Origin of the Solar System

1. Origin of the Solar System

2. Credit for the nebular hypothesis is given to: • Immanuel Kant (1755) • Pierre-Simon Laplace (1796)

3. Nebular Hypothesis The nebular hypothesis suggests that all bodies of the solar system formed from an enormous nebula. This nebula was made mostly of hydrogen and helium. There was a small amount of heavier elements present. This event began about 4.6 billion years ago.

4. Nebular Hypothesis The matter that made up the nebula began to contract because of gravity between the particles.

5. Nebular Hypothesis A nearby supernova caused the nebula to start spinning. As matter moved to the middle, the nebula rotated faster.

6. Nebular Hypothesis As the nebula rotated faster it flattened into a disk. The matter in the center formed a protosun (beginning sun). The rocky material outside of the protosun formed planetesimals (small pieces that would become a planet).

7. Nebular Hypothesis Nuclear fusion began and the Sun became a star. This marked the end of contraction. The planetesimals collided together to form the protoplanets (beginning planets). Protoplanets collided to form the planets. Smaller pieces formed meteoroids and asteroids.

8. Nebular Hypothesis The solar wind blew hydrogen and helium from most of the solar system. The planets would sweep out the excess gas and dust as they moved around the sun. The solar system had formed. 99.86% of the solar system’s mass is in the Sun.

9. Nebular Hypothesis The terrestrial (inner) planets collected rocky material. The Jovian (outer) planets collected ice and gases.

10. Review of the Nebular Hypothesis