The discovery of the first exoplanet | The 2019 Nobel Prize in Physics

have you ever seen in the news or the newspaper a Nobel Prize announcement for a discovery that was made like years or even decades ago and wondered why did they wait so long to award them the prize well the 2019 Nobel Prize in Physics was part shared by didier queloz and Michael Mayo for the discovery of the very first exoplanet so a planet not in our solar system but around another star in our galaxy the Milky Way a discovery that was made over 20 years ago the thing is it's sometimes not just the discovery itself that's worthy of the prize but the legacy that that discovery leaves so to understand why the Nobel Prize was awarded to Mayo and qualit we have to go back I mean way back all the way to the 15th century and the Italian philosopher poet Breyer theorists geared on Oh Bruno he was one of the first very vocal supporters of Copernicus's heliocentrism model this is when Copernicus placed the Sun and not the earth as the center of what was then the entire universe and in 1584 Bruno made the leap to say well if the Sun is the center of our solar system then perhaps all the other stars in the sky are just like the Sun and so therefore also have planets around them as well in his musings he also insisted that the universe was Infinite and had no center either so this guy was way ahead of his time so far ahead that the Catholic Church at the time decreed everything he said is heresy and burned him at the stake for his beliefs fast forward now to the 18th century and the publication of Isaac Newton's Principia in 1713 one of the most famous scientific works ever in the conclusion of which Newton comparing stars in the sky to the Sun he said if true fixed stars were centers of similar systems they will all be constructed according to similar design aka the stars in the sky should also have planets in them and for Newton to echo that same belief it really fixed in people's minds that the Sun wasn't alone in the universe having planets around them of course you have to then proof that that is the case and so everybody wanted to be the first person to detect an extrasolar planet and as telescopes got better towards the end of the 19th century one of the first claims are be a false claim over exoplanet detection came through when williams stevens jacob as early as 1855 announced that he'd discovered a planet around the binary star seventy offer Yuki what you've been doing was observing the positions of the stars in this binary system as they orbited around each other and he said that positions couldn't be explained if they were the only two bodies in the system there had to be some unseen body a.k.a planet that was there disturbing their orbits and giving them these weird positions but that was disproven in 1899 by Forrester a Moulton who pointed out that if you actually did the mathematics such a planet would have a completely unstable orbit and couldn't possibly exist the field of exoplanets though had to wait until 1952 for another big leap forward that came from auto strew a russian-born American astronomer who really was with the most high-profile astronomers of the 20th century and he turned this search for exoplanets from sort of a sci-fi type of thing to really something that was more realistic he published a paper that said okay if we are seriously going to search for planets outside our solar system then we have to come up with scientific methods for doing so and well here's two we could try and the first one he suggested was that we study the brightness of stars and we see if the brightness dips periodically if the brightness dips then you can say well perhaps a planet has actually passed in front of that star and we've recorded every 10 days or every 10 years perhaps and if we see that same brightness dipping occur on that exact same repeatable timescale then we can be sure that what that we're seeing there is a planet orbiting its star the other method that he suggested would also work was looking for changes in a star's radial velocity so if you imagine a planet orbiting a star you sort of tend to imagine the star being in a fixed position and the planet orbiting around the very center of the system which is in the very center of the star the thing is that's not quite true if you imagine starting with two objects that are in the same mass and they're orbiting each other then they'll orbit the very center of mass between them which will be halfway between them and they'll orbit like a binary star system does if you make one mass then much smaller then that center of mass will shift towards the larger object and if you keep making one of them smaller and smaller eventually that center of mass will shift so that it's inside one of the objects and that's what happens when a planets going around a star the center of mass is inside the star but it's not exactly in the center and so the star itself is orbiting around a point in its middle and so what that appears to us is like the Stars kind of wobbling on the sky and we can detect that wobble in the light that the star is giving out because at some points the star will be wobbling towards us and at some point it will be wobbling away from us and just like with a Doppler shift with sound when an ambulance you know come screaming pasta's when it's coming towards us the pitch of the ambulance gets much higher and when it's moving away from us the pitch of the ambulance gets much lower that's because the wave is being literally squashed and stretched by the ambulance moving towards and away from us the same thing happens to the light of the star that it's giving off and so we call that a redshift when it's moving away from us and a blueshift when it's coming towards us and by detecting that we can detect how fast the star is actually moving around that little Center and then you can determine how big the planet is orbiting around it by how much it shifted that Center by the problem was that in the 1950s the technology was nowhere near good enough to actually detect those