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Introduction to the Special Issue: Ice on Ceres
Author(s) -
Sizemore H. G.,
Schmidt B. E.,
CastilloRogez J. C.
Publication year - 2019
Publication title -
journal of geophysical research: planets
Language(s) - English
Resource type - Journals
eISSN - 2169-9100
pISSN - 2169-9097
DOI - 10.1029/2019je006012
Subject(s) - astrobiology , mars exploration program , geology , solar system , asteroid , water ice , planet , earth science , planetary science , geophysics , environmental science , astronomy , physics
Ceres is the largest body in the asteroid belt, and the most water‐rich inner solar system body after Earth. Its exploration by the Dawn spacecraft has been long anticipated, in large part because it was expected to be an ice‐rich world. A variety of ice‐ and volatile‐related physical processes were expected to occur on Ceres, including possible cryovolcanism. A major goal of the Dawn mission at Ceres was to understand the abundance, distribution, and phase partitioning of water in the subsurface. Coordinated investigations of subsurface ice during the Dawn mission benefited from the decades‐long effort to inventory and characterize subsurface ice on Mars. Specifically, morphological analysis was leveraged to bridge a length‐scale gap between geophysical remote sensing data sets that provide quantitative constraints on the abundance of subsurface ice at very shallow depths (<1 m; neutron spectroscopy) and data sets that provide quantitative constraints on composition at much longer length scales (tens of kilometers; gravity science). This morphological analysis underscores that Ceres shares geophysical characteristics with terrestrial planets, icy moons, comets, and asteroids, and blurs some of the conventional boundaries between these terms. Grappling with this ambiguity stands to benefit investigations of interior evolution and volatile‐related processes on all solid planetary bodies.