Will PLATO Be The Mission To Finally Find Earth 2.0?

we know of thousands of exoplanets and we're discovering more and more every day thanks to some incredible missions like Kepler and Tess as well as earth-based Planet hunting missions and yet for all of these worlds that we know of so far we don't know of an earth-sized World orbiting around a sunlike star in the habitable zone we haven't found Earth 2.0 and the great hope was that Kepler would be the mission that found it but too early on the mission its reaction Wheels broke and they had to change the way the mission worked they're still able to recover an amazing amount of science but they didn't find that other Earth and so now the mantle the hope the dreams move to the pl Mission from the European Space Agency du to launch in 2026 and it will be doing something similar to what Kepler did but also similar to what the test mission is doing and over the course of its 4-year Mission it's expected to find probably a dozen earth-sized worlds orbiting around sunlike stars and so unless something really weird happens Plato will be the mission that finds that Earth 2.0 when is it going to find it Well that is the topic of today's conversation and I talking with Dr David Brown from The Plato Science office he's working with the scientists who are going to be analyzing the data coming back from Plato and it's very interesting because they're actually not just going to be waiting for future transits they're going to be studying the kinds of transits that happen and then already learn as much as they can in preparation for when that next transit does happen so they can really confirm if they found that other Earth it's a fascinating conversation not just about the history of Planet hunting as well as the capabilities and how ploh is going to work and what the expectations are and then of course we talk about the future and some interesting ideas for Missions that could take Plato even farther so enjoy this conversation with Dr David Brown David now I I'm not sure if you were like directly involved in this but you know as a person who's been looking at exoplanets for a long time what was it like to be in the field when Kepler when you all realized that Kepler wasn't going to find us that other earth oh it was a bit disappointing to be honest I mean yeah um we we'd sort of spent so long thinking about Kepler as almost as something it it wasn't really designed to be which was um an earth 2.0 Hunter um and when we when we realized that that almost certainly wasn't going to happen even even sort of vaguely it was it was really disappointing actually it was and it's weird because we're here I don't know how many years after Kepler launched you know I mean we 1995 first exoplanet around a star something like star and so we are 30 years since that Discovery and yet we still haven't found that earth-sized world orbiting around a a sunlike star and Kepler could have done it and it's and it's loss was just this I don't know was just this giant Gap in the process I mean I mean how far I mean some amazing science but how hard did it kind of set us back do you think I think I think although it was disappointing when we realized it wasn't going to find another Earth um I think that that realization sort of came in two stages there was there was the bit sort of partway through the mission when we realized that um even with the limitations of being able to to follow up any of Kepler's discoveries or most of Kepler's discoveries um even with those limitations we probably weren't going to get a second Earth from Kepler um so so that was sort of part one of the realization but there was still a chance we could we could push towards it really really well um and then the second part of the realization when Kepler broke um was sort of the not not not sort of a complete disaster because we'd sort of been expecting it to happen at at any moment and I think I don't think it set us back as much as it might appear from the outside I think by that point um you know Tess was well underway to being um being a going Mission um people were starting to think about improvements that could be made um and had been thinking about improvements that could be made to our data processing and our analysis and and all these sort of things that go into finding that second Earth they'd been thinking about them for the second half of the kep mission really or and all the way through so I don't think it set us back too much I think what it showed us really was what the limitations it really firmed up what the limitations were of the methods and and tools we were using at the time really yeah and I mean I always describe it as one of the greatest recoveries of a of a spacecraft of all time uh I mean the the solution to balance it using the light pressure from it's genius and and still it's the most prolific Planet Hunter and yet now I'm sort of using this as a setup because the next machine that can maybe get us to that Earth 2.0 is the one that you're directly involved with and that's Plato so give people sort of a background of of what Plato is sure so I like to describe Plato as sort of a mix of some of the ideas from Kepler and some of the ideas from Tess so from Kepler we take the idea that you need to stare at one piece of sky for a fairly long time um and you want to stare at as big a piece of sky as you can um and in our case that field is several times the size of the one that Kepler looked at from test we've taken the concept of