Our Solar System

2. streak of light produced when a meteoroid falls towards Earth and burns up in its atmosphere
6. high, cool, light-colored cloud that rises and flows rapidly
9. (planet) an object that is spherical in shape, orbits the Sun, is not a satellite, and has not cleared the area of its orbit of smaller debris
11. occurs when Earth intersects a cometary orbit and comet particles burn up as they enter Earth's upper atmosphere
14. region of the space that lies outside the orbit of Neptune
15. an oval that is centered on two points called foci
16. piece of interplanetary material that falls toward Earth and enters its atmosphere
17. a line of cliffs produced by erosion or faulting

1. space object built of solid particles that can form planets through collisions and mergers
3. ratio of the distance between the foci to the length of the major axis (how circular an orbit is)
4. (motion) a planet's apparent backward movement in the sky
5. a small fragment of an orbiting body that has fallen to Earth, generating heat
7. (planets) large, gaseous planet that is very cold at its surface
8. (planets) rocky-surfaced, relatively small, dense inner planets closest to the Sun
10. the average distance between the Sun and Earth
12. a small eccentrically orbiting body made of rock and ice which have one or more tails that point away from the Sun
13. low, warm, dark-colored cloud that sinks and flows rapidly