The Protoplanet Hypothesis

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Space is extraordinary! It is full of planets, stars, and many other things. There are several different hypotheses that were proposed on how the solar system was created. One of these hypotheses is the Nebular that was formulated by Pierre-Simon de Laplace in 1796. Many years later, in the 1900s, the Protoplanet hypothesis was proposed by Carl von Weizsäcker and Gerard Kuiper. Forest Moulton and Thomas Chamberlin proposed the Planetesimal hypothesis in 1905. The Nebular hypothesis starts with an interstellar gas cloud spinning slowly. The cloud began to cool and this caused it to shrink into a compact sphere. The sphere increased the rotating speed and it flung matter from the cloud away. The matter that was flung away settled into …show more content…
The pieces remained in orbit, eventually cooled and solidified into the planets. A problem with the Planetesimal hypothesis is if the star passing by was larger than the Sun, why did it only take pieces instead of the whole Sun? Also, if the material pulled from the Sun was hydrogen and helium based, then how did solid rocks form the planetesimals? Although all of these hypotheses are different, the also share some similarities. The Nebular and Protoplanet both start the process with a cloud that will eventually spin. Also, somewhere in the process shrinking/compacting occurs. However, the Nebular hypothesis involves flinging matter and the Protoplanet does not. The Protoplanet has whirlpools and uses hydrogen fusion to ignite the Sun, whereas the Nebular does not. The Nebular hypothesis compared to the Planetesimal hypothesis is very different but also has features in common. In both of these hypotheses, pieces come out and in the end form the planets. However, in the Planetesimal hypothesis, the Sun is disturbed by a passing star and that never happens in the Nebular hypothesis. Also, the Nebular hypothesis uses the Law of Conservation of Angular Movement and the Planetesimal does

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