Updated at 7:40 a.m. ET
A Canadian and two Swiss scientists have won the Nobel Prize in physics for contributions to our understanding of the evolution of the universe and Earth's position in the cosmos.
James Peebles of Princeton received half of the prize, with Michel Mayor and Didier Queloz sharing the other half, the Royal Swedish Academy of Sciences in Stockholm announced on Tuesday.
"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 neighborhoods on the hunt for unknown planets. Their discoveries have forever changed our conceptions of the world," the secretary-general of the academy, Goran Hansson, said.
"This year's laureates have contributed to answering fundamental questions about our existence," he said. "The discoveries have forever changed our conceptions of the world."
Peebles was awarded the prize for creating a theoretical framework that is the foundation of our modern understanding of the universe's history, from the Big Bang to present day.
"Were it not for the theoretical discoveries of James Peebles, the wonderful, high-precision measurements of the [cosmic background radiation] over the last 20 years would have told us almost nothing," academy member Mats Larsson said.
Mayor and Queloz were recognized for their 1995 discovery of the first planet outside our solar system orbiting a sun-type star, an exoplanet. The planet, 51 Pegasi b, is located about 50 light-years from Earth in the constellation Pegasus. It was detected by analysis of the slight changes in the star's spectrum caused by the orbiting planet.
"I was not working alone," Peebles said by telephone during a news conference in Stockholm. "From the beginning, I have always had colleagues."
Referring to the growing field of cosmology, Peebles reflected on his more than 50-year career and the changes that have occurred over that time: "The subject grew and I grew with it."
Past physics prize laureates include Albert Einstein, Niels Bohr and James Chadwick, the discoverer of the neutron. Marie Curie won the prize in 1903 for her work in understanding the nature of radioactivity.
In 2013, Peter Higgs, who theorized the subatomic boson that bears his name, won the prize after the particle was observed for the first time during experiments at CERN's Large Hadron Collider.
Candidates eligible for the physics prize are nominated by qualified persons and invited by the Nobel Committee to submit names for consideration. No one can nominate himself or herself.
This year's Nobel Prize is worth 9 million kronor ($918,000).
In a previous version of this story, we incorrecly said Marie Curie had won a second Nobel Prize in physics for having discovered the elements radium and polonium. That award was actually the Nobel for chemistry.