Astrobiologist "We’ve Been Searching for Aliens the Wrong Way!" SETI's Nathalie Cabrol

What if alien life is everywhere, but we've been looking for it in all the wrong places? We assume life needs water, carbon, a warm little pond as Darwin said. But what if life doesn't care about what we assume to be necessary? There's a scientist who spent her career exploring the strangest, harshest, most brutal places on Earth. High altitude lakes in Chile that freeze solid at night and boil by day, toxic salt flats that look just like you'd expect an alien landscape to look, an environment where life should be impossible. And yet, as you know, we're not afraid to go into the impossible. Her name is doctor Natalie Cabral. She's the director of the Carl Sagan Center at the SETI Institute right here in Northern California. And what she writes about life in the universe shattered everything I thought I knew about it.

How can we communicate with the alien species? This is not a trivial thing.

We're going to talk a lot about alien life and why Earth might be a cosmic accident. We'll explore whether civilizations out there may stay silent on purpose and what it would take for humanity to survive its own future based on what we know about the deep secrets of the universe. But first, we have to ask perhaps the hardest question in all of science. Natalie, thank you so much for joining us.

Well, thank you very much for having me.

I wanna take this conversation in a very different place than I usually go because everybody thinks they know what alien life would look like. But your work really made me rethink our assumptions and then the assumption that we know what we're doing. I came out of it questioning whether or not we might be completely lost. And I wanna ask you today about the biggest blind spots in the search for extraterrestrial intelligence. How we might be missing alien life that's already here on Earth and whether humanity itself is ready for first contact. And we'll get there. We'll get there soon. But first, I wanna start with the most important, most uncomfortable question in all of science.

Are you ready, Natalie?

I'm all ready to go.

What is life?

We don't know. We don't know. That's the beauty of the whole thing, you know. And then you have to wonder how can you write 300 pages about something you don't know. Well, that's the whole thing. And I think that a lot of, you know, what you said about, you know, rethinking life and how we search for it, this is exactly it. I think we're coming at a time where we realize what we don't know, but we have a bunch of, you know, data that has been coming from forty years of planetary exploration right now. Maybe the most important thing is for us to rethink how we address those questions, how we ask them.

And you will see, as the discussion goes, that really, it's sometimes maybe only about rearticulating those questions.

Eventually, I wanna get to what we might make of biosignatures that we're missing and how we might actually detect life beyond our imagination or at least the limits of our imagination. But first, I wanna ask you, in your, you know, vast expertise, what do you think is the most dangerous assumption that members of your community are making in the field of astrobiology? Which assumption has the most biases whether intended to be prejudicial or not? What is the most dangerous aspect of the assumptions that are being made in your field?

I don't think we can say that any of them are dangerous. Not in the sense that, you know, the only dangerous danger is the intellectual danger where you are sort of bottlenecking yourself. In fact, when we are honest with ourselves, we follow hypotheses and we, you know, we develop experiments and we get more data and then that forces us to rethink. So I don't think there is a danger. There is the bias is just that we are learning. And, you know, the better our instruments are becoming, the more different the reality of the universe and how the universe looks for us, you know, change. And this is what gives us the possibility of changing our perspective. It's not really a bias.

It's just the way science work. That's the difference between science and science fiction. In science fiction, you have the answer to your question, you know, in 200 pages or two hours of a movie. Science takes time. We have asked the question about are we alone for as long as we have looked, you know, at the stars as a civilization. But today, we are starting to have the amount of data and the perspective to bring the technology, you know, to to this question, and this is becoming different. I wouldn't use the word danger or bias. Sometimes we can be a little biased, but it is a normal bias in the sense that we are going to look for life as we know it because this is the only model that we know.

This is where the bias is. But in the back of our mind, we know, you know, already that there is a possibility that there is more than just that. We are doing with what we have right now. That doesn't mean that this is the only thing that we are contemplating.

You've explored some of the most extreme environments on Earth. In fact, you recently got back from there and caught some alien bug or something like that.

Yeah. In the middle of the desert, beat me.

I was so grateful that you're spending time with us. And in these alien environments, even though they're right here on Earth, it, to me, brings up what I call kind of two path framework. Either life adapts easily everywhere and the universe should be teaming with neighbors for us because we see life in these very places that you go and visit. Obviously, you wouldn't go there just to study some dead desolate, non existent, you know, bioterrorist enclave. Or number two, Earth is an accident, an impossible cosmic fluke, and we might be utterly alone. And later, I'm gonna ask you which path you think we're on. But first, I wanna ask you, you know, has being face to face with these extreme Earth environments made you feel more hopeful about life out there or more terrified for us here down on Earth?

You know, there is no reason to be terrified by anything. I mean, yeah, maybe bugs sometimes, you know, But it's all part of evolution, co evolution, and adaptation there too, I guess. No, it makes me really hopeful. Because what you see, in fact, the simplest life form that we are finding in the Atacama Desert, because this is where I was, is really the story of species, micro organic species, that have been able to survive all the different epochs of Earth. Yeah. And we know that they had many. We had times where the Earth was completely covered in ice when it was mostly, you know, an ocean world with very little continents. And then it was very hot, much hotter than it is today.

And still, you find those bacteria that we're finding in the Atacama, they are very close to their ancestors who came about, you know, a little over three billion years ago. But what you see when you're studying them, in fact, is a time machine because embedded in their metabolism, you see all the switches on and off about that condition and that condition. For instance, when they appeared on Earth, there was no ozone layer on our planet. So the Earth's surface was just, like Mars today, bombarded by short UV, cosmic rays, etcetera. It was not a very pleasant place to be. And so they started developing these adaptation mechanism, this coping mechanism. So that was for the UV, for the extreme UV. And then there was the cold, and then there was the salt because when it's getting too hot on our planet, water evaporates.

Right? And the world becomes salty. And when you look at them, you see in them the Swiss army knife for the adaptation to all of these past times. These bacteria that we have today, they still have embedded in them the ability to fight against all of these different circumstances. And what is wonderful in the Atacama is this transect along the Atacama, the Altiplano, and the Indies where you are going up high in altitude. Then the same bacteria in the Atacama have the switch on to fight against salt and UV radiation. The salt thing is much less active. The UV one is still there.

