Oh Pluto, Pluto... You may not be a planet anymore, but that doesn't mean we don't love you. Even while you look like a big moldy ball of mud in this image capture by Hubble, the most detailed to date.
And here I was, thinking Pluto was this big blue ice sphere only good to make Caipirinhas and Mojitos. According to NASA, however, its color has changed. The hue shift happens over a two year period, in which the the ice of one pole get sun light, melts, and then refreezes on the other pole. Quite the manic depressive non-planet, this Pluto. According to NASA," the overall color is believed to be a result of ultraviolet radiation from the distant sun breaking up methane that is present on Pluto's surface, leaving behind a dark and red carbon-rich residue."
NASA's images of the faraway ex-planet will help to calibrate the New Horizons spacecraft, which will pass Pluto in 2015. They will use Hubble's images to set the exposure on board New Horizons, as it races past it. So fast, in fact, that it will only be able to photograph one of the hemispheres up close. [NASA]