1. Section 4 – pg 488 Earth’s Moon
Chapter 12
Section 4 – pg 488
Earth’s Moon

2. In 1609, the Italian scientist Galileo heard about a telescope and decided to build his own
He saw that the moon has a irregular surface with a variety of remarkable features
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3. Pg 489
The Moon’s Surface
Features on the moon’s surface include maria, craters, and highlands

4. Maria Maria: the moon’s surface has dark flat areas Pg 489
Galileo thought these were oceans
Actually are hardened rock formed from huge lava flows that occurred between 3 and 4 billion years ago

5. Craters Craters: large round pits Pg 489
Caused by the impacts of meteoroids (chunks of rock or dust from space)
The moon’s craters formed before the maria formed
These formations have not changed because the moon has no water or wind to wear them down

6. Pg 489
Highlands
Some of the light-colored features are highlands, or mountains

7. Characteristics of the Moon
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Characteristics of the Moon
The moon is dry and airless
Compared to Earth, the moon is small and has large variations in its surface temperature

8. Size and Density The moon is 3,476 km in diameter
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Size and Density
The moon is 3,476 km in diameter
This is a little less than the distance across the United States and a quarter the diameter of Earth
The moon’s density is similar to Earth’s outer layer

9. Temperature and Atmosphere
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Temperature and Atmosphere
On the moon’s surface, temperatures range from a torrid 130oC in direct sunlight to a frigid -180oC at night
Temps vary so much because there is no atmosphere
The moon’s gravity is too weak to keep gases from escaping into space

10. Water The moon has no liquid water
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Water
The moon has no liquid water
However, there is evidence that there may be large patches of ice near the moon’s poles

11. The Origin of the Moon Pg 491 Collision-Ring Theory
Scientists theorize that a planet-sized object collided with Earth to form the moon
Material from the object and Earth’s outer layers was ejected into orbit around Earth, where it formed a ring
Gravity caused this material to combine to form the moon

12. Chapter 12 Section 4 Homework - Pg 491

13. 1A. Name three major features of the moon’s surface.

14. 1B. How did the moon’s craters form?

15. 1C. Why is the moon’s surface much more heavily cratered than Earth’s surface?

16. 2A. Describe the range of temperatures on the moon

17. 2B. Compare Earth and the moon in terms of size and surface gravity

18. 2C. What is the relationship between the moon’s surface gravity, lack of an atmosphere, temperature range?

19. 3A. What theory best describes the moon’s origin?

20. 3B. What was the solar system like when the moon formed?

21. 3C. Explain the various stages in the formation of the moon