a. More than half of the Moon is visible, takes an egg
shape.

6. Section 2: The Moon-Earth’s Satellite
C. Eight Phases of the Moon
5. Full Moon
a. When all of the Moon’s surface facing Earth is lit up and
visible.
6. Waning Gibbous
a. Starts after the full Moon when more than half of the
lighted side is still visible.
b. Sliver of the right side of the moon is in darkness.
7. Third Quarter (Last Quarter)
a. Left half of the Moon is visible, right half is in darkness.
8. Waning Cresent
a. Only a sliver of the left side is visible.
b. Last visible slice before the new moon.

7. Section 2: The Moon-Earth’s Satellite
Phases of the Moon

10. Section 2: The Moon-Earth’s Satellite
D. Eclipses- when the Earth or moon casts a shadow on the
other.
1. Solar Eclipse: The moon moves directly between the
Earth and Sun, shadowing part of the Earth.
a. Under the UMBRA, or darkest part of the shadow, a
total solar eclipse occurs.
i. Only the corona is seen glowing during a total solar eclipse.
(see next slide)
b. A partial solar eclipse happens in the lighter shadow on
Earth’s surface called the penumbra.
c. A total solar eclipse is visible only on a small area of
Earth.

11. Section 2: Solar Eclipse
1. Solar Eclipse (continued)
d. Blocks the view of the sun.
e. Occur during New Moon
f. Occur every year, only seen in specific areas.

12. Section 2: Solar Eclipse
Images of Solar Eclipses
Total Solar Eclipse
Partial Solar Eclipse

13. Section 2: The Moon-Earth’s Satellite
Solar Eclipse Video:

14. Section 2: The Moon-Earth’s Satellite
2. Lunar Eclipse
a. When the moon passes into Earth’s Shadow
b. Partial Eclipse occurs when the moon is in the
Penumbra.
c. Total eclipse occurs when the moon is in the Umbra.
d. Total eclipse must occur during Full Moon (about once
a year)
e. Moon turns a blood red color.

15. Section 2: Lunar Eclipse

16. Section 2: The Moon-Earth’s Satellite
E. The Moon’s Surface
1. Has many depressions or craters, formed from
meteorites, asteroids, and comets.
2. Cracks in the Moon’s crust caused lava to fill large craters
forming maria, or dark flat areas.
3. Highlands are areas on the moon of light colored crust.
4. Igneous maria rocks are 3 to 4 billion years old, indicating
craters formed after the surface cooled.
5. Lunar dirt called REGOLITH (rock particles and dust)
a. This is not soil because it contains no water or organic matter.

17. Section 2: The Moon-Earth’s Satellite
E. The Moon’s Surface
6. Data from moonquakes suggest that under the Moon’s
crust might lie a solid mantle, then a partly molten mantle
and a solid, iron rich core.
F. The Impact Theory of Moon Origin
1. The Moon formed 4.6 billion years ago from Earth material
thrown off when a large object collided with Earth.

18. Moon’s Surface
Mare Imbrium
Mare Serenitatis
Copernicus
Kepler
Mare Tranquillitatus
Tycho
Notice the rays
from Tycho

19. Section 2: The Moon-Earth’s Satellite
G. Moon Data
1. The Moon’s average day time temperature is 214*F.
2. The Moon’s average night time temperature is -300 *F
3. Moon’s gravity is 6X lighter than the Earth’s.
4. The Moon has no atmosphere so it is always black
there.
5. Moon’s diameter is 2160 miles.