North pole postcard: Pluto

North pole postcard: Pluto
North pole postcard: Pluto Pluto's north polar regions are reddish, as are those of its moon Charon. Scientists hypothesize that methane trapped at the pole during winter darkness gets broken apart by solar radiation with the coming of spring, and the molecular bits rejoin into larger carbon-rich molecules called tholins. Read more about the image in this blog entry by Emily Lakdawalla, and more about tholins in this blog entry by . NASA / JHUAPL / SwRI