Twenty years ago, in October 1995, a team of astrophysicists led by Michel Mayor and Didier Queloz at the Haute-Provence Observatory in southeastern France became the first to formally discover an exoplanet, a hot Jupiter dubbed 51 Pegasi b. Since then, more than 3,000 exoplanets have been officially identified, while researchers still have to confirm the discovery of a further 2,400.