This picture was clipped out of the the highest-resolution color image available so far of the haze layers in Pluto’s atmosphere. New Horizons mission scientists don’t believe the haze is the result of SUVs on Pluto’s freeways. Their theory is that it’s a photochemical smog resulting from the action of sunlight on methane and other molecules in Pluto’s atmosphere producing a complex mixture of hydrocarbons such as acetylene and ethylene. These hydrocarbons accumulate into tiny particles less than a micrometer across and scatter sunlight, causing the blue haze. As they settle down through the atmosphere, the haze particles stratify into horizontal layers, some extending for hundreds of km around Pluto and extend to altitudes of over 200 km.
The irregularities along Pluto’s limb are surface features such as mountains. The blue fuzz over the planet near the limb is made of crepuscular rays of light extending from Pluto’s topographic features.
Image Credit: NASA