The Nobel Prize in Physics 2019 was awarded "for contributions to our understanding of the evolution of the universe and Earth's place in the cosmos" with one half to James Peebles "for theoretical discoveries in physical cosmology" and the other half jointly to Michel Mayor and Didier Queloz "for the discovery of an exoplanet orbiting a solar-type star."
Peebles is credited with developing the theoretical tools that allowed scientists to perform a cosmic inventory of what the universe is made from, showing that ordinary matter makes up just 5% of its known contents, with the rest being dark matter and dark energy.“I couldn’t think at all, I had a complete blackout because emotionally it was extremely intense,” said Didier Queloz in London.
When Queloz and Mayor set up the search it was with low expectations of finding anything because any planets massive enough to create a measurable Doppler shift were expected to have such long orbits that the wobble would take years to detect. Surprisingly, though, they found a huge planet sitting extremely close to its host star, with an orbit of just four days. “Because it was so near in to its star, no one really believed it,” said Queloz, adding that it took several years to convince the world that the finding was real. Since then, astronomers having found more than 4,000 exoplanets in an incredible range of sizes, forms and orbits. Learning about these strange and varied worlds beyond our solar system has transformed understanding of how planets formed and given new focus to the question of whether there could be alien life out there somewhere.
Queloz said the sheer numbers of planets made it hard to believe that ours was the only one to host life. “We may find out that life is extremely rare. We know life is special, but we may not acknowledge how special or rare it is,” he said. “It’s not impossible that in the next 20 to 30 years there will be new kinds of equipment that would be able to answer this question. Whether they will find something is open.”