Across
- 2. system the sun together with all the planets and other bodies that revolve around it
- 4. the planet third in origin from the sun
- 5. the force that pulls things toward the center of Earth
- 7. any groups of stars to which definite names have been given, such as Ursa Major, Orion
- 10. bang theory a theory that deduces a cataclysmic birth of the universe from the observed expansion of the universe, cosmic background radiation, abundance of the elements, and the laws of physics (also the name of a popular TV show)
- 12. a mass of dust and gas moving about the sun in an irregular orbit, may have a tail that streams away from the sun
Down
- 1. space explorer
- 3. a piece of a comet, traveling through space, that enters Earth's atmosphere and falls to the ground
- 6. an optical instrument for making distant objects appear larger and therefore nearer
- 8. the star that is the central body of the solar system, around which the planets revolve and from which they receive light and heat
- 9. the curved path a planet follows around the sun
- 11. any of the heavenly bodies, except the moon, appearing as fixed luminous points in the sky at night
- 13. Earth's natural satellite