How Unusual Is Pluto’s Topography?

In 2006, the International Astronomical Union determined that Pluto was not really the ninth planet in our solar system. It’s now considered a dwarf planet. But that doesn’t mean that Pluto is not interesting, sometimes in the extreme. Data from the fly-by of NASA’s New Horizons mission headed for deep space reported that Pluto has some quirky qualities, including the possibility of ice volcanoes, floating mountains and rapidly pirouetting moons. Perhaps most odd among the findings is the notion that Pluto has hills and small mountains made of ice bobbing in a huge glacier sea of nitrogen.

Wacky world of a dwarf planet:

• Pluto’s mountains are probably more like icebergs, scientists say, and are probably as large as the Rocky Mountains here on Earth. They’re buoyant enough to rise above the more dense nitrogen and carbon monoxide ices.
• Near the western edge of a gigantic ice field known as Sputnik Planum, giant sheets of water ice look as though they have been fractured and rearranged, producing what NASA’s Jeff Moore called “anarchic terrain.”
• In addition to Pluto's largest moon, Charon, the dwarf planet has four small, rapidly rotating moons, called Nix, Styx, Kerberos and Hydra. “At some point in the past, there were more than just the four moons of Pluto—there were at least six,” NASA scientists said.