Right.

And in the Andes, forget about, you know, the defense against salt. They don't need it. But the switch against UV is on, and not only during the day, but at night too. So you see in front of you what life can do on the planet.

I've had on many of your colleagues, you know, ranging from Lisa Kaltenegger to Sarah Walker and others, and Paul Davies in particular, made great contributions to looking for ways that we might be overlooking based on our, you know, geoanthropomorphic bias and so forth. We'll talk about biosignatures and shadow biospheres later on. But many people seem to be asking, you know, is there water? You know, is there carbon? Are those the essential things? And you've argued that true alien life might leave signals that have nothing to do with biology as we know it. And, you know, Sarah's book, Life But Not As We Know It, will dovetail into this. But, you know, later I wanna ask you about something even more shocking that alien life might be here, the shadow biosphere idea. But for people that have never heard an idea about this, what is an agnostic biosignature type of signature that you talk about? What is the weirdest thing that we might someday have to call alive even if it's not life as we know it?

Well, actually, everything that you say, all the people, you missed a few. Yeah. But all the people that you talked about have something in common and something that I think is really the new avenue we should be investigating for the search for life. As I said earlier on, it makes a lot of sense to be looking for carbon based life and the type of life that we would recognize and water as a solvent for life just because that's the most abundant stuff that you can find in the universe. You know? It's not by accident that we are made of these bricks of life. And we also know, thanks to Kepler and TESS and James Webb and so many other ground space telescopes now, that there are many worlds out there only, you know, in our Milky Way alone that are not identical to the Earth. It's impossible. Even within the universe, you cannot have two exact Earth.

But you have environment where we know life as we know it, which doesn't mean necessarily us, but carbon based life, needing energy, nutrients, shelters, etcetera, and water as a solvent, could still already survive in the universe. It's not stupid to think, but that's more going into the origins of life avenue, the one that we have been pursuing for the past, few decades now. And this is where Sarah, Jeremy, and Paul Davis, Lisa, and myself, and others come along, Chris Campis, and say, that's fine. But as we do this, as we are looking for life as we know it, we are bottlenecking ourselves and leading our view on what life can be. What I like about agnostic biosignatures, it's not in fact that it means that it's alien. No. Not at all. Doesn't mean that it's alien.

It means that it is a universal biosignature, which means that it's not connected to any biochemistries, something that life, as a process, will do no matter where it is and no matter what it is made of. I think that Jeremy England summarized this very clearly. Jeremy said, and he's pushed the envelope, today, we don't know if he's right or wrong, but the way he thinks is suddenly something that we need to pursue, which is to push back against, you know, a little bit of all the hypothesis that we have been reading in the past few decades. Jeremy says, life is the inevitable result of thermodynamics. Boom. Because it's the best way to beat entropy. And then you know? And he has the modeling. His idea is not new.

His idea comes from Schrodinger in 1942, biophysics. And why this is important? Because it doesn't look at life as a thing, which is the major issue that we're running into right now. If we're making life a thing, then there is the living and the nonliving. And we all agree, or pretty much all of us agree now, that there is a transition between prebiotic chemistry and biology. But if it's a transition, where do you put the demarcation?

Right.

And it may not make any sense. So what Jeremy and others and Sarah and etcetera, they are pointing to a place where you we don't need to worry about that. If we think of life as a process, a universal process, what are the agnostic, which means we don't care about the biochemistry. What are the agnostic signature that would allow me to recognize life in the universe anywhere and regardless of biochemistry? I think this is really, you know, what is opening the field that's opening wide open right now. And I'm really looking forward to the next few years because it's going to be fantastic.

Well, Natalie, we have a tradition on this show, which is to do the unconventional, to do the impossible, which is to judge a book by its cover. This book is no different. I can read the back cover, the many encomia that you have, including one from Ann Druyan. And I wanna, towards the end of the conversation, bring up perhaps a a subject that you haven't been asked about that was brought to my attention by Ann Drury and she was a guest on the podcast many years ago. But I want you first to take us through the cover. So the title, the subtitle, and the beautiful and majestic cover artwork. Would you do that for us, please?

Yeah. So The Secret Life of the Universe. In fact, you know, this book is translated from the French. And in in French, I chose something very different. The original title is Dawn of New Horizons. And the reason I chose that title was a play of words using the name of two planetary missions, the Dawn mission and the New Horizon missions. Oh. And those were two two dwarf planets.

And, also, the two mission in 2015 that actually blew our mind away and reset our thinking in astrobiology. Because when Dawn got to series, all of a sudden, it start to lit up like it had lights on. Remember? All the dissolved deposits and things like that? Right. Because that alien had the light on when we came there. So all of a sudden, we we discovered that this tiny thing, which is we still don't know. Is it an asteroid still or is it a dwarf planet? You know? There's still this discussion going on, but might still have a residual ocean. So we don't know if life had any chance there, but certainly Ceres has the potential for habitability. That was March of twenty fifteen.

That's what happened in July of twenty fifteen. You know, this supposedly dull, icy world so far away of the sun that there is nothing interesting in. All of a sudden, we discover Pluto

Yep.

And boom, there too. You know? Take that astrobiology. And then not only we have a primordial ocean, but we also have convective systems that are creating those prism in the at the surface. We have ice volcanism, and we have rain down of organic material. So to me, 2015 was really a time that taught us that, well, you know, there is maybe a lot more than middle of the eyes when it comes to astrobiology. So that was my choice as a title for the French book. But I think that the American publishing company was a little concerned with the play word and maybe not, you know, people not necessarily on Right. And then we came up with this one.

We had a list of them. I don't remember the others. And that's actually the editor that, you know, locked on this one. So the simple stuff of the universe, I kind of like it Yeah. Because it says a lot about astrobiology. All the things we don't know yet and, you know, everything that's happening already that we are really absolutely dreaming of discovering. So to me, that's the discovery. That's the mystery.

This is what the title is about.

