A new study proposes that Saturn got its rings and tilt from a long-lost moon

Saturn’s most striking feature is its rings, made mostly of small chunks of ice. It was long thought that these rings were leftover material from the formation of Saturn itself some 4.5 billion years ago, but recent studies suggest they’re much younger – between 10 and 100 million years old. If that’s the case, they could have formed from an icy comet or moon that wandered too close.

The planet also rotates tilted at a 27-degree angle, relative to the plane it follows as it orbits the Sun. This was long believed to be caused by the gravitational influence of the nearby Neptune, but closer inspection has revealed that Saturn is no longer in-step with its neighbor.

The astronomers on the new study have now proposed a story that explains both mysteries: Saturn used to have another moon.