Discovery of First Exoplanet scoops 2019 Nobel Prize for Physics

In 1995 Michel Mayor and Didier Queloz changed the face of astronomy and astrophysics forever when they announced the discovery of the first extrasolar planet — or exoplanet. The discovery is recognised this year as the pair share the 2019 Nobel Prize for Physics with James Peebles.

Michel Mayor (left), Honorary Professor of the Faculty of Science of the UNIGE. Didier Queloz, Professor in the Department of Astronomy of the Faculty of Science of the UNIGE and Professor at the University of Cambridge. (UNIGE)

It isn’t always easy to pinpoint the exact day the edifice of science was changed forever, and in the process, our knowledge of the Universe around us instantly grew. But, October 6th, 1995, is such a day.

That was the day that Michel Mayor, Professor at the Observatory of the Faculty of Science of the University of Geneva (UNIGE), Switzerland, and his doctoral student Didier Queloz announced the discovery of the first planet found orbiting a star similar to our Sun outside of our solar system.

Since the day 51 Pegasi b first entered the lexicon of scientists across the world, the search for extrasolar planets — or exoplanets — has become a burgeoning and vital field — leading to the discovery of around 2000 more such planets.

And finally, 24 years after this watershed discovery, the work of Mayor and Queloz is recognised by the Nobel committee.

In a joint statement, Mayor and Queloz say: “This discovery is the most exciting of our entire career, and to be awarded a Nobel Prize is simply extraordinary.”

The pair share the 2019 Nobel Prize for Physics with James Peebles. The latter, a professor at Princeton University is awarded for “theoretical discoveries in physical cosmology”.

“They have painted a picture of a universe that is far stranger and more wonderful than we could ever have imagined,” says Nobel Committee member Ulf Danielsson of Uppsala University with regards to the work of the pair.

“Our view of the universe will never be the same again.”

“It is a fantastic recognition of the task accomplished by Michel Mayor and Didier Queloz; it shows the rigour of their scientific approach, but also their creativity and ability to think — and work — outside the box, a true pathway to great discoveries,” adds Yves Flückiger, Rector of the UNIGE. “This Nobel prize also comes as an honour for our University, for Geneva and for the whole of Switzerland, as a recognition of the quality of its research being rewarded at the highest level.”

51 Pegasi b the first of many

As Mayor recalls before he and Didier Queloz, his doctoral student, made their announcement at a scientific conference in Florence on October 6th 1995, the scientific community was unsure with regards to the existence of planets outside the solar system.

“No one knew whether exoplanets existed or not,” recalls Michel Mayor. “For years prestigious astronomers had been looking for them in vain!”

The technological revolution that enabled the pair to made their discovery was helded with the completion of Elodie spectrograph — first put into service in 1993. Attached to a 2m diameter telescope in Haute-Provence, the spectrograph finally provided astronomers with the accuracy of measurement needed to spot an exoplanet.

And in 1994, that’s exactly what Mayor and Queloz did, spotting a stellar object, 50 light-years from Earth, circling its parent star every 102 hours or 4.2 days.

“We were so excited to have found an exoplanet,” says Didier Queloz. “But first, we had to confirm our observations before we could reveal anything.”

By July 1995, the two astrophysicists had dispelled any such doubt, finally being able to say for sure that they had just discovered the first exoplanet.

Bolstering the search for life in the Universe

To consider just how important the discovery of the first exoplanet is to science, one only has to consider one of the most fundamental questions that humanity has ever asked: “Are we alone in the Universe?”

With new perspectives and tools bolstering the search for exoplanets every passing year and the first signs of viable atmospheres on exoplanets finally being identified — the hunt for exoplanets has never been more exciting. That means this year is the perfect time to honour these astrophysicists.

As we analyse these planets and the systems in which they exist — piecing together their origins, evolution, physical and chemical constituents as we go — it’s fair to say that the next major step in exoplanet discovery is the identification of one that can or does support life.

The gigantic number of exoplanets that could theoretically exist in the Universe, in an estimated at tens of billions of planetary systems, gives astrophysicists and astrobiologists eason to believe that life is not unique to our small, unremarkable world.

With an eye to the conditions that favoured the evolution of life on Earth, we scour the Universe for signs of carbon dioxide and water —evidence that a planet is habitable — and ozone a good sign, many hypotheses suggest, that it hosts life.

James Peebles (left), Michel Mayor (centre) and Didier Queloz have bagged this year’s physics Nobel prize. (Niklas Elmehed/ Nobel Committee)

That search began with Michel Mayor and Didier Queloz — thus making them, with James Peebles, truly worthy of the highest prize in physics — the Nobel Prize for Physics.