Daniel and Kelly’s Extraordinary Universe - Could we seed exoplanets with life?

Episode Date: October 19, 2023

Daniel and Kelly wrangle with the tricky science and ethics of sending microbes to distant worlds.See omnystudio.com/listener for privacy information.

This is an I-Heart podcast. Get fired up, y'all. Season two of Good Game with Sarah Spain is underway. We just welcomed one of my favorite people, an incomparable soccer icon, Megan Rapino, to the show, and we had a blast. Take a listen. Sue and I were, like, riding the lime bikes the other day,

and we're like, we're like, we're like, people ride bikes because it's fun. We got more incredible guests like Megan in store, plus news of the day and more. So make sure you listen to Good Game with Sarah Spain on the IHeartRadio app, Apple Podcasts, or wherever you get your podcasts. Brought to you by Novartis, founding partner of IHeart Women's Sports Network. Have you ever wished for a change but weren't sure how to make it? Maybe you felt stuck in a job, a place, or even a relationship. I'm Emily Tish Sussman, and on she pivots, I dive into the inspiring pivots of women who have taken big leaps and their lives and careers.

I'm Gretchen Whitmer, Jody Sweetie. Monica Patton, Elaine Welteroth. Learn how to get comfortable pivoting because your life is going to be full of them. Listen to these women and more on She Pivots, now on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. Tune in to All the Smoked Podcast, where Matt and Stacks sit down with former first lady, Michelle Obama. Folks find it hard to hate up close. And when you get to know people and you're sitting in their kitchen tables and they're talking like we're talking. You know, you hear our story, how we grew up.

how Barack grew up, and you get a chance for people to unpack and get beyond race. All the Smoke featuring Michelle Obama. To hear this podcast and more, open your free iHeartRadio app. Search all the smoke and listen now. I was diagnosed with cancer on Friday and cancer free the next Friday. No chemo, no radiation, none of that. On a recent episode of Culture Raises Us podcast, I sat down with Warren Campbell, Grammy-winning producer, pastor, and music executive

to talk about the beats, the business, and the legacy behind some of the biggest names in gospel R&B, and hip-hop. Professionally, I started at Deadwell Records. From Mary Mary to Jennifer Hudson, we get into the soul of the music and the purpose that drives it. Listen to Culture raises us on the IHeart Radio app,

Apple Podcasts, or wherever you get your podcasts. Hey, Kelly, I have an unusual aliens question for you. It is never good for me when a question starts like that. It's I have an unusual aliens. question for you or what is in my poop? As a parasitologist, I get a lot of that. So go on. I can't wait. Where are you going with this? All right. So as a parasitologist, do you ever see a critter infected with something new and wonder, hmm, is this an alien parasite? No, never. There's so many weird things on earth. I don't feel like we need to go to space to explain them. And the other day I saw someone

trying to make the argument like in an actual like sciencey pop magazine. that octopus, like octopodes, oh gosh, let's not get into how you pluralize that, might be aliens. And I'm like, oh my gosh, dude, their genome fits nicely in the tree of life. This isn't complicated. So the answer is no. All right, but then my question is, how exactly can you tell? I mean, do you think, like, if alien parasites did come to Earth, could they do their parasiting on us?

Would they find us tasty or be, like, incompatible with us? So that's an interesting question. You know, it might be that they wouldn't be able to eat us. or that they wouldn't be able to, like, you know, bind to whatever receptors inside of us they needed to. But, you know, as far as how far or what do you need to do to tell, you know, you could, like, take a DNA sample and, you know, see if they fit on the tree of life or not. But, yeah, I don't know. Hard to know.

So I guess I'd say it's impossible to know, but I'm guessing that we do look different from the kind of things that aliens are used to sucking on out in space. I'm going to take it as a compliment that aliens don't want to suck on any parts of me. You know, that's exactly how I meant it, Daniel. Hi, I'm Daniel. I'm a particle physicist, and I'm doing my best to be not attractive to alien parasites. I'm Kelly Weiner-Smith, and you probably don't have any alien parasites, but if you do, send them to me because I'd love to see them. How are we going to find out, Kelly?

Are you planning to chop me up to see? Sure. Yeah. Better you than my kids. You didn't take very long to think about that. You went right into, yes, I'm going to chop up my co-host. Some questions are easy to answer. Oh, God.

And welcome to the podcast, Daniel and Jorge, Explain the Universe, a production of IHeartMedia, where we tackle all questions, those that are easy to answer, those that are harder to answer. Questions about the deep nature of the universe. Questions about what's out there. Questions about how it all works and questions about who else might be out there in the universe. Jorge can't be with us today, but I'm very pleased to have Kelly here to talk to us about aliens landing on Earth and potentially sending our parasites out to alien planets. Oh, the world needs more parasites. I'm so excited. The universe needs more parasites. Not just the world. Share them. No? No, is that a weird take? I don't. I'll admit I have a hard time getting

warm and fuzzies for parasites. I always think of those wasps that like lay their eggs inside spiders and then control them until they die, driving them around like some horrific bumper car. Like, oh man, that is just not a warm and fuzzy. Oh, I love watching videos of that. It's so creepy. And like usually, so I have to admit, even though I'm a biologist and they might take my biologist card away for saying this. I find spiders a little creepy. I said it, but I almost feel bad for them when I see them getting parasitized and like manipulating their web building behavior and then the babies like stick a straw in the back of the spiders and it's kind of creepy. I feel bad for spiders sometimes. They have my sympathy. And you know, if we could have those wasps on the podcast

and we would ask them like, how do you feel about zombieifying those spiders? They would answer with the same cold calculating quickness that you answered when you said you would chop me up on the podcast. There would be like, no problem. Let's do it. Yeah. Well, so fortunately for me, I am a low on introspection ability. So I'm not going to think too hard about what that says about me. But I am super glad that I am not the kind of organism that wasps can manipulate. Life is good being a human, or at least being a human in North America. Until those alien wasps land here on Earth. And it's a regular trope in science fiction that if you go out into space, you might catch some sort of weird alien virus, which takes over and infects the entire biome polluting the

