Solar Syst. Formation

Begin with your textbook from lecture, or at the following website for an overview of the nebular theory, the theory of how the sun and its planets formed.

http://www.windows2universe.org/our_solar_system/f…

(A more detailed version is here http://www.windows2universe.org/cool_stuff/tour_evolution_ss_1.html)

The basic premises of solar system formation are these:

1. A cloud of interstellar gas and dust collapsed with the gravitational influence of many gas and dust particles pulling cool gas and dust ever closer together

2. As the cloud collapsed it flattened, heated and began to spin faster and flatten

3. The hot gas that eventually became the Sun was concentrated in the center of the cloud of dust and gas.

3. Depending on the temperature at various distance from the center, metals, rock and hydrogen compounds could condense.

4. Small clumps of material formed and gradually stuck together accreting into planetesimals.

5. The planetesimals merged eventually forming planets.

6. Because hydrogen compounds could only condense beyond the “frost line”, the inner, terrestrial planets are smaller and mostly made of rock and metal while the gas giant planets contain metals, rocks and abundant ice.

7. Being farther from the sun and more massive, gas giants could capture and retain H and He and build extensive atmospheres

8. Some “leftover” planetesimals became today’s asteroids (rocky) or comets (icy).

9. The young sun developed a strong solar wind which blew remaining dust and gas from the solar system.