Across
- 3. a gigantic explosion in which a massive star collapses and throws its outer layers into space; plural supernovae
- 9. a small, rocky object that orbits the sun, usually in a band between the orbit of Jupiter and Mars
- 12. a collection of stars, dust and gas bound together by gravity
- 14. an object so massive and dense that not even light can escape its gravity
- 17. the portion of Earth that is water
- 18. one of the highly dense planets nearest to the sun; Mercury, Venus, Earth, and Mars
- 21. the change in the illuminated area of one celestial body as seen from another celestial body;phases of the moon are caused by the position of Earth,the sun,and the moon
Down
- 1. a large celestial body that is composed of gas and emits light; the sun is a typical star
- 2. a model for the formation of the solar system in which the sun and planets condense from a cloud (or nebula) of gas and dust
- 4. a large cloud of dust and gas in interstellar space; a region in space where stars are born or where stars explode at the end of their lives
- 5. a small, hot, dim star that us the leftover center of an old star
- 6. a large, reddish star late in it's life cycle
- 7. a planet that has a deep, massive atmosphere, such as Jupiter, Saturn, Uranus, or Neptune
- 8. an event in which the shadow of one celestial body falls on another
- 10. contains the sun and all of the planets and other bodies that travel around in it
- 11. Any of the nine primary bodies that orbit the sun; a similar body that orbits another star
- 13. the distance that light travels in one year; about 9.5 trillion kilometers
- 15. a small body of ice, rock, and cosmic dust loosely packed together that follows an elliptical orbit and that gives off gas and dust in the form of a tail as it passes close to the sun
- 16. a natural or artificial body that revolves around a planet
- 19. a accumulation of matter
- 20. a group of stars bound by gravity