Across
- 2. An invisible force that pulls towards Earth
- 5. The amount of matter in something
- 8. The heaviness of an object; the force of gravity on mass = weight
- 9. Making a complete turn around another object
- 11. The layer of gas surrounding planet Earth that is held in place by gravity
Down
- 1. Bowl-shaped indents on the surface of a planet, moon, or asteroid that are caused by collision with another object
- 3. Making a complete spin on an axis
- 4. A natural satellite that orbits a planet, some planets have no moons, and others have over 60 moons
- 6. An imaginary line that Earth rotates around
- 7. The star at the center of the solar system that supplies heat and light to Earth; it's enormous gravity keeps the solar system in orbit
- 10. The third planet from the sun and the only planet in the solar system where life exists
- 12. The path one object takes as it revolves around another object in space