CERES: A HABITABLE SMALL BODY? M.Neveu1,

Introduction: The main-belt object Ceres (radius≈475 km, density≈2100 kg m-3 , semi-major axis 2.7 AU), is an exciting place to explore planetary hab-itability. Abundant volatiles could have shaped Ceres in a way analogous to that suspected on icy moons. Hydrothermalism: Ceres' surface seems blanketed by products of the interaction between silicate rock and liquid water, including carbonates [1]. Could liquid water persist inside so small a world, without tidal heating, until the present day? Simulations using our detailed thermal models suggest that it could [2,3], provided volatile or salt antifreezes are present, and that long-lived radionuclide decay warms up the liquid. That is, for liquid to persist, it must be at depth in contact with a rocky core. To what extent could water-rock interaction occur? Our detailed core cracking simulations suggest that micro-and macro-fractures may pervade the entire core, providing a large interface for interaction [3]. Cryovolcanism: Ceres is releasing water vapor to space [4]. Whether this activity is cometary or cryo-volcanic is unknown. We have shown that explosive cryovolcanism on icy dwarf planets is facilitated by gas products of hydrothermal activity [5]. Species such as CH4 or H2, produced by water-rock reactions, can exsolve during fluid ascent, thereby making cryovol-canic fluids buoyant in ice. Both putative hydrothermal and cryovolcanic activity are reminiscent of processes occurring on icy moons. Europa's ridges seem filled with salt rising from its interior [6,7], and pluming activity may have been observed [8]. Enceladus displays intense cryovol-canic activity, and sodium and silica likely coming from its core are ejected in its plume [9]. Such observations have made these icy worlds prime foci for exploration , as mixing reduced rocky material with oxidized fluids and ices creates energy gradients and leaches nutrients which could support life [7,9]. Could Ceres' interior also be habitable? The implications are tantalizing: since dwarf planets make up 75% of all round worlds in the solar system, abodes for life may be much more common than initially anticipated. Clearing the Window Into Habitability Processes: Our understanding of icy world habitability hinges on surface observations, the window into interior hy-dration and transport processes that provide ingredients for life. On icy moons, this window has so far been