#12 Lisa Kaltenegger - Alien Earths, Astrobiology Controversies, Frequency of Life

welcome one and all to the cool worlds podcast with me your host David Kipping this week is my pleasure to be joined by Professor Lisa ceger she's not only a professor at Cornell University but also the director of the Carl San Institute Yes you heard that right Carl Sean who is of course a hero to myself and I think many other astronomers including I'm sure many listeners out there so you know this institute it is a unique place because it's highly interdisciplinary and is trying to bring together scientists who are approaching the question of the search for life in the universe from all different directions from chemistry biology and of course astronomy now Lisa has just written this book it's called alien Earths I had the chance to read an advance copy of it I really enjoyed it and so I thought we should talk about this book get Lisa on to the podcast and hear about what inspired her to write this book what is the latest in the search for life in the universe and her thoughts about a couple of controversial topics that we get into such as Venus whether is potentially life on Venus and also a recent claim from the James web Space Telescope that has been interpreted by some as potentially a claim for life as well so we'll get into all of that juicy gossip plus a lot more please do enjoy my conversation with Lisa ceger [Music] Lisa thank you for joining me today on the cool boards podcast thanks for having me yeah it's such a pleasure to have you we've obviously known each other for a long time in the field and seen each other at many conferences I've been to Cornell many times I think this is your first time at Columbia is that right that's actually true and it's crazy right it's just so close by so you're your neighbor practically over at Cornell and I guess you know there's a lot to talk about with you today you're obviously an expert in the search for life in the universe astrobiology exoplanets you written this wonderful book that we'll be talking about today called alien Earths that um I had a blast reading and I want to definitely talk about that but I thought we should start just for the sake of the audience of introducing your origin story and your Beginnings as a scientist I know you can go really far back with this like you grew up in Austria and we inspired by the sky at that point but I think your first real work as a scientist was with this with this proposed experiment Darwin there was an ease mission so maybe you could start by telling us about how you got into that what Darwin was and what its Legacy has maybe become so I was kind of curious about everything I think a lot of people are and so when I started studying I was picking a couple of different fields just to make sure that I wouldn't regret not studying something so I ended up with about five different things and in the end astronomy and physics so physics for engineering and astronomy with the two things that I finished and that turned out to be a perfect combination for getting a spot um the European Space Agency I'm European has this program for young scientists and engineers and I was actually close because the other thing I wanted to do was cancer research and so I had done some practice there in the United States actually came back and like okay I'm going to apply two things one is going to be this internship for cancer research in France and the other one is going to be this one Mission the mission that could find life on another planet at the European space agency and the way it works is usually you take like all the boxes of all the missions you would want to work on and I was like that one I want to find life in the universe or I'm going to uh look at the medical field because I think that's fascinating as well and so then uh there was this Mission it was called Darwin after Charles Darwin I guess after Charles St to find life in the universe and now we like back about 20 years at least but the idea was that it would have flown actually in 2017 so when I was starting working on this years ago I know seven years ago so about 25 years ago it would have flown roughly but when I was starting we had the design for this mission that could find planets and then also catch enough lights of these planets to figure out if there's something in the atmosphere these other worlds that could identify life and it's really tricky because you want a unique signature when you look back at the Earth the combination of oxygen or ozone with a reducing gas like methane tells you that there's life on our planet and it has to be the combination one is not enough because oxygen and methane go and make CO2 and water in the long run so if you see oxygen while there's methane still around that means something produces those two gases in big quantities and for the oxygen part that's life and so what's really interesting is I started with the Darwin Mission I started on the design on this mission that was a big big telescope how big was it it was actually supposed to be a flotilla of telescopes so instead of having one big one we would have three or four telescopes that work together in combination oh so ineter ineter to basically find these signs and the way that works what's really fun is when you have a couple of smaller telescopes you can mimic a big one and the big problem is that we don't have a rocket where you can actually put a big telescope in and launch it into space so if you could go into interferometry where these telescopes work together you could actually put a much bigger telescope into space because you could just fly six of those or four smaller telescopes and that was the Darwin Mission and so there was a lot lot of fun engineering things as well in addition to uh what could you look for and so we were doing this trade-off of do you need three telescopes do you need four how would you do this how would you combine the light precisely enough to not miss these signs of life and while I was working so I was working half as an engineer and half as a scientist and I was doing my PhD basically at the European space TR I was doing my PhD basically at the European Space Agency finding out what the design should be and how that would help us find signs of life and one of the things that puzzled me and I think this happens a lot when you actually Deep dive into a problem I was like so what are we looking for and what we were looking for was Modern Earth so 21% oxygen with methane and I was like but we do know that the Earth changed throughout his history and we do know that there was life for about at least three .5 billion years out of the 4.6 billion that the Earth was around and so we didn't have any idea of what to look for of what to look for if the Earth was younger you can only look for Earth as it is today and we'll get into this because I know you obviously in your book you talk about this a lot about how Earth has changed so much which is amazing to think that how transient the the current ERA of the Earth really is and so you were asking for the original story right so basically working on this design of this Mission trying to figure out how to best spot Signs of Life in the universe that's when I started to puzzle I was like why are we only looking for a carbon copy of current Earth even if it were just a little bit younger or a little bit older the science probably would change like for younger we know now roughly what it was and so I was talking to everyone I could find telling them that they needed to model this and so the problem with this really hard problem and I didn't know that because I had never modeled a planet before and there was this opportunity when I was meeting somebody at a conference that was Wesley TR at Harvard University and he was like well if you think that's something that's important to do you'd have to go and do it and I was like me you know because I was like well I've never modeled a planet before and he was like well you can learn right and I was like okay so Darwin had you know was this incredibly ambitious project then it was trying to take a photo of another planet including Earth's which are obviously the hardest type of planet of all the exit plets we found to try and go after and that's still not something we've really achieved right we don't have any images of pale blue dots except for our own and what was the what was the Legacy do we have any missions since then that have been proposed to do this and where are we at with the idea of achieving that what's kind of crazy when I think back I just finished my master CES I was looking for a PhD project and I found this opportunity at the European Space Agency to work on the design of this mission that would look at other worlds like ours so small and at the right distance to be warm to look for signs for life and there was nothing like it meaning we had never thought about how to do this before they were the first ideas of how we could design it it was called the Darwin mission that the European Space Agency so Europe and it was called the terrestrial planet finder at the NASA side so there was a counter group basically on the US side who was doing a same analysis of how we could do this and so just fresh out of University just finished a master's degree but because I had an engineering and a science degree they were like we were looking for somebody and I had specialized in Optics and in bioengineering so kind of fit what they were trying to do and so we were going through this groundwork trying to figure out how we could combine these telescopes to catch light from such tiny planets because if you put the Earth 10010 times next to each other on a string that's the diameter of the Sun so we have a huge problem engineering wise and in addition science-wise trying to find signs of light in this time tiny tiny atmosphere of the planet and so let's say you have 100 times the Earth next to each other that's the diameter of the Sun but where you trying to find the signs of life is in the air and so if you take the Earth and you just basically make it the size of an apple the atmosphere where these particles are where these chemicals are that we could look for is actually thinner than the peel of the apple and that's what you're trying engineering wise to get enough light from to actually see this and so Darwin and the terrestrial planet find out where the first steps and they were seen as too ambitious we had technology in place we're like well if we can do it this way we can sample like 10 20 planets to look for signs of life but that far back it was supposed to fly in 217 just as a reminder we didn't know how many planet they were out there KLA hadn't launched yet kepa hadn't found planets yet and so we were doing this all on an assumption of