Into the Impossible With Brian Keating - Searching for Alien Earths with Lisa Kaltenegger [Ep. 411]

Episode Date: May 5, 2024

Please join my mailing list here 👉 https://briankeating.com/list to win a meteorite 💥 Is Earth unique, or are there other Earth-like planets full of life? If so, what might life be like on these other planets? Could we even detect it? These questions have puzzled people for millennia. Now, we finally have the technology to explore it. Among the people who have taken up the search for other Earth-like planets and extraterrestrial life is today's guest, Lisa Kaltenegger! Lisa Kaltenegger is an award-winning astrophysicist and astrobiologist and the founding director of the Carl Sagan Institute at Cornell. She is a pioneer and world-leading expert in modeling habitable worlds and their light footprints. For the last decade, she has been finding new ways to discover life in space, working with NASA and ESA from Austria to the Netherlands, Harvard, Germany, and now Cornell.  Today, she will take us on an exciting journey through space in search of habitable planets and life.  Tune in!  Key Takeaways:  00:00:00 Intro 00:03:00 Judging a book by its cover 00:06:16 What kind of aliens is Lisa looking for?  00:10:50 The key technology for planet hunting  00:16:51 Modeling habitable planets 00:24:09 A trip through probability space  00:33:58 Panspermia and life on Mars 00:38:02 Proof of life 00:44:51 Information theory and identifying signs of life 00:48:11 The implications of discovering extraterrestrial life 00:53:16 The future of pedagogy  00:57:39 Outro Additional resources:  ➡️Win a copy of ALIEN EARTHS! enter here: https://kingsumo.com/g/mkl3j6/win-a-copy-of-dr-lisa-kaltenegger-s-hit-book-alien-earths  ➡️Learn more about Lisa Kaltenegger: 📚 Alien Earths: https://a.co/d/bKobTOp  ✖️ Twitter: https://twitter.com/KalteneggerLisa/  ➡️ Follow me on your fav platforms: ✖️ Twitter: https://twitter.com/DrBrianKeating  🔔 YouTube: https://www.youtube.com/DrBrianKeating?sub_confirmation=1  📝 Join my mailing list: https://briankeating.com/list  ✍️ Check out my blog: https://briankeating.com/cosmic-musings/  🎙️ Follow my podcast: https://briankeating.com/podcast  — Into the Impossible with Brian Keating is a podcast dedicated to all those who want to explore the universe within and beyond the known. Make sure to follow/subscribe so you never miss an episode! Learn more about your ad choices. Visit megaphone.fm/adchoices

Carl Sagan died over 25 years ago, but his legacy lives on, and so does the mystery that haunted him all of his life. What if Earth isn't the only home for life in the universe? Imagine the vast expanse of space filled with planets teeming with life. As Carl said, if there's no life, it's an awful waste of space. But what the space looked like? Could we even detect life on other planets? These aren't just sci-fi questions. They're the heart of humanity's oldest and most profound curious.

And now, thanks to cutting-edge technology and theoretical progress from today's guest, we're closer than ever to finding the answers. Today, we're joined by a trailblazer in the quest for worlds beyond our own, Dr. Lisa Kaltinegger, director of the Carl Sagan Institute at Cornell University. Under her leadership, a multidisciplinary team of scientists developing innovative tools to detect signs of alien life. What exactly do we need for life to begin somewhere else? This is one of Lisa's key driving questions, and her work propels us into these mysteries and beyond.

She's here today to take us on an extraordinary journey across the cosmos, seeking habitable planets, and perhaps the next Earth, the alien Earth. Stay tuned. As we embark on this cosmic voyage, you never know who or what we might meet out there. Any sufficiently advanced technology is indistinguishable from magic. Open the pod bay doors, hell. Welcome to an alien episode of the Into the Impossible podcast with a fan favorite, a personal favorite. And to my knowledge, the person who has done the most for spectroscopy since her countryman, Doppler. So Christian Doppler did a lot. And I think he would love to meet you a fellow Austrian.

How are you doing today? I just talked about Christian Doppler this week. And I told my class a cosmologist, I'm talking to you. So excited. Lisa, how are you? I am good. Thank you so much. Thanks for having me back on the show.

I would love to meet Doppler, and especially, as you said, Austrian countrymen, right? One of the things we would sit down with a great Austrian pastry, like civilized people discussing science. I always make a note that he was from the same town as another person who knew quite a bit about frequency and pitch and melody. And that was, of course, Wolfgang Mozart. They were from the same town. So when I visited Austria for the first and only time, I made sure to pay equal attention and regard to Christian Doppler. So I should give your bio. You've been a guest on The Into the Impossible podcast before, but you now have a book and we're so excited to talk about it.

You are the founding director of the Carl Sagan Institute at Cornell University, where I was almost born and almost got into, except I was rejected twice. But I said the offer is open. Come and work for me, you know, anytime. Yes, I want to do another postdoc. The new science of finding toolkits to find life on far away worlds. And this new book is about exactly that. And I think the thing that most is just so delightful about you is you're so authentic, Lisa, you don't shy away from talking about challenges. You also don't dwell on them. There's some aspects of the book where you talk about challenges of women and minorities and so forth. But you are not by any means, you know, beholden to a client. class or a status and and you're just your honesty is so delightful as a professional to another professional. I just, I want to congratulate you on that aspect. But the book is, is a triumph. It's one of my favorite new books. Talk to me as we do. Help me judge the book by its cover. What's the meaning of the title, the subtitle and the beautiful artwork, which I only have, you know,

half of the artwork, because you have another copy. Show me. This is what I was about to say, you know, you can actually take your pick so you can have the portrait. copy and you've just shown the American copy and the really interesting thing about this. Let's just bring it up here. I wrote a book and then the publishers, so Macmillan here at the U.S., that's theirs, in Pinguang Press in the UK, and I had no idea that you get two publishers for the same language, but you do. They made up their mind what this book is about, you know, and how they wanted to represent it. And so we go with the American first. So the title, I wanted the title to be Alien Earth because it has so much in it.