using multiple cameras and I I say we've taken that from Tess it's also a concept that was used for a lot of those early groundbased um projects as well where they had multiple cameras um looking at very close but slightly different parts of the sky so you could get an even bigger field of view and I love some of those missions with a whole bunch of almost consumer grade lenses attached to high-end sensors that are scanning just many degrees of the sky all at the same time um yeah yeah I think I think it's a it's a really interesting way to approach the problem so so you've adopted that for Plato as well yeah but we've sort of taken it to um a slightly ludicrous um conclusion um because I think I think Super Wasp from the groundbased projects had the the most on any Mount and that that had eight per telescope Mount um Plato has 26 cameras on it um we have 24 what we refer to as normal cameras and then we've got two fast cameras that just um observe a faster Cadence so they take Imes more quickly but those 24 we've adopted sort of an extension of that that idea of using the cameras to point at slightly overlapping but distinct Fields so those 24 are group together um into four groups of six within each group they're all staring at the same piece of sky so you have some nice redundancy there in case one of them goes wrong um but each of the groups is slightly offset from each other so you that's where you get the big overlap and so by having them overlap they're acting a bit like a telescope of a larger aperture adding together the data from the different images exactly yeah exactly but but you don't but you are reducing your your field of view I mean you could have them all pointing at completely different directions and get a much larger field of view with less redundancy yeah we could do um we certainly could do and the reason we haven't gone completely distinct um is well there's a few different reasons the first I mentioned redundancy So within the groups if you've got one camera that breaks or one CCD chip that breaks then you've still got five more um to look at the same stars um but also having those six cameras looking at the same piece of Sky um you can average together the data from those six cameras to help reduce the photometric noise reduce the random noise in your data so you get a better quality light curve from a smaller telescope so so are six separate telescopes working together for that data reduction better than one telescope that is the equivalent of the of the six together yep yes yeah yeah and and cheaper like I think I think that that was a discovery made with wasp and super wasp was that if you want a big telescope put a bunch of small telescopes together and you've you've it's a tenth of price and or I don't know what the you know what the price is and actually gives you reny and more aperture for the buck yeah because you can do then things with your Optics to maximize the the angle for your field of view with so even though you've got a small aperture telescope and a small mirror or lenses in our case you've got that big field of view that with a mirror the size of cap FL is is much harder to get um so yeah it it's taking those Lessons Learned but I mean we don't see say the extremely large telescope being built out of a thousand 6-in telescopes so where does that tradeoff switch the other way where just bigger mirror is better it depends really on the science case you want to do um so the thing with all of these exop Planet surveys is one of the key parameters that you're you're trying to maximize is the number of stars you can observe simultaneously because the more stars you can observe simultaneously the more likely the the higher the likelihood that you're going to observe a Transit at any time around one of them um whereas when you get to something like the extremely large telescope it's much more of a directed individual object or very small field of view um science case where you focus in on a particular cluster or a particular Galaxy or a particular pair of stars so it's a much more focused High um powered instrument so it just depends really on what what it is you're trying to maximize yeah I mean you're going to find the planets but you're not going to be directly observing them no exactly exactly yeah um okay so then you've got these cameras set up and then what field of view has been chosen as the as the target so we're going to have two we're going to have one in the southern hemisphere one in the northern hemisphere um they're both overlapping with the Tess um continuous viewing zones the the northern and southern ones because um again taking lessons learned from Kepler you want the long Baseline that you longest Baseline in time you can get so would take advantage of the fact that Tess has already got these year-long chunks of data that we can sort of attach on to and I think for people who don't sort of know what we're talking about here you know Tess is sort of switching every month to a new location but at the very North Pole and the Very South Pole its images are overlapping and so so it's always taking data on those those two regions and so everything else you've got one month at a time and then for the North and South Pole you've got half of the observing time for each one of them and you're picking one than the other yes yeah so the those nice year-long stair continuous stairs from Tess's end camera fit into part of our bigger field that well observe so the the southern field has been