The Hubble map of Pluto from 1994 (upper) and the latest one below. Be sure to click the image for a larger version. Image credit: NASA, ESA, and M. Buie (Southwest Research Institute)

Pluto has a surface temperature of something like 35 to 45 K (-378^oF to -396^oF). I sort of always thought of Pluto as a pretty static place, but not so.

The little world’s northern hemisphere is getting brighter and it is becoming redder as a result.  Hubblesite described it as an icy and dark molasses-colored world.

Here are some of the other Hubble images:  90 degs / 180 degs / 270 degs.  The images don’t give us a lot of detail as far as the surface features go, still a lot can be learned from these pictures.  We do have a spacecraft on the way to Pluto and in 2015 it will finally arrive – Pluto is a LONG  ways away, heck those are Hubble pictures and we still can’t resolve the surface!

Ok before I get all carried away, Pluto has a diameter of 2,390 km and if you are thinking that’s smaller than our moon, you’d be right.  Our moon happens to be the 5th largest moon in the solar system, but that’s another story.  The other thing about Pluto’s size is Eris (yeah, the one that caused the hub-bub) is maybe even a little larger than Pluto.  Pluto’s whole orbit is tilted 17 degrees relative to the ecliptic and it’s also very elongated.

I’m not going to go into the whole planet, dwarf planet debate.  I will say I’ve come to my own conclusion.  Suffice it to say, Pluto is very strange place.

Head on over to Hubblesite for the full press release, more images and even video.