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Interview: Astrophysicist and science communicator Nathalie Ouellette—free talk 12.06.19 at Canada Aviation and Space Museum

By Brian Carroll on November 28, 2019


Dr. Nathalie Ouellette of the Université de Montréal (U de M) is an astrophysicist and an avid science communicator. Dr. Ouellette researches the formation and evolution of galaxies. She is the coordinator of the Institute for Research on Exoplanets at U de M. (Exoplanets are planets that orbit stars other than our Sun.)

Dr. Nathalie Ouellette. Photo courtesy of the Université de Montréal.

She is also the Canadian outreach scientist for the James Webb Space Telescope (JWST) in collaboration with the Canadian Space Agency. The JWST will launch in March 2021.

Dr. Ouellette will present a talk about the JWST at the next meeting of the Ottawa Centre of the Royal Astronomical Society of Canada (RASC) on Friday, December 6th.

Brian Carroll interviewed Dr. Ouellette about her upcoming talk. This interview has been edited for length and clarity.

Apt613: Our readers may have heard of the James Webb Space Telescope, but what is the JWST?

Dr. Nathalie Ouellette: We usually like to compare it to the Hubble Space Telescope, because everyone has heard of Hubble. It’s a telescope that’s going to be launched into space that is going to have a lot of similarities to Hubble, but also lots of differences.

Hubble is in what we call low Earth orbit. It’s just a few hundreds of kilometres above the Earth. But James Webb will be located 1.5 million kilometres away from Earth, considerably farther away, about four times the Earth-Moon distance.

It’s going to be much larger than Hubble as well. It has a 6.5 metre wide telescope. Hubble has a 2.4 metre wide telescope.

The James Webb Space Telescope. Photo provided.

Another key difference is that James Webb will be looking in a type of light called infrared. Hubble looks in mostly visible wavelengths, which is what the human eye can see. James Webb’ll be probing the universe in infrared (wavelengths). Often we see in science fiction movies, people will have infrared glasses to have night vision. Humans and animals emit quite brightly in the infrared. But lots of interesting things in space also emit brightly in the infrared, notably planets, which is something that we’re very excited about observing with James Webb—discovering new planets beyond our solar system.

Several ground-based telescopes are nine to ten metres in diameter. The James Webb, as you said, is six and a half. Why another space telescope?

Going into space has a lot of advantages. Notably, because it’s outside of our atmosphere, we don’t have to deal with a lot of issues that are involved with looking through an atmosphere. At night, we don’t have to deal with light from the Sun, but we create our own lights here in cities. So ground-based telescopes will try to build away from cities as much as possible, but there’s always some aspect of light pollution that becomes a problem. Space telescopes don’t have to deal with that.

Space telescopes also don’t have to worry about weather. We try to build telescopes on Earth in places that don’t have a lot of clouds, that are very dry. But there’s a limit as to what we can do on Earth. But if you build in space, there are no clouds, no water vapour. That makes everything much easier. And you can observe all the time, if you position your telescope properly.

The final consideration is that when you’re looking through an atmosphere, you’re actually looking through a fluid. So the air around us, we tend to forget that it’s there, but it’s much like trying to look through a river that is flowing. And so you’re trying to look at a little pebble at the bottom of a river that’s flowing. There are deformations of the image that you’re trying to take. That’s called atmospheric seeing. That’s what actually causes the twinkling of stars when we look up at the night sky. But if you go to space, you don’t have to deal with atmospheric seeing.

For all those reasons, it’s very useful to have a telescope in space that doesn’t have to deal with all of those different things.

Transit spectroscopy. Image provided.

You mentioned that the James Webb is an infrared telescope as opposed to visible spectrum. Why infrared?

There are several questions that we’re hoping to answer with the James Webb Space Telescope that we require infrared to answer.

One of those things is searching for exoplanets. Exoplanets are usually studied in infrared because they themselves emit in infrared. Also, if we’re looking for exoplanets that are something analogous to the Earth, we are going to have an easier time finding those exoplanets around what we call an M-dwarf star. These M-dwarf stars are smaller, redder and colder than our own Sun and they emit more brightly in the infrared than they do in the visible. So it is easier to study exoplanets in the infrared. That is one of the two main questions we want to answer with James Webb.

The other one is trying to study the very first galaxies ever created in the universe. Those very first galaxies weren’t actually very bright in the infrared. They were very bright in the ultraviolet and the visible light. Because of a phenomenon called red shift, a light that is emitted by an object is then stretched (because of the expansion of the universe itself). As it’s moving closer to us, the wavelength that was initially in the ultraviolet (which is a shorter wavelength) gets stretched out when it reaches us billions and billions of light years away from the galaxy that we’re observing. It has stretched into the infrared part of the light spectrum. So in order to study those very, very distant galaxies, we have to study the infrared even though they are not emitting in the infrared. By the time we observe their light, the light has shifted into the infrared.

Our readers aren’t just interested in the science and the technology. They’re also interested in the people. So I’m going to move to questions about you. What is your role with respect to the James Webb?

I am the outreach scientist for James Webb. I’m the only one in Canada with that title. There are several people who have that role with NASA in the U.S. who do something similar to me. My role is essentially to be the link between the scientific team and the communications team that makes sure that the public are aware of what’s going on. If there’s something exciting, a new result that’s been discovered, we make sure that that’s publicized to the media, that everyone knows where their tax dollars are going and get people excited about about astronomy in general, and James Webb.

