Pluto's largest moon, Charon, is seen in a high-resolution, enhanced color view captured by NASA's New Horizons spacecraft on July 14, 2015 and released September 15, 2016. Scientists have learned that reddish material in the north (top) polar region is chemically processed methane that escaped from Pluto's atmosphere onto Charon. (Photo by NASA/JHUAPL/SwRI)
