Controversial Moon Origin Theory Rewrites History

If a new twist on a decades-old theory is right, conditions in the early solar system suggest the moon formed inside Mercury’s orbit and migrated out until it was roped into orbit around Earth.

The idea flies in the face of scientific consensus, known as the giant impact hypothesis, which holds that the moon formed from red-hot debris left over after a Mars-sized object collided with Earth around 4.5 billion years ago.

It’s too generous to call this a theory, as they do in the article. From the scant information, it sounds more like a plausibility argument; physics does not preclude the scenario, so it could have happened. But the next step is looking to see if this could be falsified by what we know or could investigate. It’s not clear to what extent this has already taken place.