# What are the white reflections on Ceres?

What are the white reflections on Ceres?

https://solarsystem.nasa.gov/planets/dwarf-planets/ceres/overview/

Several papers with data from the Dawn spacecraft have just been published. Among them, Fresh emplacement of hydrated sodium chloride on Ceres from ascending salty fluids focuses on the composition of these bright deposits called faculae. It shows that the spectral data of some faculae are best fit by a mixture of ammonium chloride (NH$$_4$$Cl), natrite (Na$$_2$$CO$$_3$$) and hydrohalite (NaCl·2H$$_2$$O). The presence of the latter specie is a strong evidence for a relict subsurface ocean. Hydrohalite is actually an insulating material and could have helped maintaining some heat, thus some brine pockets.