Pluto, the Planet that isn't, has 5th MoonYou know, for a rock that isn't a planet, Pluto sure has a lot of moons. Thanks to some images shot by the Hubble Space telescope, we can clearly see the a 5th planet spinning around the dwarf planet. Currently called P5 (or S/2012 (134340) 1, but I'm not calling it that), it joins the ranks of Charon, Nix, Hydra and the unimaginatively named P4. The first shot of the moon was taken on June 26th and 9 more shots of the moon were taken to indicate its orbit.
Scientists are apparently a little shocked that a dwarf planet a small as Pluto could have such a rich array of moons, even though most of the moons are no larger than your average asteroid (the exception being Charon, which is half the size of Pluto and nearly dwarf planet size itself).
Image shows five moons orbiting the icy dwarf planet Pluto
P5 isn't a big moon and isn't particularly interesting--it's just 15 miles across and irregularly shaped--but its existence is still interesting. It is also one of, if not the, smallest object we have spotted that far out.
Pluto remains a point of contention to many simply because it was called a planet for so long. The problem is, Pluto is pretty tiny. If we considered Pluto a planet, there were a bunch of other rocks floating in our solar system which would qualify for planethood, too, for example Ceres in the asteroid belt and Eris, which is actually larger than Pluto.
So planets were redefined to be rocks that had cleared their orbit, much as the rest of the planets have. Pluto, Ceres, and Eris haven't; Earth, Mars, and the rest have.