earth and demolishing life on Earth. Or if we land on Mars, we could accidentally pollute Mars with some sort of Earth-based microbe. This question of keeping things sterile, of keeping things separate is a standard issue in science fiction and also in real-life space missions. Yeah, we go to great lengths to try to make sure we don't do what's called forward contamination, getting Earth microbes out on Mars. And then we were very careful to make sure that, you know, when the astronauts came back from the moon, there was no backwards contamination. They didn't bring any microbes back from the moon. And so far, I think we've had pretty good success. But if I had to bet, I would bet some of our extremophiles have made it to Mars. Do you know, Daniel? Has anybody,

surely someone's looked at that. I know that there are tardigrades that crash landed on the moon in that Israeli experiment gone bad. And they're probably busy building. a colony up there and planning to like return with weapons that's pure speculation of course i feel like i have to say that since this is supposed to be a heavy science podcast anytime we say something silly i want to make sure people know when we're joking but in terms of sending things to mars you know we have sent stuff from here to mars and we have done our best to cleanse it of microbes but my wife is a microbiologist and she always tells me it's essentially impossible to remove microbes. I mean, you will find microbes in every environment on Earth

because there's always some little critter capable of eating whatever poison you're using to cleanse it of microbes. So I'd be very skeptical that our landers have no microbes on them. So since I happen to be married to a microbiologist, I thought it'd be fun to ask Katrina about it directly. And so I did. So welcome to the podcast, Katrina. Thanks very much for joining us.

Thanks for having me. And thanks for contributing your biochemical expertise. Oh, boy. So my first question is, what are the chances that we have already polluted Mars and the moon with microbes from Earth? What a great question. And, you know, there are teams of people who are devoting their life work to figuring this out. So, you know, you're asking me as a bystander to answer that question.

But there have been some fascinating experiments where people, for example, have found that up at JPL in Pasadena, California, they use these really astringent cleaning reagents. to try to remove all the microbes from the surface of the spacecraft, and they find that there are microbes that can actually eat the most difficult cleaning reagent you could imagine. It's like bleach, yum, carbon source, they'll eat that. So what are the chances that one of those microbes that survived JPL's most, you know,

atrocious molecules they could think of to kill all the microbes, and then also survived getting out of the atmosphere of Earth and the transport to Mars? what do I think the chances are? I think it's possible. Yeah, I'm not saying these are like happy dividing cells of microbes. It's just that microbes have, first of all, the most diverse strategies you could imagine. So every time you got an idea, they've got a million more. And then they can form these very dormant, spore-like or spore particles that basically, you know, squirrel away and hide their DNA inside of like many, many, many layers of protection.

So I think it's very possible that something in that type of form, ironically, the attempts to clean the spacecraft could actually select for microbes that are really extra tough and therefore they would have a better chance of having made it to Mars. Now, I'm not saying that when they get to Mars, then they're going to be like stretching out, jumping in the pool, having a great life. I mean, they're still going to be stuck in their dormant state. But is it possible that if you, like, brought some water to Mars and then it could, like, wake those bugs up, you know, that kind of thing could happen. Yeah.

So then I guess then the second question is if it can, so it would need to survive the chemicals, the vacuum of space, and then find something to eat on Mars. And that's a lot of hoops to jump through. You'd need a lot of variability in the microbes that make it to Mars. But, you know, if Jurassic Park taught me anything, it's that life finds a way. Exactly. Katrina is always telling me, like, you pick up a scoop of, like, boiling acidic water near some vent. You'll find, like, 10 to the 9 bacteria in every cubic centimeter. Or if you look at some satellite we're sending up into space, you'll find microbes at the outside that eat the bleach they were using to kill the microbes. But you're right, those microbes have survived that environment.

That doesn't guarantee that they're going to be able to survive any arbitrary environment. These extremophiles are evolved to live in their particular niches. So should we stop trying? I think we should just give up on the whole field of biochemistry. I mean, that's what I think. That's how I felt when I was in college. No, I think it is important that we try to separate these things. I mean, imagine we land on Mars and we discover microbes there.

We want to know are these Earth microbes or not. And even if they have Earth-like DNA, we want to know, did these come from Earth? Or maybe all of life on Earth came from microbes on Mars that were blasted off the surface. That's an actually legitimate, non-joking scientific theory about the potential origin of life on Earth. So we want to know if we've infected life on Mars. So I know that we have bits of like Mars that have been blown out into space. And I think they've landed in like, we've been able to find them in Antarctica. Have we looked for alien microbes in those and found anything yet?

Oh, we definitely have looked for alien microbes. And a few decades ago, there were scientists who were confident they had found them. They saw these little microtubules and even present. President Clinton made this huge announcement, like on the lawn of the White House that we thought we had found life on Mars. These days, though, we have other non-life-based explanations for those formations. So people are pretty convinced that's not evidence for life on Mars. But, you know, we've gotten like a few rocks from Mars that we could study here on Earth. And so it's a pretty small sample.

We're hoping in the next decade or so to do Mars sample return, where they pick up rocks from the surface of Mars and send them back here to Earth via some ridiculously-conciliation. complicated Rube Goldberg's set of devices, but we're all excited to study those and maybe to find microbes there. That would be exciting. I hope we can contain them and they don't take over our minds. But we can also think beyond our solar system and wonder what about microbes on planets around other stars? Do we need to take the same sort of considerations about avoiding exoplanets? Or maybe we should turn the question on its head and on purpose pollute those exoplanets with our kind of life. You know, I feel like maybe we shouldn't have two scientists talking about this.

We should have like a philosopher slash ethicist. But we've got what we've got. So let's, we don't have anybody with an ethical compass here. So let's plow forward with this question. But fortunately, we do. We got a question from a listener, Haley, who is nine years old. And she's young enough to have sort of like an intuitive philosopher's heart and sense of ethics at least. And so she wrote in with this question.

Hi, my name is. Hey Leah, I'm nine years old, and today is my birthday. I was actually wondering if humans wanted to live after Earth was gone. Can't you put, like, microbes and bacteria on different planets and let them evolve there? And I was wondering, do you think astronauts accidentally bring little small life forms to out of earth and put them somewhere else, like on their clothes or the rockets by accident. Thanks. Haley, those questions are so great and happy belated birthday.

