Cryovolcanism on Ceres

O Ruesch, T Platz, P Schenk, L A McFadden, J C Castillo-Rogez, L C Quick, S Byrne, F Preusker, D P O'Brien, N Schmedemann, D A Williams, J-Y Li, M T Bland, H Hiesinger, T Kneissl, A Neesemann, M Schaefer, J H Pasckert, B E Schmidt, D L Buczkowski, M V Sykes, A Nathues, T Roatsch, M Hoffmann, C A Raymond, C T Russell

Volcanic edifices are abundant on rocky bodies of the inner solar system. In the cold outer solar system, volcanism can occur on solid bodies with a water-ice shell, but derived cryovolcanic constructs have proved elusive. We report the discovery, using Dawn Framing Camera images, of a landform on dwarf planet Ceres that we argue represents a viscous cryovolcanic dome. Parent material of the cryomagma is a mixture of secondary minerals, including salts and water ice. Absolute model ages from impact craters reveal that extrusion of the dome has occurred recently. Ceres' evolution must have been able to sustain recent interior activity and associated surface expressions. We propose salts with low eutectic temperatures and thermal conductivities as key drivers for Ceres' long-term internal evolution.