It's us searching for planets like ours around other stars, so Alien Earth. But it's also, I bring you into the history of our own planet because you need to understand the history of our own planet to be able to not miss signs of life if the planet's just younger than ours or maybe older than ours. And yesterday was pretty funny. I talked to my husband and he was like, oh, alien Earth, because you're an alien in science sometime. That's the only woman. I was like, ooh, there's a third aspect. I hadn't even considered that he took from that.

And so I love the title, Alien Earth. And then the new science of planet hunting in the cosmos. Can I just tell you it's so funny because it's alien Earth, right? But they have the science of planet hunting in the cosmos, right? Planet Hunting in the Cosmos, the new science of planet hunting in the cosmos. So judging a book by its cover means you probably need bows if you're looking at this podcast. That's right. What you see here is artwork from inside the book because I commissioned an artist and she did an amazing job doing art.

It's in black and white, but on the cover they made it colorful. So all these very different worlds that we spotting and our cuspic horizon. And this, of course, on the U.S. side is the gorgeous nebula and the picture from the James web space telescopes, where we basically have stars and planets forming right now. So Estella Nursery, if you want, that shows you possibilities, places that could become like ours, too. And speaking of possibilities, I can't resist to quote the epigraph from chapter six entitled No Place Like Home. The Limits of the Possible can only be defined by going beyond them into the impossible. Lisa, you couldn't, you could have made me happier.

You know, yesterday I talked to a gentleman named Nick Bostrom, who is a risk analyst in Oxford, and his press release had a mention of the podcast that he's been on, including the Joe Rogan experience and the Lex Friedman podcast and Brian Keating's into the Impossible. So he won that competition for best press release, but you have the best. epigraph that I've ever read from my beloved Arthur C. Clark, but let's get into what is possible and what's impossible. When you and I were we graduate students, are we undergraduates, perhaps, it was even thought to be an impossibility that there could be other planets, let along habitable planets. And I want to ask you, how have your personal opinions or priors

been updated? Do you think that there are aliens of a type that we could collaborate with, communicate with and play out the role that seems to occur in science fiction, or are the aliens that you talk about in this book, the microscopic kinds that, you know, my toddler coughs up on occasion? So there's a lot to unpack in there. So I think what's really interesting is that by looking at the earth, we learn what you could look for. And so if you take the earth at the 24 o'clock from when it was formed to now,

about 5 a.m. in the morning is when we have signs that there was life on our planet, so 3.5 billion years ago. Around lunchtime, about 2 billion years ago, you have the buildup of oxygen in the air that with a reducing gas tells you that a biosphere is changing the planet. And then a couple of seconds before midnight, you have you and me. So the question is, what do you strive to find? And where do you have the best chances? And so it seems to me that you have the best chances if you give it the widest time window that you can to find these other planets with life signs. And so that means I'm actually pretty agnostic between having, you know, a single cellular organism or having you and me or space dinosaurs, we should definitely put space dinosaurs in here. But what that means is that this is our first step.

a biosphere that changes the planet and lets us spot life in the light that we collect with our telescopes now. And then you need bigger and bigger telescope to make more inferences telling us like, do you also see technology gases that leave a smaller imprint in the air? Or do you even find a message? Or do you find a biopigment? So a color that indicates that this looks like, I don't know, yellow algae or green plants. And so it's a puzzle piece step by step. And because you said, you know, when we were undergrads, there was no planets. I remember I started studying in 95. This is when they found the first planet around a sun-like star. And so it could have gone either way. It could have been thousands of years before we found the first rocky world in this right

distance around the star and the so-called habitable sound. But we got so lucky. And this is why I wrote the book right now, because with the launch of the James Webb Space Telescope, we have for the first time an instrument with a big enough mirror to collect enough light to not just find these more than 5,000 new worlds that we spotted, but to start to explore and characterize it by collecting the light fingerprint. Hey there, fellow alien voyagers. I'm so thrilled you're with me and Lisa today. We're having so much fun.

And I just want to ask you a small favor. I found that only about 50% of you are subscribed to the podcast on YouTube or on audio podcast formats. And I don't do this to make a living. I don't charge anything for it. I merely want you to subscribe and share the podcast with your friends. So once you do that, just hit the subscribe button or follow the podcast and leave a like or a review or a rating wherever you can. Thanks. It really helps the podcast out a lot.

and it allows me to get great guests like Lisa and many more to come. And when I think about your career, you're kind of exceptionally responsible in many ways for the quantitative prediction of these biosignatures. And I thought, you know, we'd start, I mentioned your connection to Christian Doppler and spectroscopy. Can you talk a little bit and don't be afraid to be technical? I've got the brightest, most brilliant audience in the known universe. So don't be afraid to be technical. Let's talk about the nitty-gritty details of you as an astronomer, working with instrumentalist, working with analysts, and coming up with your own models and ideas.

