1. 19-4 Earth’s Moon (pages 680–683) 1. Describe features found on the moon’s surface. 2. Identify some characteristics of the moon. 3. Explain how the moon formed.

2. Nasa's Tour of the Moon

3. The Moon’s Surface (page 681) 1. DESCRIBE FEATURES FOUND ON THE MOON’S SURFACE. Key Concept: Features on the moon’s surface include maria, craters, and highlands.

4. A telescope makes faraway objects appear closer.

5. The moon’s surface has dark, flat areas called maria (MAH ree uh). Maria are flat areas of hardened rock.

6. Craters are large, round pits on the moon. Craters were caused when meteoroids crashed into the moon. A meteoroid is a chunk of rock or dust from space.

7. Highlands are mountains that cover most of the moon’s surface.

8. telescope

9. Characteristics of the Moon (page 682) Key Concept: The moon is dry and airless. Compared to Earth, the moon is small and has large variations in its surface temperature.

10. There is no air on the moon. The moon has no atmosphere.

11. The moon is about one-fourth the diameter of Earth.

12. Temperatures on the moon range from very hot to very cold.

13. The moon has no liquid water.

14. cold

15. The Origin of the Moon (page 683) Key Concept: Scientists theorize that a planet-sized object collided with Earth to form the moon.

16. Origins of the Moon

17. Very long ago, big rocks were moving around in space.

18. Scientists think that one of these big rocks may have crashed into Earth. Material from Earth broke off. The broken off portion of Earth became the moon.

19. Answer: The moon may have formed when a big rock crashed into Earth