Replenishment of Near‐Surface Water Ice by Impacts Into Ceres' Volatile‐Rich Crust: Observations by Dawn's Gamma Ray and Neutron Detector

Ceres' regolith contains water ice that has receded in response to insolation-driven sublimation. Specially targeted, high spatial-resolution measurements of hydrogen by Dawn's Gamma Ray and Neutron Detector (GRaND) reveal elevated concentrations around Occator, a young, 90 km diameter, complex crater located at 19.82°N where near-surface is not expected. The excess can be explained impact excavation water-rich outer crustal materials their emplacement the floor ejecta blanket. This supported thermophysical models show could survive sub-meter depths, given Occator's relatively young age (∼20 Myr). We hypothesize replenished with from large impacts this process partially controls distribution depth near surface ice. results Occator similarities global pattern craters (20–100 diameter).