you know one out of 10 Planet one out of 10 Stars would have a planet that could be like the Earth and what's really great and on the other hand a little frustrating is that Kepler actually showed us that it's even better than that so one out of five has a planet that's at the right distance and small enough that it could potentially be like another Earth Earth and so we were actually over conservative if you want to think about it with the Darwin and the tpf mission but on the other hand we designed something hoping that there would be enough planets for us to look at and so it makes a lot of sense that we needed Kepler as the building step as the stepping stone to then now come back and propose a similar concept again like the terrestrial planet finder or Darwin and so these two missions are basically in Europe they have a mission called life that is um revisiting this idea of using more than one telescope combining the light and finding signs of life so in the US when every 10 years astronomers come together and decide what is really important to do next we came up with an idea of revisiting this concept and the US currently favors a very big telescope because the launch of the James web Space Telescope where they unfolded what is kind of a technical miracle that everything worked out gave us this bolster of saying okay we can build a bigger thing that we unfold while on the European side this idea of using more and more telescope what is much more scalable right you could imagine having five telescopes or 10 or 20 or 100 if you have different Rockets going up and then assemble them more or less in a formation fllying yeah you got redundancy there as well in case if one fails and so there are two ways and in a way it's great that we have two different ways because that means we going to figure out which technology works and hopefully both do and this is where this initial dive into how you could do this when I was at the European space agency and this telescope that was supposed to fly in 217 uh was the first step yeah I I think it's an extraordinary goal just and you you obviously in your book you talk of to about Sean as because you are of course the director of the car Sean Institute and so there's a there's a natural kind of handing down of the Baton there from from San to you in terms of this this overarching goal of trying to answer this question of are we alone the universe and I think it's a goal that we've long had to take that pale blue dot image of another extra Solar Planet and yet it seems like the technical challenge will be by far the greatest thing we've ever had to do in astronomy to I mean we've we've imaged black holes right we forgot the EHT The Event Horizon telescope which has taken this amazing pictures of messia 87 and Sagittarius AAR we have these two black hole photos which are doing interferometry but that's on the ground in space it's much hard cuz things are moving around I mean the engineering challeng there must be extraordinary and this is why when you want to do it in space it's a plus and a minus so the plus is you don't have to worry about the Earth moving you can actually spot or look at something for as long as you want because the Earth is not rotating out of or when the Earth is rotating these stars go out of few with their planets and one of the biggest challenging is to station keep to keep those telescopes at the precise distance and this is why we can actually only do it for the infrared because you can use visible light with it shorter wavelength to station keep to figure out where your telescopes are but you cannot use this interferometric concept for visible light where we see because you would have to use UV to station keep and we don't know how to do that not really well and so what's kind of really interesting is that there is a solution of how to do this and that we actually quite often fly things extremely precise there were some initial um experiments that actually showed that we could do it again not the full scale but what's interesting is we also have this mission for gravitational waves that's coming up it's called Lisa same as your name and the fun part it was like these were also when I was working on daring it was the next office over and so they were actually trying to get me to work for them because of the name you should come here yeah yeah it was very funny and my boss was just saying No this is Darwin's Lisa not Lisa Lisa but by chance you know for the for the Lisa Mission we need to formation fly perfectly as well but the fun part is in a way it was never because there's so many other technical challenges and this mission is on its way what I applaud fully I think it's going to be great to see gravitational waves with the Lisa Mission but it's kind of interesting that we have to develop this technology anyway for the other missions we are flying as well it was just such an integral part of the darn mission that people got cold feet what is fair because we had never proven it in space and then money got a bit tight so we wanted to prove it in space but that also requires money and so this is where it became shifted to the future but I think now with what we've learned from Kepler we actually now learned how good of a situation we are in in a way we have no idea if any of the plants at the right distance in this habitable zone where it's not too hot or not too cold could be habitable but we have options one out of five stars has such a planet way better than if one out of a thousand stars had such a planet so we can actually go and look at them and try to figure out how rocky planets work in the first place I might push back a little bit on the 105 I know this because I have to because I know there'll be cool worlds fans who have probably seen I did a video about the occurrence rate of earthlike planets and then uh it is the I think it is pretty much the canonical number you see in a lot of these planning documents one in five absolutely but I guess my my my reason why I would like more research to be done in that area that's my only request is that there's quite a lot of disagreement between different people and so you do see some papers coming out with 1% and then other papers coming out with like 90% there's like a very very big range and I think really what it comes down to with Kepler is that as successful as it was it didn't detect any true Earths around a true Sun absolutely and all of our statistics are kind of well these are the trends that we' seen we kind of extrapolate those Trends and it kind of looks like one and five but of course extrapolation is always a little bit of a dicey game so I'm I'm optimistic but I just think let's let's just nail that number down still before we totally commit to you know building before we build the glass it seems like we should probably be sure about that number and that's a really really good point to make because I keep talking about one out of five because if you going for uh for an world that could be like ours currently all of them have red suns in the sky small red stars right and you were talking about this and this is something that's actually great to bring out there when people talk about Earth like planets they mean so many different things but one of the things where we actually from kepa and from tesel and from groundbased searches like caronus and others and we'll be figuring out that the one out of five number is pretty solid for for the smallest stars and that's where it is but the problem is where we were talking about before is if you go and do inry like if you're in the infrared you can actually assess the planets around these smaller stars and 80% of all the stars around us are these small red stars but it's a completely different question and so I'm coming when I'm talking about Darwin and the search for life I'm coming from the idea of you can actually adjust the position of your telescopes thus you can see planets that are very close to the star like planets around red stars that's interesting cuz yeah I think with with lir and habex that red dwarfs are out of the question maybe the C maybe the orange dwarfs but not the red dwarves yeah and this is where your question is perfect and I also think it was great that you did this uh podcast on the occurrence rate because we have a pretty solid occurrence rate for the small because this is where we can find them yeah because it's faster they have to be closer in to be warm but extrapolating that to a yellow sun like ours is extremely difficult to do right because it depends what you assume and so if you now go to the visible to this one telescope concept this one telescope concept will only work or works very differently than interferometry because you cannot adjust the position of the telescopes you don't have two you have one and so you need a coronograph you need a mass that blocks out the light from the Star now if you want to do that the problem is that these small earth like potentially earthlike planets around red stars are very very close to the Stars so the mask will not be the same for the big yellow Suns or for the small red ones and so we making masks for the yellow Suns because the small red don't have enough light in the visible to make it worth it because most of their light is in the visible infrared and so I completely agree with you I think it's really dangerous to just say one out of five if you throw the coolest stars out the 80% of stars where we actually got the number from because then saying oh I'm just hoping it's also for the for the sunlight like analog Sun analog yellow stars that's a huge step but this is where when you go into the details of these different Technologies to find worlds you're starting to get into different extrapolations people make I'm pretty confident that red stars one out of five is a good number I agree but if I go and say you want an earth analog and around the Sun analog and it's really crazy I I agree that's the only place where we know there's life right sample of one but there's really and and there's a lot of discussing but life itself is so versatile so even if you say ooh the surface of a planet around the red sun gets like bombarded with UV radiation oh it would be so terrible well life could adapt to that and especially if you think that life started in water water shelters U radiation it's not to say that there definitely can be life on uh planets around red stars but there's also nothing that really rules them out yeah you can't exclude it yeah but this is again now if you go and say what concept do you favor one that goes to the infrared and gets all these M stars or one that goes the visible and gets the sun analog right and so in a way it's good that we have these two paths but you could also see how you could get into a quarrel because