NASA boffins are scratching their heads over some of the first digitally enhanced snaps of Pluto.
The on-again off-again planet has been too far away for Hubble to pick out a picture more than a couple of pixels.
However astronomer Marc Buie of the Southwest Research Institute in Boulder rigged up a supercomputer made from 20 homemade computers that ran continuously for four years to produce the high-resolution snaps.
The newly computer-processed images of Pluto taken by the Hubble Space Telescope have been shown off in the March issue of ye Astronomical Journal, which we get for the “spot the planetoid” competition.
Boffins were convinced that Pluto should be largely a black ball of ice and rock, a bit like Aberdeen in Winter.
However, the images show an icy and dark molasses-coloured world that is highly mottled and whose northern hemisphere is now getting brighter.
The planet turned noticeably redder in the two years after the turn of the millennium for reasons that are not clear, and its equator features a large bright spot whose origin remains a mystery.
Next to the Earth and Mars, Pluto has even more dramatic changes to its surface than anything else.
Apparently there is still little in the way to see. The atmosphere so small that all it can do is shift frost around.
Boffins think that the red tinge is carbon compounds on the surface. When exposed to sunlight, hydrogen atoms break off and the carbon atoms combine, producing complex chemicals that are reddish. The only problem there is that when all the hydrogen atoms have broken off the material should turn black and the boffins can’t work out why the planetoid isn’t completely and totally black.