NASA Probe Spies Possible Polar Ice Cap On Pluto

astroengine writes: As NASA's New Horizons spacecraft rapidly approaches Pluto for its historic flyby in July, the dwarf planet is gradually sliding into focus. And in the latest series of observations beamed back from the fringes of the Kuiper belt, surface features are becoming evident including the stunning revelation that Pluto may possess a polar ice cap. "As we approach the Pluto system we are starting to see intriguing features such as a bright region near Pluto's visible pole, starting the great scientific adventure to understand this enigmatic celestial object," said John Grunsfeld, associate administrator for NASA's Science Mission Directorate in Washington D.C. "As we get closer, the excitement is building in our quest to unravel the mysteries of Pluto using data from New Horizons."

Comments

Ice *cap*?

[erice]

I would expect the whole surface of the (dwarf) planet to be ice, much like all the other outer system objects too small to be gas giants. It would not necessarily be water ice and TFA did not suggest that it was water. In a region where methane and co2 freeze there are lots of options and water ice would not be favorite for a polar cap.

Actually, the only information so far is: "There is a spot that is brighter than the rest. We don't know why."

Re:Ice *cap*?

[tnk1]

Although there is a very substantial distance between the sun and Pluto, I'd imagine that the radiation from the Sun still causes the ices (in this case any sort of ice, not just water) to sublimate from the areas more exposed to solar radiation year-round. You'd get a cap in places where that radiation does not regularly reach, such as at the poles.

I think you actually need specific conditions of atmosphere, or at least gravity, to actually maintain a snowball planet, as opposed to a very cold, but otherwise barren rock.