On Dec. 25 at 7:20 a.m. eastern time, Christmas morning will be the last thing on René Doyon’s mind. The Université de Montréal physics professor will be among the more than 100 carefully selected scientists, engineers and journalists attending the James Webb Space Telescope launch at a spaceport in Kourou, French Guiana. The event, which has already been postponed several times, will be solemn; an Ariane 5 rocket will send into space what Dr. Doyon considers to be “in many respects the most complex machine created by humankind.”
Developing the new telescope, named in honour of NASA’s second administrator, began all the way back in 1996. Since then, it has taken close to 40 million hours of work and US$10 billion in investment. Several thousand experts collaborated on the project, which was undertaken jointly by NASA, the European Space Agency and the Canadian Space Agency. Over 300 organizations, companies and universities contributed, including Saint Mary’s University, the Université de Montréal, the University of Toronto and York University.
Dr. Doyon, who co-directs the Canadian scientific team, came on board in 2001. He helped to develop the Near-Infrared Imager and Slitless Spectrograph (NIRISS), one of two Canadian-built instruments in the telescope. Originally, Canada was only going to provide one instrument: the Fine Guidance Sensor, which steadies the telescope. “James Webb was a long saga with many twists and turns,” Dr. Doyon said. “The decision to develop the NIRISS was finally made in 2011.
The NIRISS will make it possible to capture infrared radiation emitted by faraway objects, such as exoplanets. Based on the spectra of these celestial objects, scientists will be able to determine if their atmosphere contains certain molecules, such as water, carbon dioxide, methane and oxygen. “James Webb [telescope] propelled my scientific career. Even if it hasn’t been launched yet, it prompted many initiatives on the ground,” said Dr. Doyon, who is also the director of the Institute for Research on Exoplanets at the Université de Montréal.
Signs of life?
Olivia Lim, a PhD student in physics at the Université de Montréal,, will be one of the scientists who benefits from the telescope. Under Dr. Doyon’s direction, she studies TRAPPIST-1, a red dwarf star located in the Aquarius constellation about 39 light years from Earth. What makes it special? Four of the seven Earth-sized planets that orbit this star are in the habitable zone, which is the region in the system where liquid water can exist on the surface. The telescope will bring Ms. Lim a step closer to determining if these planets harbour signs of life.
“We don’t even know yet if these exoplanets have an atmosphere. Our first goal is to validate this point,” said the young researcher, who went straight for her PhD after receiving her bachelors in physics from the Université de Montréal in 2019. Ms. Lim will be able to test her research hypotheses by observing these exoplanets’ transit, namely the moment when they pass in front of their star, which causes a change in luminosity on the infrared spectrum.
However, studying these phenomena takes time. Ms. Lim will have a total of 53.7 observation hours, which is the time needed to collect data on eight transits, two per exoplanet. This is also the highest number of hours allocated to use the telescope in Canada during its first year of activity. “As a result of its contribution, Canada was allocated five per cent of the total observation time on a competitive basis,” said Dr. Doyon proudly. “Olivia’s research program was supported under this bank of hours.”
This is even more impressive given that a committee involved in allocating observation considered 1,173 proposals from almost 200 international experts. All proposals were anonymous to avoid bias. Only the best applications were retained at the end of the process. Among the 286 projects retained internationally, many concern the study of other exoplanets such as hot Jupiters, as well as brown and white dwarf stars, super masssive black holes and even the very first galaxies that appeared billions of years ago.
A long road ahead
However, there is still some way to go before the telescope can see the farthest reaches of space. It must first be stationed at Lagrange 2, a gravitational balance point located 1.5 million kilometres from Earth. It will also have to be deployed slowly over the first two weeks of its space journey. That’s because the telescope is too massive to fit into the vehicle equipment bay of the Ariane 5 rocket, so it has to be folded up for the launch. “I call this period the 14 days of terror,” said Dr. Doyon. “There are 300 possible points of failure!”
And it doesn’t stop there. Once the telescope reaches its destination, it has to cool down and must be set up remotely, which will take five to six months. As a result, it will only start operating in mid-2022. “We could see the first scientific articles as soon as next fall if everything goes well,” predicted Ms. Lim. And if the worst happens? “I’m optimistic. We took the time to do things properly,” Dr. Doyon replied. “We predict nothing less than a breakthrough in our understanding of the universe.”