Briley Lewis (University of California, Los Angeles)

Title --- Nitrogen on Pluto, as seen by New Horizons

Abstract --- Pluto's surface is geologically complex, to a significant extent because of volatile ice ices that are mobile on seasonal and longer time scales. Here we analyze New Horizons LEISA spectral data to globally map the nitrogen ice, including nitrogen with methane diluted in it, in order to learn about the seasonal processes influencing ice redistribution and calculate the globally averaged energy balance. We present the resulting maps of the encounter-hemisphere distribution of nitrogen, as well as characterization of its average latitudinal dependence and an examination of how the distribution at the global scale depends on topography. We also use the encounter-hemisphere distribution of nitrogen ice to infer the latitudinal distribution of nitrogen over the rest of Pluto, allowing us to calculate the global energy balance. These calculations are analyzed in the context of Pluto’s recent history to better understand the factors that influence its seasonal ice transport.