First JWST TRAPPIST-1 results! Not what we expected for TRAPPIST-1c

where are we most likely to find life beyond Earth like sure there's some promising moons of Jupiter and Saturn in our own solar system what about on a planet orbiting another star in our galaxy The Milky Way a true Earth 2.0 now that has always been one of the goals for jbst to try and characterize the atmospheres of exoplanets and see if they have the right conditions for life and last week we got some results from a very promising candidate planetary system known as Trappist one it's seven planets that are all orbiting a red dwarf star much cooler and smaller than the Sun so the planet's orbit much further in the planets do in the solar system but because the star is causing the sun it means that some of them are still in what's known as the Goldilocks zone or habitable zone where it's not too hot and not too cold for liquid water to exist and therefore possibly have the right conditions for life at least as we know it few months ago we had the results from trappist-1b which is the closest planet in to the star and now it's the time for Trappist one C the second closest planet to the star but unfortunately the astronomy Community as a whole has been slightly disappointed this week when the results by zebra and collaborators were finally published because it wasn't quite what we were hoping for or at least expecting so to understand all this we'll have to chat about a couple of different things first of all why we're even looking for signs of life around red dwarf stars in particular second of all what data jwst has actually taken for trappist-1c and what we found out here third what the implications of this result are and then finally when can we actually expect jwst data on the other planets in the trappist-1 system so let's start with why we're even looking for signs of life around red dwarf stars well red dwarf stars are the most common type of star that we find in the Milky Way our nearest neighboring star to the sun Proxima Centauri is a red dwarf star for example with two confirmed planets and one candidate may be Planet so knowing whether red dwarfs can support life or not is a really good place to start if you're doing a search for signs of life habitability biosignatures that kind of thing because if it turns out they are then with them being the most common star in our galaxy it makes sort of the prospect of finding life elsewhere like much more likely but then if it turns out that they're probably not a good place to search for signs of life because the planets don't seem to be habitable then you've ruled out a huge search area in the Milky Way which is also very handy in terms of doing the observations themselves it's also very handy that the planets orbit so close in to Red dwarfs or very fast orbits that can take days or weeks so that means that these planets around these types of stars pass in front of and behind their Stars many many times in a single year giving us lots of opportunities to do the kind of observations that we do with jwst where you look at how much light from the star is blocked or light from the planet is blocked when it goes behind the star or even you know allowing the Starlight to pass through the planet's atmosphere and seeing you know what bits of the light Are We Now missing because molecules in that atmosphere have absorbed it and stolen that little bit of that light at that wavelength away so we know that they're there so that's why you'll find a lot of jwst proposals focused on these planets in orbit around these red dwarf stars not just trappist-1 but other promising systems too the problem is is that we know that red dwarf stars are incredibly volatile especially in the very early stages of their lives giving off like huge flares of radiation in the UV and in x-ray which can completely irradiate a planet especially ones that orbit very close into their star you know cutting off any chance of habitability very early on so it could be the planets around red dwarf stars are a terrible place to look even though they are very easy to observe but we won't know that until we actually get the observations of them and it's only with the sensitivity of jwst that we've actually been able to do this and of course trappist-1 being the most famous of the targets mainly because it is a seven Planet system it's very reminiscent to us of the eight planets of the solar system so people have been on tent hooks waiting for this jwst data and Analysis to be released so I was very excited when this paper by Ziegler and collaborators was published last week and compare what they found to the same exact measurement that's been taken for trappist-1b the planet closest into its star in this research paper by green and collaborators that was published back in March 2023 and I look back through my videos to see when had I actually covered this trappist-1b result and it turns out I didn't like not even in a Night Sky News episode so my my apologies for that I actually went back through my calendar and looked at what date it was released on and it turns out it was the date that my PhD student Tobias passed his Viber and actually became a doctor so I was rightfully distracted but it means we get to cover both of them today so what data is jwst actually collected here so in both cases they've taken just one measurement of this planet with Mary the mid infrared instrument on board Jetty with t which detects light at much longer infrared wavelengths and what they recorded was the brightness of the star before during and after each planet passed behind the star in What's known as the secondary eclipse the primary Eclipse being when the planet passes in front of the star on the other side of its orbit also known as a Transit so from the angle that we're looking at it as the planet moves on its orbit around the star we're seeing the fully lit side of that planet the day side as it disappears and then reappears on the other side of the star so during the eclipse you're just getting light from the Star itself but either side you're seeing both Starlight and the light reflected off the planet the deeper that drop is in the light during the eclipse and the planet is behind the star means the planet is reflecting more light from its surface the maximum it can reflect is if it's just a bare Rocky surface with no atmosphere something like Mercury and no light gets absorbed at all and all of it gets reflected back whereas if the drop in light during the eclipse is shallower then the planet isn't reflecting as much light instead it's probably absorbing sunlight its atmosphere will be absorbing that light we can work out how