The New Horizons spacecraft is the gift that keeps on giving: the probe recently transmitted more photos to Earth from its Pluto flyby, and with it, confirmation of frozen water on the the planet's surface and pictures that depict the presence of Pluto's atmospheric particle-induced "blue skies."
The dwarf planet's blue skies, or "blue hazes," are actually "haze particles"; depending on their particular formation; according to NASA's official statement on the findings, they're specifically "soot-like particles we call tholins" (on Earth, the equivalent to Pluto's tholins are nitrogen particles), and despite their dissemination of blue light, the particles themselves are most likely red or gray in color.
New Horizons also managed to snap some photos of water ice on Pluto's surface; scientists were able to identify the water ice as such using data collected by the spacecraft's Ralph spectral composition mapper.
As for the coloration of the dwarf planet's frozen water? Unfortunately, scientists don't have a clear answer.
"We don't yet understand the relationship between water ice and the reddish tholin colorants on Pluto's surface," admitted University of Maryland's Silvia Protopapa, one of the members of the New Horizon's team.
Via: The Verge