there different things we don't know on both sides we don't know how many planets they around sun analog Stars we really don't kepa didn't assess that uh we do know that around the small redar St s but then we have a planet around a yellow sun that has life we haven't had one around a red star where we can find life because we haven't found live yet there a trade-off either way it's a trade-off either way but I agree with you I think people should be much more careful with the one out of five number because it comes from the smallest stars and it's pretty open what the number will be for a yellow sun okay so that's a great correction and I'm I'm pleased that you clarify that because I learned something there that Darwin's sensitivity to M dwarfs is is worthwhile I actually was not aware of that I was mostly thinking in terms of the louvo habex the NASA view of opticus that taught me something so thank you for that I want to ask you though let's say this happens whatever however we do this we somehow get these images what are we actually looking for what is a signature of Life what for you would be the most convincing thing you saw this reported in the paper or you discovered it what would be the thing that you'd be like we're done that's it's that well I don't ever think we get to weird done but I know where you're going from well that's a good that's a good point as well it's good okay well one of the things is we need something that we cannot explain with anything else than life and then we have to throw all our criticism on it right we like for now we don't know but let's try and figure out if it could be under weird circumstances right because extraordinary results as San was saying extraordinary claims as Sean was saying require extraordinary evidence and I fully agree with that because if we say we found life in the universe we better have no other option to explain it right because other than that you can cry wolf as often as you want and it is happening in the scientific literature that people are finding life again and again and I get it right I would want to be the person who finds life and I think there's so many people who just want to be uh and they're Guided by the wish that this wiggle in the Spectre or this wiggle in the light curve that we find is actually something that they have been hoping for for 10 15 20 years or just since yesterday so there's a bi there's a there's potentially a bias there's a huge bias but I think it's every time in science right we try to find something and this is why we trained to be our own biggest critic and this is why you know with everything that we find we're like okay and now I dissect it I take it apart so what would for me be the sign for life when you take and model all these different worlds you try to figure out what could be false positives right where you basically say oh that could be life and it's not because geology produces a lot of different gases under different circumstances then you have the light of the Sun hitting it so that does photochemistry again it changes the chemistry of your atmosphere and so when you look at the Earth the combination of oxygen or ozone with a reducing gas like methane is pretty much the best combination of two gases that we cannot explain except for life but there's some caveats meaning that the planet has to be in this habitable zone so warm not super hot because if it's super hot you can actually split water into oxygen and hydrogen right so you could build up oxygen that way or if you have loads of CO2 you could do the oxygen that way and this is why methane is so critical or reducing gas is so critical because if you even if you just think of a planet that has like a little bit of oxygen let's say one oxygen molecule every minute then you wait 4.6 billion years and you'll have a lot of oxygen because nothing reacted with it and so you would again say oh my God there's life and so this is now starting to become again a question about technology right so I don't just want to find oxygen or ozone both of them they are basically traces of each so either works I also need to find methane now and how how much because obviously there's a lot of oxygen in the atmosphere 21% but there's hardly any methane it's it's like Parts some some parts per billion right you probably know do ab and so 10 uh I think it's 10 to minus 6 right now okay but the key point is even if it's just a Trace gas in the atmosphere like oxygen and methane because when you look at different parts of the spectrum you see different spectral features right so in the visible it's reflected light and so the light that hits the planet gets reflected back and part of that can get absorbed by Oxygen by Water by methane in the infrared you heat the planet and so then the emergent light or the mer mergent heat from the planet gets caught in this greenhouse gases and methane is one of the greenhouse gases and so how deep your feature is in the infrared actually has only partially to do with how much of it is there and also of where in the atmosphere absorbs so how what the temperature difference is so it's punching above its weight even even there not much of it's louder than it should be yeah and the interesting thing there is when you go back in time just a little bit there was actually more methane less oxygen well there is also this really interesting the last 500 million years where we actually think oxygen went up to about 30% and we just wrote a paper about it which was super fun because it had this link to the dinosaurs because in this area where the dinosaurs lived there was more oxygen as far as we know that also allowed for these huge dinosaurs right because they needed more energy I'd always heard that and I wasn't sure was true I don't know that's the link that the biologist and the geologists tell me right and so the interesting thing about this is that actually a planet that was in this area and a furoic there was more oxygen and there was also a bit more methane and had these dinosaurs so the Earth during the dinosaur era would have been easier to find in terms of signs of Life yeah than now makes sense and so that was the funniest part because then a journalist were asking us so you're telling me that it's actually easier to find dinosaurs out there than humans I was like but we're not saying that they have to be dinosaurs right which're just saying it's easier too late headin I know the headlines out professor says Dinosaurs most detectable oh no no the headline was even better it was like alien dinosour exist or something and it was just like I was like it it got it got pretty weird on the internet but on the other hand the fun part is like my uh my post dog uh Rebecca peny who who who let the paper she was great she was like you know what there's so many people who love dinosaurs and now they love astronomy too well it in book you actually do talk about this idea of going back in time it's kind of a nice connection to the dinosaurs it makes me think of it and I think he said that in one of your classes you ask your students to imagine like what would you bring back with you back in time and I think most people would say a camera would be like the one well maybe an oxygen mask you point out because there was an oxygen they say a camera and like okay you open the the door of your time machine and you're dead you know good luck you want some you want something to breathe as well and maybe maybe even at points it's toxic as well or too hot so you might need a space suit but it makes me wonder if you were to go back in time and have this camera is is there a question in the story of Life of this 4 billion year Evolution that most bothers you where you're like if there was one thing I could go back and and see happen and watch happen or have my microscope available or or does it all make sense to you and you're you're kind of satisfied with the whole story but I suspect there is something there that that that is an itch as an as a biologist astrobiologist that's that's making you want to go back I think one of the things that is so fascinating is that we don't know how life started we have all this discussion about what life is but we do not know how to get from non-life to life you mix the chemicals but you have no idea how long you you have to wait what temperature you have to be at and the really interesting thing is that it doesn't really matter to a certain extent what the surface conditions were on the earth it might have started on the surface in a small pond right it might have started on the bottom of the ocean the discussion is strongly ongoing it might have started in an ice shelf where on a pond or on a little kind of a little piece of water on an ice shelf that basically froze and defroze you can concentrate chemicals so there could be a tiny Niche somewhere in the Earth where life started and we don't know we have in a way not to say no idea but we have we we do not know where that was and that I think is a crucial ingredient meaning that if it always takes really hot condition to get life started or you need ice to get life started right it could tell us something about what we need to do to get it started in the lab and then what you could do you could actually mix different chemicals in and see if it gets started again because currently because we cannot make life in the lab and it's a hugely different problem right difficult to the gills but because we cannot make life in the lab we also don't know if we could actually change chemistry and get life again this is where the exploration of for example Titan the moon the really oldold cold Moon around Saturn is so interesting because it's so cold that you wouldn't have liquid water so you would have methane and ethane lakes and could you get life in these kind of environments or is it too cold or do you need water we don't know because we have a sample of one so if you could give me a time machine Doctor Who I'm coming I would want to go back to the time where life started and see you know especially when I can get a time machine like the Doctor Who Tardis exactly where it started because being at the right time will still not tell you where it started you want to be at the right time and at the right spot yeah I first I always wonder did it happen multiple times okay um it's it's the default assumption is always that it happened just once but it may have been that there's thousands of instantiations which all competed with each other and we are just the the one that that you know devoured the others or whatever it was I completely agree with you I think this whole idea of the tree of life was just a beautiful concept that people actually could remember better this is why we think about it as a tree but I think it's really like a lot of of different