Spectral Reflectivity of Phobos' Regolith within the Range 315-600 nm

Abstract Spatially resolved photometric observations of Phobos in nine narrow bands in the spectral range 315-600 nm were obtained by means of the KRFM instrument on board the Phobos spacecraft on 25 March 1989. There were initial difficulties with the interpretation of the data. However, some realistic solutions to these difficulties have been found, and now we present a revised version of the results that appears to be substantially free of the errors and uncertainties that affected previous publications. According to this version, the spectrum of Phobos (or at least of the parts of it observed by KRFM) is much redder than the spectra of carbonaceous chondrites. There are no direct spectral analogues between Phobos and any known examples of meteoritic materials or asteroids in the wide range from 200 to 3100 nm.