1. Early Astronomy 4/21/15 18-1b pgs. 486-488 IN: Draw a diagram showing rotation and revolution. Open a book to pg. 486

3. Early Astronomers Ptolemy (140 AD) – Earth was center of the Universe (geocentric).

4. Copernicus (1543) – the Sun is the center of the Universe (heliocentric).

5. Tycho Brahe (1546) – Earth was center but the planets orbit the Sun.

6. Kepler (1606) – that all the planets revolve around the sun in elliptical orbits.

7. Galileo (1642)– used a telescope to observe objects in the sky.

8. Newton (1726) – explained inertia and gravity keeps all objects in the orbit.

9. OUT: Is Copernicus’ theory completely correct? Why or why not?