Across
- 2. largest planet
- 4. closest planet to sun
- 6. our planet
- 8. rock from outer space that hits the earth
- 11. dirty snowballs
- 12. planet gets pulled together by gravity and atmosphere forms
- 15. dust grains that burn up in the atmosphere
- 16. large gas planets
- 18. rock like planets
- 20. basis of modern planet formation
- 21. dust grains in the solar system
- 22. planet that is forming
Down
- 1. heavier elements sink in growing planet
- 3. snowball effect in formation of planets
- 5. next planet out after earth
- 7. large lumpy potatoes like small planets
- 9. small objects outside neptunes orbit
- 10. long period comets
- 13. our star
- 14. between mars and Jupiter
- 17. closest planet to earth
- 19. planet with largest rings