Floating Hills

NASA’s New Horizons spacecraft has taken fascinating pictures of the frozen nitrogen glaciers on Pluto that may be the fragments of water ice. The picture was taken by the spacecraft from a range of about 16,000 kilometres from Pluto, nearly 12 minutes before New Horizons’ closest approach to the dwarf planet on 14^th July, 2015.

The hills located in the vast ice plain named Sputnik Planum in Pluto’s heart, individually measure one to several kilometres. They appear like miniature versions of the large jumbled mountains on Sputnik Planum’s western border. As water ice is less dense than nitrogen ice, scientists believe that these water ice hills are floating in a sea of frozen nitrogen and are moving over time, much like the icebergs in the earth’s Arctic Ocean.

Scientists state that the hills are likely fragments of rugged uplands that have broken away and are being carried by the nitrogen glaciers into Sputnik Planum. The picture shows the hills to be chains of drifting landmass formed along the flow paths of the glaciers.