announced um you can find the coordinates for it um online on the ISA website so if anyone's interested in in looking at where we're going to point the telescope um they can they can go and have a look and and so because you've got all that data with test you're going to be able to calibrate on can it find the same planets that Tesla was able to find and then some yes exactly so we should or or Plato should be able to find um anything that Tess has already found um and then because of the longer duration and the characteristics of the cameras we should then also be able to find um planets that Tess hasn't been able to find right so let's talk about the the durations you doing six is it just a straight six months of observation or are you switching back and forth between North and South it's two years on the south and then two years on the North oh okay and then two years two years yep so that's that's where we take that lesson from Kepler because Kepler had four years on one field um we want to split our time to get more stars so we'll take two years on each and then assuming the the mission keeps going then you just switch back and forth between the two field yeah that's one option um we'll we'll see how well whether we get an extension fingers crossed um and if we do we'll know partway through those four years so we can then adjust what we're doing to either stay slightly longer on the first one or switch to the second one as planned and then spend slightly longer there there's a few different ways we could do it so then with two years I mean we're back to an earthlike World orbiting around a sunlike star that's the kind of thing that you'll see two transits within two years so what are you hoping to see so the we are we are really pushing and the whole mission's really been designed to find this Earth Sun analog so I was talking earlier about the cameras with their overlapping fields of view and how having six cameras helped you reduce the noise down to get better quality data in the very center our field of view you don't just have six cameras you have all 24 cameras looking at the same patch of sky so the stars in there will have the best quality data we can get um it's going to be better quality than test um the Stars will be slightly brighter than the ones test can observe and so we're really designed to push the transits the the transit depth as shallow as we can to get them so what we're hoping is that see um a really shallow Transit that lasts a very long time that indicates a nice habitable zone orbital period around something a star it's kind of similar to the sun um that we can then put the other part of Plato's um data and Analysis onto which is all the Stell signs that we've got built into the mission as well when you say a shallow Transit what do you mean so the the smaller the planet um the less light um it blocks when it transits and so the change in the brightness of the star is less and so you'll see a what we call a shallower um signal so the classic Transit shape when you plot out the brightness of the star on a graph um gives you a nice sort of u-shaped dip over time um and the depth of that U shape tells you roughly how big the planet is compared to the start so what we want is a nice shallow u-shape that's nice and Broad um that gives you the long period and the small TR small planet right and I mean it's when you think about it like you might see one and then a year later you might see another and if you're really lucky on on just at the very end of year two you'll see it a third time and and get your confirmation yeah so this is this is one of the big challenges and one of the things that we've been spending quite a lot of time thinking about actually um and this is another another place where Plato differs from both Kepler and Tess so with Kepler we had the problem where the stars were too faint really for us to then do all the traditional groundbased observations with um radio velocities to to measure the Spectrum or measure the spectrum of the star to get the radi of velocity to then measure the mass of the planet or any kind of um Imaging to try and try and check that there weren't other stars there pretending to be a planet and you couldn't really do most of that with kplug just because the stars were too faint to be able to get good data Tess looks at brighter stars and so we can do all of that which is why with Tess we get nice confirmed planets with radi and masses and so Plato again we're looking at Bright Stars we can do the followup but unlike Tess where the followup is left to the The Wider physics research community in Plato we do it within the mission for our best targets so we will um we will be following up the candidates that we find and so one of the things we've been thinking about carefully is well if we see like you mentioned if we see one of these really interesting exciting transits within the sort of first six months first nine months of the mission and we know we're only going to get one more do we start trying to follow it up straight away rather than waiting a year how how do you follow it up so um if you know you'll know which star it is um and so and you'll have an estimate of how um large the planet if it's real um will be based on the transit that Plato itself observes and so what we have is a group within Plato that is um analyzing The Plato data to get those those predictions um and then you send someone um or someone looks at it and says that looks really exciting um and then