Across
- 5. Polish Scientist that suggested the sun was the center of the universe
- 6. Orbital motion that is in the opposite direction of what it is orbiting
- 10. the average distance between the sun and Earth
- 11. something that could or did come together with many others to form a planet
Down
- 1. the point of orbit where it is furthest away from the sun
- 2. one of two fixed points used to define an ellipse
- 3. the point of orbit where it is closest to the sun
- 4. German astronomer that showed that Earth's orbit was an ellipse oval rather than a circle
- 7. First person to use telescope to observe the sky
- 8. the shape of a planet's elliptical orbit
- 9. the shape of planets orbits
- 12. First to have in depth understanding of gravity