On the Study of Spatial Variability of the Composition of the Substance of Mars in Experiments on Gamma-Ray Spectroscopy on Board the Mobile Vehicle using the Method of “Tagged Charged Particles”

Methods are discussed for studying the variability in space of the substance composition of the surface of Mars in experiments on gamma-ray spectroscopy on board a mobile vehicle—“Mars rover”. It is shown that data on the elemental composition of the substance in local volumes of the matter with a characteristic linear size of the order of several meters along the rover travers can be obtained using the method of “tagged charged particles” (TCP). This method allows to exclude from consideration both the counts caused by gamma-ray radiation from the surrounding surface outside the tested local area and radiation from the spacecraft itself. The method of identifying the composition of the substance in the tested volume with the known types of Martian regolith according to the APXS experiment is also discussed. This method is based on the comparison of measured intensities of the main characteristic nuclear lines with the values corresponding to these lines for known regolith types. It is underlined that the proposed method allows to experimentally detect new types of regolith, the composition of which differs from the composition of all previously known types of Martian matter.