Across
- 5. to travel around
- 6. a structure in space made of gases in which nuclear fusion reactions occur
- 8. full journey around the sun
- 9. the planets furthest from the sun
- 10. a meteoroid that has entered Earth's atmosphere
- 13. a round depression formed on the surface of a planet by a meteorite
- 14. the planets closest to the Sun
- 15. a meteoroid that strikes a planet or a moon
Down
- 1. full turn or complete spin
- 2. orbiting objects made of gas, dust, and ice
- 3. small, rocky objects in space
- 4. when a planet's atmosphere traps solar energy and causes the surface temps. to rise
- 7. small, rocky particle that moves through space
- 11. distance of 150 million km. from Earth to the Sun
- 12. has less mass than any of the eight planets, orbits the sun, and is not a moon