Across
- 4. large body in orbit around a star that develops into a planet.
- 6. a dwarf planet (closest to the sun).
- 7. determining how old materials are.
- 10. rocky mass smaller than a planet that orbits the Sun.
- 11. a gas planet.
- 12. related to the moon.
Down
- 1. small body of gas and dust that could become a planet.
- 2. impact from meteorites.
- 3. gravity causes matter to come together.
- 5. hot dense gas that can develop into a star.
- 8. belt of asteroids
- 9. a rocky planet.