Surface Temperatures andWater Ice Sublimation Rate of Oxo Crater: A ComparisonWith Juling Crater

摘要

Dwarf planet Ceres is characterized by several sites hosting (or have hosted) ice-rich patches as revealed by the Dawn's Visible and InfraRed spectrometer. The study of the illumination conditions including the effects of the local topography become critical in the estimation of the ice lifetime as well as the water vapor production rate. In this work we applied a 3-D thermophysical model in order to study the illumination conditions on the shape model, derived on the basis of the images acquired by the Dawn's Framing Camera during the Survey mission phase, and to calculate the surface temperatures and water sublimation rates. We are interested in a crater in the northern hemisphere (42°), Oxo, which hosts water ice in its southern wall. A comparison with the surface temperatures and water sublimation rates of another Ceres' crater, Juling, is carried out.Water ice sublimation rate of its ice-rich patch suggests that the Oxo crater probably is not the source of the emission detected by Herschel, a source that could be represented instead by the Juling crater.