Originally posted by sonhouse
More evidence the moon was created by collision with Mars sized planet hitting Earth very early on in the birth of our solar system.
On a slight note of caution, what it seems to show is that the near side of the moon was molten after the far side had solidified, and that the moon was much closer to earth in the distant past. That means the Earth and the Moon formed near each other, but isn't really conclusive proof of the Theia hypothesis.
There is more evidence reported on the BBC website , based on analysis of rock samples, which seems to show the same thing.
There is also a theory that the Earth had two moons for a while, which was also reported on the BBC website . It is based on the same Theia collision, the reasoning of the authors is that if one moon could form, why not two? The seas on the moon are a consequence of a second collision between the smaller moon and the one we see now.