Across
- 2. planet A planet having a rocky surface like Earth's. Also called "terrestrial planet."
- 4. A force of attraction between all objects in the universe that is due to their masses.
- 9. system The Sun and objects that orbit it
- 10. A layer of gases that surrounds a planet, moon, or sun
Down
- 1. A large body in space that orbits a star and does not produce light of its own
- 3. The period of time that it takes a planet to complete one revolution around its star.
- 5. planet Any of the four closest planets to the sun
- 6. giant A large planet composed mainly of gas
- 7. A flattened circle
- 8. an object that orbits a star, is round, not itself a star, and is large enough to have cleared the area of small objects
- 11. The path that a body follows as it travels around another body in space