SPECTROSCOPIC CLASSIFICATION OF ICY SATELLITES OF SATURN - IDENTIFICATION OF TERRAIN UNITS ON DIONE AND RHEA

The surfaces of the major Saturnian moons are composed primarily by water ice, with a minor percentage of non-water ice materials whose composition is still debated and whose distribution is not uniform across the satellites' surface. The differences in contaminants' composition, water ice abundance and regolith grain size are revealed by variations in spectral profiles, which may be due both to exogenic and endogenic processes. One way to discern between them and to understand how each satellite evolved is to investigate the distribution of contaminants and water ice on the moons' surfaces. Here we present an automatic classification scheme for the icy surfaces of the Saturnian satellites Dione and Rhea based on the analysis of variations in their infrared spectra and the research of a correlation between the surface morphology and the variations in grain size, water ice abundance and contaminants distribution.