Across
- 1. something that orbits a planet
- 3. the gases around a planet
- 7. the only planet with humans
- 8. illuminates the solar system
- 9. earth's sister planet
Down
- 1. the red planet
- 2. planets with rocky outsides
- 4. move repeatedly around
- 5. the planet closest to the sun
- 6. planets that are closer to the sun