Impacts on Hubble Space Telescope solar arrays: Discrimination between natural and man-made particles

Micrometeoroid residues are found across the entire crater size range and dominate features of between 100 and 1000 microns, their residues are similar to those found in earlier SM-1 surveys. Fe- and Mg-rich silicates dominate; Fe sulphides are common and there are occasional vesicular Ni- and S-bearing mafic silicates of hydrous phyllosilicate origin. A single sodium aluminosilicate residue and one Fe Ni metal residue were found; as well as enigmatic Mg- and S-bearing residues, all considered as probably of micrometeoroid origin. A few Fe-, O- and C-bearing residues were classified as of ambiguous origin.