Across
- 4. cloud where comet nuclei orbit
- 11. trans-Neptunian objects abbreviation
- 14. planets like Neptune and Uranus
- 16. conversion of free gas atoms or molecules into a liquid or solid.
- 19. the solid remains of a meteor that falls to Earth
- 20. interstellar grains come together and form these
- 23. type of rocky planets similar to Earth
- 24. a stream of ionized particles evaporated from a comet and then swept away from the Sun by the solar wind
- 25. the gaseous atmosphere surrounding the head of a comet.
Down
- 1. the region where asteroids are located
- 2. the conversion of ultraviolet light into visible light
- 3. Mercury, Venus, Earth, and Mars
- 5. the force exerted by radiation on matter
- 6. planet not orbiting our Sun
- 7. planets like Jupiter and Saturn
- 8. a cloud of dust and gas in between stars
- 9. a region from which some comets come
- 10. type of giant, gaseous planets
- 12. Jupiter, Saturn, Uranus, and Neptune
- 13. the Sun, planets, their moons, and other bodies that orbit the Sun
- 15. a comet tail containing dust that reflects sunlight
- 17. a small, generally rocky, solid body orbiting the Sun and ranging in diameter from a few meters to hundreds of kilometers.
- 18. a small body in orbit around the Sun, consisting of a tiny, icy core and a tail of gas and dust
- 21. the plume of gas and dust from a comet
- 22. a "shooting star"