it's given to our follow-up group who give the coordinates to one of their observers at somewhere like the VT um or the um Harps instrument which is at um one of the other observatories in Chile and you take some um spectral spectral observations of the star so you measure the star Spectrum um and then you try and measure the radial velocity of the star from the Spectrum so how fast it's moving through space and then if there's a planet there over time you will gradually see that radial velocity of the star change because of the gravitational influence of the planet right okay yeah I mean I mean the because I was sort of thinking if you're going to try and do a follow-up then you'd have to wait for the next transit that's your followup but you don't really know when the next transit is going to happen and it's kind of mean to say we need the VT for a year just focus on our star yeah let us know when you see the dip yeah exactly but but you're saying that from the characteristics of that Transit the shallow Transit as you said you're going to know whether it's a potentially interesting exoplanet and there's a ton of observations that you can then begin making in preparation for you can calculate the radial velocity but also in preparation for when it actually does that second Transit you're ready with a lot more information exactly FR yeah so if if something looks really exciting we want to get started on those extra observations as soon as we can because you're right if we have to wait for a year then we're a year year behind that we could have been taking stuff can you get any kind of estimate for when you think it might Transit again based on the size you know the shallowness of the transit and the duration it takes for that Transit y yeah so if you have to make some assumptions as as usual um but if you assume that the planet's orbit is circular um then you can get an estimate of its period it orbital period from the duration of the transit and so you there'll be really big error bars on that estimate um but it gives you something to work with and so you can then start to plan ahead for when you think the next transit might be um and if you if you're confident enough to start on the radio velocity observations then as you go along those will help you to refine that period if you start to see the signal in the rate of velocities as well now I know that with a lot of the brighter objects the hot Jupiters and stuff you get actually multiple opportunities to observe the interactions between the planet in the star you see it when it's passing in front but you also get two when it's going behind one when it goes behind and one when it appears I mean and and that's great for observing atmospheres and stuff would you be able to detect some of those additional passes behind the in your data um for hot Jupiters gas giants yes certainly we should be able to for an earthlike Planet it's going to be tough I think still um because the the primary Transit when the planet passes in front of the star is is so shallow anyway that when it you get the occultation of the planet going behind The Star um that's going to be really difficult to detect I think right yeah yeah I mean you get the the drop in the and and to give people a sense like when an earth sized world is passing in front of a sunlike star at the distance at say one astronomical unit how much of a drop in brightness are you seeing on the star oh uh hang on so it's um Point uh 0.1 of a percent one of a percent yeah yeah so it's something like that right so like a what is a was a thousandth yeah 10,000 anyway we're off by order of magnitude here but it doesn't matter the point is not very much much less than a percent right so a big issue that's starting to people are really starting to understand is the the amount of variability of the star like one of the big side effects of tests was to actually measure variability in stars at a level of precision that's never been seen before how are you accounting for this because you could you could wipe out a planet observation with a big Sunspot yep yep um yes you're nicely picking up on all the uh all the big problems um so variability is um certainly one of our major concerns for the earthlike planets particularly um and so what we have is a few different ways we can try and limit the effect of that um so the first is that as well as the planet hunting side of the mission there's also a stellar science side of the mission so um again slightly differently to Tess and Kepler we have sort of these two halves of Plato um working together to do the best we can to learn about about the planets and stars um and so we have as well as searching the The Plato data for planetary transits we have a team who are analyzing that data using Astros seismology um and various other um Stellar science analysis techniques to both measure the mass and radius and age of the star um but also to characterize things like its rotation periods and its level of activity um and so we will learn as much as we possibly can about the activity level of the stars that we're observing um as we go along so that that helps a little bit because if we know how active the star is um sort of um if we have um numbers to put on to sort of characterize the level of activity we can feed those into then the analysis for the planetary side of things and try and adjust our searches to account for that um we are also able thanks again to that sort of test calibration um and and the existing data