So what I love about it is that you are kind of a Schrodinger's cat superposition of astronomer and biologist. You're a real true astrobiologist, and you're almost a field astrobiologist. Not that you go to other planets, although I suspect that you might be tempted into doing that someday. And later, I wanna ask you what these different, you know, discoveries that you've researched for your career, you know, mean in in terms of, you know, whether or not we're we are looking in the right place. But first, I wanna ask you, you know, what evidence would convince you that a so called shadow biosphere exist right here on our planet? So on page 45 of the wonderful book, you talk about, you know, a shadow biosphere could be here if it's ambidextrous or a mirror image of ours. More important, how do we test the shadow biosphere hypothesis? Whether it exists or not, the pursuit of a shadow life on our planet will bring intellectual and technological advances that may put us on track to discover life beyond Earth because it teaches us what it takes to recognize life as we don't know it. What is shadow biosphere?

There you nailed the scientific process. Nobody's nobody claims today that the shadow biosphere exists.

Right.

People who came up with this theory or hypothesis, if you prefer, Carol Leland and even Paul Davis, they talked about that. It's a thought experiment. Let's go back on our planet at the time of life is emerging. It probably was a difficult process because, as you know, our neighborhood was not really friendly at the time. We were taking kilometer, you know, mountain size asteroids and comets. They were literally raining down, which means that, yeah, these worlds were impacting ours. Everything that was built at some point was just destroyed the next day. We kind of agree that life the life as we know it, here on Earth, probably had a few start before it could anchor itself, and it probably also didn't happen in one place.

There is an emerging theory today which I like is just because it goes very well with this idea of life being a process and another thing, which would say that life started to emerge on Earth pretty much everywhere in all the places where it could, where, you know, this was feasible. So but that's assumed that the case. We know today that the life we know goes back to the one common ancestor that we call Luca.

Common ancestor. Right? Last human ancestor.

Common ancestor and goes back to the one ancestor there. We know the tree of life goes back there. Though the idea of the shadow biosphere is that at the time where the lookout tree of life was being put into place, then there might have been other trees of life emerging as well. They were probably based on the same thing because this is the same planet, you know, carbon, hydrogen, oxygen, and nitrogen, etcetera. But it would take only for this life to have a different number of amino acids, for the geometry of their molecules to be different for us not to be able to recognize them in our test because our tests are all tuned toward the type of life we know. It's not extraterrestrial life. It's not alien life. It's terrestrial life, but with a potential for us not to be able to know that it's here.

So, obviously, it didn't lead to super civilization, to to high technology, etcetera, but there might be microorganism, bacteria, who knows, we just don't acknowledge as being life or we don't even see or we don't recognize as being life just because of that. I would guess that viruses are some good candidates to that. I think that there was a a paper last week that says that there is they discovered something. It needs to be, obviously verified, but they find some something that looks like life but doesn't map against the tree of life that we know. So I don't know if the shadow biosphere is true or false. It doesn't matter. What matters is the intellectual process it forces us into to think about how do we search for life we don't know.

And so you brought up some of my favorite topics here, including asteroids raining down. I just wanna point out that I do give away these possible incubators or delivery seed packages called meteorites that may have delivered life here through what's called panspermia, which you talk about in the book. I give them away to people randomly who join up on my mailing list at brian keating dot com slash list. You can join up there, and I'll be writing about this episode and all the wonderful learnings from it and have some cool AI secret research that I'll get from the transcript that I will provide to my listeners. So make sure you sign up for that. And I wanna pivot now to the SETI Institute and what you do there in the search for extraterrestrial intelligence. You are the Sagan director, and I, of course, have my Carl Sagan finger puppet, you know. Our CEO was one

of those two.

Yes. Exactly. So I gave one to Alisa, and I'll give one to you when we meet in person finally. Now SETI has captured the public imagination for decades for a variety of reasons, both the subject matter and some of the technology. SETI at home was one of the first, if not the first, real citizen science, massive computing clusters, you know, distributed computing back in the late nineties. Phenomenal project.

It came out of Berkeley, actually, not of the SETI Institute. But Berkeley and the SETI Institute collaborate with each other. But that's now out of Berkeley.

Oh, okay. Great. Thank you for the correction. Now you've called out something, you know, deeply uncomfortable, in my opinion, that our search strategies that we use, that SETI uses. And I've had on you know, recently had on Shelly Wright, who's my colleague. I'm blessed to have her here, winner of the Drake medal not too long ago. And we talk about search strategies. You know, just one example that she discussed that illuminated no pun intended.

Oh, pun intended. I'm a dad, so I get entitled to dad jokes, Natalie. But illuminated by laser light. In other words, we've been looking for radio waves because that was the easiest technology to look for. But her mentor, you know, and friend, Charlie Townes, inventor of the laser, suggested in the nineteen seventies or so that actually the most one of the most promising ways would be to look for laser pulses. And then here at UC San Diego, the late great Franklin Antonio helped to fund a lot of the research projects that are going on both in what she was doing and what you guys are doing. So I wanna ask you the question. Are we looking, you know, where the light is? There's an old joke about a guy who's drunk.

A policeman sees him. He's looking underneath the light post. He says, what are you doing here? I lost my keys. And they searched together for an hour. And then the police are you sure you lost him here? And he says, no. That's where the light is, so I'm looking here. What is the single biggest possible systematic error as we scientists might say? When we search for alien civilizations, is it a error in theoretical modeling? Is it some background, you know, noise that we might get either in the radio search, the optical search, the bio signature search? What is the biggest source of systematic error, whether biological, astrophysical, or cognitive, but that we are making perhaps?

Again, I will say the same thing that I said when we had this discussion a few minutes ago about astrobiology. These are not errors. You have to go for the things you know, for it's very hard to fathom something you don't. You have to start somewhere. That's the beginning of our journey. You know? So, yeah, we could try to imagine all sorts of things, but it's a wild goose chase because we don't know what they can look like if they don't look like us. You know? You have to suggest, like, for astrobiology might not be the only thing, but it makes sense to search for these things too. We cannot ignore them.

Just because we understand them, we should not ignore them. You know? That would be to me, that would be the error. But having said that, I would agree with you that the chances for alien to be similar to us is zero. And the reason I'm saying this is because every single life is the product of the coevolution, the biological evolution, and its environment. And so this coevolution is going to be completely different from one word to another. It might have similarities. So the coevolution is different. And why does this matter? Because well, you know, Ryan, this neuro box that we have here is the product of four billion years of adaptation on this world.

