Across
- 2. has the shortest orbit around the Sun
- 3. the layer of gases varying in thickness and composition around a planet
- 6. the 4 planets in our solar system farthest from the Sun
- 8. Earth's sister planet
- 9. moves repeatedly around
- 10. the 4 planets in our solar system closest to the Sun
Down
- 1. earth-like
- 4. known as the Red planet
- 5. celestial object that orbits a planet
- 7. contains water and oxygen needed for life