Selection of chemical species for Europa’s surface using Galileo/NIMS

Europa’s surface shows evidence of active resurfacing which can be explained by either endogenic or exogenic processes. Apart from water ice, several compounds have been proposed to account for the potential complex chemistry that could take place if a connection with the subsurface salty ocean would occur. Previous spectroscopic studies that investigated the surface composition were limited by the number of compounds to consider due to the unavailability of laboratory measurements. We now have access to optical constants and laboratory spectra of synthetic chemical compounds such as hydrated sulfates and chlorinated salts under Europa’s surface conditions.