And the neuro box or the brain or whatever alien have to think is going to but the product of their coevolution. If they reach the point where they they are a technologically advanced civilization, we will share things. And this is where we need to go, you know, the sharing. What they are going to share if they survive that long is the curiosity. That's the technology, the ability to look outward and ask questions, questions that are bigger than the day to day survival mode, like humans have been for a long time. We have been the prey for a long time until we were able to protect ourself and protect no environment that we live in. But at the same time, that opened a range of different questions and a range of different possibilities for us. So there will be some overlap, and we need to think in terms of overlap.

So, yes, the overlap, the thing we share for sure is the universe we are in. We share the same universe, at least for this one. I don't know if there are multiple ones around.

I'm working on that. Leave that to me, Natalie. Leave

Yeah. I would I love the idea. In this universe, we share the same laws, physical laws. We share the same, you know, rules that we need to abide from. So it makes sense to start with that. You know, we are not disrupting any physical laws. We are looking in the radio because we think that maybe they want to radio is nice. It goes through dust.

It goes through a lot of stuff. Yeah. I'm sure. It's very convenient. Mhmm. And laser, as you say, this is the other thing. Traveling at the speed of light, this is as fast as we can go, at least as far as we know. And this is why the SETI Institute now has, you know, laser SETI.

We are developing this network of camera looking up too. But there is something else, and this is some something that I didn't even talk about so much in the book. The only thing that I mentioned in the book is that I am not too much of a fan of the Fermi paradox. I think it's a great way to start a conversation. Because if you want to speak of biases, I mean, the whole Fermi Paradox is really, psychological, you know, deep dive into human brains and how human would interact or the fears that human may have. But it asks the very wrong question. The question is not about where are they. The question is about what are they.

Because if now you are thinking in terms of life, okay. So look at where we are right now. We are a civilization that's getting to a point where, yeah, it's escaping its planet. It's capable of exploring space, not in many, you know, revolutionary ways. We are not able to travel at the speed of light. We are not you know, our fastest spacecraft is really the Parker Solar Probe is going really fast, but it would take still thousands and thousands of years to get to order the closest star. You know, our neighbor four light years away. What I'm trying to say here is that we are at the point where we are discovering all these stories.

We're discovering our universe, how we measure to it. And we are also at this point where we are developing an intelligence that little by little is becoming at least as smart as we are. Maybe one day become smarter than we are, is already faster than we are to think. I'm talking about AI here. Yeah. And what I'm saying is that traveling in space for organic bodies is dangerous. It exposes you to illnesses. Let's face it.

We are fragile. Yeah. We're fragile. We are robots and AI. They aren't. And so it may just be that right now, we are looking for an organic conversation when maybe, you know, very advanced civilization have sent an army of robots and AI throughout the universe, and maybe it's not in their plan right now to just get a conversation with them. Mhmm. That's right.

I'm having all of these scenarios in my head. What if, you know, our AI meet their AI? Tell me about the first contact. That should be very interesting. But I think, again, for SETI, as for astrobiology, it is time to revisit the way we question the universe, the way we address the major questions of astrobiology, because the SETI search is part of astrobiology. It search for extraterrestrial advanced civilization. They are life until we prove that they are AI, but this is something else. They are second generation at that point. So that's what I'm saying.

It's not necessarily because there isn't anybody out there. You know, as Carol said, that would be such a huge waste of space. It's just that well, there are a number of possibilities. The first one, I think, is an interesting one, is that maybe life as we understand it, that doesn't mean as we know it, but as we understand it, you know, an assemblage of molecule, etcetera, is a generational thing.

What does that mean?

The universe. Which means that when the universe was born, we see James Webb has been showing us the presence of organic molecule already there, like, 2,500,000,000 years ago. That was a big reveal two years two years ago when it was, you know, the fact that we have so many mature galaxies so early, just barely a few hundred million years after the Big Bang, so that raised the number of questions. But it's not so much the presence of all those things. I think it's more of the abundance of all those things. Maybe the universe is getting to a point or get was getting to a point like 5,000,000,000 ago when our sun was born or when the stars like our sun were born, you know, ten billion years ago, where these elements became abundant enough that they could be used in a way that would lead to the process of life. And if that's the case, then life and civilization are just emerging right now

Mhmm.

Universe. And we might be all young and trying to figure out, maybe we have neighbors right next to us, maybe just out or within our radio bubble, and we don't know that we are there. I really like the example of the little brother or sister of the sun. You know? Stars, as we know, are born in nurseries, multiple stars. And so a few years ago, astronomers have discovered a star that matches our sun in terms of its spectra, its identity, its composition, etcetera. So they are fairly confident that it was born in the same nursery than the star. It's about the same age and has been moving away like the sun has been, you know, taking its journey into the universe. Happens so that this particular star is now just at the limit of our radio bubble.

Yes.

So now I am going to make this completely outrageous speculation. But let's just for the sake of it Yeah. Let's just assume that for some totally weird and improbable reason, you have people looking and thinking like us on a planetary system around that star, and they're about as old as we are. And the about is really important here because if you just go two hundred years ago, the fastest way for us to go from point a to point b was the fastest horse. Right? See how it is important here synchronicity in time and space in the way that we're searching. But let's assume that they made it. They have the technology, but they are just outside our radio bubble. You know, we might touch and we might overlap within the next twenty years, but right now, we are right next to each other, and we don't know that we are right next to each other.

This is not that the space that space is empty. It's maybe that we are not connecting yet. And imagine, like, if life is really a generational aspect of the universe, imagine all of a sudden, in, say, a few decades or maybe a hundred years from now, all of a sudden, these bubbles are touching, and the sky, all of a sudden, you know, becomes just a Christmas tree lit of civilization talking to each other. That's the scenario. Right? That's one. The other one is, well, you know, everything you want to read about the Fermi paradox. They are hiding because it's a dog eat dog's universe, and, you know, you don't want to be sound. It's a very human, you know, get out of the jungle kind of beard, but it's in our brains.