What is the key enabling technology, the sine qua non, that you and your team of brilliant scientists have been able to deploy and develop for the search for alien Earths? It's peak pollination season, and my business is scaling fast. To keep the nectar flowing, I need a phone plan with top priority. data speeds. That's why I chose GoogleFi wireless. My connections stay strong even when the hive is buzzing. Plus, unlimited plans started $35 a month. Now that's a deal that doesn't stay. Explore GoogleFi Wireless plans today. Plus taxes and government fees. Google Fi Wireless is not subject to data traffic deprioritization during times of high network usage. So when you do science, you need a lot of people and a lot of ideas. And you need to put them together in a kind of a

chain. So one is the collection of light, what I just said with the James Webb Space telescope. Then that light gets onto a detector. And there's a lot of noise because the star is active. You know, when you think about the sun, they are like flares on the sun, the explosions, nothing bad. But it's just normal. It's a huge ball of gas that rotates differentially. So it's not just one sphere. It's just a lot of things going on in a star. And of course, in its core, the huge nuclear fusion. So a star is incredibly complex and very fascinating. But so we got that. Then you have a planet that goes in front of it, right? So the light of the star gets filtered through that air. But if you take a planet and if you just shrink it, like take the Earth

and shrink it to the size of an apple, then the air where we're trying to find the change that the biosphere did in gases is actually smaller or thinner than the peel of the air. that apple. So the signal we're trying to find is incredibly, incredibly difficult to spot, and the star keeps changing on a level stronger than that signal while we're trying to find it. So you collect the light. That's what the telescope does. But then you go on a detector. Then we develop a pipeline, and that's not what we do in my team. We come a little bit later, and I'll let you know once we start. But basically, there's a pipeline that looks at this light that tries to get rid of the noise from the detectors, from the telescope, from anything else.

And then somebody looks at it and says, like, okay, what is planet and what is star? So that's already a cleaned out signal that we get from spacecraft. And then we have to try to figure out which signals are now stellar and stellar contamination or stellar activity. And which signals can we say this is planet. And where we come in, so me and my team and the whole cost, Sagan Institute, I'll explain why we need that desperately to make sense of what we see, is we come from the other side. We basically say, okay, so what is this light fingerprint or the

spectrum? I call it light fingerprint because that's how I think about it, that every planet in our solar system has a different light that it reflects or emits from each other. So Venus looks different than the Earth, then Mars, than Jupiter, then Saturn. And so for me, the analogy with a light fingerprint makes sense because the spectrum is unique so far for the planets we know. And so what we do is we actually do a modeling deep dive. Think about the weather forecast for tomorrow. So I have a climate model, but I change the sun. Like now I have a red sun in the sky because most of these worlds have been found around

small red suns that are in the right distance. And I figure out what that does to a planet like ours or to an earth at different stages of its evolution, you know, when it was younger, when life just started. And what I do is I then translate that in my computer to what my telescope would see. So you see, you have the data and you have the modeling from this side. And, you know, the ideal thing would be if it's a match. And so this is why I go back to the data base of light fingerprints because we make many of those because I don't expect to be right the first time, but I hope we get close so we can figure out what that signal means, what we see. And this is, so my model is extremely complicated, right?

So you have a planet, you have sources and things, meaning like life creates gases, geology, like sucks up some gases, put some gases out, you have volcanoes, you have clouds, all of this. And this is where I need help. And this is why I've built the Kalsake Institute here at Cornell because what is all the diversity of biology? This is where the microbiology department comes in that I talk to and see what kind of life could there be under a red sun. What would they produce? Chemistry, geophysics, you know, what about if the planet is like way more active in volcanism? And so this daisy chain or this chain of trying to make sense of this light we collect, it goes deeper and deeper and deeper into what does it mean. And so the spectrum that we

get, because light and matter interact, and thus some of the light doesn't make it to my telescope. This is, I usually call it a stamp, like a stamp and a passport. The light that's missing tells me did the light encounter water vapor, did it encounter oxygen? But what does it mean? And that means, Like what does this wiggle mean? Is it CO2? Is it oxygen? Is it water? And what are the possibilities?

So that when I see something interesting, it's like, look, no, no, no. It doesn't look like us right now, right? But observe four hours longer. And I can tell you if this is a huge volcanic planet that you look for or if it's an early Earth. And so that's how everything kind of interesting. And I was curious because I've had on many, many guests, you know. But one was Tim Palmer, who shared the Nobel Prize for the IPCC and Global Climate Change.

He actually won the co-shared in the Peace Prize of all things, even though he's a physicist. And his book is called The Primacy of Doubt. And that is a phrase from Richard Feynman, who spent some time at Cornell, by the way. And Feynman was an advocate of always doubting yourself and actually using doubt as a way to stimulate creativity. And I wonder when you make these models as he does, Tim Palmer on the climate, there's inherent uncertainty. And in fact, he's claimed that just for our own Earth, we need to have a CERN level of advocacy and actually hardware and software and people working at the $10 billion level, say. What do you say to people that say, Lisa, we can't even model the climate, the atmosphere on Earth and the weather on Earth, you know, a week from now? What hope do you have of modeling it on something on, you know, Trappist 1 or something that's light years away, dozens of light years away?

What do you say to such critics? Well, I think, as you said, criticism is essential. It's essential in science because the problem is if not, you get led to what you want to find. And that's one of the things that we learn as a scientist. So when we, you and your field, me and my, we find something interesting. The first thing we do is we throw all our doubt on it. And we assume we made a mistake and we restart our computer. We do the analysis again and again and again because it's hard to sometimes not

interpret something the way that you wish it were. And so absolutely, the good news I have for you is it's a good and a bad news, depends on how you see it. It's basically the details that we worry about here with climate change on the Earth that can make our life a living hell, like if we cannot produce enough food and so on, they will not generate any discernible signatures in the light fingerprint of a planet. Like as long as we're not destroying everything, right, that you could see. We actually have a paper on that.

