Across
- 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
Down
- 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