passes that could have been going on and then one just was optimal for the conditions or for eating everything around it right and so when people say like oh if the conditions were just a little bit different life couldn't have started I think everything we know about life would prove that wrong because life is so incredible versatile in adapting so if the conditions were different yes a lot of times even on the earth like 80 90% of all life died out and then we have this beautiful diversity of the other ones that developed further and so I think that life started once is very unlikely as a story I think it started under many many different conditions and some were just once they got out of their local conditions better and adaptic and you could see this or you see this play out through Earth's history first there were this kind of life that dominated the planet then Evolution happened another kind of life started to take over and basically pushed the earlier dominated species into tiny niches and so I think that happens again and again and what was really interesting I just was at a talk by Charles coel he's a professor in nber and there's this idea that I had never heard about it I don't know why but so I was just at the talk that jles coala professor in Edinburgh gave and he postulated something different he postulated that in the bombardment that happened early in Earth's history we had all these different impacts you actually generated very very different chemical environments you had the energy from the impact and that could have given thousands of opportunities of life to try to evolve under condition that we might not even consider right now because we usually don't consider like super hot and then it freezes out or and so I thought that was interesting and this is why my uh my story about going back with the Tardis and Doctor Who to the exact right point or to the exact right points where it started over and over again so it's so exciting to think about so much we don't know about these questions and it's frustrating but also I think so appealing as a scientist to be in a field where there's so so much it's kind of I remember studying physics maybe you felt the same way and it a part of it feels frustrating because it kind of feels like so much of it has been figured out when you're learning like electromagnetism and classical mechanics and with the story of life on Earth or even our own story of humanity anthropology there's just a vast open ocean of things that we don't know you know it makes me also wonder about life borrowing from each other and horizontal Gene transfer we look at um UK carots right which is this confluence of a mitochondria somehow getting eaten up by bacteria and kind of not getting eaten yeah but forming a a symbiotic relationship and yeah I kind of wonder if there were these many starts of life on the origin of Life perhaps they were borrowing and swapping materials with each other to get to that thing that we call the lowest Universal common ancestor so it could be it could be Beyond any of our imaginations what what really happened in those early days I think I completely agree with you I think that fascinating diversity of what could have happened and we just scratching the surface of imagining what what it could have been and I think it's in science a lot of times it gets taught as you were saying as you go from point A to B to C but it's really not you go from a to F and then F didn't work out so you go somehow you get bounced back to the other one and so it's kind of so many different things that you get wrong to then figure out when more puzzle piece and that's what I love about science and yes it is kind of frustrating sometimes to be at this part where you're like oh and now I would like to look up how this works and nobody has figured it out and you have to go and you do it yourself and this is a trial and error sometimes you get it right sometimes you don't get it right uh but I think this is where the search for life also helps us on other planets because there's only so much we can learn by going back in time because the rock record becomes harder and harder to read the further back you go there's less of it it has been incredibly modified and so this is where the search for life on other planets if we found Signs of Life on for example all the planets that we know have been frozen at one point or all the ones that we know have never been frozen right so that should also give us some pieces of trying to understand what happened here on Earth and in general the search for other Earths gives us these other puzzle pieces of how an earthlike Planet evolves and I'm not talking about you have to have a yellow sun I'm talking about under any sun if your rock that has liquid water on its surface and you start to develop whether you get to life or not these are pieces that tell us about our own planet in our own future so whether you care if there's life in the universe or not it be interesting and good to know how our planet works better certainly appreci the choir here and obviously your your book goes into this a lot I have to say by the way the it's such an accessibly written book I really enjoyed how you know you could it assumes no knowledge this could be the first astronomy book that you ever pick up and it explains things like how spectroscopy works when how do astronomist actually probe the atmosphere of another plant how do we detect these plants in the first place so it assumes no knowledge but at the same time it has a lot of respect for the reader in terms of intelligence I think that's always the best writing when you assume your reader is smart but you also don't presume they have any prior knowledge on this particular topic and so it w you know I could give this to uh anyone from you know a teenager all the way up to my grandma and I think everybody would get a huge amount out of this book and it keeps you up to date with everything going on in the current search so I really did enjoy it and you do spend a lot of time in in the midsection of the book talking about the early Earth which was fascinating to get into and it made me wonder about your thoughts on Rare Earth so you've probably heard this idea of the rare earth hypothesis absolutely and probably some of our listeners have as well and you talk about some of these events that happen in the early Earth's history like the impacts you were just describing the formation of the oceans and then how on early Earth there wasn't even really any continents and then the continent the continent started to form we start to get land masses then we had the you know maybe the water was delivered from comets maybe before that but then afterwards we start to get the of oxygen on the earth due to photosynthesis emerging you have UK carots emerging which allows for these multicellular things and so it seems like there was a lot of steps a lot of steps and that when I was reading those steps I was thinking I wonder how Lisa feels about the rare earth hypothesis because it seems like you're an optimist in this book and I know you're an optimist from talking to you and the rare earth hypothesis tends to be more of a pessimistic view so I just was curious how do you how do you square that what what's your response to rare earth proponents I think this idea that there's a rare earth or that not many places can actually form life is a little bit seated in this misunderstanding of the tree of life that is just such a great picture in your head right and so then you can imagine oh the tree of life so if you cut the part of the tree right the trunk then it will never develop then if you cut the the trunk then it will never develop and I think this is where biology is very misunderstood because you could argue this again and again with you know the 90% of Extinction on Earth life always finds a way and life actually is all the way down to about 5 to 10 kilometers underground so actually to sterilize a planet you would have to melt it all the way down yes it would have to get started again right yes it might need time but there is so much Evolution going on even around us I think a lot of times what's hard and this is why I built the Carl second Institute a lot of times it's hard to understand the other fields to the depth that you understand yours and so you have to have somebody that you like comfortably can talk to and so the Carl Sean Institute is these 15 different departments chemistry biology astronomy physics engineering whatever you can imagine kind kind of we have because when I go in and for example we had this idea we were talking about the red Suns and then there's a lot of UV hitting the surface of the planet because red Suns especially when the young they're very active and so they basically push a lot of radiation on their planet and so the astronomers are very likely like I I know my community well to say oh there can't be any life on that planet go to a bi ologist and they say why not because subsurface or in the ocean you shelter from UV and also life can evolve for terrible conditions right yes you and me landing on the planet would probably be incredibly unhealthy because we never had to develop for it and so this is what actually made me more of an optimist in this search for life it's kind of really fun because the biologists whenever I come with a question was like oh and so this will preclude life just like why I was like oh you know because the sun is the wrong color and the biologist like well 3/4s of life on the earth do not use Sun but of course we are only kind of aware this is why I run you in the book I run you through what is life and that there's so much life that we usually don't interact with that we don't see that has completely different conditions and they can strive even you know with no sunlight and all of this I think as to the rare earth hypothesis because if you're not aware about this huge expanding knowledge right about what life is what it can do where it can actually live then it's easy to think oh if the condition are just a little bit different everything's sterilized you have to melt a planet down to 10 kilm to sterilize it right what hopefully doesn't happen that often even with big impacts I agree I try to be very balanced on this and I've I go both ways and people people who've listen list to me on the on the podcast and the YouTube channel know that and I tried to keep it very balanced VI and I guess my my devil's advocate my internal de Devil's Advocate to this is that's true to like sterilize the earth now even to sterilize our spacecraft is incredibly difficult it's basically impossible like we're always going to contaminate things when we fly to another planet and it was kind of fun in the book you talk about how there's bags of uh poop on the