to see how active the star has been in the past which isn't always a good indicator but you can see how much the brightness of the star intrinsically varies over time and so we can get an idea there as well of how much um we need to account for when we're we're doing our search there are also people within the planetary analysis side of things who have been developing methods to um filter out that variability or to account for it as part of the search for the transits so that you can adjust what you're looking for to account for that variation from variability now you have I'm assuming done simulations you've looked at test data calculated how many interesting planets tests found you know what Kepler saw so based on your expectations what do you think we'll find and when with Plato say in it's its primary Mission what will be the hall how many Pokemons will you've collected um so yeah we have done some run some numbers on that um we are expecting um around 50 um planets the size the size of Earth or up to a couple of times the size of Earth at various orbital periods so that's not just habitable zone ones that's that's across the whole period range so we're we're thinking sort of um true Earth Sun equivalents um then we're looking at maybe a dozen a couple of dozen hopefully wow now but still like a couple of dozen more than we know of already yeah yeah um now you we sort of obviously don't know whether we'll get those in the first couple years or the second couple of years and because of those orbital periods those long yearlong periods it's going to take us a to figure them out as you've already mentioned um the time it takes to just get the transits but then to get the follow-up Rage of velocity and then to be really confident that what we found is really an earth sun equivalent yeah then it's going to take a long time right and I think we go with I mean let's say first detection and then you make a second detection and you've got a candidate and then you make a third detection and then you're you're confirmed but I think a second detection that's news when you catch the second one so I want to sort of manage people's expectations here give them the timeline from when Plato launches to let's say it makes its first detection within its first year and then makes that second year makes another detection and we get a candidate Earth second Earth Yep when people can mark their calendars now about when they should be expecting this to happen sure so at the moment we're planned to launch at the end of 26 um then we fly out to L2 which is the same piece of Sky piece of space that jwst is at um so we need to get there we have to do the commissioning flight calibration make sure everything's working properly that's supposed to take three months um we've then so that's by the time you do that we're sort of at Spring 27 so then let's say we find an exciting Transit with in the first six months so by the end of 27 um we have to process all the data so mid 28 add another year so probably in terms of the most exciting stuff I don't think we'll see anything that we'll be confident about until 2029 right probably right but but there's nothing else like unless someone really locks out with you know I don't know something like was it speculas like the one that found the trapis or stuff you been working on with super wasp yeah um nothing else can find this planet no I think I think it' be really interesting to see what Tess is able to do in the coming years I mean Tess has been an absolutely fantastic Mission um I was at the science conference last week um and it's really exciting to see how many new results that that mission is still producing and that there's no sign of it stopping either um so I think it's going to be interesting to see how the next extension to Tess pushes what it's able to do they're not sure what they want to do in terms of observing strategy yet um so there's a chance they could find something um still but they do have this disadvantage of only observing pieces of sky for a month at a time right like unless it happens to be in the in that Northern patch or the southern patch the chances of them finding it being looking at the right place at the right time yeah for two years in a row is you know remote it's low yeah exactly so so no there's not much else yeah yeah and I talk you know when I interview the test people they they they say yeah the chances are incredibly SL small I mean maybe if it's something if it's a trap S one like if there's something that just happens to be in the right location that's really bright the transit is really solid the star is not that variable maybe but don't count on it that there's too many other interesting planets and so so really you know this is the Expedition when I sort of that has been sent out next after Kepler learning from Kepler to go okay find the planet and that first delivery of data shows up in 2029 well yeah for for an earth sun equivalent yeah I mean yeah we should hopefully hopefully we will have done a good enough job that there'll be you know interesting Jupiters and things like that coming out sooner but the thing everyone wants to know yeah 2029 I reckon um okay so so I mean obviously that this is the thing that everyone is is really focused on let's say that we do find the Earth house World orbiting around or we find 12 of them right uh maybe four years in we've got a nice a nice dozen of them what can we do with that with our current Suite of telescopes and missions yeah