So that's the dark forest. And so on and so forth. There is the zoo. We are not, you know, evolved or intelligent enough. They are looking at us. They are letting us, making our decisions. They don't want to intervene. They will show up when we are grown up.

You know, we can say whatever we want. The ultimate, the end member hypothesis is the rare earth hypothesis. Yeah. And this one, I took a stab at it in in in the book. Because as a scientist, yes, it's an hypothesis. And as long as I cannot falsify this idea, it's still out there.

Yeah.

There is still a probability that we are alone, you know. As probable as it looks, it could be as long as I cannot prove that it's not the case, it's still out there.

It should be the baseline null hypothesis. Right?

Exactly. The problem with that, the rare earth hypothesis, is that the equation that they tried to mirror with Frank's equation, the Drake equation, but the problem with that equation, they said that they were bringing in all the information we didn't have that, you know, when Frank created the equation. But the issue is that in building this equation, they actually input everything that makes Earth the Earth.

It was biased. Yes.

Very surprising that at the end of the equation, what comes out, it's the Earth. And I can, you know, I can agree with them on this that you could have exactly the same ingredient, exactly at the same time in the universe, exactly at the same place with everything being the same. But just send that planet on its orbit a millionth of a second before the other. Just because of that, the timing of extinction would be different. The timing of impact and collision with comets and asteroids would be different. Everything will turn out different. Exactly. So, yeah, you cannot have two Earths in the universe, and there are trillions and trillions of galaxy, each of them containing billions and billions of stars.

Yeah. And I've heard that argument from Adam Frank, you know, that, basically, it's the Carl saying an argument, but made quantitatively accurate by saying, you know, how many stars have there been and planets have there been in the history of the observable universe. But, of course, that's a sphere with a diameter of 90,000,000,000 light years and it, you know, lasting going back 13,800,000,000 years. So, of course, you're gonna find a very low probability that Earth is the only example of life whatsoever, and then certainly technological life. And then your colleague Jill Tarter, who's been on the show before, you know, she'll say things, well, we've only searched the equivalent, you know, of a bathtub out of the Pacific Ocean. And, you know, to which I replied to her, well, if we did search and we found no microbes inside of that bath tub and no life whatsoever, it still puts a limit on our product.

Would push back on this argument Uh-huh. For one reason. And the reason being that you're saying, you know, we haven't found anything. But the thing is that we are only starting to search. And there is this myth in people's mind that we have been searching for life forever. That's not true. The only effort that was made to searching for life on Mars was in '76. That was the Viking experiment.

Right.

And you know what happened there, and that's the reason why we didn't search for life for another 50. Well, even more than that. Yeah. It's because we couldn't tell the responses that we have, the data, which by the way was very ambiguous about, like, lowlife, and people are still arguing today. The reason being that we didn't know the Martian environment, and therefore, we had nothing to subtract the signal that we are seeing from that environment.

Exactly.

So this is when we decided to have an integrated program that would tell us everything we need to know about the Martian environment, about the Martian climate past and present, and then send two rovers, Spirit and Opportunity, to check for habitability. We demonstrated that. And then curiosity was spirit and opportunity in on steroid. We wanted to learn more. We had the evidence was that Mars was habitable for life as we know it a long time ago. So we had that evidence. And now in 2018, we sent Perseverance. And Perseverance, although it says that it's searching for life, is actually still very much a habitability kind of mission.

But now what it's trying to do is to cache some samples that are going to tell us a lot more about, you know, the possibility for long ago molecule to assemble. And by the way, look what happened last week. We found this very, very long chain of molecules on Mars. So this is where I push back. Haven't searched for life in the source system or in the universe for a long time. Yeah. Just starting, Brian. We are just starting.

So it is not only incorrect, but it would be very unwise for us to say that there is no life out there. Alright. So just starting to have the knowledge to search for it where it should be.

This is gonna be controversial. Some argue that we should be sort of announcing to the universe because it might be our best chance to survive that we exist, that we should be, you know, sending out invitations to what some call, including the late great Stephen Hawking, warned us that it might be ringing a dinner bell, you know, for other, you know, catastrophic invasions of the planet itself. And later, I wanna ask you about an even wilder idea that life might exist without planets at all. But first, I wanna ask you about the messaging of extraterrestrial intelligence in an actual image that that Carl Sagan again was instrumental in putting, the Voyager and Pioneer probes. It's a plaque that shows not only what men and women look like, but and I wonder if he could get that done now a day, you know, if that would be controversial and politically incorrect. But we'll leave that aside. And then he mapped out where we are, and he put a hydrogen atom there. And I actually talked to Andrewian because I used to ask guests what they put on a time machine that could last for a billion years.

And she said, oh, I did that. You know, Carl put my brainwaves on it on the disk after we fell started falling in love. So she already did that. That will last a billion years. But my question to you related to this, do you think that humanity should stop broadcasting our location onto the universe?

This is so deliciously human, Brian. You know, this really makes me smile every single time I am being asked this question. And this is the thing too that always stop me because you have these incredible geniuses, right mind like Stephen Hawking. And all of a sudden, they have these little boys' fears about, oh my god. You know, we shouldn't be broadcasting because the big bad wolf out there is going to come and eat us. And of all people, you should know that we have been broadcasting. Whether you want it or not, we have been broadcasting. This is the radio bubble I'm talking about.

It's about 200 light here, 240 light here in diameter around us. It's not waiting for us to message anything. It's pretty clear if, you know, somebody's watching and really wanted us had some bad ideas about us, they would be here already. So I I have no fear about that. For me, it's not fear based. It's not fear based because every single day in our life, we are emitting. And if you already have alien civilization that is more advanced than we are, they know we are here. And if they are not showing up, they have a reason.

Maybe they don't care. Maybe they just don't. And maybe we go through the Fermi paradox once again, or maybe there is this generational aspect of life in the universe that comes into play as well. But I think that, you know, there again, it's just like everything else. You cannot really get rid of it. This fear base is in our brain and it's It's

part of evolution.