move from the astronaut like we've and this Gres now sprayed all over from this failed experiment you talk about in the book and it's totally true and those things are probably going to hang around there for a long time but tardigrade or these bacteria that live deep down they're very sophisticated machines they're not you know we tend to think or they're they're basic life things but they they have you know very sophist they're four billion years of evolution down the line so they're they're complex machines that have adapted to the environment and yes life can adapt and will adapt to changing conditions up to a up to a point I suppose but surely that's a a different question to how fragile how uh peculiar do the conditions need to be specific to the conditions need to be for life to start I think to Me Maybe maybe I'm making mistake but I try to divorce the origin of Life conditions to what life can do once it gets going it seems like once life gets going it it's almost like got a superpower right it can just pretty much adapt to anything and we don't need to worry about it it's going to be hard to get rid of but I guess the real question is how how specific are the conditions on that beginning point which is the thing you wanted to go back and see exactly and that's exactly why I would like to go back and see because it is completely diversed I agree to you once you have life it seems to be incredibly good in adapting to so many different environments but is there one specific Niche that it needs to get started right that's the big question we don't know how to answer and this is where the search for life on other planets will actually be a key because if we find Signs of Life on many many different worlds very very different ones then it can do it under many many different conditions if we don't at all right then the question becomes do we just not see signs of life because it hasn't gotten to the point where it changes its biosphere with unique signatures Like Oxygen and methane before that we had life but it produced methane and CO2 what I can get out of geology or is it not there but when I just think about the incredible amount of places that we found one out of five stars has a planet at this right distance where you could have liquid water and you will have some radiation hitting this planet you have liquid water and you have different chemistry around in very different niches I tend to be an optimist because you would have to restrict the condition so minutely so precisely to not have it anywhere else if there are rocks at the right distance with a similar composition because if you look around the universe everything is roughly similar composition in terms of stars and planets but I do agree with you as long as we do not know how to make life uh the answer and this one I borrow from Michelle mayor who is one of the two people from the first planet around the sunlike star I love his answer they were basically asking Michelle so what's the probability of Life on another planet and he said 50% and people like oh my God and then he said plusus 50 and he is right right it could still turn out that there's no life in the universe except for us but I think the research that we have on life and its Evolution and especially of all this Extinction events and then life like rallying back and coming back suggests more that life is way more resilient or way more creative I would say um then we think about when you cut off one stem or one yeah one branch it's like I guess it's like weeds isn't it you I I would think it weeds is a good thing it's like a foilage you know or if you go to to a forest everything that I've learned about life since I studied this because I'm an astronomer so I had to learn the other part is that it's incredible how tenacious this is but it goes back to the question how does it get started and there's fascinating research that seems to indicate that what we need is actually maybe some UV radiation to get it started to give it this additional energy this additional kick but there uh my knowledge starts to actually go out because this is where I my colleagues to tell me what's the newest things on the evolution of life on the original life because it's incredible it's fascinating but it is such a fast developing field that it's really hard to uh keep up so this is where we have the ksan Institute where it just goes like so what's new in the original of life and get up it's an exciting place to work with so many different colleagues that's why I've always been drawn to the subject as well so you get to interact with so many different people from different backgrounds who think about these problems and as you mentioned the book sometimes have different language like you mentioned how geologists talk about glass as being cool magma and when they would talk to astronomers they would be like you mean glass like like a cup like what are you talking about like it was yeah ex so I mean you must you must have those kind of challenging interactions a lot the girl this too absolutely but this is why we implemented this cofy because it's basically everybody sitting next to each other and if it's kind of a moral informal place right you can actually see yourself saying like what do you mean by glass right this is not glass it's not seethrough and I mentioned in the book this was this one story where we actually were working on this and the geologists were saying well yeah it produces glass and then the astronomers in the room were like couple right we're like what and I was like okay you know what screw this I'm just going to ask right and I was like so you mean it's a Cinderella slipper kind of planet right because I had this image of a see-through Planet I'm like this can't work right now for I know and the geologists were like what do you mean right he was like well you guys keep saying glass and the geologists were like well you know everybody knows when you say glass what do you mean is I was like what do you call this cup right and then a lot of teasing iser but at least we understood each other and this is where it's so interesting I find too that even if it's science we have our own language that sometimes we don't really realize so if you say something is big as an astronomer I say something is Big we think about like huge billions of kilometers one of my geology colleagues or like atmospheric chemist colleagues say like big it means like one part in a million is huge right for a change in the atmosphere and so it's really worthwhile to think about the language and when I wrote the book that's where I wanted to come from I want like I want to talk to a friend of mine who has no idea who is smart or interested right because as you were saying the search for life we are at a crossroad right now we are at the beginning with the James web Space Telescope at the verge of technical possibility it's not easy it's going to be so hard I don't know if we're going to find something with the telescope we might need a bigger one but for the first time ever we have the possibility to investigate these small rocky worlds around these small red stars because the telescope became big enough to catch enough light and I think there's so much bad things going on in the world right and sometimes it's really frustrating where you say oh my God you know it's a bleak future we going towards but there is so much amazing things going on as well that get covered up with all these things you have to worry about and the sech for other planets that we found other worlds and that we had the verge of pro in them to figure out if we're alone to me this is one of the huge achievements of all of us together it's International you need everybody in it and I think if we had more of this in terms of what people actually understood what we achieving all together maybe we could just fix the other problems too by saying oh come on we actually finding small earth like planets and other stars we can do this it definitely changed your perspective and I think your uh enthusiasm and your passion for this subject it it it's infectious like it comes it's always been you know something I've enjoyed talking with you about because you talked to Lisa about the search for life and you just come out of that conversation feeling excited about it I always feel that way you're very positive about it and it's uplifting to talk to you and it really comes through in your writing as well this is like a Feelgood science you come away feeling good about the future of science to me science is an adventure and I think we are sometimes not that good in sharing it because there's so many things that are going right even so there's lots of things that are going wrong but I think especially the Young Generation and this is why I wrote the book for everyone and this is why I wrote the book for everyone so everyone can pick it up even if you thought o science I'm not sure if I can do this because there are so many voices that we need need so many thoughts that we need in the search as I said we have 15 departments in The colen Institute and sometimes the Performing Arts question are the ones where we're like oh we probably should have thought about this like if one of our colleagues is like did you think about this and we're like oh somehow we didn't right and so there's a place for everyone but I think we also need hope because we need something to strive for and I have this High Hopes in as somebody who is like oh I could like get a Love of Money building weapons and do some terrible things it was like or I could get less money but have a super great uh time trying to find life in the universe so I'm basically also trying to get really intelligent people into a different kind of profession but I do have to say I didn't even talk too much about exom moons in there you're forgiven it's okay no no but the great thing about this is I was actually in a way conservative if you think about it because if you were to add exra moons as potential places for life and there we go into sci-fi and Avatar then the chances seem to be forever in our favor well only helps yeah and I know you I know the problem is you've work on too many things because I know uh when we were first uh working together at Harvard uh you were telling me about a paper you were writing about the detectability of atmospheric signatures from exomoons I don't know if you remember that it was this must been like 2012 201 just came to H yeah remember and we we first started talking about that subject and yeah so I appreciate that you you definitely are an advocate of exomoons and uh I think obviously I'm pleased to have seen that paper and of course the thing that you're I think that you've been working on really hard over the last few years and you do talk about in the book