Across
- 3. Planet furthest from the sun
- 4. Force that keeps a planet moving in orbit
- 6. A star and the planets orbiting around it
- 9. Planet closest to the sun
- 11. Planet named after Roman goddess of love and war
- 13. Layer of gas that surrounds a planet
Down
- 1. Largest planet in our solar system
- 2. Now called a dwarf planet
- 5. Covers 70 percent of the Earth's surface
- 7. Closest star to Earth
- 8. Planet named after Roman god of agriculture
- 9. Our solar system is part of this galaxy
- 10. Third largest planet in our solar system
- 12. Nicknamed "The Red Planet"