It's part of evolution. It's our safeguard. It's what allowed us to be here, you know, and to avoid getting in trouble. It's the fear of base of saying, maybe somebody is watching me beyond that rock or something like a big cat or a bear. So today, these translated into aliens. Aliens might not be so good after all. And we can blame ourselves for that because I think that a lot of the science fiction has a lot to do with that. You know, when you are looking at alien or when you can get v or all these things, they are not very friendly.

No. But this is really our psyche psyche here Yeah. More than anything else. So to go back to the question itself, there are two ways so far of doing study. I mean, two domains. One is the passive listening and watching, which is, you know, we listen with big antenna. This, these are the radio telescopes, and we are watching with the camera that's laser SETI. We are watching for messages.

And there is METI. METI is the active part of SETI. The SETI Institute doesn't do that. What they are trying to figure out, which I think is really interesting, trying to figure out, you know, how can we communicate with the Indian species? And this is not a trivial thing. In 2018, I organized a workshop at the SETI Institute that was entitled decoding alien intelligence. And I brought together people from many different discipline. Of course, you had the usual suspect, Paul Davis and Lawrence Doyevan, you know, and and people you know that are related in one way or another Yes. With intelligence, consciousness, and study.

But I also contacted someone that nobody saw it coming and not even hers. Many years ago, I read a book that got stuck in my, you know, in my mind. One of these books that you read 12 times, this book by Roger Felt, that's called Next of King. And it's about his history and his meeting with champion chimpanzees and his career, you know, helping them, basically protecting them. He was not meant at all to do that. He did this is not what he wanted to do. He wanted to be a psychologist and help people with autism, children without and, you know, but he was without a penny. He was about to get married, and he was looking for a job, a summer job.

And there was this last thing, you know, this job at a lab for a professor to help him just take care of the chimpanzees. So he went there, had a five, ten minutes interview with the professor in question, and very quickly understood that he wouldn't make the cut. The professor was very polite and actually walked him back to his car. Just before he got to his car, it was this little black dot, you know, coming bigger and bigger. And all of a sudden, he has this baby chimpanzee jump at his neck and grab him by the neck and just cuddle. And the professor in question looked at him and say, well, apparently, you have something with chimpanzee. So he hired him. And that chimpanzee, her name was Washoe, and she changed his life.

They were not speaking English to this chimpanzee. They were doing American sign language. He discovered he he recreated the journey about the discovery of language through these apes. I mean, I recommend that book to anybody listening in this question because to me, that was such a reveal, you know, and also showing how complicated it can be to communicate with our next of kin. They have shared.

Right. 96% revolution. And our They

have 98% of our DNA.

Yes.

And it's not that easy. There are very, I mean, delicious scenes in that book when they have, you know, a a couple of the female chimpanzees in the living room with catalogs, men's fashion catalogs, and they are assigning to each other that they find the guy cute. And one of this female teaching her baby the sign language. These are different things. So I tried to contact Roger Fouts. I sent, an email, and I received a note that he was retired. I connected with the person we replaced him, Marie Lee Chenvault. And when we met the first time on the telecom, for me to tell her what I wanted from her, we had the best time of our life because for the first ten minutes, we couldn't stop laughing.

She looked at me and she said, you know Natalie, I was really wondering what the director of the Carl Sagan Center at the Said Institute really wanted from the director of the Primate Center. Let me explain. And Mary Lee just nailed it. Just nailed it and explained, you know, how come we are sharing this space, sharing this coevolution with each other, and yet it's so hard to communicate with anything or anybody in our biosphere.

Even human beings. Right? I mean, we don't understand each other, and we're a % similar. Right?

And and there is culture, and there is other thing, you know, coming on top of each other. So you have to start from that base. All of this needs to be considered when you are thinking about extraterrestrial intelligence. I don't think that the messaging is going you know, it's such a big issue whatsoever. If it had to be an issue, we wouldn't know it. And by the way, why would extraterrestrial just wait now? Like, we are starting to be able to maybe a little bit be able to defend ourselves. We lived in cave with spears and arrows. For god's sakes, if they wanted to take the place over, they are ten thousand years late.

Right. You know? Yes. Now now we have, TikTok to to fend them off.

Oh, well, that's That's

our only hope. That's

Maybe here's an example of why maybe they don't want to show up here. You know? Jokes aside, this is a very complex question. And then Betty, you know, this is not what the SETI Institute does. Right. But I understand that it is extremely important for us to understand, you know, what language means, how language evolves, how do we communicate. As you mentioned so rightfully, this will help us first and foremost on our planet to start with. And then you have people like Lawrence Doyle who is trying to understand how we can communicate with other intelligent species. When it comes back to the basics, we are sharing the same planet, and it's not ours to use as a playground just for the sake of it.

No. Absolutely.

And if we can communicate with whales, with dolphins, with others, these are the obvious, but Lawrence will show you that every species that we consider intelligence like ants and bees and, you know, others, we have the same syntax.

I have two final questions for you, and this has been so generous of your egg. Can only send you a thousand in my primitive high school French that I got the

That's that's that's that communication.

Exactly. I remember the first time I went to Paris, I was a new graduate student. I wanted to see it. I was visiting from London, Took it to, you know, the Channel Tunnel and got across there. I'm like, I'm gonna be okay. I took, you know, three years of high school French and I get off the metro, you know, get the Gare Du Nord and get out and go into the streets. And I see this little boy and he's playing with his dog. And I see him, you know, he's talking to the dog.

He said, He's talking to I'm like, that dog knows 10 times as much French as I know and will ever know. So I just gave it up, and I figured, why deny the Parisians the pleasure of, you know, correcting an American's bad French and just speak to them and

Oh, you shouldn't have any complex about this.

No. I don't. You know? I I love it.

The the French and the American have exactly the same superiority complex.

That's right.

To you.

And I'm a New Yorker, so, you know,

I've got many more. People think that they don't need to learn any other language because everybody speaks English. Right?

Right. That's right.

And the French, well, at least the past generation, this is much less true with the new generation. But they thought that they were speaking the most beautiful language in the world, so there was no need to learn any other language. Yeah. So no worries. No. Actually, I've been going back to France from time to time, and the first time was after seventeen years of not being there. So Wow. I discovered a newest generation was more keen to, you know, speak foreign languages, more welcoming.

