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Good afternoon, everybody. I apologise for the delay. So first, I would like to welcome you to the 16th lecture.

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As you know, the lecture series is one of the many activities that is being supported by the Cancer Family Charitable Foundation.

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So very big thank you to Sir Michael and Lady Dorothy Hinson for their support over the years.

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So of course, our speaker tonight, we're very delighted to have Professor Brendan Doyle from the University of Montreal,

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known locally of course as the when you see them all well so.

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And he is director of the institute. I need to get this right the Institute for Research on Exoplanets as well as the Omega Antique Observatory.

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The Omega Arctic Observatory operates a smallish telescope, but is a very effective platform, in fact, for instrument development.

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And you'll see that that Aeneas made a name for himself by developing innovative, cutting edge instrumentation.

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And that telescope is really a precious resource for those instrument development efforts.

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So actually, Rodney started his career not too far away from here.

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He got this from Imperial College in London in 1990 and then moved back to

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Montreal fairly early on and was a post-doctoral fellow there and a research

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associate before getting what is called a Canada research chair that is offered by the National Science and Engineering Research Council of Canada,

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the equivalent of The New Yorker I here in the UK.

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And that is meant actually to promote links, I guess between academia and industry.

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So that's where the incidental development comes about.

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And after that, he moved on to a professorship at the university.

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And as we'll hear today, his fame, I guess, really started ten years or so ago when he probably made his biggest discovery.

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So I think was the first person to take a direct image of a planet around another star.

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And that was, in fact, the combination, again, of very effective and ingenious instrumental development.

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So we'll hear undoubtedly about this today. In fact, he's been involved in many instrumentation efforts.

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His babies, as he says now, are the instrument, spittle and nips, one on the left hand side telescope in Hawaii,

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the other on a 3.6 metre at the Sea Observatory in Chile and is all about high resolution

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spectrograph to detect and characterise exoplanets using the so-called radial velocity method,

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which I suspect we'll hear about as well today. He's also involved in an instrument on the Gemini telescope.

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Of course, the UK is a partner along with Canada and the US in operating that scope and is developing a planet imager for that.

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And perhaps his biggest expectation now is is involved with the James Webb Space Telescope,

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the successor to Hubble in an instrument called NEAREST that again aims to characterise exoplanets.

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So I'll just mention a few prizes and then we'll move on.

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So here's one, in fact, the the polonium prize song from NASA, again, this Canadian Research Council,

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as well as the 2009 prize from the American Association for the Advancement of Science and the National Medal of the National Assembly in Quebec,

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amongst other things. So anyway, without further ado, here is an and he will tell us about the quest for nearby habitable world.

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So thank you very much. Many thank you, Malcolm. It's really a great pleasure and a great honour to be here today to talk to the subject,

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which I you know, I have to be honest, I've never I've not always studied exoplanets.

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I started my my career as not to mentioned as an actual galactic astronomer.

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So but it's like in 1995 when the very first time it was discovered, that was really a turning point for me.

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So today I'm going to talk to you about this quest,

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this quest about finding habitable worlds that is planet that are potentially inhabited by my life.

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So that's the main question I wish try to answer. It's a long term question.

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I'm not going to it's not going to happen any day. But I, I think I hope I can do to you that we may have an answer to this in a few decades.

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So many of you will probably see that for me, not within my professional lifetime or probably by my late, my and my courage when that happens.

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But it will happen. We will likely see that discovery.

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So but just to be clear about what I'm going to talk about, why don't we mention about we mentioned life.

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You probably have all kinds of a picture and in your mind you're thinking in bacteria, you know,

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little plants, animals, and of course, you're probably thinking of the most powerful species on earth.

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Right. Those people. Right. Or perhaps that species.

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Right. Or perhaps you have another idea about life outside the solar system.

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Those guys. I'm not going to talk about those. No, that would be a fantastically fine, intelligent life.

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That's not what I'm going to talk about. I'll we'll talk about a more modern life bacteria that have an influence on on their on a planet on earth.

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The the oxygen is produced by by plants.

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CO2 is produced by by us.

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Methane is really coming from cows. And so this is what we're trying to do.

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So it's the plan is to detect a biosignature, trying to detect the effect of life in its on its atmosphere.

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And that's the main goal, detecting the atmosphere of an exoplanet and actually measuring its chemical composition.

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As you can see, as you will see, it is very hard,

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but that what we're rapidly reaching humanity is reaching the technological maturity to actually do this.

