RocketSTEM Issue #13 - September 2016 | Page 94

Figure 12: Halo Craters and methane distribution on Pluto. In the upper image, shown in visible light, the craters’ bright rims stand out sharply from their dark floors and the surrounding terrain. In the lower image, created from composition data gathered by the Ralph/Linear Etalon Imaging Spectral Array (LEISA), there seems to be a correlation between the bright halos and distribution of methane ice, shown in false colour as purple. The floors and terrain between coloured blue, show evidence of water ice. The largest crater here is 50 km across. Credit: NASA/JHUAPL/SwRI Figure 13: The eastern edge of Cthulhu Regio, at the margins of Sputnik Planum, a region where tholins have coated the pre-existing relief with a dark reddish-brown layer. Credit: NASA/JHUAPL/SwRI 92 92 www.RocketSTEM .org