Across
- 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. an event in which the shadow of one celestial body falls on another.
- 7. one of the highly dense planets nearest to the sun; Mercury, Venus, Earth, and Mars
- 10. a planetlike body that orbits a star other than the sun.
- 11. The solar system is about _____ years old.
- 12. The fastest moving plant.
- 14. the change in the illuminated area of one celestial body as seen from another celestial body; phases of the moon are caused by the positions of Earth, the sun, and the moon
- 16. This planet is hot, and its atmosphere contains large amounts of sulfuric acid.
- 17. a natural or artificial body that revolves around a celestial body that is greater in mass.
- 18. a small body of ice, rock, and cosmic dust 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.
Down
- 1. celestial body that orbits the sun, is round because of its own gravity, but has not cleared its orbital path.
- 3. a planet that has a deep, massive atmosphere, such as Jupiter, Saturn, Uranus, or Neptune
- 5. a large cloud of dust and gas in interstellar space; a region in space where stars are born.
- 6. a celestial body that orbits the sun, is round because of its own gravity, and has cleared the neighborhood around its orbital path
- 8. is a large cloud of dust and gas in space
- 9. the portion of Earth that is water.
- 13. Which outer planet is the largest gas giant?
- 15. a small, rocky object that orbits the sun; most asteroids are located in a band between the orbits of Mars and Jupiter.
- 17. the sun and all of the planets and other bodies that travel around it.
- 19. the only planet we know that sustains life.