And how sad is it that we have to rely on nine-year-olds to be our ethical compass? Yeah, no, I think when my kids grow up, it's going to be everyone for themselves here. So I thought this was a really fun question, and I started looking into it, and I discovered that there's a whole project, a whole group of people with specific plans and ideas to do just this, to send our microbes, our bacteria, two different planets around other stars and to see them with life. And is the goal so that you can make those habitats more hospitable if humans ever decide they want to move there or are they just doing it like as a fun, you know, an n equals two for like the possible past evolution could take?

You're asking if they're being responsible or if they're just like mucking around out of curiosity? No, they're pretty clearly mucking around that I want to know how they justify the exercise. Well, that's exactly what we're going to be talking about today as we answer the question. Could we seed exoplanets with basic life? Well, we should see what the listeners have to say. Thank you very much to our group of listeners who answer these random. and sometimes weird questions. We love hearing what you have to say

and hearing your voice on the podcast. If you'd like to be part of this not very select group of elite volunteers, please write to me to questions at danielanhorpe.com. Everybody is welcome. Think about it for a minute. Do you think we could seed exoplanets with basic life? Here's what people had to say.

I reckon we could seed life on an exoplanet if the environment was suitably similar to Earth and there was some kind of energy source for the life to capitalize on. I imagine it would require a little bit of engineering of the life unless we got very, very lucky with the environment. I believe it may be possible to seed exoplanets with life. However, I don't think we're anywhere near that capability. We're probably many centuries, if I'm millennia, away from that. I think that if an exoplanet has no existing life, then seeding life should be possible.

But if there's anything there already, then the differences in proteins and whatever else it may have developed there would mean that it would be pretty on the unlikely without wiping out whatever was there first. I think we could, although precisely sending a rocket to an exoplanet would be really tricky. But should we? Maybe while trying to see life we may end up disrupting already existing ecosystems. Yes, I think we can. If the exoplanet has the right habital conditions and you could maybe put the organism of the life on the planet, so I think yes.

thing, yes. I was impressed by all the different angles the listeners came up with to address this question, like, well, it's really far away. Is that going to be a problem? You know, what kind of, what would the environment need to be like for them to survive? Lots of cool ideas from the listeners on this one. Yeah, exactly. Lots of different scenarios. Can we get it there? Would it survive? Why should we even do it? And so I think we should start with your question there, Kelly. But like, what is the motivation here exactly? Like, why would you build a little rocket, put a bunch of bacteria in it, and send it to an exoplanet, what exactly is the goal you're trying to achieve? I mean, so I personally am a big fan of life, and I'd like there to be lots of life

and lots of biology everywhere. But I feel like it's complicated when you get to adding biology to places that it doesn't necessarily belong. I don't like invasive species very much here on Earth. I'd like less of that. So are we, like, doing the ultimate experiment in invasive species? I think there are lots of possible angles here. I think maybe the most generous motivations are just the ones you expressed.

Like, life is awesome. Let's have more of it in the universe. So imagine you could find some currently sterile planet where there is no life. And you're confident life would not arise naturally. Why not seed it with life? Turn it into a petri dish. See what would happen. And potentially creating biomes that might be habitable for humans in the deep, deep future.

That way you wouldn't be displacing any current life. So you don't have to worry about the ethics of life. like invasive species and colonialism. But so that assumption is a really hard one for me to accept, though. So, like, you know, we are not even 100% sure that there's no life on Mars. You know, it might still be in like the lava tubes or something, sort of like hiding out. So it's even harder for us to study far out exoplanets.

How could we ever convince ourselves that a planet is sterile and definitely doesn't have life when we only know what life looks like on our planet and we can't even tell you if there's life on the planet in our solar system. So I would have trouble believing we could ever get certainty about that assumption. But what do you think? No, I agree with you. And it sounds like the set of first science fiction novel where scientists get humbled because

they didn't understand what life could be. And they marched forward with their hubris too quickly. I agree. We don't know what life could be like in the universe. So it's hard to be certain that any planet really is sterile. And it's also basically impossible to be certain that a planet will always be sterile. What if life was going to evolve next week? And then you showed up with your zillions of micros.

and you now made it impossible. That's not something you can ever probe, right? Especially because we don't know how common life is and how likely it is to be created from non-living environments. So it definitely would be taking a gamble. But I think the motivations are the ones we expressed earlier. It's just like, wouldn't it be nice to have more life? Imagine if we are the only life in the galaxy

and there are all these habitable worlds out there with nothing on them. That does feel like kind of a waste. It does. And, you know, some of my favorite life is life that I can eat. And so after the break, let's talk about whether or not we can create essentially grocery stores

on other exoplanets in case we ever decide to go shopping there. The U.S. Open is here. And on my podcast, Good Game with Sarah Spain, I'm breaking down the players from rising stars to legends chasing history. The predictions will we see a first-time winner and the pressure.

Billy Jean King says pressure is a privilege, you know. Plus, the stories and events off the court and, of course, the Honey Deuses, the signature cocktail of the U.S. Open. The U.S. Open has gotten to be a very fancy, wonderfully experiential sporting event. I mean, listen, the whole aim is to be accessible and inclusive for all tennis fans, whether you play tennis or not. Tennis is full of compelling stories of late. Have you heard about Icon Venus Williams' recent wildcard bids or the young Canadian, Victoria Mboko, making a name for herself? How about Naomi Osaka getting back to form? To hear this and more, listen to Good Game with Sarah Spain,

an Iheart women's sports production in partnership with deep blue sports and entertainment on the Iheart radio app, Apple Podcasts, or wherever you get your podcasts. Presented by Capital One, founding partner of IHeart Women's Sports. I don't write songs. God write songs. I take dictation. I didn't even know you've been a pastor for over 10 years. I think culture is any space that you live in that develops you. On a recent episode of Culture Raises Us podcast, I sat down with Warren Campbell,

Grammy-winning producer, pastor, and music executive to talk about the beats, the business, and the legacy behind some of the biggest names in gospel, R&B, and hip-hop. This is like watching Michael Jackson talk about Thurley before it happened. Was there a particular moment where you realized just how instrumental music culture was to shaping all of our global ecosystem? I was eight years old, and the Motown-25 special came on, and all the great Motown artists, Marvin, Stevie Wonder, Temptations, Diana Raw. From Mary Mary to Jennifer Hudson, we get into the soul of the music and the purpose that drives it.