I have a PhD in astrophysics, but I also have a lot of experience in doing outreach and education work. I make sure that all the communications material is scientifically rigorous. And I make sure that every time our scientists talk to the public that they are comprehensible… and interesting.

You’re the coordinator of the Institute for Research on Exoplanets at the Université de Montréal. How will the James Webb impact the research of your institute?

That is going to be really revolutionary. It’s going to be really incredible. And it’s not a coincidence because the director of our institute is also the principal investigator of the Canadian instruments on the James Webb Space Telescope. He’s a clever man. He built an instrument that would benefit his area of research a lot. The instrument that Canada is providing to the telescope was specially built to study the atmospheres of exoplanets.

One of the ways that we can detect that an exoplanet exists is by looking at a star. If we see that the light of that star dips periodically, we can tell that a planet is passing in front of it periodically and causing a small eclipse. That’s how we detect it. But if we have a very, very precise instrument, we can actually look at the starlight streaming through the atmosphere of that exoplanet.

We could potentially find the first sign of extraterrestrial life on an exoplanet using James Webb.

It’s really remarkable because these are planets that are tens of light years away, hundreds of light years away. We’re basically looking at a slice of that atmosphere that is the equivalent of an apple peel… so thin! As we’re studying the starlight streaming through that atmosphere, we can find a signature of certain types of molecules within the atmosphere of that exoplanet to determine the composition of that atmosphere and detect very interesting things like if there’s oxygen on that exoplanet or water vapour or carbon dioxide or methane or ozone. Some of those are what we call biomarkers or bio-signatures. If we find them, they can indicate whether that exoplanet is habitable and even potentially inhabited. So in the ideal world, we could potentially find the first sign of extraterrestrial life on an exoplanet using James Webb and our team here at the Université de Montréal is at the forefront of that research. We’re going to be involved in those discoveries!

As a science communicator and a media contributor, do you have any thoughts about making massive subjects relevant or tangible to everyday readers?

Astronomy I think is one of the easiest sciences to sell. It just sparks people’s imagination so much. I think that we’re very fortunate in astronomy where it’s a very visual science. We have gorgeous pictures to show. A lot of the questions that we’re asking are very philosophical that have been around for millennia. Questions like—are we alone in the universe and where did we come from and how did everything start? So I think that’s quite easy.

I think one of the roles of astronomy not only is trying to promote itself but is also to try and get people more interested in science more broadly. So I like to talk about astronomy as a gateway science, especially for children. So a kid won’t necessarily grow up to become an astronomer, but if he or she can get interested in science because they’re interested in alien life or black holes or becoming an astronaut, they will be more interested in pursuing math and science in school and potentially become an engineer or a doctor or any kind of scientist later on.

Even beyond that, I think that our modern everyday life is so intertwined with science. Often people don’t understand the science that’s all around them. Even now, I would say that there’s almost a mistrust and distrust of scientists. Because astronomy is much more palatable and much less controversial than some other branches of science like climate change and a lot of things in medical sciences, we can use astronomy to try to make people trust science more, be interested in science more, but also becoming better critical thinkers and becoming more scientifically literate. And I think a scientifically literate society is a much better and more engaged society. They will be able to take their own future in their own hands rather than sort of blindly following whatever is happening around them.

I think that astronomy has an easier time talking to the public about scientific or relatively obscure subjects. Because of that ease, we have a responsibility to benefit all of society.

Is there a question I should have asked you?

A question that I sometimes get asked—and I think that the answer is pretty important to get out there—is it worth the money we put into it?

For James Webb, it’s a $10 billion mission. It’s been in development for over 20 years and once launched, it will last between five and ten years. So it’s $10 billion spread over 30 to 35 years, say, but it’s still quite a bit of money.

Our contribution is on the order of $230 million. We calculated that, since Canada’s been involved, it’s about a 25 cents per Canadian per year to be involved in this mission.

Even beyond just answering the really fantastic questions that we’re hoping to answer and trying to encourage people to go into science later on and just being more scientifically literate, a lot of the technologies that we have to develop to build something as complex as the James Webb space telescope end up having everyday applications that people don’t realize come from astronomy. So the money that we put into these kinds of investments have great day to day paybacks.

When people take their selfies, they are actually benefiting from technology that was developed for astronomy.

Astronomy has led to lots of technologies we use every day. WIFI was developed first by radio astronomers. A lot of medical imaging had its roots in imaging that we have to develop to take really breathtaking and scientifically significant pictures of very, very distant, faint, far away objects.

When we’re launching things into space, every time you launch something, it costs a lot of money. So you try to miniaturize things as much as possible. We have to miniaturize our cameras to launch them into space while making sure that they are still high quality. And that led to the creation of the cameras that people have in their smartphones. So when people take their selfies, they are actually benefiting from technology that was developed for astronomy.

Even if it’s not immediately obvious, a lot of the money we put into science affects our everyday life.

Dr. Nathalie Ouellette will present her talk about the James Webb Space Telescope during the next meeting of the Ottawa Centre of the RASC at the Canada Aviation and Space Museum, Friday December 6, 2019, at 7:30pm. For more information, see the Ottawa RASC website. The meeting is open to the public. Admission to the meeting is free. Parking at the museum is $4.