Planetary Science Seminar spring-2016

Ceres's surface: its composition and implications for Ceres evolution

As the Dawn spacecraft started its encounter with dwarf planet Ceres in early 2015, the IR spectrometer confirmed previous observation of a low albedo surface (0.035) and the presence of bands at 3.1, 3.3-3.5, 3.9microns. In addition, a band at 2.72 micronS has been clearly identified. The best fit of Ceres' average spectrum over the infrared range is obtained with a combination of phyllosilicates, ammoniated clays, carbonates and a dark material such as magnetite. These components are present everywhere across the surface although with different relative abundances. The retrieved composition indicates that during its evolution Ceres experienced an aqueous alteration process that was global and complete. In addition, its surface enrichment in ammonium bearing species poses questions about its origin, formation and the conditions in the very early solar nebula.