After sharing the 2019 Nobel Prize for Physics for the discovery of the first exoplanet, Didier Queloz talks to Rebecca Pool about the future of planetary exploration
How did you learn that you had won this year’s Nobel Prize for Physics, which you shared with Michel Mayor and James Peebles?
I was in a meeting when it was announced and so didn’t actually take a call from the Nobel Foundation. I first heard about it from the press office at the University of Cambridge who asked me whether I was aware that I had won. I simply replied, “You’re kidding me?” At first I didn’t accept it and had to double check.
Did you ever expect it would happen so soon?
Yes and no. We had been told for almost 20 years that our discovery would be worth a Nobel prize, but you can’t keep thinking about it otherwise you become obsessive. I was expecting it a little after the 20th anniversary of the first exoplanet discovery – which myself and Mayor made in 1995 – but after that I gave up. So the news caught me by surprise.
Has it had an impact on your life and research yet?
My research is a disaster at the moment. The number of e-mails I receive has exploded and I’m spending a lot of time answering calls. When you win a Nobel prize, you become an ambassador for science. Everybody in the field knows my work but other people will want to hear opinions about research. This is new to me and I don’t know exactly how I’m going to deal with it but I feel too young to give up on research. It’s in my blood, so I will find a compromise.
How did it feel to discover 51 Pegasi b – the first exoplanet?
Initially, bad. I was just a PhD student at the time and it is not easy to digest such a big discovery when so young. At 29, I had probably made the biggest impact I would possibly ever make. It changed my life.
What was the reaction to the discovery?
For years, most people didn’t believe that this kind of planet existed, but I always knew the field would advance. I started to enjoy the discovery about 10 years ago. But looking back I realise how stressful this has been to live with.
Did you ever imagine that so many exoplanets would be found following your discovery?
In my PhD defence, I noted that 51 Pegasi b is the tip of the iceberg. This was based on our then limited capacity to detect planets. But what is happening now is beyond my most optimistic expectations and we have since discovered over 4000 planets orbiting other stars.
How has it changed our view of the universe?
It has completely changed our understanding. We now know that our solar system is not unique – although we have not yet found a solar system-equivalent. We now need to better understand how solar systems form. It is a fascinating time.
What is the future of exoplanet research?
To understand the origins of solar systems, we need to really understand all the planets we are finding. This includes the structure of these planets as well as the size, mass and atmosphere. Does a planet have a primary atmosphere from when it formed or a secondary atmosphere which could show geophysical effects? Or perhaps there’s a third atmosphere from biology or chemistry activity at its surface? These are the questions that the next slew of experiments will address. Beyond this, is the question of life in the universe.
Do you think we will ever find evidence of life on an exoplanet?
I’m part of the Terra Hunting Experiment that will aim to detect an Earth-twin. Once we find it, we’ll need to design a mission to learn about this planet. Hopefully within 50 years we will find life.
What upcoming space-based exoplanet missions excite you?
Europe has a couple of major missions planned in the coming decade. In 2026 the European Space Agency will launch the Planetary Transits and Oscillations of stars to search for planets around a million stars, while two years later the Atmospheric Remote-sensing Infrared Exoplanet Large-survey will take-off to study and characterizing exoplanets’ chemical composition. Before then, NASA is expected to launch the James Webb Space Telescope in 2021.
What impact do you think the prize will have on new exoplanet missions?
As the field already has a lot, it may not get so much out of this prize in the short-term. But the impact of a Nobel prize is to go beyond a particular field of research. For example, I’m now talking with geophysicists and chemists to study the origin of life on Earth.
Were you surprised that the Nobel committee split the 2019 award between cosmology and exoplanet research?
There could have been a prize just for discovering exoplanets so why did the Nobel committee include cosmology as well? I don’t know, but I’m glad it did. Looking for planets or investigating the origin of the universe is the same topic. Some colleagues say that cosmology is different from planetary research, but I think this is nonsense. We’re all looking for the origin of life and the universe and we need to work together more.