Across
- 3. Large, empty plains resembling bodies of water from earth
- 4. The moon lacks a dense envelope of gases called _?_
- 6. Seismic waves on the moon are called _?_.
- 7. The moon's gravity compared to the earth's.
- 8. Lunar depressions created by impact with meteoroids.
- 9. Long, twisting canyons of unexplained origins
- 11. Light lines of debris ejected from some impact craters.
- 12. a famous crater of the moon's southern hemisphere.
Down
- 1. He's often observed during a full moon
- 2. A weak _?_ doesn't protect the moon from solar wind.
- 5. High hills on the moon's surface.
- 10. His invention, the telescope, revolutionized astronomy.