“It is in the mind of everyone involved that what we are doing should lead towards an understanding of life in the universe”

The Kepler space telescope’s search may be at an end, but Didier Queloz, who found the first world around a sunlike star, says more planet hunts are afoot

In 1995, you discovered the first exoplanet orbiting a sunlike star. Did you foresee just how far the field would have come since then?

At first looking for exoplanets was seen as weird. A lot of people were negative about it. Then the field began to grow, and the establishment of the Kepler mission in 2009 showed the field was fully mature. In parallel, exoplanet meetings also grew. Many other disciplines are also interested now; it is much wider than just astronomy.

But isn’t NASA’s Kepler space telescope all but shut down now?

Yes. They wanted to push the mission as long as they could to increase exoplanet detections, and they found many super-Earth and Neptune-size planets. But unfortunately attempts to detect an Earth-sized planet orbiting its star with an Earth-like year seem to have failed.

Does that mean the search is off until 2017, when NASA launches its Transiting Exoplanet Survey Satellite?

No. Ground-based photometric technology has been pushed to a point that the bulk of detection can now be done from the ground by targeting smaller stars. That’s where the Next-Generation Transit Survey (NGTS) comes in.


What is the NGTS?

It is an array of 12 small telescopes being installed this year at Paranal in Chile’s Atacama desert – an ideal location because it is extremely dry and has clear sky about 80 per cent of the time. The reason we don’t need bigger telescopes is that we want to focus on small, bright stars.

Why limit your planet-hunting to these stars?

We don’t want to repeat Kepler’s observations of faint stars. Also, if you find a planet transiting in front of a faint star, it’s very hard to get other information about it because the signal is too weak. Bright stars offer the possibility of learning more about the planet, by making it possible to do work such as atmospheric analysis.

What kinds of planets will NGTS detect?

We plan to be able to detect almost anything that takes up to two weeks to orbit its star. If we are lucky, we may get a couple of objects very close to the size of Earth.

Beyond identifying them, is characterising exoplanets the next big thing?

The field is definitely moving more towards the astrophysics: climate, weather, atmosphere. I think we will be amazed by the diversity of these worlds.

Will exoplanets reveal life beyond Earth?

It is in the mind of everyone involved that what we are doing should lead towards an understanding of life in the universe. On the practicality of life existing elsewhere, I have no idea. In theory, finding a planet is a way to tackle that question. Once we find such a planet, there is no way we will be able to fly there in a reasonable time frame, but we can probe the atmosphere from here. Will that be enough to answer the question of whether life exists there? That part is still highly debatable.

Profile Didier Queloz is professor of physics at the University of Cambridge and the University of Geneva in Switzerland. He is a key collaborator on the Next-Generation Transit Survey

This article appeared in print under the headline “One minute with… Didier Queloz”