Across
- 4. called Earth’s “sister planet.”
- 5. everything that exists; all matter and energy; also includes all of space and time.
- 9. an object, either natural or human made, that orbits a larger object
- 10. terrestrial
- 11. holds our planet together
Down
- 1. scientists who study the universe beyond Earth
- 2. an imaginary line that runs from the North Pole to South Pole through the center
- 3. the four planets farthest from the Sun
- 6. rings of dust and rock encircling a planet
- 7. has a short year, orbiting the Sun in just 88 Earth days
- 8. dark, solid, flat areas of lava