Across
- 3. the most distant planet from the Sun.
- 5. the only planet known where life exists
- 6. first planet so far away from the Earth
- 8. No planet has sparked the imaginations of humans
Down
- 1. is the one most similar to Earth
- 2. the first of the gas giant planets
- 4. planet made mostly of rock
- 7. is the second largest planet