much light is actually reaching the planet at whatever distance it is away from its start and so from how much of that light is actually absorbed or reflected back we can work out okay well then how hot is this planet so so a bare atmosphereless Planet like Mercury will have its surface absolutely scorched and so the planet will be much hotter when you calculate the temperature whereas if you have a planet with an atmosphere that can absorb that energy and then spread it around to the nighttime side of the planet just all around the planet and the planet's average temperature will be a lot cooler so here's those graphs of the secondary eclipse for both trappist-1b and 1C now annoyingly the graphs aren't on the same scale because they're from two separate papers but thankfully in the captions of both figures they give you the actual depth of the eclipse for trappist-1b the depth is 861 plus or minus 99 parts per million and for Trappist one C it's 421 plus or minus 94 parts per million so the Trap is one B eclipse is deeper meaning it reflects more like back than trappist-1c that's not surprising because strappers 1B orbits closer to its star so there's going to be more light to reflect there but if you take into account how much light is actually reaching each planet then it turns out that trappist-1b is a lot hotter than Trappist one sees the eclipse depth is actually consistent with the reflection of nearly all of the incident light onto trappist-1b meaning it likely has no atmosphere at all its surface gets absolutely baked to a very toasty temperature of 500 Kelvin that's about 226 degrees Celsius trappist-1c though is a bit more complicated from the depth of the eclipse the temperature is estimated to be around about 380 Kelvin which is around about 107 degrees C so about half that of Trappist one B that's lower than the 430 Kelvin that you'd expect if the planet had absolutely no atmosphere like it seems that trappist-1b does but also higher than the 340 Kelvin temperature you'd expect if it had a very thick atmosphere like Venus for context mercury has an effective temperature of 440 km oven and Venus with its racic atmosphere has an effective temperature of 227 Kelvin so it kind of also makes sense that it's in the middle of these two things no atmosphere and very thick atmosphere as well and the reason I brought that up is because astronomers are expecting that trappist-1c would be very similar to Venus they actually receive very similar amounts of light from their respective Stars so trappist-1c gets about eight percent more light from trappist-1 than Venus does from the Sun but because of that people are expecting that they would have very similar atmospheres with some of the chemistry going on in them and that scenario becomes even more likely if you consider sort of what the conditions are in a system of terrestrial planets around red dwarf stars so you know if we think about the fact they are terrestrial planets just like Mars Earth Venus and Mercury in the solar system and if we assume they have a similar mix of molecules to have been able to make rocky planets like that so we're talking things like water and carbon dioxide and carbon monoxide and then also things oxygen so O2 and also nitrogen molecules N2 as well and we go back to this idea of red dwarfs having a lot of this variability with these flares of radiation if you have that mix of molecules in the atmospheres of planets in the sort of very early days of the evolution of the system then that radiation what it will do is it'll come into the atmosphere and it'll cause a water molecule so H2O it will cause it to disassociate and essentially what that means is the hydrogen will split away from the oxygen hydrogen is much lighter than oxygen and so it's very easily lost into space from the atmosphere so losing all your hydrogen you get left behind with a lot of oxygen that means you could end up with a really oxygen-rich atmosphere in O2 but if there's a lot of carbon there it's probably also going to bond with the carbon and make lots of CO2 as well just like in Venus's atmosphere which is dominated by carbon dioxide CO2 it's also why this team of astronomers used Miri on board jusst as well because Miri can detect wavelengths of light at 15 microns which is a wavelength that we know that carbon dioxide absorbs light at so a shallower Transit depth meaning more absorption could be because you've got a carbon dioxide Rich atmosphere but the data from the Eclipse which is shown by that red point in this plot here doesn't match with that model scenario so first of all a fairly oxygen-rich atmosphere and carbon dioxide shown by the red line in this plot but then also a model venous atmosphere which is mostly just carbon dioxide shown by the yellow line here although technically the statistics doesn't allow you to sort of throw out that idea of a Venus like atmosphere just yet but it is sort of right on the edge of the threshold that we usually use in sort of these sort of tests to be like is this a good model or is this a bad model instead it seems like either a very thin oxygen atmosphere would just Trace carbon dioxide fits best as shown by the purple line in this plot or even that no atmosphere but a surface made from a specific type of rock that absorbs some of the light as shown by the black line might also be a good fit so because of all that I've heard a lot of people saying okay maybe trappist-1c is more Mars like than venous light but even Mars has a thicker atmosphere than that incredibly thin atmosphere that seems to fit that data point best so what are the implications of all of this well this could mean that trappist-1c has been through like catastrophic atmospheric loss so not just the hydrogen from water molecules that's associated but its entire atmosphere perhaps from just radiation from the red dwarf star Trappers one or it could mean that it Formed with less of these volatile molecules in the first place these molecules are just very easily lost into space so you things like water that you need for life that last scenario is quite worrying because some people have suggested well if trappist-1c formed with less water in the vicinity perhaps that means the entirety of the trappist-1 system formed with less water in the vicinity which yeah would be a big worry if you're thinking about you know the planets that do orbit further out that are actually in the sort of Goldilocks habitable zone but I think that is a bit of a stretch you know the distribution of water in the system could be different than we expected plus you know to put it into context like that'd be like judging the solar system based on Mercury and