that's that's where things start to get interesting I think so with what we currently have on the table um we can um we can get radius Mass age so we can get bulk density um which already tells you quite a lot um and we can tell how old it is um how old it is based on the age of the star yeah exactly and and and this like thanks to Tess with the Astros seismology work which is amazing yep yep and then and added to our own Astros G work as well yeah yeah but just this whole field I mean this is knowing the age of a star is actually was always such a a inexact science and now thanks to Astros seismology the kind of work that's being done by Tess and you'll be able that that actually that age of the star problem has been much better solved yeah I mean you a St Stellar ages is something I've done a little bit of work on um in the past and yes before without Astros seismology the methods we have are so imprecise and inaccurate that it's it's it's incredibly hard to get the age of any single star and and Astros seismology has been a complete Game Changer on that actually for people who aren't sort of familiar with this revolution because I don't think it it has really been transmitted that form can you just explain how you determine the age of a star using Astros seismology uh I can try um so the whole concept of of seismology Astros seismology is to look at the way that stars um vibrate essentially um so different Stars vibrate in different ways um you can detect the frequency of the waves and the frequency of the Vibrations by looking at the brightness of the star um and if you measure the look for frequencies of um changing brightness within within that that star's um light curve um then you can see these frequencies showing up that indicate different oscillation and vibration modes so the star might be passing inwards and outwards or it might be pulsing up and down or it might be doing multiple different um pulses at the same time and so measuring the the frequency of those vibrations um helps you to measure then the internal structure of the star so you can get an idea of um by using the other information you have um you can get an idea for what the star looks like internally um and because Stars change internally over the course of their life depending on what type of star they are then you can get some idea of of their age from that and do you know what the sort of error margins are on this now um we are pushing down um to sort of 10% or better on the best best ages now which is Inc incredible when yeah you know when I was looking at Stellar ages you're looking at errors of about 50% if you were lucky so yeah yeah yeah so now you might know like if you see another son you'll know its age with in say 500 million years but in the olden days you could say that star might be a billion years old and it might be 8 billion years old it might be two billion year old it might be seven you know like it's crazy exactly and the and the implications for planets around those two different kinds of stars are are dramatically different so I think um yeah yeah I've been absolutely fascinated by this this story and I I don't think that people know this happened and no it's it's not very useful no I think I mean as a as an Planet person um I feel that the exoplanets steal a lot of the Limelight um from Kepler and Tess um and even when we're talking about Plato as well you know it's it's it's sort of an it's an easier story to sell when you're talking about the planets and looking for another Earth but the the Stellar science revolution has been almost as big and impactful you you can observe sunspots on the far side of the Sun by detecting the um you know the way the waves are moving through the sun you know activity that's on the far side of it's incredible it's absolutely amazing all right so you we talked about sort of follow-ups and so you're gonna you know you rightly pointed at first you know we we can measure all these characteristics about the planet we can measure things about the star that's today we can't observe it directly yet no not yet so what I guess other tools at our disposal that are coming online I mean we could potentially detect its magnetic field oo I think magnetic field might be pushing too far um but I certainly think there are missions and projects in development where you could potentially start to take images of those planets um so you look at things like the the very early ideas for the habitable World Observatory that are going around um you look at some of the other coronagraph um designs that are floating around out there um where you basically put a Blocker in front of the star and to block out its light and then you can you can see much fainter objects close to it um those kind of ideas are really interesting yeah I've done a whole series of interviews on the the road map for uh building a chronograph that would be capable of of doing this and the work that's happening with the Roman telescope as sort of a first step and then the various technologies that are being proposed to get you to the habitable worlds but but maybe the extremely large telescope is the is the next big machine that could potentially spot it um I think I think trying to get an image of it from Alt will be a challenge I think elt potentially has the capability to do atmospheres um I haven't looked closely at How likely it is that elt could do atmospheres of an earthlike Planet but I think there's potential there to do it and I think when you start to