Ceres: Sulfur deposits and graphitized carbon

Abstract

AbstractWe report new results from observations of the dwarf planet Ceres using the Hubble Space Telescope in the spectral range 1160–5700 Å. Comparisons between Ceres' UV‐visible spectra and laboratory measurements indicate that both sulfur species and graphitized carbon are important on Ceres' surface. We find a latitudinal gradient in UV absorption, with northern latitudes being more UV absorbing than southern latitudes, a trend that can be explained by increasing abundances of sulfur and SO2 toward northern latitudes. The presence of graphitized carbon is consistent with the surface of this airless body being carbonized in response to processes such as charged particle bombardment. The presence of volatile sulfur species is consistent with the idea that Ceres exhibits geothermal activity. Spectral differences with previous UV observations are likely due to the changing sulfurous and carbonaceous surface of Ceres.