This was Astronomy Picture of the Day on 22/7/11.

The two photos, taken five days apart less than a month ago, show the four moons of Pluto; Charon, Nix, Hydra and P4 – so young it’s not yet been named – obviously in orbit around the main planetoid.

Four moons. Not bad for an object that was downgraded from planet status only recently.

Earth only has the one. (Cruithne isn’t properly a moon of Earth.)