The components of ammonium were likely already in the foundation of Ceres. Gradually, it built up into a thick layer of brine that extended from the dwarf planet's mantle to the crust. Then ...

specifically a liquid layer between the mantle and crust, over billions of years. While most of the deposits found in Ceres' ...

"We see bright spots elsewhere on Ceres, and so this is not a process ... "The diversity of materials implies either that there is a mixed layer underneath, or that the impact itself changed ...