Explaining Saturn's ravioli moons

Saturn's moons are weird.

I mean, really weird. When the Cassini spacecraft showed up at Saturn in 2004 and started doing flybys of some of the inner moons, the images it sent to Earth were so bizarre I actually had to look at them for a moment to even understand the shape I was seeing.

That's because some of them look like, well... ravioli. Yes, seriously.

Saturn’s moons Atlas (left) and Pan (right), both of which have large flattened rims around them, making them look like ravioli. Credit: ...