But how can you actually spot the death off the Earth? It's not out yet, but we're working on it. But what's really interesting is that when a planet is very far away, you only see currently, even with the best telescopes we have, large amount of gases in the atmosphere or like substantial amount. So if the amount of gas changes by about 10%, which is like huge, it's a whooping 10% more CO2 would be terrible for us, you and me and for all the food production, right? But in a planet's fingerprint, that just will make the spectral feature a little bit broader,

right? So in a way, we are not good enough to find these small changes yet. And what I teach my students, another thing that I think is really important to help you is to do a parameter exploration. So what I mean is I don't model one planet. I talked about this database of spectral fingerprints of planets. I model many. And the way that I do that is I always change the parameter, let's say, the distance to the star. I change it and I make it a bit cooler and a bit of cooler and I'd be cooler, and I run my modeling. And sometimes what can happen is you have a model and it does, you know, what roughly you would expect it to do, and then all of a sudden it does something else. And that tells you that the numerics in your model broke or that there's some problem

that you really need to fix. But if you only would have modeled that planet in this one, you would have never figured it out. And so a parameter exploration helps you to figure out if the physics you have in your model is solid enough for what you're trying to figure out. But even then, it's only the best we can do. And especially if you wanted me to actually envision a completely different geology, a completely different life, this is where it becomes really, really hard to make any predictions, because I don't have any data to verify it against. So we focus on our planet and it's history until now, because there we have data where we can verify how this would look to my telescope and so how I would be able to spot it.

And then we keep the eyes open for anything. So how sensitive are you to Earth? You know, in previous conversations, I think you mentioned the Earth is sort of like a rosetta stone. It has some, you know, outsized importance over some other piece of rock, you know, that we might find. Can you expand on how you use the Earth's history but also are informed by the fact that there's been many Earths.

You actually describe a multiplicity of Earths in this book. There wasn't just one past history. So if we do see a planet, which could have life in the future, there might be no sign of it today. So to what are you sensitive to systematic errors, say, biases in only having N of 1 for any life whatsoever? Absolutely. N of 1. This is why we're searching. I would like an NO2, 3, 4, 5, you know, finding other planets in the universe that also show signs of life.

But the really good thing is that our planet is 4.6 billion years old. And the way that I try to think about this is if you had a time machine, what does not work? You cannot go back in the past. I can show that. But let's assume you did have the tortoise. I would love the tortoise. Oh, my God. I so would love to be on Doctor Who being the Tartis and be like the helpful scientist, you know.

But if you were going back, I don't think you would be able to actually identify our planet. Because, you know, continents move. You wouldn't have any Himalayas anymore. You would not even have the same constellations in the sky anymore because those stars just happen to make a similar pattern in terms of brightness. But over billions of years, they move different directions in their paths in the cosmos. So if you landed on a young Earth, and let's assume you had an oxygen mask because there was no oxygen. so be careful, you wouldn't be able to tell it apart from an alien planet. And so even though we have a sample of one, and for life, that is a problem, because we have

carbon-based, water-based life, sample of one, our planet kind of can stand in for different kind of other Earth, younger versions of it, that gives us a bit of a range of how long we can spot signs of life. And then what we do is we dive into diversity of life if we know it now. And as it has been through the ages, and we just had a paper out recently that's called Purple is the new green. And there we just picked out a biota, a purple bacteria that could live in oxygenic environments, so with oxygen or unoxygenic ones. And so then the question also comes up, well, maybe the Earth was purple at one point.

How would we know? And so just expanding creatively, but with a lot of scientific input from different fields, our search gets us a little bit away from NO-1 to be able to spot other ends out there, hopefully. I want to take us on a trip through probability space, and that really came through this lovely illustration in chapter two, how to build a habitable world. And your predecessor in the namesake of the Institute

that you founded and direct, Carl Sagan, once said, to make an apple pie, First, you have to make the universe. So this incredible illustration depicts all of cosmic history, not in 24 hours, but 13.8 billion years. And it starts off with the, and this is starting off with the Big Bang. And then it spirals out. There's a cosmic dark age, the CMB. Thank you, Lisa.

Thank you. You didn't put Brian Keating as born in 171. But anyway. You know, I didn't want to pander to it, right? You know, people will know this. They don't have to hear your name. And it spirals out. got Irundi, Trappist one, Alpha Centurion. It keeps spiraling up. And eventually you get to the

first planets with first plants on land, ice age, Cambrian explosion, dinosaurs, the Himalayas form, homo sand. It keeps going, as you know, about a week ago now, as we're speaking in the end of April, there was a total solar eclipse visible from, not from San Diego, sadly, but nearby where you are. I don't know. Did you see it? Oh, absolutely. I went to Burlington, Vermont, to the University of Vermont, and they had a 20% chance to have a clear day. So they invited me as a speaker in case we couldn't see anything to actually have a little bit of an interesting entertainment. And we got so lucky. It was like clear and it was gorgeous. And a lot of people got sunburns. What is very unlikely, you know, beginning of April,

northeast. Yeah, you're more likely to have a heart attack from too much Ben and Jerry's there. But I want to, I'm a simple cosmologist, right? I build experiments. You know, I turn wrenches and screws. But if I just took every one of these steps, and I put like a one-tenth of a percent chance of them happening, you know, that there'd be a first planet plant on land to occur. There'd be the late heavy bombardment, which reminds me to remind people out there that Lisa has their own asteroid named after her, Kaltanager. What is it? 77.34. Yeah. Yeah.

And that is actually a giant chunk of this, which is a meteorite, which is a version of Lisa's asteroid. I don't have an asteroid, so I'm jealous. But this can be yours if you have a dot edu email address. If you go to Briankeating.com slash edu, I will send one to you. And if not, try it, try your luck. But Lisa, if I, by my simple calculations, if there wasn't at least three different types of bombardments, the initial bombardment of Thea, which created the, moon from the earth by something that was like Mars, then we wouldn't have the moon. Many scientists believe the moon is critical for plant life and single cellular organisms to have evolved. Then,

later on, if we weren't bombarded and had the dinosaurs, or sorry, even before that, if we didn't have cometary bombardment, right, we wouldn't have had the oceans on Earth. Correct me if I'm making any, you know, freshman mistakes, because I'm going to be your student. I'm more than happy to talk about it, but just keep going to the third one. Yeah. And then the third to the third. one being the extinction level event that took out the dinosaurs so that little rats and varmints like those people at Dartmouth, you know, I went to Brown, and you're at Cornell, so we can make fun of Dartmouth or Harvard. Let's say Harvard. Ooh, oh, I work with people. I know, I know. And Harvard, you know, you make fun of whoever you want.

