2. The Origin Of Our Solar System There are many theories or Hypothesis of how our Solar System came to be. In this presentation I will go through three of those theories.

3. The Big Bang Theory The most known theory is the Big Bang Theory. According to the most recent observations the Big Bang occurred approximately 13.75 billion years ago, which is the estimated age of the Universe.

4. The Big Bang Theory Continued According to the Big Bang theory, the universe was once in an extremely hot and dense state which expanded rapidly. (The Big Bang) The rapid expansion caused the universe to cool and it resulted in this present continuously expanding state.

5. The Big Bang Theory Simplified. Extreme hot dense atmosphere Start Atmosphere expanded rapidly The Big Bang It Cooled Down and continued to expand. So…

6. The Big Bang This is a picture of the Big Bang that some scientists believe caused our Solar System to be.

7. The Nebular Hypothesis -The start Around 1755 a man named Immanuel Kant hypothesized that the Solar System formed from the collapse of interstellar gas. And about four decades later a man named Pierre-Simon Laplace independently proposed the same Idea.

8. Nebular Hypothesis Continued. And so their ideas were combined to form the Nebular Hypothesis. And this hypothesis was popular during the 19 th century but in the 20 th century it was questioned by scientist who thought it was lacking information. And it later became known as the Nebular Theory.

9. Nebular Hypothesis Collapsing Clouds of Gas and Dust In this Hypothesis, a cloud of gas and dust collapses by gravity, and begins to spin faster because of the angular momentum conservation. Angular momentum basically is when a small objects is moving around in a circular motion around a larger object.

10. Nebular Hypothesis continued The cloud then spins faster and faster as it contracts because of angular momentum conservation. Because of the competing forces such as gravity, gas pressure, and rotation, the contracting nebula then begins to flatten into a spinning pancake shape with a bulge at its center.

11. Nebular Hypothesis continued As the Nebula collapses, local regions begin to contract gravitationally on their own because of the instabilities in the cloud. These local regions of condensation become the Sun, Planets, as well as their moons and debris in our Solar System.

12. Evidence For the Nebular Hypothesis The Nebular Hypothesis provides and explanation for some of the basic facts about our Solar System: the orbits of the planets lie In a nearly plane with the Sun at its center, the planets all revolve and rotate in the same direction.

13. Close Encounter Theory Another way that our Solar System came to be is the Close Encounter Theory. This theory states that the planets formed from debris that had come from a near collision of a star and the Sun.

14. Close Encounter Theory Continued The Theory says that the Planets then formed from gas that was gravitationally pulled from our Sun during the near Collision.

15. OH NO!!! Close Encounter Theory But…. The Close Encounter Theory CANNOT account for the orbital motions of the planets NOR can it account to how the planets are divided into Jovian and Terrestrial. Also the chance of two stars passing close enough together to cause debris is SLIM. And the chances of this happening several times to form all the planets is even more unlikely!

16. What Scientists Believe: Some Scientists believe that our Solar System is continuing to expand, and may continue to expand then suddenly stop, or continue to expand then get smaller and smaller. I Believe that…..

17. My Thoughts: I think our Solar System came to be by the Big Bang theory. They say the Big Bang happened almost instantly, and I believe that. But I think the Big Bang was when God said “Let there be….” I don’t know what you may believe but this is what I believe.

18. What do you think? How do you think our Solar System came to be? Please email me your thoughts solarsystemorigin@gmail.com I would much appreciate it!

19. My Resources: For the Big Bang Theory: http://en.wikipedia.org/wiki/The_Big_Bang_Th eory For the Nebular Theory (Hypothesis): http://csep10.phys.utk.edu/astr161/lect/solarsys/ne bular.html For the Close Encounter Theory and the Nebular Theory: http://ksspaulding.wordpress.com/article/origin-of- the-solar-system-3smazt4fj02nv-11/

20. My Resources continued For angular momentum: http://csep10.phys.utk.edu/astr161/lect/sola rsys/angmom.html