Space stuff

6. a steep cliff seen commonly on Mars
11. a small body of matter from outer space that enters the earth's atmosphere, becoming incandescent as a result of friction and appearing as a streak of light.
12. Earth-like planets made up of rocks or metals with a hard surface.
14. bits of comet debris, most no larger than a grain of sand, create streaks of light in the night sky as they burn up in Earth's atmosphere.
15. giant planet composed mainly of hydrogen and helium
16. large objects made of dust and ice that orbit the Sun.
17. when one object in space, like a planet or moon, passes through the shadow of another object in space.
18. Objects in space that range in size from dust grains to small asteroids.

1. the main constituent of gas giant planets.
2. the apparent backward movement of a planet
3. a measure of how circular an orbit is
4. a rock-type object formed in the early solar system from collisions with other objects in the solar system.
5. celestial body resembling a small planet that lacks the needed criteria to be a planet
7. high cool light colored cloud that rises and flows rapidly
8. a doughnut-shaped ring of icy objects around the Sun, extending just beyond the orbit of Neptune from about 30 to 55 AU.
9. low warm dark colored cloud that sinks and flows rapidly
10. a rock that falls to Earth from space
13. the average distance between Earth and the Sun