And then last and not least, you know, if that didn't happen, we wouldn't, so if any one of those events didn't happen, we wouldn't be here having this conversation about life. So my, my always, My supposition is there has to be some way to explain that because or to take into account that. Because if those are contingent features on which the existence of this call represents, then it seems to be very unlikely that there's even single cellular life, let alone, you know, multicellular and complex technological life like the woman named Cornell, formerly Cornell, now Tartar, Jill Tarter, who was at Cornell, said, you know, it's an awful big waste of space.

So tell me, please, Lisa, where? am I wrong, if not in my supposition, that life is extremely rare. And Earth is extremely rare. So what's really compelling about this, and this is, I think, why it is sticking so well, is this idea that sometimes we equate life with our evolutionary stage in us. So I'm not saying that I think it's likely that another Lisa, another Brian, somewhere else will have a conversation and similar to us. So that way, we are unique. I give you the uniqueness of the human species. I'm pretty sure that's going to happen because, you know, an impact that kills whatever other space dinosaurs there might be might or might not be happening. But I think it's very misunderstood.

And this is very, very normal because astronomers have been doing most of this. When you talk to biologists, they see life much more like, you know, we usually see this beautiful tree of And that was a great way to actually make people understand that life evolves, right? And so it stuck. But it is actually a pretty bad analogy because the way that if you talk to biologists is that life is much more like weeds. And depending on the conditions, then one of these life forms will succeed. And the conditions are just perfect for one wheat or one seedling for a tree. And that one becomes the dominant one, maybe eats everything else or out competes everything else.

like Darwinian evolution. But let's uncouple this, right? So now we have the stage where we had the last bombardment. So the bombardment and killed the dinosaurs. So if that's not happened, there will be other life that forms from after the dinosaurs. And there's a really interesting discussion going on that the oxygen level in a planet is actually not set. You can't have more than 35 percent because then fires will never go out, but anywhere in between. And there's an argument that maybe the dinosaurs were on the way out already because the oxygen started to drop in the atmosphere. So do we need an impact? I can tell you because we have a sample of one, so I'm glad that we're here. But let's go further back. Once you look at life, on the earth, 75% of life

doesn't need light. So what that means is that if you don't have stable surface conditions, life's going to be okay because if it, for example, forms on the bottom of the ocean or a subsurface, it doesn't care for stable conditions. What that means, you don't need a moon. And then if life actually gets to the surface of the planet without stable conditions, and there, of course, winter is coming would be the phrase you want to add here, then life should evolve for that. Life would actually have different capabilities than you and me.

And the life we see around us because it didn't have to evolve for a kind of different conditions. It's specialized perfectly for its niche that happens to be our planet. And when you go to other kind of niches like hot sulfur springs, life will have developed for that. If you take it out and put it on the normal surface, it's not going to be happy. If you put me into a hot sulfur spring, I'm not going to be happy. So life's incredibly good to adapting. So now we had the second, so we had the dinosaur bombardment, right? Maybe not you and me, but life's going to be fine. And now we go to the moon that the impact that formed the moon. So if you don't need stable conditions on the surface, then you can live without a moon and without the impact of generating the moon. And now we go to the

first one that is highly debated, very interesting, about where did the earth's water come from. And so the idea is that that was brought to the earth by impact. But with more and more understanding in each of these fields is developing so fast, that's why I formed the Kalsaken Institute, because I cannot keep up with the literature, right? Because coming from university, I would have completely gone with your argument, right? Like, it's very unique, life cannot. It's very compelling in an argument. But so if you go to the really, really interesting side of geology,

this is now this discussion whether or not there actually more than 10 oceans worth of water locked in the rock of the earth in the first place, meaning that you don't need the bombardment per se, that you could actually have it locked in the rocks that form the rocky planets initially. And this is why it's really exciting because even so sometimes it's very frustrating, but you know, you have to throw out what you learned in university, most of it, or at least use it as a stepping stone, and then go talk to someone else. And I find it fascinating that we can do that, that we can decompose it. And when we think about life as

weeds, the probability seems to be, you know, the numbers seem to be ever in our favor. but one of the things we don't know is what condition do you need for life to get started. We know it adapts, but we don't know if it can get started under different conditions.

And so that's the thing that we're trying to work on in the lab, and that's where this search becomes so important to try to figure out where we find it. A lot of times it's so fun and it's perfectly fine. I do the same,

that they are in-baked ideas on the base, you know, where you're like, oh, it has to be like us, It's like, no, it really doesn't. It could be like a yellow space dinosaurs. Who is talking in a podcast and saying, oh, I don't know what these earthlings are saying right now. I wish they'd stop talking about us.

There's a concept mentioned in the book called panspermia, which I always say sounds dirty, but it's not. I think it was either coined or popularized by Fred Hoyle, who also coined the term Big Bang as a term of disparagement for the origin of the universe, which you also talk about in the book. talk about the following challenge that I'm going to present to you. The fact that we don't observe life on Mars, can that not be said to limit the biologist's claim that you said that life is like a weed? In other words, the fact that Mars rocks have landed on the Earth, as you talk about in the book, and I actually have a tiny sliver. I actually gave a tiny sliver to Joe Rogan, if you can believe it, and I think he smoked it.

