It's been known for a number of months now, before the time NASA's New Horizons spacecraft approached Pluto, that the dwarf planet's moons had a strange orbital movement to them. In fact, some of the moons even had a weird "wobble" to them.
But, data obtained from New Horizons before, during, and after the fly-by has helped astronomers better understand the wobbles and how they work.
In this NASA animation, you can see how all of the moons move relative to Pluto. They all rotate at different speeds; in fact, the one furthest from Pluto, Hyrda, rotates like there's no tomorrow.
Interestingly, when you see Nix up close, you'll see what the wobble looks like. It's very unusual for a moon orbit.