1. FORMATION OF THE SOLAR SYSTEM Chapter 28.3

2. Began as a solar nebula  Cloud of gas and dust  4 to 5 billion years ago  Fusion began in center SUN! –Triggered by a nearby supernova? –Sun is 99% of the matter in the SS

3. Solar nebula

4. Current dust cloud around a star

5. Formation of planets  Dust is attracted to other dust making PLANETESIMALS (baby planets)  Planetesimals get larger by their gravitational pull attracting more matter creating PLANETS  accreation

7. Formation of planetisimal

8. Planetesimal forming into a planet

9. Rings will eventually coalesce to become planets

10. Formation of planets (cont.)  Heavier elements stayed closer to the sun –Rocky planets –Mercury, Venus, Mars, Earth  Lighter elements went farther from sun –Gas planets –Jupiter, Saturn, Uranus, Neptune

13. Leftovers at the outer edge of the SS  Kuiper belt  Oort cloud