| __ | 1. | Brahe | | A. | Greek astronomer believed earth at center |
| __ | 2. | Copernicus | | B. | planets,moons,asteroids,comets orbit sun |
| __ | 3. | Galileo | | C. | planets, sun, and moon orbit the earth |
| __ | 4. | geocentric | | D. | German mathematician discovered shape of planets orbit |
| __ | 5. | heliocentric | | E. | Polish astronomer first to believe in heliocentric system |
| __ | 6. | inertia | | F. | Greek meaning wandering stars |
| __ | 7. | Isaac Newton | | G. | English, Gravity and inertia work to keep planets in orbit |
| __ | 8. | Kepler | | H. | the tendency of an object to move in a straight line |
| __ | 9. | Planets | | I. | 1st to use telescope,found moons revolving around Jupiter |
| __ | 10. | Ptolemy | | J. | Danish,studied planet-20 years,accurate observations |