shifts the instruments they were using were giving measurement errors of over a thousand meters per second in a velocity change whereas if you compare that to the velocity change that Jupiter gives to the Sun it's 12 meters per second and earth is something like point one meters per second so they were nowhere near the level they needed in order to actually detect exoplanets at the time when auto Struve suggested this method but that paper did make the prospect of detecting exoplanets much more scientifically realistic and it did kept people thinking so much so that Hawaii in 1959 published a really famous paper where he introduced the idea of a habitable zone around a star the region around a star where the temperature on a planet would be between zero and a hundred degrees centigrade ie the freezing and boiling point of water it would be the region where you would find liquid water know that it doesn't mean that it's habitable to humans because well Mars is in the sun's habitable zone but it doesn't have an atmosphere that can support human life it's lost it all to the solar wind and so obviously that's not habitable but it is a good way of at least characterizing it the ideas of the 50s and presumably the space race in the 60s as well really spurred people on in this search for exoplanets so much so that there was a huge flurry of false alarms again one of the most high-profile of them by Pieter van de Kamp in 1963 who claimed he discovered a planet around Barnard star which is one of the closest stars to the Sun he claimed he detected the star wobbling in its orbit but not using the redshift like auto storybird suggested but actually by studying the position of the star on the sky his paper suggested that from the changing positions of Bernards star that he'd measured that there was a 1.6 times the mass of Jupiter planet they're orbiting at about four point four times the distance of the Earth and the Sun he then refined that estimate in 1969 to say actually I think there's two planets one that's 1.1 times the mass of Jupiter and one that's naught point 8 times the mass of Jupiter the problem was that many astronomers could not reproduce his observations at all not for want of trying but they couldn't find these changes in positions that he'd claimed and it actually took until 1974 when swathmore showed that the changes in the positions that van de Kamp had actually recorded correlated with the times when the telescope that he'd used had maintenance on it or was recalibrated and so the changes in the positions in the star that he recorded were actually just a change in the position in the telescope that's how accurate these kind of observations need to be if you don't account for the fact that your telescope has changed ever so slightly on its mount then you're gonna incorrectly assume that there's a planet around a star when there's not but the 1980s telescopes had improved leaps and bounds so much so that Bradford Smith and Richard teal actually managed to image material all around the star beta Pictoris what that image was sort of a a dusty disc surrounding the star which from planetary formation models was expected if you were forming brand new planets around that star it was the first time any material around the star had been detected in visible light and it really spurred people on again to actually try and find the first fully formed planet around a star as we head into the 1990s the first thing I want to mention is that the Hubble Space Telescope was launched in April 1990 a mere months before I came into the world after a few minor teething problems with its mirror it became a telescope that was instrumental in the study of exoplanets then in 1992 the first discovery of a planet finally came but in the most unexpected of places it wasn't round a star like the Sun it was around a pulsar this is something that's formed at the end of a star's life a massive star that's gone supernova and left over this remnant of a neutron star that's spinning and giving off radio waves so much so that we detect them as pulses of radio waves on earth that you can literally set your watch to they are incredibly precise and it was alexander wall Kazan at del fraile that showed that the arrival of the pulses from pulsar 1257 +12 were off ever Society and that could only be explained by the presence of two planets orbiting that pulsar that as they orbited it they would actually delay the radio pulses arriving to us on earth even in follow-up observations and released another paper in 1994 to say actually the two planet model wasn't quite right and we actually need three planets to describe this system I cannot stress enough how much of a surprise this discovery was to the Astronomy community nobody expected everyone literally had to rethink that entire view of how planets formed you know the originally people thought that they formed as a star formed from the leftovers of whatever didn't form the star but define three planets that were only slightly bigger than the Earth orbiting around a pulsar that would mean either the planets had to fully survive the supernova that formed the Pulsar in the first place so perhaps they were big gas giants like Jupiter that had all of that gas stripped just leaving the core around the pulsar or perhaps you've had like a secondary stage of planet formation where the supernovas happened destroyed everything around it but then left all this debris where you've had this second round of planet formation around the Pulsar so it wasn't necessarily the result that people wanted but it definitely gave people a lot to think about it was then finally in October of 1995 that michel mayor and didier queloz discovered the first EXO planet around a normal star in fact it was a star that was just like the Sun to do that didya in May or studied a hundred and forty two different styles for over a year watching for those little blue and red shifts that would suggest that there's a planet going round it and finally found this one 51 pegasi B but it was a planet that was 2 times the mass