The Solar System

1. a planet that orbits a star outside of our solar system
3. a small, rocky object that orbits the Sun
5. the name given to the four inner planets: Mercury, Venus, Earth, and Mars ("relating to earth")
10. light and dark bands on some gas giant planets
13. (LY) the distance light travels in one year
15. compares orbital period and radius of orbit of a planet to other planets; gives description of time and distance for orbit
18. the time required for a body to complete a single orbit, one year
19. states that each planet orbits the sun in a path called an ellipse, not a circle
20. planets similar to gas giants, but with a higher concentration of ammonia and methane in their atmosphere

2. describes the speed at which objects travel at different points in their orbits
4. the sun-centered model of the solar system
6. the movement of one object around another, one year
7. (AU) the average distance between the earth and the sun
8. half of the major axis
9. the spinning of an object on its axis, one day
11. Planet a celestial body resembling a small planet but lacking certain technical criteria that are required for it to be classed as such
12. a region of the solar system that is just beyond the orbit of Neptune and that contains small bodies made mostly of ice
14. the name given to the four outer planets: Jupiter, Saturn, Uranus, and Neptune ("relating to Jupiter")
16. a large planet that consists mostly of gases in a dense form
17. a representation of the universe in which starts and planets revolve around Earth, Ptolemy's proposed model