The moon could have formed immediately after a cataclysmic impact that tore off a chunk of Earth and hurled it into space, a new study has suggested.
Since the mid-1970s, astronomers have thought that the moon could have been made by a collision between Earth and an ancient Mars-size protoplanet called Theia; the colossal impact would have created an enormous debris field from which our lunar companion slowly formed over thousands of years.
But a new hypothesis, based on supercomputer simulations made at a higher resolution than ever before, suggests that the moon's formation might not have been a slow and gradual process after all, but one that instead took place within just a few hours. The scientists published their findings October 4 in the journal The Astrophysical Journal Letters.
