Canadian-American cosmologist James Peebles and Swiss scientists Michel Mayor and Didier Queloz won the 2019 Nobel Prize for Physics on Tuesday for shedding light on the evolution of the universe and discovering planets orbiting distant suns.
Peebles, of Princeton University in the United States, was awarded half the 9-million-Swedish-crown ($910,000) prize while Mayor and Queloz, from the University of Geneva in Switzerland, shared the other half.
"This year's Laureates have transformed our ideas about the cosmos," the Royal Swedish Academy of Sciences said in a statement accompanying the award.
"While James Peebles' theoretical discoveries contributed to our understanding of how the universe evolved after the Big Bang, Michel Mayor and Didier Queloz explored our cosmic neighbourhoods in the hunt for unknown planets. Their discoveries have forever changed our conceptions of the world." Physics is the second Nobel to be awarded this week; William Kaelin, Gregg Semenza and Peter shared the medicine prize on Monday for discoveries about how cells respond to oxygen levels.
Among the Nobels, physics has often taken centre stage with winners featuring some of the greatest names in science like Albert Einstein, Marie Curie and Niels Bohr, as well as ground-breaking inventors such as radio pioneer Guglielmo Marconi.
Using theoretical tools and calculations, Peebles was able to interpret trace radiation from the infancy of the universe and so discover new physical processes, the academy said.
It said that Mayor and Queloz announced the first discovery of a planet outside our own solar system, a so-called "exoplanet", starting a revolution in astronomy. Over 4,000 exoplanets have since been found in the Milky Way.
"With numerous projects planned to start searching for exoplanets, we may eventually find an answer to the eternal question of whether other life is out there," it said.