1. Aristotle-ancient Greek scientist, lived over 2300 years ago. Taught that the Earth was the center of the Solar System.
2. Ptolemy- another ancient Greek scientist, believed in Aristotle. Wrote a book and made drawings to explain how the geocentric system worked.
3. geocentric model- belief that ALL objects in the solar system orbited around the Earth, that Earth did NOT move and was the center of the universe.
4. heliocentric model-the Sun is the center of our solar system and the Earth is orbiting the Sun.
5. Copernicus- Polish astronomer who thought of the heliocentric model. He wrote a book, was afraid to publish until dying, fear of the Church.
6. Kepler-German scientist who supported the heliocentric model.
7. Galileo-Italian scientist who used a telescope to prove that the heliocentric model was correct.
8. Sir Isaac Newton-English scientist who defined gravity and explained how gravity proved the heliocentric model was correct.
9. gravity-force that holds the solar system together.