“It was very emotional – scary but exciting. We knew we had found something unusual,” recalls Didier Queloz of the discovery of 51 Pegasi b, which was later confirmed as the first known planet orbiting a sun-like star.
As a doctoral student in 1995, he already knew that he had stumbled upon something extraordinary – a discovery that confirmed the existence of solar systems similar to ours. But he could not have foreseen the further consequences of this discovery, namely the beginning of the “exoplanet revolution”, the boom in the search for habitable planets on which life may exist.
“When I wrote my PhD thesis, this was a very obscure topic, but now there is a whole wave of PhD students and postdocs working in this field,” says the Swiss astrophysicist.
Since he and his supervisor Michel Mayor at the University of Geneva – with whom he shared the 2019 Nobel Prize in Physics alongside Canadian cosmologist James Peebles – discovered 51 Pegasi b, more than 4,000 exoplanets have been discovered – largely thanks to Professor Queloz’s work in improving the telescopes and instruments needed to discover distant celestial bodies.
In return, a thriving space industry has been built, estimated to be worth $1.8 trillion (£1.4 trillion) by 2035, driven by the prospect of eventually reaching these Earth-like planets.
It is a good example of the great influence that the study of distant celestial bodies – 51 Pegasi b is about 9.6 trillion kilometres away – has here on Earth, said Professor Queloz last month at the annual meeting of Nobel Laureates in Lindau in southern Germany.
“We are using the universe as a laboratory to explore bigger ideas in physics,” he explained. “The entire science of nuclear energy – including thermonuclear weapons – arose from a curiosity about the universe. It turns out that if you know how the sun works, you can reproduce it – that’s one of the greatest transfers of knowledge of the 20th century,” he said.
GPS satellite navigation systems – a spin-off technology from the space race of the 1960s – are also among the inventions inspired by space exploration that have profoundly influenced the way we live.
“Einstein’s theory of relativity was born for aesthetic reasons – he wanted to find a symmetry in the universe by understanding the contact of space and time. It was not considered useful, but it turned out to explain the orbit of Mercury,” added Professor Queloz.
According to Professor Queloz, other major societal changes can also be attributed to space exploration. “The American Revolution was inspired by ideas that were directly related to the concept of the universe and its laws. At that time, the law was established by kings and could not be questioned. But if there is a law of the universe, then the ‘king’s law’ is less important. It was not the decisive element that inspired people like Thomas Paine, but it helped change the way people thought at that time,” he argues.
It remains extremely important to think about the cosmos and the Earth’s place in it, Professor Queloz continued.
“We know that our solar system is not that common – it is the only known solar system that supports life. So, knowing that we are so special as a planet, maybe we should be more careful with it. Not just for ourselves, but for the universe,” he mused.
Professor Queloz has been working at the Cavendish Laboratory at the University of Cambridge – and at Sir Isaac Newton’s Trinity College – since 2013, where he heads the research group for exoplanets. His Nobel Prize has now enabled him to set up a second research facility at ETH Zurich – the Centre for Origin and Prevalence of Life, which is investigating the causes of the emergence and spread of life on Earth and the question of whether the conditions on certain planets are suitable for life.
Although the question “Why are we here?” has captured the human imagination for centuries, serious scientific investigation of this ancient idea has only become possible in the last decade, explains Professor Queloz, whose centre brings together chemists, biologists, geoscientists, physicists and environmental scientists to pursue the question.
“This topic is still in its infancy – the amazing advances in the life sciences allow us to now think about the chemistry of life,” he said, noting that genome coding, which not long ago took a year, can now be done in minutes.
“There has been an amazing push in the discovery of exoplanets, but now scientists from all disciplines are coming together to ponder the biggest question of all – why there is life in this universe,” he said.
That’s certainly a daunting question, but given that Professor Queloz has already followed in the footsteps of Galileo, Kepler and Copernicus and expanded our knowledge of the universe through stargazing, he might be just the man for the job.
