Fragments of the hellish, lava-covered "proto-planet" that existed before Earth 4.5 billion years ago have survived unaltered in ancient rocks, groundbreaking new research reveals.
The fragments contain telltale potassium signatures not seen in any other rocks or meteorites that scientists have examined so far, according to a study published Oct. 14 in the journal Nature Geoscience. Theoretically, these signatures should have disappeared in the giant collision that formed the moon, but it now appears that a handful survived this cataclysmic event and subsequently withstood the test of time.
