Across
- 1. dirty snowball
- 3. planet that rotates on its side
- 10. home to 5 dwarf planets
- 11. rock in the earth's atmosphere
- 13. largest planet in the solar system
- 17. closest star to the sun
- 18. 99% of the solar system's mass
Down
- 2. defines solar systems boundary
- 4. smallest gas giant
- 5. where comets are born
- 6. sometimes found in the kuiper belt
- 7. found on the earth's surface
- 8. 3rd planet from the sun
- 9. rotates the sun in 88 days
- 12. rock in space
- 14. least dense planet
- 15. home to olympus mons
- 16. sister planet of the Earth