Listen to Culture raises us on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. Imagine that you're on an airplane and all of a sudden you hear this. Attention passengers. The pilot is having an emergency and we need someone, anyone, to land this plane. Think you could do it? It turns out that nearly 50% of men think that they could land the plane with the help of air traffic control. And they're saying like, okay, pull this, until this. Do this, pull that, turn this.

It's just, I can do my eyes close. I'm Mani. I'm Noah. This is Devon. And on our new show, no such thing. We get to the bottom of questions like these. Join us as we talk to the leading expert on overconfidence. Those who lack expertise lack the expertise they need to recognize that they lack expertise.

tease. And then as we try the whole thing out for real. Wait, what? Oh, that's the run right. I'm looking at this thing. Listen to no such thing on the Iheart radio app, Apple Podcasts, or wherever you get your podcasts. Hey, sis, what if I could promise you you never had to listen to a condescending finance bro? Tell you how to manage your money again. Welcome to Brown ambition. This is the hard part when you pay down those credit cards. If you haven't gotten to the bottom of why you were racking up credit or turning to credit cards, you may just recreate the same problem a year from now. When you do feel like you are bleeding from these high interest rates, I would start shopping for a debt consolidation loan, starting with your local credit union, shopping around online,

looking for some online lenders because they tend to have fewer fees and be more affordable. Listen, I am not here to judge. It is so expensive in these streets. I 100% can see how in just a few months you can have this much credit card debt when it weighs on you. It's really easy to just like stick your head in the sand. It's nice and dark in the sand. Even if it's scary, it's not going to go away just because you're avoiding it. And in fact, it may get even worse.

For more judgment-free money advice, listen to Brown Ambition on the IHeart Radio app, Apple Podcasts, or wherever you get your podcast. Okay, so we all agree, life is awesome. And as long as we're not wiping out other life, it might be cool if there were more life in other places. And we could sort of see what kind of amazing biodiversity ends up being created in new environments. But let's talk about being able to eat that biodiversity. So say we were seeding other planets in case humans ever come along. What do you think the chances are that you seed a planet, like how long do you need to wait before you can harvest it? Yeah, that's a great question because I think you pointed out to me many times.

and is described in your upcoming book, if we do land on another planet, we need to find some way to be self-sufficient. You can't rely on like shipments from Earth forever, which means you need to be able to create your food locally, which means you need like a whole biome. You need like plants and you need microbes. You need all this stuff to create your life.

And that's difficult to arrive with. So it would be wonderful if you showed up and there's like plants or at least microbes or, you know, the basic foundation of your ecosystem that you could build your grocery stores on top of. And so in a few minutes, you'll hear an interview I did with a microbiologist or asked him essentially that question, like, how long would it take to go from injecting bacteria into an ocean to showing up and finding redwoods and dinosaurs, you know,

things that you could hunt and climb around on and eat. And so you'll hear him say, it's a very, very long time. It's not something you could expect to do in a million years or maybe even in a billion years. But, you know, on this podcast, we are very forward thinking. We are not just planning for our children and our children's children, we're planning for the deep future of humanity, right? Infinite time horizons. Nothing here limits us. Which means we can ask for infinite budgets, right? I mean, because like a dollar today is worth so much more in the future. But I think the picture you should have in your mind is the earth is the only place in the galaxy with life or one of few places. If life in the galaxy is rare and it takes a long time to develop, then it

seems like an attractive idea to take a little bundle of our microbes, send it to another planet, have it develop life there, because then it would be more life in the galaxy. And also, as you say, it would be the kind of life that we can eat, which is our favorite kind of life. Because, you know, even if you show up on an alien planet and it has some kind of life, it's not guaranteed that you could eat it. What, I don't necessarily even know it's guaranteed if you could eat it if it was growing somewhere else. You know, it's not safe for us to eat all the life on Earth. There are definitely mushrooms that you ought not to eat, for example. You know, I guess the question would be like, how often do you see to plan it and it doesn't

take? How often do you see to planet, but you come back and it's filled with toxic mushrooms or something like that? And so, you know, I think there's lots of ways this could go that might not be exactly what you want, but I think all of those ways would be interesting and would teach us something cool if I can ethically, you know, jump the hurdle of feeling comfortable with this experiment. And you raise an important point earlier, which is like, how do you know which planet is a good candidate for sending your microbes, which planets might have the right conditions or which planets might be sterile. And so there's a group of folks that's called Project Genesis that have actually thought this through and worked on a little bit of the engineering

to make this possible. Oh, tell me more about that. The idea is to do it in two stages. The first is to send out a bunch of probes to find good candidates, to gather data and beam it back. So the first wave is like, go out there and find planets in the galaxy, which might be good candidates. candidates. And then a second wave is to actually send the microbes. And this is important because the first wave can be a lot faster than the second wave because the first wave doesn't have to stop at the planet. You can just do like a quick flyby and see these planets. And then shoot the data back to us. And shoot the data back. And this has to do with the physics of interstellar travel. All of these stars, even the ones close to us in the galaxy, are pretty far away. Like the nearest star is like four light years away. And the whole galaxy. is 100,000 light years across. So getting from star to star takes a long time because it takes you a long time

to accelerate anywhere near the speed of light. So even getting to the nearest star could take you thousands of years, especially if you have to bring with you all the fuel that it takes to accelerate. And the more fuel you bring with you, the more fuel you need because you have to accelerate all that fuel.

So you very quickly have extraordinarily expensive rockets. So even that first pass is not going to get done in our lifetime. And I can imagine it being super frustrating to, like, put a bunch of equipment on there. And then 500 years later, you're like, oh, I wish we had put this other piece of equipment on there. But I guess you'd make do with what you had. Are there options that don't require just, like, ridiculous amounts of fuel? There are some really clever options.

