
The New Horizons spacecraft is nearing a possible launch in mid-January. Despite the moniker its mission is to explore the Pluto/Charon system and any Kuiper Belt objects beyond. We know from looking at their spectrums that Pluto and Charon are different--Pluto is covered in nitrogen ice (brrr) and Charon has water ice. Pluto itself has significant albedo differences, including presumably brighter icier poles and darker warmer equatorial regions (although mixed in everywhere are bright and dark areas--are they cryovolcanoes and geysers or just cratering?).
Young, Galdamez, Buie, Binzel, and Tholen used a series of mutual occultations of Pluto and Charon to figure this out in this paper (Link may require a subscription to read).
The Official New Horizons web siteWas this a wasteful governmental project? Nope. It cost less than 1/10 (one-tenth) of a single B-2, or about the same as the Ketchikan, Alaska bridge to nowhere. For the same price we get the first close-up views of the Kuiper Belt.
I have an older animated image I took of
Pluto taken from Ryerson here. It shows Pluto appearing to move over an hour and a half, near the center left of the image.
Via
http://planetary.org/blog/article/00000334/.