SINGAPORE He was the first to discover a planet outside the solar system, but his work was dismissed for a decade before being rightfully recognised with the 2019 Nobel Prize in Physics.

Delivering the opening lecture of the 11th Global Young Scientists Summit at the Singapore University of Technology and Design on Tuesday, Professor Didier Queloz shared about his scientific journey as an astronomer.

He specialises in exoplanets, looking for planets that orbit sun-like stars outside the solar system.

The Swiss Nobel laureate was the harbinger of the exoplanet revolution, which has catalysed the discovery of more than 5,000 exoplanets to date.

Yet, even he and his supervisor, Professor Michel Mayor, doubted their own discovery in 1995.

Nobody was expecting a planet back then, so it was a big surprise when I saw the data. I found the planet and said: Whats going on? I thought something was wrong with the equipment, but after checking, I realised there really was something orbiting that star, Prof Didier, 56, told The Straits Times in an interview.

First I had to convince Michel that I was right, then the scientific community, which was really tough. For the next 10 years, nobody believed it, so it was a rough time for me as a young scientist, said Prof Didier, who was a PhD student at the University of Geneva at that time.

Only when the physics was more understood and established did people start to realise, oh, that guy did it.

Prof Didiers discovery of a class of giant gas planets closely orbiting their parent star, known as hot Jupiters, upset existing theories about the formation of the solar system and other planetary systems. Hot Jupiters contradicted predictions that only rocky planets orbit near the parent star, while larger gas planets do so further away.

Before his findings, theories were based only on observations made in the solar system. Astronomers are now working on theories that account for the migration of gas giants from outer to inner orbits.

The first shock was that the theory was incomplete, nobody would have guessed that planets such as gas giants could move around in their system. The second shock was that we (the solar system) may not be the dominant structure in the universe.

Prof Didier, who is currently a professor of physics at the University of Cambridges Cavendish Laboratory, plans to continue leading the hunt for Earth-like exoplanets that might support life.

However, current detectors are not sensitive enough to do so.

Im a bit upset by the fact that we have not found an Earth-like planet, so Im helping to set up a new kind of equipment to detect these exoplanets. I would also like to establish a chemical pathway for paving the way for looking for life on other planets. I have teamed up with chemists, geochemists, biochemists and earth scientists to collaborate in this area.

When asked what he feels is the main takeaway from his success, Prof Didier credited his obsessive curiosity that enables him to persevere with his beliefs and ignore the naysayers. He aims to continue probing for the next astronomical breakthrough.

We believed we were the centre of the universe. We believed everything was orbiting around us. We believed the solar system was this then we realised the universe is expanding and so on. Id expect that our next breakthrough will be one where we find life plenty in the universe, where we realise how boring and insignificant we are.

The summit, organised by the National Research Foundation and being held from Jan 17 to Jan 20, features lectures and panel discussions with 21 eminent scientists, including Nobel laureates and winners of the Millennium Technology Prize, awarded by independent foundation Technology Academy Finland. More On This Topic Once in 50,000 years comet may be visible to the naked eye Nasas Moon capsule Orion due to splash down after record-setting voyage