New maps released by NASA show that the dwarf planet has more water ice than previously thought. The data taken by the New Horizons spacecraft captures more prevalent frozen water on Pluto's surface, an "important discovery," according to researchers.
A false-colored map taken by the Ralph/Linear Etalon Imaging Spectral Array (LEISA) instrument shows the areas on Pluto's surface are concentrated with frozen water. The images were taken on July 14, 2015 during New Horizons' flyby from a range of about 67,000 miles.
NASA has stitched together two images taken about 15 minutes apart. Instead of having a flat image, scientists combined the images to have a multispectral "data cube" of Pluto covering the full hemisphere visible to the spacecraft as it flew past the dwarf planet.
LEISA shows mapped concentrations of water ice, but the scientists have found that the spectral readings could be thrown off if water ice is combined with frozen methane. They have also modeled the contributions, and in effect, the map now shows wider concentrations and stretches where water ice should be present.
"The much more sensitive method used on the right involves modeling the contributions of Pluto's various ices all together. This method, too, has limitations in that it can only map ices included in the model, but the team is continually adding more data and improving the model," NASA said.
Though the map shows widespread frozen water concentrations on the surface of the planet, there is little or no water ice on the western region of Pluto's "heart", dubbed Sputnik Planum, and the far north on the encounter hemisphere, Lowell Regio.
Where's the water ice on Pluto? False-color pic from @NASANewHorizons shows us: https://t.co/6ffUfOrE0w pic.twitter.com/yjUm4rThbL
— NASA (@NASA) January 29, 2016
According to prevailing hypothesis, Sputnik Planum is a gigantic glacier made of methane ice, nitrogen ice and carbon monoxide, which makes it free from water ice. In these areas, frozen ice might be hidden under a thick blanket of the giant glacier.
The New Horizons spacecraft has sent photos that revealed bright methane ices located on various rims of the planet's craters. The photos show a collection of little, red soot-like particles called tholins created by reactions between methane and nitrogen.
