Franz Renz has been a professor at the Institute for Inorganic Chemistry at Leibniz Universität Hannover since 2008. In addition to coordination chemistry with a focus on “molecular switches” with potential importance for technology (e.g. storage, energy conversion), medicine (e.g. tumor detection) and geology (e.g. earthquake prevention), his areas of work also include his favorite element iron. He followed his favorite method, Mössbauer spectroscopy, to Mars and has been a member of NASA-JPL’s Mars Exploration Rover Mission since 1998.