High Thermal Inertia Zones on Ceres From Dawn Data

Abstract

AbstractThermal inertia is a key information to quantify the physical status of a planetary surface. We derive the thermal inertia of the surface of Ceres using spatially resolved data from the Dawn mission. For each location, this quantity can be constrained by comparing theoretical and observed diurnal temperature profiles from retrieved temperatures. We calculated Ceres's surface theoretical temperatures with a thermophysical model that provides temperature as a function of thermal conductivity and roughness, and we determined the values of those parameters for which the best fit with the observed data is obtained. Our results suggest that the area of crater Haulani displays thermal inertia values (up to 130–140 J·m−2·s−½·K−1) substantially higher than the very low to low values (from 1–15 to 50–60 J·m−2·s−½·K−1) derived for the overall surface of Ceres. The results are more ambiguous for the bright faculae located in the floor of crater Occator.