What happens when a black hole spins? According to general relativity, it doesn't simply rotate in space, it actually drags spacetime around with it.

This episode explores the strange phenomenon known as frame dragging, from its first predictions more than a century ago to new observations that may let astronomers watch it at work around supermassive black holes. We'll visit a distant black hole where the remains of a shredded star appear to be wobbling through twisted spacetime, then return to the center of our own Milky Way to meet S301, a star racing around Sagittarius A* at more than eight percent of the speed of light. Its extreme orbit may eventually help astronomers measure the spin of our galaxy's central black hole.

And there's plenty happening closer to home. A spent Falcon 9 rocket stage is expected to crash into the Moon o ...