Unit 9 Vocabulary

4. Earth-centered; a system of planetary motion in which the sun, moon, and other planets revolve around the Earth
6. A streak of light in the sky produced by the burning of a meteoroid in Earth's atmosphere.
11. Jupiter, Saturn, Uranus, Neptune (gas giants)
13. A meteoroid that passes through the atmosphere and hits Earth's surface.
14. Unit is the average distance between Earth and Sun -150 million KM or 93 million miles
16. He believed in a heliocentric, or sun-centered, conception of the universe. He argued that the Sun was at the center of the universe.

1. states that every object in the universe attracts every other object.
2. The theory that the universe originated in a rapid expansion that released all matter and energy
3. relating to the land
4. A force of attraction between objects that is due to their masses.
5. a frozen ball of gasses and liquids with small amounts of rock in space
7. Italian astronomer and mathematician who was the first to use a telescope to study the stars. His observations confirmed the Heliocentric model.
8. Mercury, Venus, Earth, Mars (terrestrial planets)
9. distance light travels in one year. (about 5.88 trillion miles)
10. sun-centered model of the universe
12. a relatively small, rocky body that travels through space
14. large boulder-type objects in space, these are smaller than planets and can be found orbiting the Sun between Jupiter and Mars
15. a large cloud of dust and gas in space