as well is this color catalog which is is kind of a beautiful idea the idea of just what is the basic color and Hues of the planet and how do they evolve and blend into each other and change which certainly in the on the east coast and Northeast you see that changing Hues of with the seasons but on a longer time scale there's changing Hues of the entire planet what was the uh maybe you can tell us a little bit about what this catalog is and how your team are trying to use it to answer these questions one of the really interesting things so first I thought about the Earth evolving through time and we are looking or we were looking for a carbon copy of Earth so that means 21% oxygen and some green plants basically but if you just look this is when you go to the diversity of life on the earth you see that there are so many different places that have so many different kinds of life but a lot of them are colorful because pigments do a lot for you so pigments is the express color right and they can actually help stressed organisms protect themselves so then the idea well actually I was at Yellowstone National Park and I saw all these beautiful colors and then somebody said was like you know what this is all different kinds of life you know when you go from the outside to the inside of this hot sulfur um Sulfur Springs and I was like what what do you mean this is all different kind of Life of course it's all different kind of life but it never clicked is it all bacteria or is it all appr it's all different kind of it depends a little bit what the temperature range is but it's very versatile difference thermopiles you know if they're closer but the interesting thing was I was like hey um I don't think we know what that would look like in my telescope and then I looked around desperately right everywhere and I went through the literature and it turns out we don't and so this idea again that we are it or or we are looking for us right it's like the it's a little bit like the Earth being the center of the universe right now we're trying to find Earth around a yellow sun right we want green plants I was like but the diversity even on our planet shows us how different it could be right just change the conditions a little and maybe some other kind of things would have been dominant life forms or you would have purple vegetation you know under a red Sun because it would absorb more of the light and reflect less and so we made this color catalog of life it's basically just to say if you have a variety of different kind of life forms from microbiota to something more advanced single cellular to more advanced mats and structures how would that actually look like so if you saw it in your telescope if light reflected it um or if it reflected light incoming Starlight back to your telescope what would it look like and the fun interesting thing is that this color Hues of Life are so diverse and beautiful and it's basically like you take a cosmic paintbrush and you pick any color and you probably find an organism that uses those pigments and the next question so now we we've established this catalog and there's so many more ways to go and I always call it bag Bor and steel because we don't have much money for this work so I always like whenever I meet a biologist was like so do you have something left over that you might want it to send me and I can grow it and I can look what it would look like in my telescope because most biologists don't do that right They Don't Really Care at a certain point uh what the color is because it's not so useful for them and so we have this amazing collaboration with people all over the world who like yeah sure I have like five things I can send you and so we're now getting this FedEx back boxes it's super funny we get this fed boxes in the astronomy department and then we just run them to the fridge because you can do this over overnight right this thing will survive you know it's not all extremal files it's just whatever we can get our hands on because the diversity of Life on our planet should inform our search for Life surface life right on other planets and so we go uh to the biologist so caran Institute combination of different departments but so we have a lab in the biology department and my post dog liia coo is an amazing researcher she can grow this she's my mob biologist she can grow it and then we basically take this beautiful colorful flasks of different kind of life and then we put it in a rook and we walk half of our campus to the remote sensing lab where another colleague of mine actually has a setup where we can put those different biota we usually put them on a filter right to just to have like a a solid line of biota not just a flasks and then we uh hit it with light and see what it reflects back and it's really funny because it's like we go from this one Department to the other department and then we use the information and we put it into our models for other Tru interdisplinary truly into the spin full out and uh but it's it's and it get added to your catalog so you just you take all these different examples of life and catalog their colors and this forms a sort of basis set for which we can then go out and these signatures and we call it color catalog but it's really the reflection of the light at different wavelengths right for this wide diversity of biota and the interesting thing is like we call it color catalog of life and it's available online at the colan Institute website anyone can use it for all the other things they want to use it for and for example one of the things that's very interesting is we have life in ice it's one of the questions that we were asking is like if we had an icy world or if you had an icy moon what could be things we should look for what other patterns reflectivity patterns we should look for because we know life can strive in ice and snow and so now this is also something that's really important for climate change because one of the problems is if the glaciers or the ice actually gets less reflective because biota actually lives there more and more it brings down the reflectivity and thus it melts the glacias faster and this is why this color catalog of life we use it for something trying to find life in the universe but it's there for everybody to use for whatever they want and in case you're looking listening to this podcast and you want to send me a sample of an interesting life kind of organism that you have you know just let me know look me up on the Internet nothing dangerous nothing dangerous nothing dangerous that is very true even so my microbiol just knows what to do but yes nothing seriously dangerous yeah you kind of worry about people sending stuff in the mail that immediately disturbs me but uh that's true now yeah I hope first yeah I hope these FedEx packages uh I'm sure handled carefully but yeah it's a wonderful resource that you've given to the community to help us in this Quest you mentioned there the possibility of of life in icy worlds which I think is just such especially someone who's interested in moons that seems particularly fascinating and you talk about the prospects of life in the solar system you mentioned sort of Mars as an obvious place people have looked at for a long time but also Europa and Enceladus which have got increasing interest and we have these missions there's Europa Clipper and juice which I think are fairly similar timelines of the mid 2020s are we no mid 2030s mid 2030s there mid 203 yeah because it's mid 20 20s now so mid 2030s we have these missions arriving are they going to do anything for the search for life or or they more or less setting the stage for future missions I think to a certain degrees stay setting the stage for future Mission except and this is where this interest in our life in ice is going and so one of my uh posts Le that I mentioned before uh she's developing this into now what about if in our solar system we had such pigments life and Ice Could you actually observe it in the ice because that's one of the ideas people have is to look at the structure at the surface where the cracks are for the icy moons well there is this red stain with your rope isn't there that you get exactly and in the in the cracks and also on the I think they're called lenticula the little spots yeah and the question is can you explain all of this right with geology or with kind of minerals or is there some kind of pigment that might have exactly the same color right but if you have enough of a resolution in wavelengths so when you actually look carefully enough what you can when you're there could you actually tell apart that this is a reddish kind of rock feature or a reddish kind of pigment that life on the earth makes and these are some things that we're investigating and this is where this research can hopefully help missions uh get a first idea of uh you know if they spotting broken pieces of Life Broken Pieces of pigments or pigments in the IC uh IC worlds in our solar system so you don't you don't mention Venus and obviously Venus has been a subject which surpris you know I think to many of us it was surprising that there was asist interest penus given what a extreme environment it has but maybe I can ask you sort of out outside of the book it's not in the book but what is your thoughts on the the recent interest in possible life on Venus I think Venus is really important and interesting because it's just somewhere between Earth and Venus uh planets lose their water and so at that point we have a limit of what we call this habitable zone it doesn't mean that there can be life outside of it but if you can't fly there to investigate we won't be able to tell because it doesn't sufficiently a biosphere doesn't sufficiently change the atmosphere and now when you go to Venus I think it was actually a beautiful example of the excitement of trying to find life in our solar system and our holes in our knowledge because Venus wouldn't be a place where you would expect the life to be able to thrive right now even if it's incredibly good and adapting at Venus you would actually have to make it somehow get up in the atmosphere into a part of the atmosphere where it's just the conditions are are okay for Life as we know it and so the excitement was the convolution of where they sought they found signatures that could identify life because it was at this Cloud layer where you could say oh you could actually have a surface right because clouds are particles so there was a Confluence of uh of hopeful ideas that could give you this one opportunity of maybe finding life on Venus and just background here we're talking about phosphine we hav maybe given that pointedly but there was a claim of phosphine which is a possible bio signature in the claimed in the atmosphere of Venus and so the big