Earth’s Moon is among the strangest planetary bodies in our Solar System. Its orbit lies unusually far away from our planet, with a surprisingly large orbital tilt. And now there’s a new theory to explain how it got where it is, which puts some twists on the widely-accepted ‘giant-impact’ theory. This is an artist’s depiction of a catastrophic collision between two celestial bodies; such an impact between the proto-Earth and Theia likely...