Chapter 11

1. Chapter 11 Section 4 Earth’s Moon

2. I. Big Ideas • What features of the moon can be seen with a telescope? • How did the Apollo landings help scientists learn about the moon?

3. Structure and Origin of the Moon • Moon is 3,476 kilometers in diameter, little less than the distance across the United States • Diameter is only ¼ Earth’s diameter • Moon contains only 1/80 as much mass as Earth • Moon’s average density is about the same density of Earth’s outer layers

5. Theory about Moon’s origin • When Earth was very young, an object at least as large as mars collided with Earth • Material form object and Earth’s outer layers was thrown into orbit around Earth • Eventually material combined to form the moon

6. What does God’s Word say? • Genesis 1:14 • Genesis 1:16 • Psalms 8:3

7. Looking at the Moon from Earth • 1609 Galileo Galilei heard about a device that made distant objects appear closer • Galileo soon made his own telescope • When Galileo pointed his telescope at the moon he was able to see much more detail than anyone had ever seen before.

8. Galileo saw features on the moon’s surface: • Craters • Highlands • maria

9. Craters • Galileo saw round pits • Some were hundreds of kilometers across • For years scientists thought the craters were made by volcanoes • In fact just recently scientists discovered the craters were caused by impacts of meteoroids, rocks from space

10. Highlands or Mountains • Peaks of highlands • Rims of craters • Dark shadows cast across moon surface

11. Maria • Dark, flat areas • Latin word for “seas” • Each one is a “mare” • Galileo thought maria might be oceans • Are actually low, dry areas that were flooded by molten material

12. Missions to the Moon • “I believe that this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the moon and returning him safely to Earth.” • President John F. Kennedy (1961)

13. Between 1964 and 1972 the US and the Soviet Union sent dozens of rockets to explore the moon • Surveyor spacecraft was first to land on moon and prove that the surface was solid • Lunar orbiters photographed the moon’s surface so scientists could find a flat, safe spot for the rocket to land.

14. Moon Landings • July 20, 1969 • Three astronauts circled moon in Apollo 11 • Neil Armstrong and Buzz Aldrin took Lunar Module (Eagle) and flew from main spacecraft to moon • Michael Collins stayed in the Command Module and continued to orbit around the moon.

15. Eagle descended toward flat area on moon’s surface called the Sea of Tranquillity • “Contact light! Houston, Tranquillity Base here. The Eagle has landed.” • After landing Armstrong and Aldrin left Eagle to explore the moon

16. Armstrong first to set foot on moon • “That’s one small step for man, one giant leap for mankind.”

17. On the surface of the moon • Armstrong and Aldrin were only able to stay on the moon for several hours • In later missions astronauts were able to stay on the moon for days instead of hours. • Lunar buggy

18. Moon Rocks and Moonquakes • Much of what scientists have learned about the moon came from detailed study of the moon rocks gathered by astronauts. • Almost all rocks were formed from cooling of molten material. • Some rocks show they have been broken apart by impacts and reformed

19. Astronauts brought measuring instruments to the moon to record some of the meteoroid impacts. • Seismometers on the moon detected weak moonquakes

20. Photos of the Moon • Apollo astronauts circled the moon by rocket and photographed its surface. • Pictures show that the far side of the moon is rougher than the near side and has very few maria.