And we've talked about on the podcast once before. There's this plan for something called a solar sale. The idea is don't bring the fuel with you. Don't load up a rocket with fuel and then need fuel to push that fuel. fuel to push that fuel. Don't bring any fuel at all. Have all the power come from the sun and just have a sail. The solar sail is just a huge mirror and all the photons from the sun bounce off of it and give it a little push. Photons are these tiny little particles, the quanta of light, and they have no math to them, but they do have momentum, which means when they bounce off of

something and go the other direction, they give that something a kick. Like when you're standing in the sun, the sun is literally pushing on you. with all those photons. It's a very gentle push, which is why the sun doesn't usually knock you down, except in Southern California in July, but it is there. And if you had a very lightweight spacecraft

and a very large sail, you could accelerate up to near the speed of light pretty quickly. That sounds like it's even faster than the method that uses fuel, is that right? Yeah, exactly. It's much faster than the method that uses fuel. The disadvantage is that there's no way to slow down. Like this thing can accelerate up to near the speed of light,

And then it can whizz by your planet quickly. But it could take some pictures and it could send you some information. That's why this first phase is just information gathering and then beam you back the data, of course, at the speed of light. So this first phase, when you go out and look at planets, you say, like, is there oxygen on them? Is there water on them? What is the basic environment like? This could be a very quick survey. Okay.

So if you're doing these surveys, what kind of things are you looking for? I assume oxygen. Well, I mean, there's bacteria that don't require oxygen. But I guess if the plant is you're seating it for food, you're going to want there to be oxygen for us. So probably you want a planet with oxygen? That is the first and the hardest question. Like, do you want planets with oxygen or without oxygen? And it's interesting to think about like where planets do get their oxygen.

Are there planets out there that are sterile but have oxygen? Or is oxygen purely just a product of life? And it's interesting because actually most planets do have oxygen. oxygen on them very, very early in their life cycle. Most planets are made with water because water is everywhere in the universe. And in the early phase of the life cycle of a star, they tend to emit a lot of ultraviolet radiation. This is part of their life cycle called the pre-main sequence. Like before they settle down and really just doing all their steady burning of fusion, they emit a huge amount of ultraviolet radiation, which can break up that water and produce

oxygen. So very early in the life of a planet, they do get some natural oxygen. without any life, right? So you can get planets with oxygen on them. Problem is that for a lot of stars, this early phase is not very long. It's just a few tens of millions of years. So it doesn't make very much oxygen. And because you're blowing off so much solar radiation, a lot of the atmosphere of a planet can just get blown off. And this is what happened to Earth. We had a little bit of oxygen made early on through this UV light from the sun, but then the sun basically blew away our entire atmosphere, the one that was formed with the original planet. Whoops. So then do we want to send photosynthesizing organisms then? Well, it's an interesting

question, right? Like on Earth, life started without any oxygen because the atmosphere was replaced by volcanic outgassing, which got nitrogen and CO2. And then photosynthesizing organisms did create oxygen. But it's interesting because a lot of biochemists tell you that having oxygen makes it harder to form life like a lot of the chemical building blocks of life couldn't have formed if you had a lot of oxygen in your atmosphere that the anaerobic procedures are actually more important and they're inhibited by the presence of oxygen so if what you want is to like start life on a sterile planet you probably don't want oxygen but if you want to cede it with life like ours then probably you do want to find oxygen rich planets because they're more conducive to our kind of life

and they're probably sterile because the oxygen is like poison to those early forms of life. So how do you know that the planet your seeding hasn't like progressed as far as Earth? And that's why it's got oxygen. I guess because your flyby was that accurate? Yeah, on the flyby, you're going to do more than just test for water and test for oxygen. You can also look for methane, for example. Methane and oxygen together are a pretty good signature of life. You know, you can look for phosphine.

It's a whole really difficult question of like, how do you know if there's life on that planet? But I think in general, looking for oxygen-rich planets that don't have obvious signs of life is a good target because oxygen tends to prohibit the formation of early life. And it turns out it actually is possible to have planets with lots of oxygen that isn't produced by photosynthesis. And where do we get it from? So there are a few different ways that planetary scientists think that it's possible to have a bunch of oxygen on your planet and not have it be blown. away in the early life cycle of the star and not have it come from photosynthesizing life. There's a few different configurations that at least their models tell them this can happen

in. Like if you have a planet that has a huge amount of water, like a water world, then all that water will put pressure on the crust of that planet, which basically shuts down the geologic activity, like all the plate tectonics and the volcanism that we have. And it slows down the weathering and the melting of the rock. Both of these things absorb oxygen from the atmosphere. And so if you have a huge amount of water, you can shut down these sort of like oxygen slurping mechanisms. Like, you know, rocks out there on our planet have rusted because they have oxygenated.

All the weathering of rocks on the surface of the earth has slurped a huge amount of oxygen out of our atmosphere. So if you have a planet where you basically suppress the oxygen slurping mechanisms, then you can maintain some of the oxygen in the atmosphere. That's sort of like one mechanism to make an oxygen-rich exoplanet without life on it. So to get an oxygen-rich exoplanet without life, you can do it by having tons and tons and tons and tons of water. Can you get more dry versions or does it always have to have loads of water? Yeah, exactly. You can. The sort of desert planet can also do that. If you have a little water but not in zero, then you end up with like a solid surface and a lot of steam in the atmosphere.

It gets very, very hot and all the water becomes vapor. It provides this like big reservoir of oxygen in the atmosphere. and then the sunlight breaks up the water molecules, the hydrogen floats off to space because it's very light and the oxygen sticks around. And if the planet has like a solid desert surface, it can't weather, it can't absorb that oxygen. So then the oxygen stays in the atmosphere. So you have either like water world or a desert planet with like a steamy atmosphere. All right. Is there anything in between or those are the two ways you get high oxygen environments? There is one other speculation. If you have a planet that has like a very high initial ratio, ratio of carbon dioxide to water, then you end up with a runaway greenhouse effect,

sort of like Venus. It gets super duper hot and you have no oceans because all the water is turned into steam and you have no volatiles in the planet's mantle because it's too hot. These volatiles would do the same thing of like sequestering all the planetary oxygen through chemical reactions. Instead, the volatiles are now in the atmosphere where they're unable to remove the oxygen. Or having a really significant runaway greenhouse effect is another way to suppress some of the oxygen slurping mechanisms that would normally remove oxygen from an atmosphere.

