Across
- 4. equation used find the amount of extraterrestrial life
- 5. the paradox asking where the aliens are
- 6. permanent day and night side
- 8. the presence of ____ indicates life on the planet
- 9. 600 light years away
- 10. Earth has all three forms of this
Down
- 1. mass of 4x the Earth
- 2. Life is based on ____ and water
- 3. searched for microorganisms on the martian surface
- 7. One of Jupiter's moons
- 11. One of Saturn's moons and atmosphere made of nitrogen