| A | B |
|---|
| geocentric | A description of the solar system in which all of the planets revolve around the Earth. |
| heliocentric | A description of the solar system in which all of the planets revolve around the sun. |
| ellipse | an elongated cicle, or oval shape; the shape of the planets orbits |
| inertia | The tendency of a moving object to continue in a straight line or a stationary object to remain in place |
| Ptolemy | thought that earth is at the center of the system of planets |
| Coperincus | thought that the sun is at the center of the planets. Galileo's observation supported capernicus's theory |
| Kepler | decovered that the orbits or the planets are ellipes. |
| planet | five points of light that seem to wander among the stars |
