NASA Floating Hills on Pluto's Sputnik Planum

The nitrogen ice glaciers on Pluto appear to carry an intriguing cargo: numerous, isolated hills that may be fragments of water ice from Pluto’s surrounding uplands. These hills individually measure one to several miles or kilometers across, according to images and data from NASA’s New Horizons mission. via NASA http://www.nasa.gov/image-feature/floating-hills-on-plutos-sputnik-planum