Across
- 3. billions of comets beyond Pluto
- 4. "dirty snowballs"
- 7. Line planets rotate on
- 9. between Mars and Jupiter
- 12. A meteor that strikes Earth
- 13. largest planets
Down
- 1. distance between Earth and Sun
- 2. first four planets
- 5. meteoroid burning as it enters Earth's atmosphere
- 6. huge chunk of irregularly shaped rocks
- 8. space dust or rock
- 10. planets with no solid surface
- 11. Planets small Earth like planets