Pluto's global surface composition through pixel-by-pixel Hapke modeling of New Horizons Ralph/LEISA data [EPA]

http://arxiv.org/abs/1604.08468


On July 14th 2015, NASA’s New Horizons mission gave us a first view of the Pluto system. The complex compositional diversity of Pluto’s encounter hemisphere was revealed by the Ralph/LEISA infrared spectrometer on board of New Horizons. We present compositional maps of Pluto defining the spatial distribution of the abundance and textural properties of the volatiles methane and nitrogen ices and non-volatiles water ice and tholin. These results are obtained by applying a pixel-by-pixel Hapke radiative transfer model to the LEISA scans. Our analysis focuses mainly on the large scale latitudinal variations of methane and nitrogen ices and aims at setting observational constraints to volatile transport models. Our findings are consistent with expectations of vigorous spring sublimation after a long polar winter. The latitudinal pattern is broken by Sputnik Planum, a large depository of volatiles, with nitrogen playing the most important role. The physical properties of methane and nitrogen in this region are suggestive of the presence of a cold trap or possible volatile stratification. Furthermore our modeling results point to a possible flow of nitrogen from the northwest edge of Sputnik Planum toward the south.

Read this paper on arXiv…

S. Protopapa, W. Grundy, D. Reuter, et. al.
Fri, 29 Apr 16
44/57

Comments: 37 pages, 7 figures