New Horizons sheds light on Pluto's floating hills
NASA has released a new image taken by the New Horizons spacecraft as it sped past the dwarf planet Pluto, displaying the locations of a number of "floating hills" composed of water ice. It is believed that these mobile peaks broke away from the highlands bordering a region known as Sputnik Planum, and subsequently carried with the flow of the nitrogen ice glaciers.
The New Horizons spacecraft has already succeeded in discovering a wealth of unusual quirks in the geology of the dwarf planet, and it seems to be far from done. NASA scientists believe that the vast chunks of water, some of which measure several miles across, float on the denser nitrogen ice flows that carry the fragments to an unusual landscape characterized by cell-like formations.
This region of Pluto's surface is believed to continually refresh itself, with the material at the centre of the cells falling beneath the surface, leaving only the edges of the cells behind, to be filled in by warmer blobs of nitrogen ice that rise from the reservoir below.
As a side-effect of this mechanism, the water ice fragments are dragged to the edges of the cells, sometimes clustering in groups 12 miles (20 km) across. The recently-released image of Sputnik Planum displays an unusually large cluster of the icebergs some 22 miles (35 km) across and 37 miles (60 km) in length.
The unusual grouping is currently believed to be evidence of chunks beaching in an area where the nitrogen ice is particularly shallow.