problem is there we go back to does it have to be biological right so I've been been talking a lot about extraordinary claims uh and we had the situation in Mars too right with the methane on Mars of course I wish it to be life right but the problem is if I have 99 explanations that don't require life and one that requires Life as a scientist I'm unfortunately trained to not just jump on the last one but I do get that people wanted to be the last one even scientists right sometimes feel like oh my God this would be like the best ever exponent and I think what was really great about Venus is that people now updated their Venus models right because the Venus models were just not and it's not anybody's fault but you just have that much time there's not much money usually for Venus models and so this actually kickstarted uh the community's interest in Venus again uh updated models kind of showed that the cloud layers wouldn't be where they start the Venus observations the phosphane OB obervations were what is now starting to become more and more tricky to try to know actually because ven phosphane somewhere in the atmosphere is not as compelling as phosphane at a as a as phosphane detections at a place where you could have some kind of surfaces like a cloud layer oh so just needs something to stick to basically if you want it to be life uh you might want to have something it's not just free floating particles the argument was that there could be some kind of organisms that would produce it because they were stuck on the uh on the surface of these clouds but I think what it showed is this excitement and I think it took the scientific Community generally by surprise that these observations and then these ideas where they could come from uh formed such an excitement in the general population too about trying to find life um I think what it did what I think is great is it actually allowed us to investigate this further so there were more observations that some of them did not find phosphane at all some of them are not sure they found out some issues with the pipeline so this thing that actually develops the observation to a certain point for us for as scientists before we analyze them um but uh it gave a reason for us to go back to Venus and study it more that we might not have gotten by just saying oh come on we need to learn about Venus because somewhere between the Earth and the Venus habitability as we know it starts to fade and we don't know where and so learning more about Venus will give us some information on that I don't think and this is why it's not in the book I don't think the phosphane detection on Venus is as solid as we hoped it would be and thus I haven't put it in because it would have required a couple more chapters and theun part is like my editor was like no you have this page number I was like okay the most important things totally appropriate I wasn't it's hard to cover and give it due diligence and not you you want to be fair to to all the sides and so that takes a lot of pages to cover so I totally understand why it wasn't included I think the interesting thing to me about the story of vus is the uncertainty that we have about a planet in our own solar system when it comes to the question of life and we've seen that before with Mars uh with the methane but also with the um Alan Hills meite that Bill Clinton and you mentioned in the book St the White House lawn and said this you know this could be evidence for life and even before that we had persful LOL one of my favorite stories imagining canals on the surface of of Mars so people have been claiming life in the solar system what that at least four times now probably even more than that if we go through the history books and yet in of those well maybe the the uh the case of the canals we can scr scratch that off as sorted but pretty much the other three are still kind of unresolved to some degree and is that is that a reason to be worried in the search for exoplanets if we can't conclusively figure out what's going on with potential bio signatures on our two neighboring planets where we can send probes we can you can visit these things we can put orbiting satellites how are we going to do it for a pale Speck of light that's light years away I completely agree with you that we need a strategy and the problem is we also need to agree to a strategy what always will be the biggest problem and so for example there were some recent claims of a wiggle in one of the spectrum of an extra Solar Planet that is a mini Neptune so it's a gas ball it's super hot I know exactly what you're talking about a small wiggle right and then the scientists were very excited about that this wiggle could mean more than it is right and the statistical significance was also unfortunately not there we usually say it has to be three times bigger than the noise right for us to say we find something that was like 1.2 times bigger than the noise but I can get it right somebody was like oh I could have found life right I want to claim this you know I get it and so I think uh it's not just uh our own solar system and people claiming life right I think we just have to get used to it that somebody claims life or chres wolf right and then people come together and say like look right these are rules that it doesn't come up yet it's not to say it's not life but it is not the extraordinary evidence that we actually as a community require to say so and so what I think will happen is that there will be a lot of people claiming life with these Wiggles and these detections of light from extras solar worlds and some of them might in the long term actually teach us something about chemistry we never understood because one of the problems and this is where the catalog uh the color catalog of Life came from is that if you only look for green plants you'll miss a lot of other options right but you also want to mistake anything that's at that wavelength where the green plants would reflect and you you won't immediately think about oh it could be chemistry oh it could be geology it could be a mineral right because your view is there is green plants or nothing and so I think by widening our approach for life and for its signatures and also being more aware that there could be some false positives I I think what we're teaching ourself is to be cautiously optimistic but maybe not to cry life every time we think that we f a wiggle that we can explain but it's everybody's personal thing I kind of go back and forth on it a little bit I know it's easy to sort of poo poo the scientists who say this and not too many people come to their defense and I'm not trying to defend these scienes necessarily but I do think it's hard if you see something in your data that is consistent with X there's some certain bi signature but it's but it's marginal it's maybe two Sigma as you said not normally the threshold what do you do with that do you not publish it do you just say I'm going to kind of keep this to myself as a little top secret thing that because that that feels anti-scientific to not to to say that there's a you've got this evidence for something but at the same time it's unlike any other scientific topic that just the the very mention of the word bio signature two Sigma detection of Bio signature to wor we understand a scientist that means basically ignore it but that could so easily get picked up and it does get picked up and get sensationalized that others would say you know we can't trust we basically can't trust the media or even the public to some degree to digest this and so we have to sort of censor it and that's where I get conflicted cuz I don't feel comfortable censoring even if it was 1.2 Sigma of DMS dimethyl sulfide in this case the case we're talking about I I feel that's obviously not statistically significant of a life detection but do they not also have an obligation as a scientist to put that in there that's why that's where I go back and forth in my head how do you feel about that absolutely so I have no problem whatsoever in actually putting it in there because I think we should um even so one of the problem with such a small signal is that if you do basian statistic statistics and you do right retrieval is like if you tell the code that it's something is in there you know that there's a certain threshold that it will tell you it's there even if it's not and so 1.2 is not above that threshold so it basically tries to find a solution to uh accommodate your guess that it could have been there so you have to be very careful but no absolutely this data needs to go into a scientific paper and the scientific paper actually did it right right the scientific paper just said that there was a hint of 1.2 for dietal sulfur right the problem was the press release they added to it and I think one of the things we have to learn as scientists I think especially in this case and in many other cases the enthusiasm of having been the person to find something sometimes takes over and it is not fair to assume that the public will understand what this means this is where as scientists we are communicators right and so what I should say or what I would say and what just went out of context in this context for example and again I don't blame the scientist for putting this in but I do have a choice when I talk about something to be uh less enthusiastic about it right to say look this is really exciting but currently the data is just not there yet but we going and I think that was lost in terms of nuance again not necessarily the scientist's fault but I think the press release was incredibly unfortunately structured and I think as a scientists we have to figure out that we are communicators you cannot just say well they wrote a press release I said it was fine and then this happened you when you read a press release you have to also think about what this probably will lead to you know as good as you can and sometimes you cannot anticipate what's happening yeah I think I might be Mis I thought the I only saw the NASA press release yeah I I didn't feel like it overbaked it but I I agree with the way the media picked it up and I'm I'm certainly cognizant of that with exomoons we've when we first made our exomoon candidates we didn't really it's not that we didn't believe that they were real but we were very cautious about their reality I would say it's probably the right way to describe it and so we we tried to emphasize that but there's still there's I kind of learned there's almost nothing you can do how cautiously you frame it in interviews it still there will be headlines this it's and that's very frustrating as a scientist that you feel somewhat powerless to control the message that's why I kind of love doing the the podcast and the the YouTube channel because it gives me a