Blues Skies and Water Ice on Pluto

NASA has recently sent back new photos of Pluto with the spacecraft Hew Horizons which reveal that it has a blue sky as well as water ice. 

The pictures show how the atmospheric haze around the Kuiper Belt reflects blue light, even though the particles are actually a red or grey color. This blue color reflects characteristics of the atmosphere, including information on the size and composition of the haze particles. 

Blue skies are a result of sunlight scattering very tiny particles, which are often nitrogen. This phenomena is found on Pluto, however the particles are larger than on earth, but still relatively small. These particles are called tholins, which form high up in the atmosphere where ultraviolet light breaks apart the nitrogen molecules and ionizes them. This allows them to react with each other and create more positively and negatively charged ions in the atmosphere. 

Water Ice was also discovered on the surface of Pluto. Scientists are still trying to understand how the water forms, while ice is abundant on the surface. The water ice that was detected on Pluto radiated a red color which corresponds to the red tinted color of other tholins. 

These tholins are produced by ions that recombined with each other after being broken apart by the ultraviolet rays of the sun. The recombined molecules form complex macromolecules which keep expanding. These molecules combine to form gases which cover themselves in ice before they fall through the atmosphere of Pluto.