I'm not sure what he did, but I'm not sure. Joe, tell me what you did with that Mars record. But tell me, the fact that we don't observe life, there's no historical record. Now, yes, we haven't checked all of Mars and so forth. So there's some caveats. But am I wrong? Couldn't the non-observance of life right now limit how actually efficient panspermia is to spread life once it arises, not solving the origin of life? But can we not say that life in the universe might not be as abundant as those biologists think?

because we don't see any on Mars, and you would expect that a binary planet system that is exchanged material for four billion years should have some contact biologically. So where am I wrong there? It's a great, great question. And it has been active debate and research for the last couple of years. And what they came down to is that you actually, life's really good to adapt, but you have to give it its environment where it strives to give it a chance to adapt. So you don't just have to bring life to another planet. You actually have to bring enough of its environment to another planet for it to be able to evolve and adapt to the new conditions.

So currently, if you had, like let's say an asteroid, right, that brings the material to Mars and then hits Mars, you immediately have no water and you have no atmosphere, right? And so that is a huge change from the conditions you have on the Earth. And so even from the conditions you had on the early Earth, so I'm not so worried about that not having a panseparmia tells us something about the prevalence of life. I'm more wondering about the different moons in our solar system where we have hopes that the liquid water under the icy surface of Eurobor

Enceladus or the cool moon of Titan could harbor a second genesis. If we found life somewhere else, Let's say in the depth of Mars, right, this is why all the new missions now have something to dig and trying to look at the material, or under the ice layers in Europa on Enceladus or on Titan with the new dragonfly mission that we're sending. If we'd have life twice in our solar system, and it looked different. It's a key point. And it looked different. So it wasn't panspermia.

It's actually life that arose again. Then it must be everywhere in the universe if we get two. if we don't get two, that doesn't mean it's not everywhere in the universe. But I do think pansepermia has this added problem now that you not just have to bring the life, but also enough of its environment to get it to the point where it can evolve for new environments. And the way that I usually says in class, if I take my basil plant that's not as healthy even on in ethica. Yeah, I know.

We're talking winter. Yes, I know. But it's just like, if I would take it and I would pop it. on Mars, it would not have a chance, you know, evolution or not. And so even single-necellular organisms are incredibly complex. We think of it being basic, but they're really not. They're doing a lot of amazing things and like blopping them in a completely different environment without the nutrients they need and without the chemical gradient that they're accustomed to is going to be a shock. And so most of them will make that.

You have many different wonderful turns of phrase in the book, but, you know, one of them is about proof of life and what would constitute proof of life. Again, we're not talking about, you know, brilliant, you know, Ivy League professors like you and discovering them, but just finding life. And you focus primarily on oxygen and methane. And I think a good question for you to tackle might be the fact that there was life that produced that oxygen. So if you looked at an early earth, at least again, I'm sorry to be so geocentric as, you know, Copernic. has warned us against doing. But nevertheless, Lisa, we only have anabone right now. But tell me, if you had looked at that planet, would you have concluded that, no, there's no life there,

even though it would eventually turn into the Earth as we know it, teeming with you and me. And it was actually anaerobic bacteria that were doing their job to make the oxygen that we know and appreciate and love. Absolutely. So we are incredibly conservative in our search. And we incredibly conservative because extraordinary claims require extraordinary evidence, right? Sitting in Carl's Ossagan's office right now, I have to do this.

Thank you for bringing color. Would you actually like to own a piece of the early cosmos? This is a meteorite, a 4 billion-year-old fragment of the early solar system, and it can be yours if you're the lucky winner in this month's drawing of my subscribers to my Monday Magic mailing list, where I send out something amusing over an appearance, that I've been on or been featured in recently, something genius, something imaginative and inspirational, an image that astounds and delights, and a conversation, just like this one that I share with all the listeners. So join over 10,500 subscribers to my Monday Magic mailing list, and you might win

one of these meteorites. Go to briankeem.com slash list. And if you're a student and you have a .edu email address in the U.S., you'll automatically win a meteorite. The interesting thing is that if you say that you found life, you want to be sure that you have no other explanation than for life. And when we go back to the 24 hour clock of the earth, right, we said at 5 a.m. life starts, but only at lunchtime, two billion years ago, actually builds up oxygen with methane. And even there, there wasn't so much oxygen starting up. So it's harder and harder to spot the further you go back in time. But before it produced mostly CO2 and methane, and I can get that out of volcanoes. So I won't be able to tell and just go back, you know, to the idea of methane on Mars, it's life, is it not life?

If I have an explanation that doesn't require life, then I can't consider it as an extraordinary evidence. And so we are incredibly conservative in our search. I completely agree with you. There's going to be a lot of life we will miss. But there we have the statistics in our favor because we figured out that one out of five stars, that's what the Kepler mission did for us, by looking at 150,000 stars and trying to get the frequency of how many planet per star. One out of five stars has a planet that's small enough to be a rock, so below two Earth's radio, and at the right distance and not too hot, too close to the star,

or not too cold in the habitable zone. And then, of course, we know that there are 200 billion stars roughly in our galaxy alone, and then billions of galaxies. So we kind of have, sitting in Kallasek's office, so having to say there are billions of billions of possibilities, even in our Milky Way alone. And so even though we're going to miss a lot of life, remember, at least half of this 24 hour clock, we have no signs that are unique. So if you have enough options, hopefully you will still spot some. You talk about the catalog of our solar systems and not only the major planets, but their moons.

And I thought it was kind of delightful. Recently, I read a quote that Johannes Kepler speculated that Jupiter had so many moons for at the time because it was lonely. I think I might have heard that from your co-author, Marcelo Gleiser, whose episode I recorded a while before this, but yours is going to come out first because, anyway, you're a two-time guest-get priority on the Into the Impossible Focus.

