One of the weirder headlines of the week: Giant Propellers Discovered In Saturn's Rings. It's a tad misleading. They don't spin or anything. And as far as I can make out, they aren't even really solid. The center is a brand new class of moon, one that is mid-size and embedded in the rings, and (I think) there is material streaming out thousands of miles in both directions, held in place by gravity and resonance, a concept I must admit I don't entirely understand.