Across
- 4. rocky debris that collides with our atmosphere, creating colorful streaks
- 7. the shape of a planets orbit
- 8. a region of space between the orbits of Mars and Jupiter
- 10. long cliffs on mercury's surface
- 11. the area around a star where it is not too hot and not too cold for liquid water to exist
- 12. the average distance between Earth and the Sun
- 13. orbital or rotational motion of an object in the direction opposite the rotation of its primary
- 15. lumps of rock or iron that orbit the sun
- 16. the main constituent of gas giant planets
- 17. a doughnut-shaped region of icy objects beyond the orbit of Neptune
Down
- 1. large planet mostly composed of helium and/or hydrogen
- 2. Earth-like planets made up of rocks or metals with a hard surface
- 3. has not cleared the neighborhood around its orbit and is not a moon
- 4. a small body of matter from outer space that enters the earth's atmosphere
- 5. a rock-type object formed in the early solar system from collisions
- 6. space rocks that fall to Earth's surface
- 9. a measure of how non-circular the orbit of a body is
- 14. large objects made of dust and ice that orbit the Sun