Across
- 5. the inward force that causes objects to move in a circular path
- 7. He believed that planets orbit the sun in elliptical paths
- 9. the energy of motion
Down
- 1. the sun and all of the planets and other bodies that travel around it
- 2. he observed the phases of Venus
- 3. when a planet is closest to the sun and orbits the fastest
- 4. a celestial body that is composed of gas and emits light
- 6. an object in motion stays in motion
- 8. a force of attraction between objects