Extraterrestrial Mössbauer spectroscopy: more than 3 years of Mars exploration and developments for future missions

After almost 4 years of operating on the surface of Mars, Mössbauer spectroscopy has become a mature technique for robotic planetary exploration. The combination of quantitative information about the distribution of Fe among its oxidation and coordination states, identification of Fe-bearing phases, and relative distribution of Fe among those phases provides valuable contributions to the search for past water activity, the assessment of past environmental conditions, and the suitability for life of the two NASA Mars Exploration Rover landing sites. Experience from the Mars Exploration Rover Mission highlights needs for improvement of the instruments for future missions such as the Russian Phobos-Grunt and the European ExoMars rover.