Thank you. But talk about the role of moons and where life might be hiding close to home and these beautiful, stunning images from Webb of Titan and the moons in our solar system, might they have life? Absolutely. And so the really fascinating thing is, like I said one out of five and billions of possibilities, right? but I'm not even counting any rocky moons around gas giants that could, in addition,

and here we're going to Avatar and Pandora, right, science fiction is actually showing us, helping us, imagine this, provide other boats or abodes of life. So I'm not even talking about that because actually characterizing a moon is even so much harder than a planet around another star. But when you can get to it, and now this gets us to our solar system, it becomes much more interesting because even though there is no biosphere that changes the whole moon in our solar system and when you do this search around other stars that are so far away, the biosphere needs to change either the surface or the gas, the air on that planet for me to spot it in the light that I collect. We talked about this before.

But in our solar system, even for this really, really interesting places, it doesn't, right? So we have an ice layer around Europa and Enceladus in a subsurface ocean where we hope there could be life. And so we're sending missions to investigate that. But because we're sending it, and currently we can't, but we will in the future, we could land and actually drill a hole in the ice, or fly through the plumes of these gaseers on the surface of these icy moons to analyze specifically if they're like broken pieces of DNA or a cell structure or something, that we can only explain with life. And of course, what's really cool is we're sending a quadcopter to Titan, where it's basically going to land, get a sample, analyze it,

go somewhere else, lane, get a sample, analyze it. And if I would love the search for life in space, I would love to be like the person who flies the quadcopter on Titan. You're like, oh, you know, just flying the quadcopter on Titan. I just think that would be such a cool job description. I'm good to put on my pilot's license. Here you go. You are actually closed.

You should try to figure out and see if you're going. do that. So let's talk about the paper that you wrote with Marcello and I think it's his student, Sarah, Vanna. Yeah. So what is information theory and in what sense can it help to identify signs of life on planets as they transit like make it like giant annualer eclipses around their host stars? What way can information theory, after you define it, can it aid the search for a extraterrestrial life. So the way I see it is the artificial intelligence, machine learning, you know, allows us to actually scout through data or to analyze data much more effectively. And so we have been starting to explore different algorithms in machine learning that could,

if you give it a spectrum, so the reflected light from upon it, take it apart into, ooh, there's some green plants or there's some sand, there's some oceans, there's some clouds, right? And even so I can do it with my eyes or I have the hardest time trying to figure it out with a normal algorithm, machine learning, you can train fast. And it doesn't matter if you give it like a hundred different surfaces. It will just check what makes the most sense, right? Which combination would actually, if you train it. And now we have the computer power.

So we generated like 300,000 different kind of planet models and let it train on it to see how good, the algorithms would be to retrieve different surfaces. And now add to this what we do in language. Because, you know, we have machine learning algorithms that have like a specific task and their specific algorithms that everybody uses in the different fields. But we have also language. It's pretty complex. And so this kind of using the tools that already exist for different fields and now feeding it into the analysis of this data was where Sarah led this amazing paper with Machello, where she basically took the models that I made for the Earth through time and said, so could I use these algorithms or these methods that have been developed for something

completely different to actually spot biosignatures? And maybe they are even more helpful because they were developed for something very different, but the way that they approach information is not unique, but it's very, very effective, trying to get all the information pieces together to get a result. So if you apply that to spectra, you get actually quite amazing results.

And some of the things that we learned, what was very interesting because nobody knew before, is, of course, the star makes a big difference, right, in how these spectra look like. Makes sense, red light coming in or yellow light coming in, getting reflected is different. And so Sarah Explore. that and we basically figured out what kind of template you'd need to use to guide the search.

And that was the first step. And now we are happily discussing other language models and other models that we could use. And kind of, it's not misappropriate that we can appropriate for this search even so they were never, ever done for it. But they have tools that we haven't. So here at Public University in California, there are spectrometers. So we might find one of these beautiful purple planets like you talked about before. So I have a few more questions. If you'll beg my pardon my indulgence and my request of you, that's just too much fun to keep talking about it.

I wonder if we could sort of start to wind up by talking about the philosophical, the societal implications of discovering extraterrestrial life. First of all, there are claims right now by government agencies, by scientists that not only have we detected life, but they're visiting Earth and they have technology. What do you make of these things, these claims by people like David Grush that we've discovered non-human biologics? How do you react to those claims that have been made recently? I so wish they were true because they would make the search so much easier if somebody was coming or we had non-Earth-like biota. Great because it's really hard to envision it and also to get the data to figure out that this is the right way to go with non-Earth-like biota.

biology. But the problem is that that data is always kind of out of context and a lot of it is like bad data that you cannot verify. And a lot of it is just not, it doesn't hold up under scrutiny. This is where we were talking about before, right? You have to throw all the criticism at and unfortunately none of it holds up. And there's there's now agreements like in NASA looking at this and trying to figure out what it is. But there's a lot of stuff we also, some of it is easily dismissed, but some of the other things, like for example, weird weather phenomenon that makes something look like there's a reflection that's not there, right? All of this is really, really time-consuming to get to and to explain otherwise, and most scientists have other things

to do, you know, that they really want to do something else and not debunk this. And so this is why there was a lot of vacuum, I would say, and that allowed some voices to grow very loud that wish that it was true, right? I wish it was true too, but unfortunately I'm trained in scientific methodology, so unfortunately, no, not yet. I can't say, I cannot just claim it. You know, I wish I could, but no. So we haven't found life outside of our solo system yet. And what's kind of interesting here, and I think that might be where you're going with us, what's kind of really interesting thing here is if we have billions of possibilities, right, of planets that could be like ours, then it's,

falls back to this question, is this eerie silence scary? Why has nobody talked to us? Why has nobody come? Is everybody dead? Or did they never start? Right? And this is where your question come in and this is why it sounds so logical that it must be hard to get life evolved to a certain stage, right? Because if this impact didn't happen or that impact didn't happen, it would be very different here and our. But when you look at this question and that's what I did in the book. It's a very private interpretation of it. But I'm like, if there were lots of interesting worlds out there, right? And I tend to ask my students, I'm like, one of the classes I always ask us like,

okay, so we have two planets hypothetical that show signs of life. One is 5,000 years older. One is 5,000 years younger than us. Which one do you want me to go to? And reliably, it's the more advanced one, except if they've seen the three body problem. That actually made a really statistical change in my or read the three-body problem. It was really interesting because some people now got scared. But for those people, don't worry, the distances I've asked.

