Incredibly fascinating article by Kristen Bobst for Mother Nature Network explores the new theory that our very own Earth may actually be the result of a fusion of two celestial bodies, Earth (as it was 4.5 billion years ago) and the head on collision and subsequent fusion of it with a Mars-like proto-planet called Theia…

Is Earth Actually Two Planets?

This idea is not new.  In fact, most scientists feel that evidence of that collision lies in our Moon, which appears to be a residue from that very collision.  But the theories were that Earth was “sideswiped” by this planet and the resulting debris caused by the impact caused the Moon to be created over time.

Now, based on close examination of the composition of material from the Earth and Moon, scientists now think the collision was more direct.  The debris from the collision still caused the creation of the Moon but now it is thought our planet is actually the direct merging of what was the Earth and Theia.

Which makes one wonder: What was the Earth like before the collision?  What was Theia like?

Fascinating, fascinating stuff.