Through their study of the process of magma ocean solidification in the terrestrial planets, Genda, Hamano and Abe have found that the birth place of the terrestrial planets influences their early evolution in a way that can be categorized into two types:

Type I: planets that solidify in a short period of time forming oceans

Type II: planets that solidify over a long period of time losing their oceans through the long solidifying processes.

Earth corresponds to Type I and Venus, with almost no water, probably corresponds to Type II.

In the traditional view of Venus having lost its ocean by evaporation after its planet solidification, there remained the unresolved question of why there is no water in the interior of Venus and why oxygen, a heavier element than hydrogen, did not accumulate in the atmosphere of Venus.

If Venus is in the Type II category, the loss of interior water can be attributed to the long duration of the solidification process. In addition, the oxygen which was produced by dissociation of steam would have been absorbed by the oxidation of the abundant magma covering Venus' surface.

This research was supported by KAKENHI (23103001) and the Global COE Program "From the Earth to 'Earths'"

Appearing Publication: Nature

Title: Emergence of two types of terrestrial planet on solidification of magma ocean.

Authors: Keiko Hamano, Yutaka Abe, Hidenori Genda

DOI #: 10.1038/nature12163

http://www.nature.com/nature/journal/v497/n7451/full/nature12163.html