Across
- 3. Greek astronomer who said planets moved in small circles carried along in bigger circles.
- 6. Model system where the Earth and other planets revolve around the sun.
- 7. Discovered Jupiter's four moons and proved not everything revolved around Earth.
Down
- 1. Discovered that planets orbit in ellipse.
- 2. Person who figured out the arrangements of the known planets and how they moved around the sun.
- 4. Model system where the Earth is at the center of the revolving planets and stars.
- 5. An oval shape