Advantages of Synchrotron Mössbauer Spectroscopy in Relation to the Studies of Extra-terrestrial Objects

The lunar sample delivered by the Chang’E 5 mission consists of mostly lunar basalt and regolith. A minor part turned out to contain also some fragments of micrometeorites, fragments of glass of volcanic origin, various kinds of minerals and rocks. It is suitable specimen, due to presence of iron, for the Mössbauer spectroscopy that offer nowadays the great opportunity to exploit the special properties of the synchrotron radiation (SR), which differ strikingly from the properties of the radiation generated by the radioactive sources used in laboratory setup for Mössbauer spectroscopy. The main advantages of the SR compared to γ-radiation from radioactive sources are the extreme brilliance, polarization, pulsed temporal structure and the directional nature, which allows us to apply the stringent linear or point-like collimation to obtain the microscopic spatial resolution, that is of extraordinary importance to study the particulate matter in extra-terrestrial samples. Using conventional radioactive sources, Mössbauer spectroscopy typically identified in regolith the phases of olivine, pyroxene, lunar glass, magnetic α-iron, and superparamagnetic iron resulting from the solar wind reduction. It is highly hoped that with the new SMS (synchrotron Mössbauer sources), unique troilite/pyrrhotite particles and an unusual magnetite phase will be available for Mössbauer spectroscopy research in the very near future.