Six primary mirror segments of the James Webb Space Telescope at NASA's Marshall Space Flight Center. NASA/MSFC/David Higginbotham
Last November, Montreal astronomer René Doyon met Michael Gillon, a leading researcher on exoplanets, at a conference in Brussels. The two knew each other by reputation, and over a friendly coffee, Doyon asked his colleague about a rumour he’d heard about the discovery of four new exoplanets, nearly forty light years away, that had the potential to support life. Gillon was reluctant to answer. It’s not unusual for members of the scientific community to share research—astronomy requires so much money, expertise, and machinery that it’s usually more of a collaboration between countries and scientists than a competition—but Gillon’s data wasn’t the kind that allows for advance previews. His earlier research on three other exoplanets had garnered a lot of attention last year, and both scientists knew that any new results would make headlines.
Doyon kept pressing him until, without giving up any details, Gillon admitted it was possible the rumours were true. A few weeks later, when Doyon was back in his office at the Université de Montréal, he received an unexpected email from Gillon. It contained an advance copy of Gillon’s soon-to-be-published paper, along with a request to work together.
But despite the detailed illustrations provided by NASA last week, the truth is that we know very little about the Trappist-1 system. We can’t actually see the planets, nor can we visit them. At this point, we can only guess their size, mass, colour, and temperature by measuring changes in the infrared light emitted by Trappist-1. Any slight variation, astronomers say, means that a planet is passing in front of the dwarf star, distorting or blocking out light. Such evidence is all that Gillon’s team has had to work with for years. After JWST is launched next year, though, astronomers will be able to point it in Trappist-1’s direction. They will use its instruments to detect the existence of biomarkers—methane, ozone, oxygen, carbon dioxide—that would hint at the possibility of alien life. If those chemicals are found, Gillon says, they “would tell us that there is life with 99 percent confidence” on that exoplanet.
The telescope will be operational in the spring of 2019, and the first chance to observe Trappist-1 will come in June of that year. Making use of Canada’s privileged access, Doyon’s team will be observing at least two Trappist-1 exoplanets. Using Gillon’s data, they’ve been running simulations since last December and working out the intricacies of how to conduct the research. They now know exactly how to spot an atmosphere similar to Earth’s. “It’s certain that research on two of the three [exoplanets in the habitable zone] will be led by Canadians,” he says. “In all likelihood, Canada will have the first data on the Trappist-1 system.”
Of course, it’s hard to predict what that data will show; perhaps the exoplanets are barren, more like Mars or Pluto than Earth. But there’s a chance that at least one of them isn’t. If there are extraterrestrial beings out there, breathing some mix of oxygen and carbon dioxide and drinking fresh water, Canadian astronomers could be the first to find evidence of them.