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Old 07-28-2012, 07:28 AM
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Saquist Saquist is offline
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Apparently not. I always thought that was true way back when but currently from what I've read planetary formation can happen very quickly. From the time the sun formed to 100,000 years is the cap for planets growing from the nebula. Further growth happens by collisions. This time period would have been extremely volatile and prevented water from forming because it vaporizes at too low a temperature but hundreds of millions of years later Earth's surface and atmosphere may have been high but from what I've read...not what you would call molten at this point. It would be like Venus.

Remember the solar system was in a molecular dust cloud high in temperature because of the sun but if the temperature was too high it would be hard for the planets to form from the excited gases. Accretion happens quickly and gradually. It would make rocks 200 meters wide and then those rocks would accrete together. A good example of this is looking at asteriods which are huge collections of Rocks held together by dust and ice. Earth would have been held together by it's own mass from heavy elements that came together first like nickel and iron. Everything else gathered around that or impacted the planet during the heavy bombardment. They believe collisions are how the planets got to this size but apparently the moon formation is far removed from the initial formation of the solar system where large planetoids were especially numerous, although still frequent.

(At the same time take what I say with a grain of salt. Orogenesis is not my field of intense interest so I'm familiar with somethings and the processes but not as familiar with the time line.)
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