add that to the bulk density that you get from Plato then you start to get into the territory of or what does this thing actually look like now there's the aerial Mission which is another Isa Mission that's coming up in 2028 y do you think it could give us more information about the about any of these planets sadly not about the Earth Earth so it's re aeriel is a great Mission um it's really interesting um in the way it's designed and it's its goals but it's very much looking at Jupiter size planets um down to sort of Neptune size planets so it's it's looking more at the sort of bigger bigger side of things um I think an Earth is going to be pretty much impossible for them to do sadly um so now I want to step away from your specific role and responsibilities I think anyone from Isa who's listening is absolutely you know knows that you are grateful for um the incredible uh funding that's happened for PL how could it be better so what could be a a better version of Plato what could be the kind of king of all all Planet Hunters do you think if someone was willing to spend say web kind of money on on a mission like this what would it look like do you think yeah I think you would want to have multiple I think you probably end up with something that looks like a cross between Plato and Ariel or or web so I think you have something that looks at not just the visible light but also other wavelengths at the same time or or is able to get Plato quality data in different wavelengths does okay so hold on like doesn't that potentially mean that you only need one Transit because you're detecting essentially both the dip and brightness and the the presence of an atmosphere simultaneously um yes potentially wow so so what would it take that's interesting yeah what would that take I think you'd need something with mult a lot more I think it would be really hard to do with something of Plato's kind of design where you've got all the multiple telescopes because you'd need to have the multiple telescopes for visible light and then the multiple telescopes for infrared or whatever other wavelength you wanted to aim at and so suddenly you start you start to be building something that's got you know 100 telescopes on it which is is just a little ludicrous so I think it's fine this is a safe space we can be ludicrous I mean so would you still go the multiple telescopes route versus the one big mirror with a wide field of view like Roman yeah I don't know Roman Roman I think is fascinating because they' it's such a different design and it's still a you know it's not a compared to something like um Tess or Plato the field of views relatively small but compared to something like elt is still pretty big um so yeah maybe you maybe you take take advantage of something like the Roman design um and accept that you're not going to get all of the many many stars thousand hundreds of thousands of stars that you that you can do with a Widefield of view and just take you know tens of thousands instead right I mean there is a second of those Miss telescopes collecting dust somewhere at the national reconnaissance office and was offered to NASA yep so maybe we've maybe we we've got the solution here you build a a vers of Roman that is both taking I guess photometric data and spectral data at the same time you know at the same time and you're getting your you're getting your one observation and you're determining the presence of the planet just purely through the atmosphere yes yeah I think I think that that being able to detect and do atmosphere simultaneously I think would be a big game changer because at the moment you have to do the detection and then try and get the atmospheres later but if you can get it all at once do do you know of anybody proposing this Mission I mean this you know I'm assuming you didn't just invent this today but I don't actually um I think I mean we're still at the really early stages of habitable worlds um and so it'll be interesting to see how that develops but I think I don't think anyone's proposing as far as I know a joint detection atmosphere Mission I mean it's always this balance because like on the one hand you things like test will will drop thousands of exoplanets in your lap but something like the H worlds Observatory will will show you everything you want to know about one and if the one is really important then then that's also interesting in its own you know in that case it's quality over quantity um but but there isn't a quantity the successor to Plato proposed today not today yeah interesting okay um so David what are you obsessed with um at the moment I'm obsessed with circum binary planets which are very cool um and I'm working with um a PhD student to see if we can find any new ones in the test mission um because we don't know about many of this kind of planet so um anyone who's seen Star Wars has seen a circumbinary planet is the classic tne planet where you have a binary star and the planet instead of going around one star is going around both of them um and they're very rare um we know of um 14 um transiting ones um and so they they any new ones we can find is sort of it's like going back to the the early days of of transiting ex planets generally if you can find one you've already made a massive increase in your sample um and they're just fascinating things um because that's they're very weird and we don't really fully understand all the constraints on them and um how they form or how they get there and this kind of thing I