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Okay. So there's no there's no speculation about the fact that these exist.

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It's not a scientific fact. And it's so many possibilities.

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We're estimating there's probably tens of billions of habitable planets in our own galaxy,

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and probably the closest one is in our in the start to just us at four and four like years.

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So what we're looking for is something that looks like us,

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a rocky planet with water on it and an atmosphere that's key, again, to actually to hope to detect a biosignature.

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So and we're also looking for a planet at the right place around there, star.

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That's what we call the habitable zone is this distance not too far,

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not too close to the star so that you can hope to have liquid water at the surface of the planet.

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Now, the the question of the planet being habitable is a very complex one.

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It's just it's much more complex than this simple criteria of finding where the star is next to the star.

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But that's the first thought. That's the very first thing we can do. We can actually there's so many whole planet,

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so we can choose those that are most likely inhabited and we're concentrating on those that are within their habitable zone.

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Okay. So how do we detect is it possible to do it live from afar?

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So imagine you are on the moon during a moon eclipse.

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So in face of all these would be completely dark. It's not dark.

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You can watch the moon, it's actually red. And that's because of the atmosphere.

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The atmosphere is filtering light from the sun.

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And if you are on the moon with a spectrograph, something that measure that bisects light into its colour,

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that we express in wavelength, this is what you would see. So you'd see, you know, this is the visible part.

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This is the infrared part. And all these wiggles are the spectral signature of molecules.

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So if there's one that is mind boggling, it's the O2. This is Oxygen.

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This band here is water. There's little dips. Here is methane.

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So you can see from a distance with the right instrument, it's actually possible to detect that that planet, that atmosphere has life on it.

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Now, of course, that's easy on the moon. Now, try to imagine being a bit more further away.

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So this is a picture of the earth as seen from by the Galileo spacecraft in 1990 on its way to Jupiter.

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Galileo was it was to study Jupiter. And this man, Carl Sagan, propose a very interesting experiment.

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So let's point all our instruments toward the earth while we're there.

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And we're going to. Analyse the data as this. This was a data from an exoplanet and let's see what are we can actually identify life.

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So it's basically a control experiment. Can we actually detect life from afar using our instruments?

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So it made it to a nature paper back in 1990.

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And lo and behold, Carl Sagan demonstrated that there was lots of oxygen in a spectrum.

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We can can see it here. We can even detect pigment from that chlorophyll, which is very exciting.

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And we can also detect methane in a very unnatural abundance, which it can only explain if there's active biological activity.

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And there's even even suggestions there's the radio signal to receive on this planet suggests that there may be intelligent life on the planet.

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So this is a controlled experiment that, again, from afar you can actually detect life from exoplanets.

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Okay. But of course, it's much harder than this.

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So Voyager one in 1990, as it was leaving, it was leaving the solar system well beyond the orbit of Neptune.

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Took that picture. That's the Earth. And it's now called the Pale Blue Dot.

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So this is the challenge.

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So you have to take that life and analyse it and and determine that this planet has an atmosphere and that it has oxygen, methane water.

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So that's our goal. But that planet that that picture was taken, only one six thousands from that, the closest star.

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So you can see this is difficult. But I hope I will convince you that quite soon we'll have the technology to to do that, that task.

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Okay. So how are we going to do this? Well, we need ways of first detecting planets and characterising this atmosphere.

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So I'm showing here you hear a picture of the sky, which you can probably look nice, but that's actually the the the great square.

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I guess this I'm showing you that region here because there's three stars in that in that region

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that you can see with binoculars that really made history and have an excellent research.

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So I'll walk you through all these these stars. So the first one is 51 Pegasi.

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So that's the first planet around which we discovered a planet around a normal star.

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So the way it was done, so this what we call the wobbling technique of it's basically literally watching stars dancing.

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So basically, you know, we always think that the planet revolves around the star, but really the star also revolved around the planet.

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In fact, they do revolve around the common point, a centre of mass.

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As a result, because of the the period of the planet, the star is moving.

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And so you can actually measure that by taking a spectrum, again, of the of of the star.

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And while the the the the star moving away from you, the spectrum is blue shifted away redshifted.

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So it's very simple. And now we have instrument that can actually do this with very high accuracy.

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So those are the data. So basically the plan is you go with your telescope, you're in Studio Spectrograph,

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you take a spectrum and you had it lost, and then you plot it in time and you can see that with time it will oscillate.

