Canadian-American cosmologist James Peebles and Swiss astronomers Michel Mayor and Didier Queloz on Tuesday won the Nobel Physics Prize for research increasing our understanding of our place in the universe, the jury said.
Peebles won one-half of the prize "for theoretical discoveries that have contributed to our understanding of how the universe evolved after the Big Bang," professor Goran Hansson, secretary general of Royal Swedish Academy of Sciences, told a press conference.
Mayor and Queloz shared the other half for the first discovery, in October 1995, of a planet outside our solar system -- an exoplanet -- orbiting a solar-type star in the Milky Way.
"Their discoveries have forever changed our conceptions of the world," the jury said.
Peebles is Albert Einstein Professor of Science at Princeton University in the United States, while Mayor and Queloz are both professors at the University of Geneva. Queloz also works at the University of Cambridge in Britain.
The Swiss pair hailed their win as "simply extraordinary".
The prize consists of a gold medal, a diploma and the sum of nine million Swedish kronor (about $914,000 or 833,000 euros).
The trio will receive the prize from King Carl XVI Gustaf at a formal ceremony in Stockholm on December 10, the anniversary of the 1896 death of scientist Alfred Nobel who created the prizes in his last will and testament.
In 2018, the honour went to Arthur Ashkin of the US, Gerard Mourou of France and Donna Strickland of the US for laser inventions used for advanced precision instruments in corrective eye surgery and in industry.
After Marie Curie in 1903 and German-American scientist Maria Goeppert-Mayer in 1963, Strickland became just the third woman to be awarded the Physics Prize since 1901.
This year's Nobel prize season kicked off on Monday with the Medicine Prize awarded to Americans William Kaelin and Gregg Semenza, and Britain's Peter Ratcliffe.
They were honoured for research into how human cells sense and adapt to changing oxygen levels, which opens up new strategies to fight such diseases as cancer and anaemia.
The winners of this year's Chemistry Prize will be announced on Wednesday.
The Literature Prize will follow on Thursday, with two laureates to be crowned after a sexual harassment scandal forced the Swedish Academy to postpone the 2018 award, for the first time in 70 years.
On Friday the action moves to Norway where the Peace Prize is awarded, with bookies predicting a win for Swedish teen climate activist Greta Thunberg on betting sites such as Ladbrokes.
The Economics Prize will wrap up the Nobel prize season on Monday, October 14.