Newborn moon may have had many mini-siblings in Earth orbit long ago

Illustration of a protoplanet slamming into the proto-Earth in a catalclysmic collision.

When Earth and our moon were much closer together than they are now, the duo could have had tiny companions, or a disk revolving around them in orbits around the pair's poles, a new study finds.

These findings suggest that similar moonlets could orbit distant exoplanets and their moons, researchers said.