mean from the 14 that we know are there some common threads about I mean I think about like you you can only be so close to the the Stars you know before the it just gets too chaotic and the planets get thrown out or gobbled up by stars but yeah so we at the moment there seems to be some kind of inner limit um some multiple of the the binary period where the planet any closer than that and the planet as you said it's just too chaotic for it to survive there also seems to be um a limit on the orbital period of the binary itself as well so if the binary is too short period Then it seems as though um it's much more difficult for a planet to survive around there also um which sort of makes sense because if you start to get the Stars too close together then they start sort of physically interacting as well as gravitation so you start to get much more activity and flaring and ejections and all sorts so there's some kind of binary limit as well um one of the things that I'm particularly interested in is whether um all these circum binaries are nicely aligned with the binary star so where like in the solar system they sort of all orbit in the same plane or not um now all the transiting ones have to well seem to they have to sort of cross the binary the stars at some point to Transit but what we don't know yet is whether that's whether we're only finding aligned ones and we just haven't found any ones sort of tilted over at weird angles or whether they just don't exist we just don't know yet I mean I know that polar exoplanets have been found which is a bit of tricky work because you have to calculate the rotation of the star and then figure out the rotation of the or the orbit of the of the planet so do you think that that the the way the St the two stars orbiting around each other would would draw a planet back into their orbital plane or does it feel possible yeah I think that certainly seems likely at the moment um and the other thing is going to be just the formation mechanism from the disc probably um or possibly being more likely to be nicely aligned although you know we were we have counter examples of that where you have a disc around a binary star that's sort of polar inclination so um it's always the exceptions I think that are interesting here there was a paper that I reported on this week about a not a circumbinary but I don't know what the term is where you've got two a binary star but both have planetary systems around them and they're and separated a wide binary anyway um and all observations of protoplanetary discs around both of the stars that are in orbit around each other yeah has anyone found a protoplanetary disc around a circumbinary um yes I want I want to say yes that we we've seen protoplanetary discs around binary stars um I can't but but specifically where where the disc is around like the two stars are orbiting and then the disc is wider and around both of them which is which is what gets you your your tatooes right yep yeah we know we know some of those yeah and so I wonder you know you would that would be the thing that would show you the orientation because You' actually see the disc with Alma and then the stars going in some other orientation and I wonder but I'm I'm assuming that has not been seen yet uh not that I know of um although yeah I'd have to maybe literature search after this yeah yeah yeah um well David it's absolute pleasure to talk to you and I hope people you know people there's some memes going around on my Channel about the kind of missions that I bring up again and again and again and I talk about Tess I talk about guy I talk about uh ver Rubin but Plato is is people need to add another slot to their bingo card because I'm going to start going on and on and on about Plato as we get closer and closer to Launch a lot of our hopes and dreams are resting has it got good reaction Wheels yes yes it does good thank you for your time and good luck finding Earth 2.0 I hope you enjoyed that conversation with Dr David Brown I'm going to give you some more thoughts in a second but first I'd like to thank our patrons thanks to Abe Kingston Adam Schaefer David Gilton and David matz Dennis alberty Dustin cable Jeremy murn Jim Burke Jordan young Josh Schultz Paul Roach spiders swap. Steven cak Steven fer only and Vlad chiplin who support us at the master of the universe level and all of other supporters on patreon when Kepler failed it's primary Mission I was heartbroken because like most of you many of you like this is the dream the other Earth the science fiction future that we were always hoping that for the longest time was just in our stories and in our TV shows and our movies and yet this was the mission that would have found it and then it wasn't able to and we've had to sort of think about planets around Red Door stars um but we want to find that other Earth and so Plato is is the one that's going to do it and I think it's so interesting that we're going to go from the time before when we don't know how many other Earths are out there we don't know have a sense of just how many terrestrial planets orbit around sun like stars within the habitable zone and so on and then there will be a time after when we do know when we know what roughly the percentages are that we can look out into our galaxy and count the number of planets and estimate with pretty good accuracy how many Earths there are in our galaxy and in the universe I can't wait and we're only just a few years away all right we'll see you next time