Researchers led by Andreas Nathues from the Max Planck Institute for Solar System Research in Germany have determined that the bright spots on Ceres have a composition of magnesium sulphate (a type of salt) and likely contain subsurface water-ice. “Currently we can see mainly salt. We do not see the ice itself. What we see is a haze layer, and we know this is very likely water vapor. If it is, then there must be some ice deposit in the centre of the spots,” said Andreas Nathues to IFLScience.