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That's that, the telltale signature of a planet.

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Now, just to give you an idea of the difficulty on this, so this the first one was an average of 50 metres per second,

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but now we can actually detect planets with as low as one metre per second.

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I'm walking here at the speed of about less than four or five metres per second.

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Okay, so one very famous discovery that was done back in June of 2012 by the Swiss team,

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which arguably one of the best in the world to do this kind of work is what we detect a nought mass planet around Alpha Centauri.

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B So Alpha Centauri is the closest star system to us.

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It's actually three stars. It's two stars. It's a binary system component A and B and the Swiss found an earth like planet around component B,

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so it's about an Earth size, not in the middle of a zone. But yeah, that was quite, quite a groundbreaking discovery.

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They had found it a rocky planet. Now, it turns out four years ago and I have to say that the actual signal is is marginal.

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So what you see here. Yeah. Just physicist in the room.

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Right. So every point is a radial velocity.

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Now the scale is change from before this is metres per second. And you think the average of all these points you get the record.

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So yeah, it was convincing enough to the community to say, yeah,

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it looks like we've detected a rocky planet around Alpha Centauri B until a team of astronomers,

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in fact Susan and Ryan here at Oxford realised that data do in fact show that it was not.

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It was actually stellar activity. The issue is that a star has spots.

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As the star rotates, it can fool you that the star is moving, but it's not.

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It's just bubbling on the surface. So that is very important.

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And in fact, I'm showing this because, you know, even though you need a very powerful instrument to do this kind of work to detect them,

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you really need very, very important data analysis tool.

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And that was one that is very powerful and one that will continue to be absolutely crucial in our quest to detect a biosignature.

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Okay. So people do not give up. So around this pair of stars, there's a third one that we call Proxima B.

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This one is a much fainter star. You cannot see it with your eyes.

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You need a small telescope. It's a red dwarf and Orion it.

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There is a planet that was detected to rate of lusty.

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And now you can see the signal. It's much better behave. But I still put a question mark and that one is right smack into the habitable zone.

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So then there we go. We have we have one. This one is around.

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This is the closest habitable that will ever find. Right.

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Okay. So we'll see with time whether this planet turned out to be to be true.

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But I have to say that the signal is much stronger. We'll see.

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Now moving on to another star, HD 29458b.

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So this one is very is very similar to 51 figures. And I do not make sure that the the that the planet around 51 because it's a hot Jupiter.

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It's a planet, the mass of Jupiter, but much closer.

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It revolves around this star in three days instead of 12 years, go for Jupiter.

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So that's why we know that they're very close to their star. They're very hot. So that's why we call them measure hard to believe.

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So 29458. Was also discovered as a hot to return to the wobbling technique.

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But that one is very special. The the orbit happens to be aligned with you.

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So that's when this planet go in front of this star.

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It is a small eclipse and you can actually detect that. In fact, it's correcting the easy.

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And this was done by Didier Tamano and back in 19 into Tarzan.

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And so basically with the stars winking at you. So the bigger the planet is, the bigger the wink.

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So this is a very powerful technique because we actually know quite well the radius of stars.

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So we can measure that depth and you can do that especially in space.

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You can measure the radius of the other planet, which is a very fundamental continent.

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And you want to know, are we dealing with a rocky planet, a small earth sized planet, or a big giant planet?

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Okay. So that was the trigger to actually of a new mission called Kepler, which was launched in the late 2000.

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And Kepler has a small telescope that look at this piece of this patch of the sky, which is not much bigger than your hand projected on the sky.

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And the vast majority of the close 2 to 4000 exoplanet that we've found so far are from Kepler.

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So Kepler, the goal couple was to find Rocky Planet around Sun Like Star, just stars like our own.

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It did find many of them.

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The problem is that most of these planetary systems are relatively away from us, so it's very difficult even to measure the mass of these planets.

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Okay. So what did Kepler found?

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So this is a picture of our family portrait. This is the gas giant planets Jupiter, Saturn, Uranus, Neptune.

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The rocky planets are very small on the earth. Venus, Mars, Mercury.

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And I think this is Pluto here. So what they will point out, do you think Kepler found why?

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It was a big surprise. It found something like this. We don't know how to call them because they don't exist in our solar system.

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So we call that either super earth, meaning Neptune's.

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We don't know what they are. We don't know what they are. In fact, we're going to learn a lot about those in the coming years.

