Across
- 4. Forms behind comets when it is close to the sun
- 7. A cloud of icy planetesimals
- 8. Long line of asteroids that lies between Mars and Jupiter
- 10. When several meteors enter Earth's atmosphere at the same time
- 11. The distance from the sun to the Oort Cloud
- 12. A meteor after it has collided with Earth's surface
- 15. One of the frozen gases in the nucleus of a comet, has the chemical formula CO
- 18. Orbits the sun but is not a planet due to size or not being spherical
- 19. The abbreviation for Trans-Neptunian objects
- 21. The center of a comet
- 23. One of the frozen gases in the nucleus of a comet, has the chemical formula CH4
- 25. The most visible part of a comet
- 26. The area of space beyond the orbit of Neptune
- 27. One of the frozen gases in the nucleus of a comet, has the chemical formula CO2
- 28. The time it takes for Halley's comet to pass Earth's orbit
- 29. The distance from the sun to the Kuiper Belt
- 30. Another name for comets
Down
- 1. Large asteroids might have these
- 2. The direction a comet's tail will face
- 3. The tail of comets is formed from this
- 5. Objects that orbit the sun at a farther distance than Neptune
- 6. Objects made of ice and a rocky core with two tails
- 9. The range of the center of a comet
- 13. A small, rocky object from space that is heated as it enters Earth's atmosphere
- 14. One of the most famous comets
- 16. The eighth planet in the solar system
- 17. Something an asteroid lacks
- 20. The type of orbit comets have
- 22. A meteor before it has entered Earth's atmosphere
- 24. One of the frozen gases in the nucleus of a comet, has the chemical formula NH3