1. Outer Space Chapters 25 and 26

2. 1. Solar System Made up of: Sun (a.k.a. star) Planets Moons (yes plural) Other small objects

3. 2. Models of solar system Geocentric – Earth is stationary and everything moved around it Heloicentric – Earth and other planets move around the sun

4. Heloicentric – Earth and other planets move around the sun Aristarchus (Greek), Copernicus (Polish), Galileo Galilei (Italian)

5. 3. Heliocentric Explains: – Earth is not only revolving around the sun but it is rotating on an axis – Motion of sun, moon, and stars

6. 4. Planetary Orbits Johannes Kepler, (1600) discovered that planet orbit the sun in an elliptical path. Newton’s laws of motion show that planets are acted on by the gravitational force of the sun Inertia too

7. 5. Components of the Solar System Ancients knew of six planets Telescope discovery 3 more were discovered Uranus 1781, Neptune 1846, Pluto 1930 Pluto has been reclassified as a dwarf planet Mercury and Venus do not have moons