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The 2019 Nobel Prize in Physics has been awarded to three scientists for their discovery of planets outside the solar system and work in understanding the evolution of the universe.
The three new Nobel laureates are James Peebles, of Princeton University, and Michel Mayor and Didier Queloz, both of the University of Geneva in Switzerland. In the 1980s, Peebles used theoretical tools and calculations to trace the evolution of the universe from the big bang almost 14 billion years ago. His results showed that the visible universe of stars and galaxies is just a small fraction of the total mass and energy in the universe, laying the groundwork for research into dark matter and dark energy, two unseen components. “I was very uneasy about going into cosmology because the experimental observations were so modest,” said Peebles, who the Nobel prize committee reached by phone for an interview at a press conference announcing the prize today in Sweden. “The field grew and I grew with it.” Peebles was profiled in a 1998 Science feature.
Mayor and Queloz are pioneers in the burgeoning field of exoplanets. In 1995, they discovered the first planet outside our solar system orbiting a sun-like star. It was called 51 Pegasi b—a gas giant comparable in size to Jupiter, but orbiting its star more closely than Mercury does the sun. Many of the exoplanets that were discovered subsequently were these so-called hot Jupiters—a big surprise for researchers studying planet formation. “They challenge our preconceived ideas about planetary systems and are forcing scientists to revise their theories of the physical processes behind the origins of planets,” said the prize committee in a press release. To make their detection, Mayor and Queloz pioneered the use of spectrographs to look for the tiny Doppler shifts in the wavelengths of the starlight, due to the gravitational tug of the unseen planet at opposite ends of its orbit. Since their discovery, thousands of other exoplanets have been found.
This is a developing story.