Free Astronomy Magazine November-December 2019

19 SPACE CHRONICLES observers, having participated in hundreds of observing runs at ESO with a variety of instruments. In 1996, ESO commemorated Mayor and Queloz’s groundbreaking 1995 paper by placing it in a time capsule that is still buried in the wall of the VLT enclosure. It is a testament to the rigour and determination of their work that their discovery is being recognised with a Nobel Prize in Physics over twenty years later. shifted, and redshifted correspond- ingly when it moves away from us. By looking for regular shifts in the spectrum of the star — and so meas- uring any velocity changes — any pe- riodic effects due to the influence of a companion can be seen. Both Mayor and Queloz have long- standing collaborations with ESO and have been involved with the or- ganisation’s governing and advisory bodies. They are very experienced visible light reflected off an exo- planet. Mayor and Queloz were in- strumental in developing the revo- lutionary radial velocity technique that is still used to search for exo- planets today. This method looks for tiny backwards and forwards mo- tion of the central star, due to the changing direction of the gravita- tional pull from an (unseen) orbit- ing exoplanet. If the star is moving towards us, its spectrum is blue- !