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And some of them could be water well, rocky planets covered in oceans.

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And those things are theoretically possible, but we haven't found any evidence of that yet.

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But that's a very important discovery. Do to remember that the the most typical exoplanet in a solar neighbourhood does not exist in our solar system.

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Okay. Now, even more powerful technique relative to the transit method.

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Now imagine that while the star of the planet grows in front of a star, you take a spectrum, so you measure its character.

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This is symbolised by various wavelengths.

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And so if there's a molecule in the atmosphere that happens to block life like water, the planet will look bigger.

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So by measuring the the relative that of these at various wavelength of various colour,

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you can actually have some insight about the chemical composition of the atmosphere.

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Now, I have to say this is very difficult to do. We can do it right now.

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We can do it especially with the Hubble Space Telescope. So here's an actual measurement of the this this this, this contributors to a945 HD.

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So this is the transit, the depth and the the the black points are the actual.

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Data obtained with Hubble and the include this is the model of water.

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So we have detected water in the atmosphere of an exoplanet. But this is a hot Jupiter.

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It's not a rocky planet. And doing that for a small planet, it's much, much more difficult.

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But as you can see, as you will see later, it becomes it will it will be the next few years.

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Okay. Now, moving on to my favourite star, H.R. seven, 99.

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So this is the start around, which we actually found the very first image.

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So as I said, after 1995, I became very interested in trying to find means techniques, how to actually take pictures of those.

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So this is illustrated here, how we do this. We basically masked the star.

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And by doing so, the actually the planet is very faint.

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Next to it becomes revealed. Now, historically, it wasn't done quite like this.

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So but we you needed to the biggest telescope. Yeah. You could have in hand and telescope and the best instrument to make your image very, very sharp.

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So an actual image of a star on an individual telescope looks like this.

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Once you remove the actual main signal from the star, it's a it's a complete mess.

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Okay. So to detect a planet around that mass is very difficult.

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And this is where two of my students actually got involved in developing new techniques,

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new observing strategies with these telescope and data analysis tools to to process the data to turn them into this so suddenly that without,

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you know, changing any instruments, just new data analysis tools, new tricks, we are able to to to detect very, very faint companion.

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Now, we got excited many, many times,

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but it turns out that the vast majority of those are background stars that happens to be that they're not exoplanets.

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So it took about ten years to do to do this. And finally, we got lucky.

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We found that this system this was led by two some our my first student.

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So we we reported three planets and a year later we found a fourth one.

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So if you're not convinced those are planets. So this is a movie of all the data we've acquired on the system in last ten years.

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And lo and behold, they're really rotating right in the same direction.

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It is a genuine planetary system. Now, those, even though it was very difficult, it took ten years of effort to actually do this very easy.

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The brightness ratio of the planets, the stars, about ten, 20,000.

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Now, if you want to detect the earth around the solar type stars from afar, that's a ratio of 10 billion.

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Now, not quite ready to do this, but we think we know how to do it.

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Okay. And just to give you an idea how difficult that is. Now you have to take the.

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Oh, yeah, I want to I want to mention something that is really frustrating.

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Soon after that discovery, we went back and look in the data archive to find out that each are in its own 99 had been observing in 1998.

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So our discovery was in 2008. And so this is what the image was reported.

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Okay. But that they had developed these fancy data analysis tools apply is algorithm and and they turned to this.

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It was there. So I get mad when I think about it.

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Yet all these years we didn't have a the tide that went to to telescope two pages all these efforts finally we got lucky.

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But it it it was there. It was on the Internet. All we needed was a few seconds worth on the laptop to release that up and it was there.

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So again, I want to emphasise one very important point.

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When you think you have the most powerful facility in the world, the largest telescope, the best instrument to make a groundbreaking discovery.

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Ask yourself, do I have do I have the right analysis?

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Do you know this is absolutely fundamental. Okay.

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Now, so this is a new discovery that was done with the Dewey Tunnel in New Jersey.

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That discovery triggered the even more powerful instrument.

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So this is another planet. You can barely see it here. But this time, not only do we have an energy, we have a spectrum and height.

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And you can see that as we go along the spectrum and that that absorption here is due to methane.

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So these images really do show that these planets have methane.

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And I'm showing this just to show that the imaging technique allows you to probe the atmosphere of the planet.

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And this is a very powerful technique indeed. And maybe the way one day we will find a biosignature.

