The 2016 Jean Dominique Cassini Medal & Honorary Membership is awarded to Michel Mayor for his major discoveries in the field of exoplanets, both by observations and theory and through detection methods and instrument developments in this rapidly developing new domain of modern astrophysics.
Michel Mayor, Emeritus Professor at the Astronomical Observatory of the University of Geneva, is a major figure of modern astrophysics. The research of Mayor and his team has had a unique and major impact in the field of exoplanets. The detection in 1995 of 51 Peg b, the first extrasolar planet orbiting a solar-type star, by Mayor and Didier Queloz, initiated a fantastic and rapidly developing new domain of modern astrophysics, re-actualising fundamental questions about our origins and the place of humankind in the Universe. Today, several thousands of exoplanets are known. Mayor’s contribution to the field has been far more profound than the single detection of the first exoplanet. He has been continuously working on the improvement and the diversification of detection methods for exoplanets and on their characterisation. In particular, he led the development of the HARPS (High Accuracy Radial velocity Planet Searcher) spectrograph for the European Southern Observatory (ESO), which is today, 12 years after installation, still the most precise instrument in the world for the measurement of the masses of rocky planets. Very early on, he also contributed to the measurement of the radii of exoplanets giving access, together with the masses, to the planet mean densities, a bridge towards geosciences. Mayor is also an active contributor in the research and exploration planned by current space missions by organisations such as NASA (e.g. in the Kepler telescope) or ESA (e.g. CoRoT, the Convection, Rotation and planetary Transits mission). He has been the leading figure in the development of a new domain of astrophysics, interdisciplinary in nature and opening to adjacent fields as geophysics, climatology, mineralogy, and astrobiology. For all these reasons, he is a worthy recipient of the EGU Jean Dominique Cassini Medal 2016.