Venus alone as well what I think is promising is this sort of the beginnings of a gradient in temperature that we're seeing as you get further away from the Star which means that one D1 E1 f are also likely cooler as well if that gradient continues and so that is also more promising if we're thinking about finding water on those planets now of course there was one bm1c this is only one data point at the minute so we still can't make any sort of definitive conclusions ideally what we need is a spectrum where you split the light through a prism to get a trace of how much light each wavelength you receive so essentially you're observing that eclipse or a Transit many wavelengths and what that would allow you to do is add a lot more points on this plot and then you you can work out with more certainty which atmospheric model is more likely now spectral data is a lot harder to analyze it's a lot more complex than just sort of using Imaging data to observe the eclipse so you just get that one data point of the eclipse depth and so that does mean it takes a lot more time but you could argue that maybe they are taking longer than we originally expected to release the Spectrum which analyze the Spectrum and then release it which is why I think a lot of people were expecting to see that first when sort of the news of like oh trappist-1 c data has been released from Jada Bristol I was expecting to see a full spectrum as you could probably tell from the live reaction I posted as a short Spectrum show me the Spectrum show me the Spectrum well that's a bit disappointing and we can really only speculate why that might be you know I know that work is ongoing but that's really all my colleagues that are involved in these these big research teams can actually tell me at the minute my best guess would be that they're having problems with analyzing the data because of the Star right dwarf stars we know are incredibly variable and they can give out these huge flares of radiation and so if that happened while they were taking an observation of one of these eclipses then it's going to be really hard to pick out you know what is the star doing something weird and what is you know the planet contributing to that light Instead This is why they also usually take multiple observations of transits and eclipses and average them out in case you do get flares from the Star you know what's actually from the eclipse or not so they could just be waiting for maybe another observation to be taken and then of course you've also got to remember the the star and Planet itself are incredibly incredibly faint this is something that jwst can do with its sensitivity but it's so incredibly faint so if you've got any extra source of noise in there you're just going to have some insanely messy data to deal with now I do know that my ex planet colleagues have dubbed this the summer of Trappist one with lots of new observations of Trappist ones scheduled for this summer with Jay Bruce T just because now the star is in a better position for it to observe it including the very first observations of Trappist one e which is very similar to Earth and its mass its size its density so its gravity is pretty much the same as well it has a similar amount of light incident upon it from its Star as the Earth does from the Sun and it's in that Goldilocks zone so it is definitely the planet in the trapezoan system with the highest of hopes but if those observations are only being taken this summer I don't think we're gonna see that data and the analysis of that data for six months best probably more likely a year so if you were hoping like me that we were going to see sort of like you know habitable zone Trappist one JD Rusty exoponic data like this year I think that's incredibly unlikely and I'm sorry to be the bearer of bad news but that data and the analysis of it will slowly be released you know especially the the spectral data for trappist-1b and trappist-1c so we can sort of fill in that Gap and work out you know what is the atmosphere of trappist-1 see and what's going on there plus you've got jws T data from planets around those other red dwarf stars coming as well all with the aim of working out if planets in orbit around red dwarf stars are a good place to search for signs of Life out there in the universe before we get to the bloopers a huge thank you to brilliant for sponsoring this week's video brilliant.org is a website and an app that helps you learn new Concepts in science and maths interactively whether that's the foundations of maths or astrophysics or the neural networks at the heart of all of the new AI tools we're seeing lately I know that a lot of you are hoping to be research scientists one day as well and I love hearing all of your stories but I also know how it feels to start off on that journey and feel just so incredibly overwhelmed at how much there is to learn but the trick is just learning a little bit every single day and Brilliant can help you build those good habits to keep at that goal with thousands of lessons to keep you on your toes including a great astrophysics course with a whole section on exoplanets and how we find them if you want to know more after watching this video so to try everything that brilliant has to offer for free for 30 days head to brilliant.org Dr Becky or you can click on that link in the video description down below to let them know that I sent you and the first 200 of you that do will get 20 off an annual premium subscription so thank you so much to brilliant for continuing to support this Channel and now roll those bloopers so to understand this we're gonna have to chat about a few things first of all why are we really why we're a real one well it could just mean that trap is one thing one thing one fee I always wonder what the auto captions on YouTube are coming up with when I say jellyfish tea very very quickly over and over again because like Instagram and Tick Tock Auto generated captions are like Judas or like jdbst sometimes it gets as well I don't know if it's my accent or just I say it's so pretty quickly but it's just like I have no idea what you said when you said Jenny Brewster [Music]

Channel: Dr. Becky

Views: 176,057

Keywords: JWST, james webb space telescope, TRAPPIST-1c, TRAPPIST-1, TRAPPIST-1b, TRAPPIST, MIRI, astronomy, astrophysics, space, science, physics, atmosphere, astrobiology, exoplanet, life, habitable zone, goldilocks zone, aliens, water, carbon dioxide, venus, mercury, earth, dr becky, becky smethurst, rebecca smethurst, women in STEM, women in science, webb, unfold the universe, NASA, ESA

Id: cVO02Abfs84

Length: 19min 31sec (1171 seconds)

Published: Thu Jun 29 2023