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But again, I won't just show you the difficulty of doing this by showing you one of the deepest image ever obtained with the Hubble Space Telescope.

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These are galaxies. There's no stars there, but just like the faintest galaxy in there.

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Okay. And that's a signal of an earth around a solar type star at about ten light years away.

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The only problem is that that planet is around a very bright star.

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You cannot see it. This is very, very difficult. Okay.

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So what's the road map to find life? Well, the very first things that we need to find more this when you find the closest habitable zone,

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the closest planets, we need to measure their radius, their mass.

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Because we want to find out if you have to reduce the volume, if you have the mass, then you know the density.

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So you know that you're living with a rocky planet. I guess that's absolutely fundamental.

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And as I said, you want to focus on the ones that are in the habitable zone to maximise the chance of detecting life.

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And finally, which is the most difficult part, you want to probe the atmosphere either with imaging or transit spectroscopy,

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with two techniques that we have in hand to do to do this.

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Okay. Our best shot in the near term is to focus on these very faint stars, these red dwarfs.

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Why? Well, because those are the most common stars in the sun.

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And what do you think of all you around the sun and you count all the stars?

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80% are these red dwarfs, typically a quarter or a fifth of the radius of the sun.

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And they are very, very faint. And they they are very bright, mostly active fed wavelength and driven by a special aspect.

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Is that because the star is very faint, the regions where it's habitable, it's much closer.

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It's actually well within the orbit of Mercury. In fact, a year on the planet around them, dwarf takes about two or three weeks.

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Okay. And. And, yeah, so basically much easier.

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And in general, detecting a planet, detecting its atmosphere around a planet,

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around a red dwarf is just easier because the planet is much fainter and smaller.

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Okay. I just want to show you a very famous system.

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This is the the Trappist system that was discovered a few years ago.

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The the star. And this is hard to scale here. So this is a red dwarf.

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And around this set of the planet, all they all have about the size of the earth and their transit.

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They're under their stars. And three of them are very close, in fact, is right in the habitable zone.

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So those that are really real candidates to actually study in detail.

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And in fact, we will study them later with the James Webb Space Telescope.

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I'll come back to this. Okay. So what's coming up?

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You may have seen the launch of this test scope last week, a very small telescope, which is basically the successor of the Kepler mission.

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So that's mission is to find very close nearby planets through the transit method.

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And it will do so by a full camera that can take a picture of, you know, from above 90 degrees.

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It will tell the sky to buy for 27 days and then move to the next one.

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So we'll take about one year to do the sun in the sky and then another year to do it the northern sky.

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So this is thousands of these you'll find out that the system will find and about a dozen rocky planets right in the zone.

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So those are the pearl in the sky to study for future calculation.

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Okay. So and it's not it's not enough if we measure if we'll have the radius of these stars, but we need the mass.

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As I said, we really need to determine whether they have you know, they are these are rocky or dangerous.

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So these are the names of the instruments currently under development in the world to do this.

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So there's a lot of effort and many of them actually to look at these Red Dwarf.

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And I live all in two of those instruments and I want all to very briefly spew and arbs.

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So basically these are machine to use the wobbling technique to measure the mass of nearby exoplanet.

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So one is on the kind of fronts that we telescope. Yes. It's actually operational.

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We're just getting the first light. And one is on the 2.6 metre telescope and on the cap.

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And we'll have lots of observing time. More than 100 more than 100,000, like of going to have some in time in the next five,

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six years to to measure the mass of this planet that Tess will find, but also to actually find the closest other worlds.

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So here's a movie showing you the current census of planets in the solar nebula.

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Now, this is a depressing sight because it's far like this kind of this than unit just one fly by three, and you have just like the night years.

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So every point here is a planet that has been discovered in blue.

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This is a planet that is in you have a was on. So you see Proxima B is right here.

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So this is the current census. So over two years it will take about five years.

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We will interrogate every star in the sky on the close red dwarf and ask, Do you have a planet and is it small?

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So this is what we expect to find about 100 planets around that, the close to the sun and about a dozen very close to the.

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I'm in the habitable zone. Okay.

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Now moving on to the James Webb Space Telescope. I used to write for 2018, 2019, and now this is 2020.

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So Tess is about the size of a washing machine.

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And so you can see the it's mirror, it's much smaller.

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And this is a gigantic telescope, a collaboration between Nassau County and Space Agency and the British Space Agency.