of Jupiter and it orbited only 5% of the distance between the Earth and the Sun that would be inside the orbit of mercury in our own solar system once again though the Astronomy community was absolutely stumped by this result it was a Jupiter inside the orbit of mercury no one had ever considered that before because all planetary formation models have been based on well the one example we had to go off which was the solar system where we find rocky planets in towards the Sun and the big gas giant things up to the size of Jupiter way out on the skirts people then started to consider the idea of planetary migration where you could form something like Jupiter from the Isis and the gas that were found well out from a star and then it could actually migrate and move inwards so that its orbit was ever smaller and smaller even now we actually think that that was supposed to happen in our solar system but you think we've sort of held back from doing that by the presence of Saturn so we should all be very thankful for Saturn it's why it's my favorite planet but after this momentous discovery by didier and Mail the floodgates really did open on the field of exoplanets in particular Butler Marcy Williams houses and shirts found a planet around epsilon Andromeda in 1997 and then in 1999 with the help of a couple of other colleagues including Fisher Kongos kaznyk Nissen Santino's realized that the observations of these little blue and red shifts of the star on Andromeda this radial velocity measurement didn't match a one planet model they needed three planets in orbit around that star to be able to explain what they were seeing this was the first multi exoplanet system found and it showed that the solar system wasn't unique in the universe at all into the 2000s which was really a decade of firsts and in particular the very first planet that was detected using the transit method now it already been found using the radial velocity method where you look for those blue and red shifts of the star but that meant that people knew when to look for the transit and so two groups did that independently and published at the same time and announced that they had observed transits of HD 2 0 9 4 5 8 meaning that the planet around it was HD 2 0 9 4 5 8 be the observant among you will notice that you're gonna see that planet popping up a lot in the next couple of results so just to make it clear how many firsts that this planet is involved with I'm going to nickname it Heidi HD Heidi before we get to Heidi though in 2001 newest Santos and collaborators found the very first planet in the habitable zone around a star it's five point seven times the mass of Jupiter so it's not exactly earth-like under any definition but it is still in the habitable zone which was a major advancement for the field of exoplanets and now the golden age of our friend Heidi HD 2 0 9 4 5 8 B in 2002 Charbonneau and collaborators managed to detect sodium in the atmosphere of Heidi ie in the light that had passed from the star and through the atmosphere on its way to earth and it became the first exoplanet ever to have its atmosphere characterized in some way or form in 2005 Deming and collaborators then managed to isolate the light from Heidi and it became the first exoplanet ever to have radiations specifically from the exoplanet detected in 2007 two independent groups one led by Richardson and one led by grill mare then managed to isolate the light from Heidi split it through a prism and produced the very first spectrum of the atmosphere of an exoplanet and once those two groups had shown that was possible speculation run right through the community of what we do with that method would we be able to detect water oxygen ozone carbon dioxide the markers of life on a planet using that method an excitement which was only fueled further later in 2007 by barman who then managed to take a spectra of Heidi's light and actually say I've detected absorption by water vapor in the atmosphere ie the light on the way from the star through the planet's atmosphere was absorbed by water a very very specific wavelength that we've seen here on earth in the lab as well and they managed to detect that dip at that wavelength and so Heidi became the first exoplanet to have water vapor in its atmosphere okay so Heidi hysteria aside in 2009 despite all of these detection of exoplanets we finally had the first image of direct image of an exoplanet around another star this was a group effort led by Paul Callas and it was at the planet forum halt be upon it a hundred and nineteen times further out than the earth is from the Sun there is three times the mass of Jupiter and detect it they needed the Hubble Space Telescope to do that and what they did was they put a mask on the detector to block out all of the light from the central star and they took an image in 2004 and noticed oh that little bright spot there and maybe that's the planet took another image in 2006 and saw that that bright spot had moved on its orbit around the star bomb holes this image is one of the most famous scientific images of the 21st century it is momentous in its achievement the fact they've been able to TechEd something that is so faint it doesn't give out light of its own it's only reflecting its star's light next to this blindingly bright star is incredible and the Hubble Space Telescope has gone back to that star and done the exact same thing and found it's moved even further around its orbit since we last observed it in the end of the decade in 2009 so the launch of the Kepler space telescope a mission that would go on to detect 2662 exoplanets in its nine and a half years of service to detect those planets the Kepler space telescope stared at the same patch of sky for that entire time in the constellation of Cygnus and it was basically recording constantly the brightness of those stars looking for those dips where there would be a transit of the planet in front of its star it was a phenomenal group effort by NASA and ISA that allowed that mission to happen and it's legacy will continue to