New Hubble images of Pluto have revealed that the surface of the dwarf planet changed between 2000 and 2002. Pluto has become significantly redder, and the northern hemisphere – currently illuminated by the Sun – is getting brighter. Ices are believed to be sublimating on the sunlit pole at the moment, and then refreezing on the South Pole as Pluto heads into the next phase of its 248-year seasonal cycle. This is causing the dramatic change in surface features seen by the team from the Southwest Research Institute in Boulder, Colorado.
Pluto is so small and distant that the task of resolving the surface is as challenging as trying to see the markings on a soccer ball 40 miles away.
Plans are now being made to use Hubble’s new Wide Field Camera 3 to make further Pluto observations prior to the arrival of New Horizons in 2015. Advanced Hubble images will help the New Horizons team to take better shots of the dwarf planet when the probe arrives, and to make the most efficient use of time as it explores the Pluto-Charon system.
The new images have also been combined into a great video showing the current surface of Pluto rotating. You can find a small (iPhone-friendly) version right here or you can grab the HD one from the NASA site by clicking here. Read the full NASA press release here.
Thanks to Mike Brown (@plutokiller) for pointing this out via Twitter.