So to me, that was good. I it it felt really good.

Well, I have, these these two final questions. Yeah. The first one is about the meaning of discovery of plausible evidence for extraterrestrial life. And it reminds me of a scene from the movie Contact, which is based on the book by Andrew Inyan and Carl Sagan, of course. And it's a wonderful movie and and partially based on our friend Jill Tarter's life at some level. And that is the scene in which they have a act real footage of president Bill Clinton. And he's speaking on the White House lawn. And it's a true thing.

It actually occurred in 1977.

That was the Mars meteorite. Right.

And so there was a meteorite. So here's a meteorite. Again, you can get at brian keying dot com slash list. Although, if you have a dot e d u email address and you live in The United States, you're guaranteed to get one of these. And that's a brian keating dot com slash e d u. But they found a meteorite and I'm always told that it would be the greatest discovery of all time. So first of all, that discovery was never confirmed, but it never was really fully excluded at, you know, say, 10 Sigma. You know, it wasn't it's kind of ambiguous still to this very day, which made me think.

The general public, to the extent that they know anything about this event, was probably left with the impression that was on the front page of the New York Times and, you know, for days and in this press conference held on the White House Lawn and later in the movie Contact that this actually occurred and, you know, we don't know. Maybe it is extraterrestrial life. And yet, Natalie, we still treat people rather horribly as you, you know, and I can admit. So it hasn't really changed the way that humans look at each other.

What do

you make of this kind of ambiguity and this always I always hear that, oh, it's gonna change everything. It changed nothing as far as I can tell. And

Well we

know it's not real. Yeah. Go ahead. Sorry.

You know, you're touching on, a very sensitive point here. First, for the Martian meteorite, Dave McKay was a good friend of mine. Actually, I shared some of my samples from The Indies with him because he was trying to understand, you know, what he was seeing. And what happened during the whole episode is some of the best example of what science debate should be. Yeah. Because David's team and the opposing team, if you prefer

Yeah.

Were just respectful of each other. They respected each other very much. It became a show every single year at the Lunar and Planetary Science Conference. We're expecting the new evidence, the new thing, because, obviously, David was presenting some evidence, and the other team was countering with other evidence, saying you can recognize that. I personally, you know, being a geologist by background, I disagreed with David, but we had this discussion. I said, you know, David, this looks to me more like a pattern of geological origin. And also there is no need for a Martian bacteria and his sister earlier first to be a bacteria and to look like a terrestrial bacteria. Right.

You know? So all these discussions were going on at the time. So now why it didn't have any impact? And by the way, the sequence that was taken for Clinton was used in the movie to actually confirm a much bigger event, which was the discovery of this alien civilization. But let me tell you something. First, there is the fact that the reaction of the public, I strongly believe, from the public will be very different if we find microbial life than if we found an extraterrestrial civilization. Because maybe, you know, it is the view of the general public that, well, yeah, that's great. You know, that means that there is life elsewhere. But, you know, I really like to talk to an alien. I would like to share Right.

Emotions. I would like aliens to tell me about their planet and their philosophy. And, you know, did they ever get to religion? Is this part of evolution or is just, you know yeah. What whatever. You know, science, technology. So this is probably why on the general public, the discovery of microbial life would have less effect than alien life. On the other hand, the public should understand something, is that we live in a very statistical universe, which means that the more microbial life we find, the greater the chance we have to find an extraterrestrial civilization. So that would be great news, and not only for micros.

We

also all the other guys. If it was Mars or if it was our solar system, wherever it is, that will be also noting that you have now found life on two planets out of eight. It's 25% right away. That tells me something about what's, you know, the ability of life to to survive in the universe. And there is something as well, is that it might be, you know, a little remote for the general public. But microbes can talk, and I'm not talking about speak here.

No. They can mimic.

Metabolism, where you know, what makes them. Everything tells us about the planet they are coming. Obviously, we would find them on the planet. So but also what they went through. Just like the bacteria we're talking, you know, at the very beginning.

Right.

They have embedded in them the history of their evolution. They are literally, you know, planetary journeys trapped in a small body. Of course, you have to speak the language, and this is what puts a little separation between the general public and people capable of reading the microbes. But the discovery would be equally important. Of course, the extraterrestrial discovery would be on another levels. How did you make it? Because right now, we are trying to figure out as human. You know? I am not looking at finding extraterrestrial to help us find solution. We need to find our solutions ourselves and our world.

We need to be better humans and better top of the biosphere. We need to take care of our planet, all the beings, all of them that are living on on them, and we need to take care of each other. But it would be important for us to see, at least for me, to try and understand what an alien civilization went through. Did they meet the same challenges? Are they at each other's throat, or is this a a trait that is typical of apes? We know that's the number of apes are not aggressive, but many are. So maybe it's a trait that we're carrying from the time, you know, we're still living in the forest.

That's right.

I'd like to ask so many questions, especially, you know, in terms of spirituality, asking if religion is just a moment in evolution when we just discover this big universe. You know? Your mind is discovering that there is a big universe around you, but you have no way of explaining it. So all of a sudden, you create gods and you create religions to try to make sense. You know? This is the same thing, science and religion. We're science is trying to measure nature to understand it. And religion, spirituality, they are trying to explain what cannot be measured. And it's this attempt for us to find our place here. I'd like to have this discussion saying, do you think that religion is this moment when we realize that there is a big universe and we have to create something to make sense of it and feel safe in it, but it's just a passage? Or is it really that we evolve and all of a sudden, our mind becomes open to the possibility of something greater than us.

I am not a religious person, but I'm open because I think this is another way to getting access to the world that surround us, the universe that surround us, and each human should be entitled to, you know, express this connection in the way they desire. This kind of question for me, you know, the hoops and loops and, you know, how did you get there? How did you make it?

It's wonderful. And in the book, you know, just to conclude, you describe humanity as being in the sort of chrysalis, you know, one that's unfinished, evolving, dangerous. Remind me of my wife, bought some butterflies in chrysalis form, monarch butterflies for my kids a couple years ago. And she was, like, so fascinated with these things. You know, they sit there. They just look like they're a dried piece of wood, you know, which they're camouflage to look that way to avoid predators, I suppose, and they've evolved that way. And then over a course of a couple days, you don't do anything. You don't water it.

