Across
- 4. radiation from the sun has burned off most of Mercury's ___
- 5. Known as earth's twin
- 7. mars has frozen ___ under a layer of frozen carbon dioxide
- 9. TV signal part
- 11. Neptune is the smallest of the ___
Down
- 1. Venus is the ____ planet in the sky.
- 2. Mar's length of _____(daylength) is almost the same as planet earth's.
- 3. filters slowly
- 4. uranus was the first new planet discovered since ___ times
- 6. largest of the terrestrial planets
- 8. Uranus has ___ like saturn
- 10. noted literary pseudonym