live on in the decades to come 14 then saw the detection of an earth-sized planet in a habitable zone by eliza Quinn tano and collaborators kepler-186f is 10 percent bigger than Earth and is the outermost of a 5 planet system all of which in the habitable zone around their star and that was the most earth-like planet that we knew up until 2015 when the mantle was stolen when John Jenkins and collaborators discovered kepler-452b this is a planet that's just over 50% bigger than the earth but it's orbiting a star exactly like the Sun every 384 days and that puts it well within it star's habitable zone and so all of those properties the fact that it is so similar to earth have earned it the title of earth 2.0 then in 2016 and GLaDOS CUDA and collaborators discovered the closest exoplanet to Earth in Proxima be this was a planet orbiting Proxima Centauri aka one of the closest stars to Earth in the Alpha Centauri triple star system not only that this planet is about 30% bigger than the earth but it orbits a lot closer to its star so much that its orbit only takes it 11 days so you would think that it would be scorching hot however its star is only a red dwarf star it's a very small much cooler than the Sun star and so this planet is actually in the habitable zone as well so not only do we have the closest exoplanet to earth but the closest exit planet in the habitable zone as well then in 2017 the record for the number of exoplanets in a single system was broken twice in quick succession first of all Gillan and his collaborators announced that they had found a seven planet system around the star Trappist one all of which were rocky planets and in the habitable zone around this dwarf star again then later in the year Shalu and Vanderburgh announced the discovery of an eighth planet around Kepler 90 Kepler 90 I this made it as big as the solar system and the biggest exoplanet system known but it was also a landmark discovery because the planet Kepler 90 I was discovered in the data using machine learning it was an algorithm that had been developed by the team at Google brain so not only like the biggest exoplanet system known but also the first planet that was discovered by machine learning then earlier this year in June 2019 the number of known exoplanets went over four thousand for the first time then in September two separate groups one led by T's eros and one by Beneke announced the first detection of water vapor in an exoplanets atmosphere that was in the habitable zone around its star so because this planet was in the habitable zone it was much more likely that this water would be liquid rather than vapour form this planet was k2 18b and it was very much a mini Neptune it wasn't earth-like at all it was a big gas giant its atmosphere was mostly hydrogen but it was still the first planet detected with water in its atmosphere in a habitable zone as well the obvious next step to me is detecting water in the atmosphere of an earth-like planet in a habitable zone you know water in the atmosphere of an earth 2.0 where you can imagine perhaps also it would have liquid water oceans that'll probably comment with the launch of the test mission in 2018 this is the follow-up to the Kepler space telescope which is already facilitated the discovery of hundreds of exoplanets and with the launch of the James Webb Space Telescope which is the follow-up to the Hubble Space Telescope which will allow us to get much more accurate and precise spectra of these exoplanets in the infrared where this water absorption takes place all of these discoveries emissions though are just the of the iceberg in this field that was fully made possible by that first discovery in 1995 by koalas and mayo I might have mentioned 50 or so results in this video whereas in reality the number of scientific papers in this field must be in the tens of thousands it's that legacy combined with our new understanding of the fatten the solar system and earth are not unique in our universe the prompted the Nobel Prize Committee to award the Nobel Prize in Physics for 2019 to quell ups a may or even 24 years after that first world and life-changing discovery I didn't even mention planet hunters what am i doing oh my god that's been running for years planet hunters it's a website that lets you search for exoplanets in the data so all of the data from the New Testament will go online and you'll need to search through it to try and find the stuff that computers and algorithms miss because you can only teach an algorithm to search for something that you know what about the stuff that we don't know what it looks like so I'll put the link in the description below if you want to take part in that because it's a really cool project and wondered one is that they wait so long to award them the prize I wait wait don't pay it no it's brilliant tree and the publication of Isaac Newton's Principia in 1754 so 1713 good guess not right they needed three planets around Upsilon and drama to it and drama 2 in 2007 two independent groups one them by Richardson and then one led by grill mah grill Mayer grill Mayer grill Mayer guerrilla more grill Mayer grill my hair grill meh video killed the radio star you'll kill the radiostar in my mind and my car country wine we've got too many exoplanets Ron Harry and Hermione I'm very happy about one of these exoplanets discoveries aren't you guys talking to inanimate people I'm a t-shirt now you

Channel: Dr. Becky

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Keywords: dr becky, exoplanets, nobel prize, physics, astronomy, astrophysics, planets, sun, stars, universe, galaxy, kepler, hubble, hubble space telescope, space telescopes, TESS, pulsars, neutron stars, planet formation, michel mayor, didier queloz, isaac newton, giordano bruno, extra solar planet, habitable zone, habitable planet, earth like planet, hot jupiter, mini neptune, super earth, rebecca smethurst, doppler shift, radial velocity, velocity shift, science, nobel prize 2019

Id: 6_bJXZuREOA

Length: 27min 38sec (1658 seconds)

Published: Wed Oct 16 2019