And it would be very stupid for an advanced civilization to land on an inhabited planet, no matter what Star Wars or Star Trek do. Because just think about vaccines. Think about the war of the worlds, right? What's going to get you is the viruses that you know nothing about if you're also carbon-based. So you'd rather go to a planet that has no life. I don't worry so much about that scenario. But reliably, they take the more advanced one.

And then if you turn it around, why would you call us? You know, we are just starting to get to the exploration at this edge of looking out in trying to find life in the universe. We have boots on the moons, but we didn't have boots on. We don't have boots on Mars yet, right? We have rovers, but end in helicopter. But we don't have boots on Mars yet. So why would you want to call us? And so this whole concept of whether we alone, to me, it's a gorgeous connection for us with the cosmos,

because the Earth is not a globe that's like beautifully protected under some kind of, I don't know, glass thing. But we are part of the cosmos through and through. That means we should understand our environment. And one of the parts is we should understand how our planet works in the best way we can do this is by finding many plants like it to figure out how an earth really works. You said this place was steps from the water. We just haven't found the steps yet. How much did we save?

Enough. Enough to get lost. Or you could book a stay with Hilton. Welcome to your ocean front room. Just steps from the water. The Hilton sale is on now. Book on Hilton.com or the Hilton app and save up to 20% to get the stay you expected. When you want savings, not surprises.

It matters where you stay. Hilton, for this day. Oh, Lisa, this has been tremendously enjoyable for me, as I knew it would be. Dr. Professor Lisa Kaltanager is an award-winning astrophysicist and astrobiologist and the founding director of the Carl Sagan Institute at Cornell. She's a pioneer in world expert in modeling habitable worlds. They're light fingerprints and has spent the last decade trying to spot new ways of finding life in the cosmos. NASA and Issa and many other of her collaborators and teammates.

I can't resist asking you because one thing that always resonates when I think about you is that you're an educator, not just of the public but also of your students. How has education change? How is being a professor changed since you started a little while ago? How is it changing? What do you see is the future of our profession? You know, it's a thousand years old. I call it the second oldest profession after you know what.

But how has it changed, you know, and what, yeah, sure. But how is it changed? And what do you make of the prospects for us? Are we still going to have, you know, cushy jobs? And, you know, will tenure still be relevant in 2100, you know, for our future and your granddaughters and our professors, Lisa? What do you think of the future of academia as a professor? To me, my personal philosophy about teaching is to teach.

students the way I see the world. And what that means is everything I've read, every experiment I run, everything I've done informs how I see the world. And so this is how I think as an educator, and this is what I was trying to pack into the book. This is how I can teach effectively, because you don't have to read all the papers I read. You don't have to do all the experiments I did, but I'll show you how all of that combined to how I see the world now. And if you approach teaching like that, then there is no other thing that gives you that, but a person who actually has this experience and wants to share it. I am actually really excited about the artificial intelligence tools that we're developing right now,

because, as I said before, there is too much information. What's a good thing? There, sometimes people say like, oh, the good old times. Renaissance scientists where one person knew everything. It was like, yeah, because there wasn't so much to know, right? I'm not dissing any of the amazing scientists from that time. It's just, it is just not possible right now to do it anymore. And it's even hard to do it for your field, let alone many different fields. Again, this is why I've built the Calzagan Institute. But I want to use this artificial intelligence to help my students curate that information, but intelligently. Because there's so much information and some of it is really bad. And you, and you You need to be able to tell the difference. That's going to be the next. I think we're going to have to put much, much more emphasis as teachers onto how to vet information, how to figure out if this is reliable or not,

and how to ask smart question of where it comes from, you know, try to find a secondary source, things like that. And in that sense, I think teachers and mentors, whatever you want to call us, you know, we're professors and teachers. But in a way, we are mentors to, to, that you figure out how to understand the world around you. And I hope when I teach, I don't just teach my students about the cosmos and their place in it. I teach my students of how to best access the information around them and use them, like, you know, the best way they can, but also

responsibly. And so in that sense, I see things like AI that a lot of times was like, oh, it's going to replace teaching. It is all that information, but it needs to get curated. And And I love it because, you know, I tell my students use this, right? And I explain something. But, you know, maybe my student doesn't want to raise their hand and say, ah, I really didn't understand the third time you explained it. It can go to AI or let's say chat chit or something else. It's like, explain it like an eight year old,

explain this concept for a 13 year old, explain this concept for an 18 years old. And so they can actually go up themselves. And I take this prerogative for myself too. if there's something I don't understand in another field. It's like, I'm the director of the Carl Sagan Institute. It's an elementary school. Oh, my God. And then it's going to say like, A, B, C.

Well, it's such a delight. Your writing style is just like your conversational style. It's delightful. It's informative. It's educational. And it's inspiring. And I know my audience is going to love this book as they, as much as I did, I listened to it.

I read it in digital and paper form. I want to thank you so much, Lisa, for your gift of this wonderful new book. Thank you so much. Thanks for the kind words. When you write a book, the one thing that's so amazing is when people actually take something from it and then you hear that you did it and they enjoyed it. So thank you so much for saying that. Absolutely.

Thank you so much, Lisa. Ambition comes in all shapes and sizes. At First Citizens Bank, we roll with your goals because we're built for what you're building. Fit for your ambition for Citizens Bank.