Didier Patrick Queloz (didje kəlo, kelo; born 23 February 1966) is a Swiss astronomer. He is the Jacksonian Professor of Natural Philosophy at the University of Cambridge, where he is also a fellow of Trinity College, Cambridge, as well as a professor at the University of Geneva. Together with Michel Mayor in 1995, he discovered 51 Pegasi b, the first extrasolar planet orbiting a Sun-like star, 51 Pegasi. For this discovery, he shared the 2019 Nobel Prize in Physics with Mayor and Jim Peebles. In 2021, he was announced as the founding director of the Center for the Origin and Prevalence of Life at ETH Zurich. Queloz was born in Switzerland, on 23 February 1966. Queloz studied at the University of Geneva where he subsequently obtained a MSc degree in physics in 1990, a DEA in Astronomy and Astrophysics in 1992, and a PhD degree in 1995 with Swiss astrophysicist Michel Mayor as his doctoral advisor. In the area of religion The Daily Telegraph reports him as saying, "although not a believer himself, “Science inherited a lot from religions”". Didier Queloz is at the origin of the “exoplanet revolution” in astrophysics when as part of his PhD at the University of Geneva , with his supervisor, they discovered the first exoplanet around a main sequence star. In 1995 with Michel Mayor announced a giant planet orbiting the star 51 Pegasi; the planet was identified as 51 Pegasi b and determined to be of a Hot Jupiter. The planet was detected by the measurement of small periodic changes in stellar radial velocity produced by the orbiting planet. Detecting this small variability by the Doppler effect had been possible thanks to the development of a new type of spectrograph, ELODIE, installed at the Haute-Provence Observatory, combined creative approach to measuring precise stellar radial velocity. For this achievement, they were awarded half of the 2019 Nobel Prize in Physics "for the discovery of an exoplanet orbiting a solar-type star" resulting in “contributions to our understanding of the evolution of the universe and Earth’s place in the cosmos.