chance to like talk directly not through an intermediary because if if I learned anything about science communication is that the intermediaries rarely do a good job of translating uh there are some very good ones but so often often so often there's terrible examples and so I I have some sympathy on both sides I guess and it's um it's it's an unresolved problem and it seems like with life there's something special about that case it's always going to get a lot of attention I agreed to a certain extent so I think the problem is also we are not trained to communicate right as a scientist we're not trained to tell you oh you know what 1.2 Sigma doesn't mean what you think it means right just like uh this detection if it can be substantial would be super interesting right but I do think that um there's a lot of people who trying to communicate it the right way the journalists I generally work with they want to get the story right and so a lot of times what I get to ask is like can you just send it back to me let me just read it right because there's a lot of things that are easy to misunderstand because I know the stuff and I might not have explained it right and so in a way that's also where the book comes from to give people a little bit of um a tool to say okay so now what do I need to check right and like okay if somebody says oh I found life on this it's like is this A rock right is there actually surface where life could get started yes no right and then if there's not like a mini Neptune then interesting but from everything we know so far probably not the best Contender and so I hope this is when some of the journalists are like so what can I read on have you written a book book so I can read up on this right this is the book this is like I can now send you the PDF right as like look through this look through this chapter and I hope that will help but I think it will with time people will understand the nuances like for example now you know with meteorites right um Second Time Around people will like but could it be this and this and this I take it in a positive spin that the excitement is there right the excitement is there and we just waiting for it to be a true signature for life unfortunately sometimes we're going to get it wrong but in a way we can also teach people that that's okay science gets it wrong and then it adjusts yeah I appreciate you you are very cautious in this book and absolutely not sensationalist so that's certainly something I appreciated when maybe she when does this when does this book come out 16th of April okay so not too long and what was the what was the inspiration for you to write this book what drove you to do it I had a sabatical coming up and I was thinking about trying to figure out because I work on many different aspects of the search and the easiest way to think about it for me and to see if I've actually collected all the connected all the dots that I think are important is to write it down in a very simple way and so this is where the idea was born that I'm going to write a popular science book because if I talk to a friend about this and I say look this is important and this is important and so I sketched it out and one of the things that um Rob Hazen who's another person who writes science books so I just chatted with him I was like well you know how do you read a science book and he was like put a small chair in front of you and I was like why and imagine the friend you're talking to so you don't forget that you're actually talking to a friend because that's the best way of writing it and I was like I also in a second form wrote this book so other scientists in their field please write a book like this so I can actually learn as much as I can about other fields in a deep dive without having to know something that would be wonderful yeah I wish you know that we had this on gravitational waves neutrino physics CID this would be wonderful yeah you have something to do in your sabatical right ex I mean seriously yeah that's uh that'd be fun to write a book at some point so let me finish off because we're coming up to the end of our time but you you know in this book you obviously you write very passionately about the fragility of our own Planet you've spoken eloquently about how you feel today how science could be you know a unifying thing that can give us maybe some hope and optimism about the future of our planet and the future of our society and in a way that kind of carries the message and the torch of Carl Sean who was not just an optimist about the search for life in the universe but also a humanist and he saw it as part of our journey as a species to try and answer these questions so I was kind of curious just to finish what impact has maybe not just the work of Sean but your own work as a scientist how has it altered you in going from that student who was working on Darwin you know and doing these cancer experiments to writing this book um how has the search for life in the universe changed you what it has given me is an incredible appreciation of how incredibly wonderful bizarre and weird our planet actually is things I had never thought about like for example what life can do in all these different niches how your curiot you know was just like engulfed something and all of a sudden there was New Life And now when I look up at the sky this Cosmic connection that there might be somebody else looking out and wondering if they're alone all of this to me makes my VI of just looking at my surrounding or looking at the night sky so much more profound and deeper it's a little bit like a painting that you love and then when you know why it was made who made it what are the tools to do it it gets this additional depth and for me my view of the world now is just more in depth than it was before and I can look at a piece of moss for example right now and like oh my god there might be like tardy grds in there and I can imagine how they look like in the do trop and I can look up at the sky and imagine the Stars the huge gas balls igniting and allowing the light to hit the potential planet and maybe have life start there too that's beautiful yeah it has it shifts your mindset you see the world differently yeah So Lisa this has been wonderful for those who uh are interested in learning more about the search for life in the universe I recommend this book alen Earth it's really fantastic beautifully written informative and very accessible and keeps everyone up to date and and also down toe on the search for life out there so please check that out and thank you Lisa for joining me today thanks for having me [Music] so that was my conversation with Lisa cenega I hope you enjoyed it as much as I did it's always wonderful for me to get to catch up with Lisa because frankly we just go a long way back as you heard on the podcast we were at Harvard together not as students but as posts both as active researchers looking for exoplanets and even starting to think about their search for life in the universe back then but more than that we just got to chat on a regular basis on coffees every morning we would get to chat about the various latest EXO Planet news and also remember heading over to her apartment a couple of times for parties that she held so she's always been a good friend of mine and it's really wonderful to see her blossom into this incredible scientist and now she's the director of The caran Institute and she's written this wonderful book which by the way is out now alien Earth you can find it on Amazon.com or your local bookstore wherever you get your books from go check it out we obviously recorded this episode what probably a month or two ago but I thought we should save off releasing this until the book comes out to kind of give it like an extra bump so go check that out right now now I think leaving this conversation I have to say the one thing that I'm left with as a feeling about the search for life in the universe is obviously something I think a lot about and my feelings on it do sway dayto day as I think many scientists do but the feeling I'm left is with just thinking about that solar system example of phosphine with Venus and how incredibly challenging and difficult it is to make sense as to whether there is potentially a signature of life on a planet that is literally next door I mean you there is no Planet closer than Venus to the Earth and yet even in that case we still are arguing and fighting about whether what we saw was really life or not that's humbling right that's humbling because it makes you realize that one day when we build Darwin or tpf or lir or the Carl Sean Observatory maybe whatever it will be called when we build this telescope that we'll hopefully be capable of detecting these kinds of signatures that is not going to be the end of the story there will surely be a huge amount of work that's going to have to come after that but it will be the beginning of a very exciting journey of getting our first hints of potentially life in the universe maybe we'll find nothing who knows but if it does find those first hints it is still just the beginning of a very long journey of hard science figure out how the chemistry the geology of other exoplanets work and I think we will learn a lot in that process it's a lot of hard work but hey that's what science is and I'm certainly looking forward to getting into that hard work and seeing those first hints or absences who knows of what else might be out there so if you enjoyed this podcast if you're enjoying the previous conversations we have had then and you want to support us then the best way to do that is to head to coolworld la.com ssupport that's cool worlds.com ssupport if you do that if you head over that and you pledge to become a donor various monthly levels you are supporting really the research team directly which in turn supports the podcast and the Outreach videos the way this works is that your money basically just goes to research funding exclusively here at Columbia University you know we use that to publish papers to do research to hire researchers that kind of stuff and then that means I have to write less Grant proposals and that means I have more time to do podcasts to do the Outreach videos as well so I think it's a unique proposition to you guys that if you do want to support us you are not only supporting real research in the field of astronomy and astrophysics and the search for life in the universe but you are also supporting all of the Outreach work that we do at the same time so if you're interested please do check that out cools.com ssupport so until next time stay thoughtful and stay curious

Channel: Cool Worlds Podcast

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Id: cI_5gdHaAac

Length: 92min 5sec (5525 seconds)

Published: Tue Apr 16 2024