Across
- 2. the oval-shaped path of a planet around the sun
- 7. the point around which two objects orbit each other
- 8. tides with the smallest difference between high and low
- 9. the theory that the solar system formed from a cloud of gas and dust.
Down
- 1. the rules that describe how planets move around the sun
- 2. a measure of how stretched out an orbit is
- 3. a group of planets that is made mostly by gas and has a large size.
- 4. a unit used to measure distances in the solar system
- 5. a word describing a place where life could exist
- 6. a planet made mostly of rocl or metal