1. Solar System 6th Grade Science

2. Earth Center Greeks Noticed that dots in sky moved Called them planets (wanderer) Romans Gave these wanderers names of Gods (current names) Ptolemy’s Model Earth as center (Geocentric) Accepted for 1,500 years (good approximation)

3. Sun at Center Heliocentric Copernican (1543) Not accepted easily Tycho Brahe (1580) Orbits could not be circular Kepler (1601) Orbits are Ellipse (Matched observations perfectly) Galileo (1610) Used telescope to show moons circle other planets Church reacted violently to his work

4. Planets Mercury Small planet Dense metal 430 °C to -170°C

5. Venus Same size as Earth Hottest planet 460°C average temp.

6. Earth

7. Mars Same as land area on Earth -87°C to -5°C

8. Jupiter Gas giant (spot) -148°C

9. Saturn Gas Giant (largest rings) -178°C

10. Uranus Gas Giant (Strange orbit) -216°C

11. Neptune Gas Giant -214°C

12. Pluto Not a planet (size of our moon) Not in same plane as rest of planets (Comets)