For a brief, but exciting, time last year, Earth had two moons. A small asteroid lingered close to our planet in its orbit around the Sun, temporarily caught by Earth’s gravity to become a far away mini-moon. A closer look at the space rock reveals a rather familiar origin: Earth’s mini-moon might actually be a broken-off piece of our regular Moon.

An asteroid that orbited near Earth for a few months as a mini-moon may be a chunk of the moon that was blasted off by an impact thousands of years ago.

New research suggests that Earth's recent mini-moon might have originated as part of our actual moon long, long ago.