Evidence for Ammonium-Bearing Minerals on Ceres

Science  20 Mar 1992:
Vol. 255, Issue 5051, pp. 1551-1553
DOI: 10.1126/science.255.5051.1551


Spectra obtained from recent telescopic observation of 1-Ceres and laboratory measurements and theoretical calculations of three component mixtures of Ceres analog material suggest that an ammoniated phyllosilicate is present on the surface of the asteroid, rather than H2O frost as had been previously reported. The presence of an ammoniated phyllosilicate, most likely ammoniated saponite, on the surface of Ceres implies that secondary temperatures could not have exceeded 400 kelvin.