You don't feed it. You just keep it away from one of my kids who's very dangerous. And then eventually, they start to wiggle, and then they start to chew, and then all of a sudden you see this thing, and then it flies. And, you know, I don't necessarily believe in miracles, you know, religious type of miracles, but it's as close to a miracle as you can possibly witness. I mean, you can't witness a human fetus, you know, being conceived and then ripping, you know, coming out of an egg and divide you can't witness it, you know, and the kid live, but it does seem sort of remarkable. And I wanna ask you, you know, as we wrap up, you know, are we worth saving? What is our best hope and the greatest lesson that we could be left with of all, in your opinion?

Of course, we are. And it's important that we will be, you know? But what you are describing, The Butterfly, which is actually the cover of my next book that came out in general in French, is that what's happening right now is not so surprising. I think it's part of the growing pains. You know, this transformation from the chrysalid to the butterfly is not easy. No. It's painful. It's hard. And on top of that, you know, there are the pains we create for each other that don't help.

This is why the overview effect is so important. And we are at this threshold. This is what pandemic exploration, what astrobiology brings back, which is this mirror effect that, in fact, you are starting from the Earth. You are looking, you know, outward in the universe to ask those questions. And because we are the only model of life we know, all the questions we ask are, in fact, a reflection of the answer we would like to have for ourselves. So, basically, we are learning about ourselves by looking outward, and then we are bringing those questions back here. So what's happening right now is that we are still hanging for dear life to this primordial brain that really think that we should be afraid of the dark forest, that we should be afraid of the alien, and the alien's so convenient in English because the alien can be the extraterrestrial, but it can be the neighbor that doesn't look like you, that doesn't speak the same language, that doesn't have the same religion, spiritual belief, or none of them. Right now, we are still stuck here because being weary is what allowed us to survive.

But, hey, something happened. One picture happened, which is the view of our Earth from space. And from space, when you are looking at this blue planet, this is the color of all of us. We are all blue. Mhmm. Because from there, as Carl said, you know, the clouds don't know any frontiers. There is no geopolitics from space. The atmosphere is moving freely.

The ocean are going about their business, and this is the image that we need to embody. This is the picture that we need to keep in mind. This is the only way humanity is going to survive, that becoming one. The fear for people when we say that, they say, oh, well, you're a globalist, and we know we are all going to lose whatever it

Gaia. Right.

No. Absolutely not. What you have here, the color of people's skin, the way they speak, you know, what they look like is the product of environment, time, and history. We are the same. Yeah. It's just that we are an example of the wonderful biodiversity that life and Earth is capable of creating. Yeah. And you know what is very funny somehow or ironic, I would say rather than funny, and I took that example somewhere else, is in 1980.

I happen to be a soccer fan, what you call soccer that in France we call football. And in 1998, the French were world champion for the first time.

That's right.

France has a different form of racism. It's but it exists, you know? And, of course, like anybody else, when something goes wrong, it's always the fault of the guy that doesn't look like you. So in 1998, the French team is composed of all the prism you can imagine, all the colors, all the body shape, all the religions, all like thereof. You have 11 guys running on the field. The metaphor here is fun because they, of course, are wearing a blue shirt. That's French blue, and they are becoming world champion game after game. And in the stand, they are all French all of a sudden. All of these people.

They are not blonde and blue eyed, which was the archetypical French

Garlic. Right.

A hundred a hundred years ago, which is true now, but people don't care. No. They are French. They are rooting for them. You know? So why aren't we able to do that for our planet? These supporters at that time, and I don't know what happened after the world championship, but why can we see the goal and that we are all rooting for a goal, you know, in those instances and not realize they didn't think that they were losing anything by supporting that team. They were embracing them. We can do the same for our planet. We are not losing our identity.

We are bringing our identity as added strength to the team Earth, and this is what should be happening. That's my soccer metaphor. Ultimately, we are tiny well, you said, just like you, I don't like miracles. But when you think about the odds of us being on that rock, launched so fast in a universe so big and actually at each other's throat. Yeah. That doesn't make any sense.

No. It doesn't. But, hopefully, it won't be universal. And I really think this is the greatest lesson that, you know, I took from the book that the search for alien life is searching for who we are and who we want to become. As you said earlier, it's not, you know, where are they, but what are they? And that includes the full panoply of their existence because, you know, if life does exist out there, it might be unrecognizable. But we know for sure that life exists down here, and it's fragile, and it's messy, and it's beautiful. And the real question is not whether we're alone, as you say, but whether we're ready. And I think this is the greatest lesson of all.

And I think for my audience out there, I enjoy this conversation so much. And if you wanna understand how rare life may be and what we can do about it and what it means for our future as human beings on Earth, Natalie breaks it down fully in this wonderful book, which is over a year old. I've been trying to get you on for all that time via every mode of communication possible. I was sending many

August of last year, so it's not quite a year old.

Yeah. Almost a year old. Get the secret life of the universe and follow-up with some of the great episodes I've done with Natalie's colleagues from Shelley Wright to Jill Tarter to Sarah. Why do you think so many women, so many wonderful brilliant women are attracted to this field? Do you have any idea why?

I don't believe that there are more women in astrobiology than any other science. While it's getting better or it was getting better, maybe they are more vocal, or maybe they bring I'm not going to say that guys are not passionate about what they're saying because they have tons of evidence, you know, of wonderful men colleagues Yeah. Who are as passionate. But maybe we see them more or the public think that they are more visible because of that subject itself. Yes. Maybe the subject is also creating the aura against, you know, the backdrop of all of this.

Natalie, I wanna thank you so much and remind people if you wanna get some extraterrestrial material, some possibly technology, you know, according to some. I'm not giving this away, but I will give away meteorites. Go Go to briankeen.com/youtube and get the secret life of the universe. It should not be a secret. And I can't wait to have you on for the next book. That just sounds wonderful. So, hopefully, that'll take less than nine and a half months to organize and get together. Now thank you so much.

Weekend.