What if Saturn's moon Mimas orbited our Moon as a submoon? Mimas circles the Moon at roughly 7,500 km — well inside the lunar Hill sphere of about 60,000 km — while the Earth–Moon pair continues its familiar path around the Sun. Submoons are theoretically possible but thought to be short-lived: tidal forces from Earth and the Sun quickly destabilise small satellites of moons. Mimas, only 396 km across, would raise additional tides on the Moon and create a spectacular double-satellite system visible from Earth. Real submoon searches around Jupiter's and Saturn's moons have so far found none, suggesting that nature rarely permits this nested orbital architecture to persist.

Earth–Moon System with Mimas as a Submoon

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