in the UK. With his Ph.D. student they demonstrated a significant number of the planets were surprisingly misaligned or in a retrograde orbit, providing a new insight about their formation process. In 2017 he received the Wolf Prize in Physics 2017 for that work and all the planet discoveries he had made. The special geometry of transiting planets combined with precise Doppler spectroscopic observations allow us to measure the mass and radius of planets and to compute their bulk densities to get insights about their physical structure. In 2003 Didier Queloz, recently appointed at a faculty position, with his research team pioneered and established the combination of these techniques by first measuring bulk density of OGLE transiting planets. They also looked for transit opportunities on known radial velocity planets and they found the first transiting Neptune-size planet Gliese 436 b. In the course of this program and a collaboration with his Colleague S. Zucker from Tel-Aviv University, they developed the mathematical foundation to compute residual noise they encountered during the analysis of transit they were trying to model. They established statistical metric to address pink noise in the data. Today this concept is widely used in the field to estimate systematics in light-curves and transit modelling. In 2007 Didier Queloz became associate professor. Over the next 5 years following his nomination his research program based on the combination of spectroscopy and transit detection intensified. He took the lead in the spectroscopic follow-up effort of the WASP consortium and the CoRoT space mission. The combination of WASP and Corot data with follow-up observations using EulerCam (CCD imager ), CORALIE spectrograph, HARPS spectrograph, and other main ESO facilities was amazingly successful. It led to more than 100 publications, some of them breakthroughs providing new insights on the formation and nature of hot Jupiter-type planets. Further, in the same period, the detection of COROT-7b combined with an intensive follow-up campaign established the first planet detection with a bulk density similar to a rocky planet. All follow-up expertise he developed naturally extended to the Kepler space telescope era with HARPS-N consortium confirming the Earth-like bulk density of Kepler-10. On the ground-based transit programs, Didier Queloz was deeply involved in the design and installation of a new generation of survey telescope: the NGTS Observatory. His role was decisive during system tests in Europe and to establish the facility at the Paranal Observatory in the Atacama