So either you have a water world or a desert planet or you have like a crazy Venus greenhouse effect. Well, frankly, I don't want to live in any of those environments. So I'm hoping whatever microbes we dump makes everything a lot nicer, much longer after. Let's take a break and then we'll talk about one other nice option for where we could be seeding our microbes. The U.S. Open is seen. here. And on my podcast, good game with Sarah Spain. I'm breaking down the players from rising stars to

legends chasing history. The predictions will we see a first time winner and the pressure. Billy Jean King says pressure is a privilege, you know. Plus, the stories and events off the court and of course the honey deuses, the signature cocktail of the U.S. Open. The U.S. Open has gotten to be a very fancy, wonderfully experiential sporting event. I mean, listen, the whole aim is to be accessible and inclusive for all tennis fans, whether you play tennis or not. Tennis is full of compelling stories of late. Have you heard about Icon Venus Williams' recent wildcard bids? Or the young Canadian, Victoria Mboko, making a name for herself?

How about Naomi Osaka getting back to form? To hear this and more, listen to Good Game with Sarah Spain, an Iheart women's sports production in partnership with deep blue sports and entertainment on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. Presented by Capital One, founding partner of IHeart Women's Sports. Culture eats strategy for breakfast. I would love for you to share your breakdown on pivoting. We feel sometimes like we're leaving a part of us behind when we enter a new space, but we're just building.

On a recent episode of Culture Raises Us, I was joined by Volisha Butterfield, Media Founder, Political Strategist, and Tech Powerhouse for a powerful conversation on storytelling, impact, and the intersections of culture and leadership. I am a free black woman who worked really hard to be able to say that. I'd love for you to break down why it was so important for you to do C. You can't win as something you didn't create. From the Obama White House to Google to the Grammys, Malicia's journey is a masterclass in shifting culture and using your voice to spark change. A very fake, capital-driven environment and society will have a lot of people tell half-truths. I'm telling you, I'm on the energy committee.

Like, if the energy is not right, we're not doing it, whatever that it is. Listen to Culture raises us on the iHeart radio app, Apple Podcasts, or wherever you get your podcasts. Imagine that you're on an airplane, and all of a sudden you hear this. Attention passengers. The pilot is having an emergency, and we need someone, anyone, to land this plane. Think you could do it? It turns out that nearly 50% of men think that they could land the plane with the help of air traffic control. And they're saying like, okay, pull this, until this.

Do this, pull that, turn this. It's just, I can do my eyes close. I'm Mani. I'm Noah. This is Devin. And on our new show, no such thing, we get to the bottom of questions like these. Join us as we talk to the leading expert on overconfidence. Those who lack expertise lack the expertise they need to recognize that they lack expertise.

And then, as we try the whole thing out for real. Wait, what? Oh, that's the run right. I'm looking at this thing. Listen to No Such Thing on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. I had this overwhelming sensation that I had to call it right then. And I just hit call. I said, you know, hey, I'm Jacob Schick.

I'm the CEO of One Tribe Foundation. And I just wanted to call on and let her know there's a lot of people battling some of the very same things you're battling. And there is help out there. The Good Stuff Podcast Season 2 takes a deep look into One Tribe Foundation, a nonprofit fighting suicide in the veteran community. September is National Suicide Prevention Month, so join host Jacob and Ashley Schick as they bring you to the front lines of one tribe's mission.

I was married to a combat army veteran, and he actually took his own mark to suicide. One tribe saved my life twice. There's a lot of love that flows through this place, and it's sincere. Now it's a personal mission. I don't have to go to any more funerals, you know. I got blown up on a React mission. I ended up having amputation below the knee of my right leg

and a traumatic brain injury because I landed on my head. Welcome to Season 2 of the Good Stuff. Listen to the Good Stuff podcast on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. Okay, so there's one other nice option for places we could see. Maybe there's more than one, but one that we're going to talk about today. And those are planets that have these short windows of time as they're sort of developing and going along. where they might be a nice place to seed with earthy microbes. Could you tell us about that?

Yeah, I remember the big idea is to look for places where our life might survive, but life wouldn't grow on its own, where we're not displacing native life like original species. So one idea is oxygen-rich sterile planets because the oxygen prevents life from arising. The other is to look for places where life doesn't have time to arise. Like it might be that there's enough time for us to seed it with life, which could then take off, but there aren't like the billions of years it would take for life to start on its own. An example of that are brown dwarf systems. Brown dwarf is a star that's not hot enough

to fuse the way that our star does. It doesn't have enough mass, so there's not enough internal temperature for fusing to kick off. So they call these sometimes a failed star. They're just big blobs of hot gas and they're hot, but they're not fusing. They're not glowing, right? This does provides some temperature to create a habitable region for your planet. And it could remain habitable for like a few hundred million years or a billion years, but not like a long time the way that our sun and our Earth has many, many billions of years as a window. So the idea is to look for brown dwarf systems where life could survive, but maybe doesn't have enough time to develop on its own. And seed planets in those systems, that's a place where like our life

could again survive, but we wouldn't be displacing any native. species. But so then we would need to move our life somewhere else? I mean, I guess it would have millions or billions of years. And so it would have some, you know, time to run its course. But is, I mean, is that enough time where we could imagine that something we could eat could have developed and that that would be a useful run for the experiment? Yeah, exactly. So you send our life there, and it has enough time to flourish and develop and do something before we arrive and set up our grocery stores. Okay. I know, I feel like there's still a part of me that feels like if it's enough time for our seeded microbes to do their thing, that should be enough time for life to potentially

arise on its own there. So I'm not 100% convinced that we wouldn't be snuffing out some other possibility for the start of life on another planet. But am I missing the point? No, you're not at all. And I totally agree. All these calculations assume that life takes a long time to start. And if it doesn't, if life starts pretty quickly when there are good conditions, then all these places potentially could have life already. or could start life any moment, right? And if you seed them on a Tuesday, you could be displacing life,

which would have started on a Friday. And so before we do this, we definitely need to understand that a lot better before we're confident in saying, like, oh, this is a sterile place, and it's unlikely for life to arise anyway. Okay, so let's assume that we've convinced ourselves we've found a sterile place

that we feel comfortable seeding microbes. How do we get the microbes there? I assume some of the methods that we use to survey could also be used to deliver microbes. So it's a great question. How do we deliver the microbes, right? Say you actually have this little blob of stuff and you want to send it to a planet around Alpha Centauri or something. What we talked about earlier, the solar sail is great for getting up to high speeds, but it's not so great for breaking. You don't want your microbes to hit the planet at like 95% of the speed of light because then they'll just like core sample the planet, right? They need a gentle landing if you're going to disperse them, sprinkle them on top of the ocean, right? So somehow you have to figure out how to slow down. You don't just want to accelerate and zoom through the system. You want to arrive at a gentle speed. How do you do that?

