The general scientific consensus is as follows: early Earth collided with something roughly the size of Mars, chipping off a bit of our planet which would become our Moon. But there's new research to suggest the Moon was formed by a whole bunch of tiny collisions instead, over millions of years, with the fragments eventually forming the Moon we see today.

The researchers say this would explain why the Moon appears to be composed largely of Earth-like material, rather than a mix of Earth and another planet.