III.7.5. Mass of Protoplanet, III.7.6. Giant Impact

A protoplanet scatters another neighbor protoplanet. The scattered protoplanet increases the eccentricity during the scattering, but the eccentricity is quickly dumped by the dynamical friction of small planetesimals. N-body simulation discovered that the distance between growing protoplanets is about 10 Hill radius. We estimate the isolation mass of a protoplanet using the distance between protoplanets. Some terrestrial planets such as Earth and Venus are formed by the merger of several protoplanets. At the very last stage of the formation process of the Earth, a collision of a prot-Earth and a protoplanet produces a number of fragments. These fragments stick together right beyond the Roche limit and form the Moon.

#Astrophysics #Physics #Planet #Formation #Star #Disk #Science

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