Yeah, it's tricky, but there's a really cool technology called magnetic brakes, which are very similar to a technology that you and I talked about in that science fiction novel Orbital Cloud. Remember that they had this technology in that book to maneuver satellites by using the Lorentz Force. They had these long space tethers, these long wires. If you put a current on the wire, it would interact with a magnetic field of the planet. and put a force on the object. It's a very similar idea here. The physics is fundamentally the same,

though the mechanism is a little bit different. What you do is you bring a loop of wire and you make a current. That current makes a magnetic field. And you can use that magnetic field as a break because space is actually filled with stuff that you can push against. Because the sun is not just putting out photons,

it's putting out protons. Part of the solar wind are these charged particles, these protons flying through space. And as you approach this distance system, you can turn on this magnetic field, which will push back against all of these protons in a way to slow you down. Could you turn on the magnetic brakes from Earth? Like, how do you make sure the brakes don't turn on too soon? I got no brakes, no brakes. No, it's important that you time this right.

And yeah, you could turn this on from Earth or you could pre-program it to know where it is or you could detect a certain level of protons. There's lots of various ways to turn it on. But yeah, you could send this thing messages, which would catch up with it because it's not flying at the speed of light. And so your photonic messages from Earth could always catch it. Now, unlike a solar sail, which people have built and tested, magnetic braking is a little bit more theoretical. Nobody's ever built one of these things as far as I could tell and demonstrated that it could actually work out there in the environment of space. But in principle, we have some ideas about how to do this, how to send something there really, really fast and slow it down. in time to enter the system okay so let's assume that we can send something out to our chosen exoplanet

and we can stop it so that we don't accidentally core the planet like how do you pick which microbes you send yeah that is a great question what do you send how likely it is to survive you send one thing you send 10 000 different things you send more of one than the other how does this all work what do microbes need anyway so i didn't know the answers to these questions so i called up a friend Will Ratcliffe, he's an evolutionary microbial biologist at Georgia Tech, and he studies the evolution of multicellularity. Like, how did critters go from individual cells to working together as single organisms? You have such interesting friends. Let's hear the interview. So here's my chat with Will Ratcliffe.

All right, so then it's my pleasure to welcome the podcast, Professor William Ratcliffe. Will, welcome to the podcast. Thanks very much for joining us. Thanks for having me. So Will, we are talking about dropping a load of life on some alien planet, some exoplanet. And I'm just wondering, like, first of all, what are the chances of microbes surviving? If I take a bunch of stuff I've scraped out of sewage here on Earth or, you know, from underneath some trees or something in a forest, and I launch them to an alien planet, are they just going to dry up and die?

What are the chances that they can survive? So the answer to this I think really depends on the existence of a few things. You need liquid water. There's really kind of no getting around that. If you have an exoplanet that doesn't have liquid water ideally on the surface, then it's going to be an uphill battle for life. You might have things which persist but don't flourish. But if you have liquid water, then it becomes a question of what kind of energy sources

and what kind of carbon sources are available for that life. We're used to life that sort of makes a living largely either. eating other things, which we do, right? We take large chains of carbon and break them down and get both of our carbon, which is what we use to build bodies and our energy, which is what we use to power those bodies from those big chains of carbon. But there's actually a lot of different niches that life has sort of evolved to take advantage of and dissipate energetic equilibria and build bodies with carbon in different ways.

One that's really common and I think it's common in the universe and really impactful is light. So, you know, photosynthesis. So being able to use light for energy is a really common way of making a living because there's a ton of energy in light and it's relatively straightforward for organisms that have evolved the ability to use it to just put it to work powering cells. But didn't we have life on Earth for millions of years before we had anybody taking energy from photons? Yeah, it's a good question. It's actually, it gets really difficult to infer back that far. So we likely had photosynthetic behavior pretty soon after. the origin of life. Although, again, it's difficult to really see back beyond a couple billion

years. By 2.1 billion years ago, we had had so much oxygen pumped into the atmosphere on Earth that we oxidized our atmosphere. And we have, you know, we basically couldn't absorb and react away any more of it. But life arose around 3.5 billion years ago. But you're right. There's other ways to make a living that don't depend on light. And in fact, if we look at those, those are things which are probably pretty common in the universe as well. So, you know, the main way that metabolism works is by taking something which is at a high energy state and reacting it into a lower energy state and using the energy that's released to power metabolism.

These redox reactions are common. There's many different ways to do it. A simple way is to take hydrogen, right, and sort of burn it into, with oxygen and burn it into water. That releases a ton of energy and that can be used to power metabolism. You may not have oxygen. I mean, hydrogen, that's really common in the universe. So I think we can assume that there may be some hydrogen around, right?

You may not have oxygen, however, on one of these planets, although I will say on a planet that has surface water, it's not that unlikely to think that there will be some oxygen every now and then. And that's because if there's light, light will take water, it'll break it apart. You know, ultraviolet light will break it apart. The hydrogen will escape into space and you'll be left with oxygen, which is persistence time depends on whether it reacts with things, but you can have oxygen around. So you're saying we basically need liquid water, we need some light, and we need some some carbon and some hydrogen, and then probably the microbes will be happy munching away.

Pretty much. And it turns out that we can even make it less restrictive than that. You can take light off the table, although I think, you know, since planets usually around stars, light's usually not off the table, but you could take it off the table. And if you have hydrogen or if you have iron, those are also very common, very effective sources of generating the electron flow during a redox reaction that can power life. So there's life on earth that can literally rust iron and grow using the energy that comes from that. That same life can take carbon dioxide and fix it, meaning turn it into longer chains of carbon.

And so you can basically, if you have carbon dioxide and you have iron or if you have hydrogen and carbon dioxide, you are good. If you have light, you are really, really good. And if you have oxygen, light, iron, and carbon dioxide, it's chill. You can easily have life. Well, as a physicist, I worry about other things like levels of radiation. You know, if this thing is getting like impacted by huge numbers of cosmic rays, I worry about them getting shredded. On the other hand, I have in my head my wife's voice and she's always telling me that life survives everywhere. You know, they find it on the outside of the space shuttle and they find it, you know, it's basically impossible to fully sterilize anything.