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So this telescope will revolutionise astronomy in all fields and including exoplanet.

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So I'll just going to give you another know what this telescope will do.

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So this is the actual telescope. It's not a cat drawing.

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It's a real telescope built. The instrument that I doing for Canada was delivered July 21st, 2012.

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So it takes a long time to actually build is a big, big telescope.

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One important feature of this telescope is the SUNSHIELD, which is about the size of a tennis court.

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And all of this is folded into the rocket of a I inside rocket.

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I'll show you at the end of my talk me a very scary movie, which is the the deployment sequence of this telescope.

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Okay. So there's four science instruments and all have the capability to actually study the atmosphere of exoplanets.

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As I said, this is the key to one. They find a biosignature.

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So I'm responsible for this one. It's called nearest million to know what it means.

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But it's a camera with some very specialised models to actually study atmosphere.

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So I show you that that picture. So three of those played out will be studied by my instrument probably towards the end of 2020.

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And I will just show you an actual simulations of what we should expect from that for the planet.

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So this is done by my colleague, John Bennett. You know, this is my are.

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So this this is actually a data that will show and it's not going to be images.

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These are spectra. So what you see in blue, this is the the model of an atmosphere that will be rich in water.

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Let's suppose that this artist's view is correct, that Trappist one F is a Waterworld.

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It's got lots of water. So we should expect water in it in its atmosphere.

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And if that's the case, then we should measure the the blue signal.

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So in black, those are the data points that the newest instrument will will give us in about 10 hours of observations.

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So in only 10 hours of observation with this powerful telescope, we'll be able to tell whether there's water in that in the atmosphere on this planet.

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Okay. But I have to say that this is probably a very optimistic simulations.

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You can imagine all kinds of scenarios whereby water would be trapped and then you would not see it.

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And so this is a I'll show you another simulation to to ask the question.

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Is it possible that Webb will one day detect about nature?

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I'll answer by a big, big maybe. So the reason is that this is probably a more realistic simulation spectra that that well will will give us.

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And the and so you see various features here, CO2 and the water features only a few parts per million.

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This is very difficult. The best sensitivity that we can do nowadays with the Hubble Space Telescope is about 1020 BPM.

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So we need to improve our sense D by about a factor of ten.

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And but there's one feature it's very interesting, which is this one here.

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This is ozone around nine micron and the MIRA instrument built by Europe could actually detect us and that we all

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understand the performance of this instrument and the telescope to make simulations of how long it would take to do this.

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So here's an example of a of a planet NHS 1140 B, which is a rocky planet.

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Right. And you have ozone that was discovered by then it Charbonneau. So we do have targets to look out.

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And this is the actual simulated data that we will observe after observing that the

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planet that by 15 times 15 tens of events and the the ozone feature is is shown here.

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But the reality is that the stars are always visible.

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And so it would take actually four years of clock time.

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So a very significant fraction of Web time to do it.

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But you can bet that we will look at this star very, very intensely with the James Webb Space Telescope.

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Okay. Now, I just want to move on to the future. So this is an animation of a very powerful disco that is currently under development in Europe,

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the European extremely large telescope, a 40 metre telescope, which will have a lot of chemical data to study exoplanets.

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And there's others I'm involved in kind of the 30 metre telescope.

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I'm showing this one because it will likely be the first one, probably a good five years head start compared to other big giant facility in the world.

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And but the e-elt remains on the major. A very powerful scientific opportunity for.

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For Europe to study not only exoplanets, but also the early universe and much further along into the future.

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Yes, there is a flagship mission that we want and deserve. So this one is a 12 metre telescope.

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The web is a 6.5 metre telescope, so it looks very similar.

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And so this would be launched in maybe 2040 ish.

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And that that that telescope would be designed to actually paint a picture of an earth so this one would look like this.

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And this maybe this could be the very first base in Asia.

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I put a question mark because I'm sure the first time we we claim that it will be very controversial because I won't have time to go into the details.

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But you can imagine false positives that will generate that signal.

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And so this will be highly debated. Okay.

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I want to finish this by just mentioning that probably the most important part of all this is,

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yes, of course, these big facilities that cost billions of dollars. But the people so these are the faces of my team at the memorial.

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And there just are just one team among many others in the world that are all focussed on to one common goal,

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which is do exploring new worlds and searching for life.

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And on this I will thank you and mention my funding agency and our generous donors that may just decide this role that just where possible.

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Thanks very much.