Nobel prize for physics: exoplanets and cosmology

THIS YEAR’S Nobel prize for physics was split two ways, but both halves went for discoveries beyond Earth. One was for a finding that is, by astronomical standards, quite close by—a planet going around a star a mere 50 light-years distant. The other was for an overview of the entire universe.In October 1995 Michel Mayor and Didier Queloz, a pair of astronomers then working at the University of Geneva, presented a paper at a scientific conference in Florence. A few months earlier they had discovered a planet beyond the solar system. It was a gaseous ball roughly twice the size of Jupiter and was going around a star called 51 Pegasi, at a distance of about 8m kilometres—a twentieth of the distance from Earth to the sun. As a consequence of this proximity it orbited 51 Pegasi once every four terrestrial days and had surface temperature in excess of 1,000°C. The discovery was a puzzle for astronomers. Until then they had thought that such large, Jupiter-like planets could form only far away from their host stars.