1. Bell-Ringer
Explain how you believe the Solar System ended up with the Sun in its center.

2. FORMATION OF THE SOLAR SYSTEM (Page 41)

3. EQ 1 – How does gravity affect the solar system?

4. What is Gravity?
Gravity is a force of attraction between all objects in the universe

5. Law of Universal Gravitation
Sir Isaac Newton (1600s)
All objects in the universe attract each other through gravitational force.

6. How did the Solar System Form?
A solar nebula collapsed.
**nebula - a huge amount of space dust and gases
*the explosion of a nearby star caused this to happen

7. Nebula

8. Horsehead Nebula

9. Nebula

10. 2. Gravity pulled the spinning material inward, causing the nebula to flatten into a disk

11. 3. As the disk spins, gravity pulls most of the material into the center, compacting it into a ball. (Protostar)

12. The intense pressure, friction, and heat causes the ball to glow
The intense pressure, friction, and heat causes the ball to glow. It becomes the Sun.

13. 4. Away from the Sun, the trillions of remaining particles of gases, dust, rocks, and ice start colliding together, forming small planetesimals.

14. 5. As planetesimals collided, some became large enough to form the planets. The rest became moons, asteroids, comets, meteoroids, and dwarf planets

15. Solar System – a central star and all the planets and other objects that orbit it.

16. EQ - How does gravity affect the solar system?

17. Bell-Ringer
Scientists from years ago believed the Earth was the center of the Universe. What are some reasons why they might have thought this way?

18. EQ 2 – What causes objects to orbit a star?

19. The sun’s gravitational pull on the planets and other objects keep them in orbit

20. Models of the Solar System

21. Models of the Solar System

22. *Geocentric Model – Earth in the center

23. *Heliocentric Model – Sun in the center

24. Conclusion
Quick Write – Explain how the Solar System might have been affected if the Sun had been much smaller when it was formed?