Inside Chernobyl, you know, you find things that are rad hard. So do we have to worry about these critters being fragile or we're pretty sure? if we have a big enough sample that some of them are going to survive? I think it's not a big worry. If you have a large sample, you'll have things that survive, plus you could have them inhabit environments that are somewhat protected. You know, hydrothermal vents on the bottom of the ocean, for example, will buffer you from a lot of stuff.

And then organisms can evolve mechanisms that make them much more robust to the damage to DNA that's caused by high intensity waves and particles. So, you know, a lot of organisms like tardigrades are often touted as a cool example of something which is robust to DNA fragmentation. They've evolved a lot of cool mechanisms that can take DNA that's been busted into a bunch of small pieces and reassemble it in a pretty accurate manner. All right. So say you're tasked with developing this payload, we're going to drop it on some random alien

planet you know very little about just because you've seen maybe some spectroscopy from its atmosphere. What cocktail do you recommend sending? I mean, should we just scoop up a sample from a local forest? Does it really matter if they're all so hardy? I think it does matter in that a local forest, the surface. of local forest is probably a very different environment than what you're going to find there in it. And it's an environment that is not wet. I think we're going to have our best bet with

something which targets oceans because oceans are large. Oceans are relatively stable. And if let's hope that this planet has has surface water that's liquid. And within those oceans, I think I would, I would have a mixture of things which inhabit both the surface and are phototrophic. So things which can photosynthesize using light and things which inhabit like seafloor niches where they can do chemical chemical autotrophy, where they would be basically breaking down hydrogen, using hydrogen sulfide as an electronic sector, doing things which allow them to make a living that is completely independent from a light-based ecosystem. So then what do you expect we might get? Say we drop this thing on an alien planet and we come back in 50 million years or our descendants eventually make it

out there on slow colony ships. Are we going to end up with just like a frothing ocean filled with microbes or are we going to show up and there's going to be dinosaurs in redwoods or you know some alien version of these things 50 million years is pretty short in this in the scheme of things so i think you're looking more at a frothing ocean filled with microbes okay um although they may terraform the planet in the sense of creating enough oxygen you know the amount of oxygen that we have in our atmosphere 20% of our atmosphere that's all coming from life right that's all coming from photosynthetic organisms and so if this planet doesn't have life already if it's a sterile planet there won't be much if any oxygen available.

Like the amount of oxygen that we have is because of life. And so I think if we could get, you know, very photosynthetically active ocean microbes, it might take a little longer than 50 million years, but you could terraform the planet in a way that would probably result in more of an aerobic atmosphere, something which we're more happy with. But to get something like dinosaurs and redwood trees and stuff,

I would probably actually jump the gun a little bit here and seed the world with more highly, more derived organisms than just these bacteria. which are hearty, which can live, you know, bacteria are like the ultimate metabolic, you know, toolkit masters. If there is an energy source to be dissipated, there's a bacteria or an archaea, a single-celled organism that has evolved to dissipate that. You know, there's bacteria living miles deep in rocks, eating only hydrogen.

Amazing. It's outstanding. You know, they might divide once every thousand years. It's really cool. But these types of more complex organisms, generally speaking, these multicellular organisms that we can that have, you know, complex morphological features, they evolve from eukaryotes, which are a different kind of organism. It's actually the result of a symbiosis between a bacterial cell and an archaeal cell. And that symbiosis started on the order of two billion years ago. And these organisms

have compared to bacteria, they have a lot more complicated sub-cellular features. They have their DNA encased within a nucleus. They have more complicated mechanisms for generating and moving proteins. And have many more opportunities for within-cell gene regulation. And it's within this more complicated kind of cell that you've gotten the types of multicellular organisms that we know and love, plants, animals, fungi, dinosaurs, redwood trees. And in fact, even those lineages, which have evolved pretty sophisticated forms of multicellularity, it took them quite a while to do that. So animals have been around for, you know, on the order of at least 600 million years.

plants cropped up around 420 million years ago is kind of when they got their start fungi have probably been around for about a billion years although it's hard to tell when they became multicellular but it often actually took quite a while for this origin of multicellularity play out but I will say once you give them a toolkit where they have the ability to have cells that remain attached to one another and to specialize in different behaviors and you know regulate that specialization through communication or other bioelectric sensing and response mechanisms, once they have those toolkits for how cells grow into bodies

and specialize and undergo morphological, novel morphological function, they can diversify very quickly from that starting point. So I think what you'd want to do is like seed that world with maybe relatively hardy, relatively simple plants, animals, and fungi. And then let those things diversify into the various ecological niches that they find. Although you might actually have to do a sequential, now that I think about this sequential seating, hidden with the basic stuff to get, you know,

a carbon-rich ecosystem going and then toss in the more complicated stuff, you know, a couple thousand years later. So what do you think is the most complex form of life that might survive this kind of trip? I'm imagining this thing is like frozen or desiccated and then dropped into the ocean with basically nothing and we hope it just sort of reconstitutes itself.

You can't do that with like a dog, right, or a tree. So are we seating this planet with tardigrades to come back, 50 million years later to find a human-sized intelligent tardigrades. That's a fantastic question. So freezing things for interstellar travel, like a lot of smaller organisms, there's probably a way to work that part out without too much difficulty. You can freeze, you know, you can't freeze a fly, but you can freeze a, you know, a number of smaller animals.

Certainly tardigrades would have no problem being desiccated and shipped around the, around the universe. But I don't think that they're going to become, you know, large and complicated. They make their living basically sucking up bacteria. plants I think I would take advantage of resting stages like spores in ferns or or you know heart very very durable seeds of angiosperms that being said I don't know what if anything could survive these extremely sterile conditions that we would find ourselves with on a new planet I mean I think I think bacteria are really like they should do fine you know if you

throw enough stuff enough different types of bacteria with enough different forms of metabolism at a blank slate environment where there are energetic, you know, conditions, energetic equilibria to be disequilibria to sort of be taken advantage of and be used for energy, you're going to get something which grows on that. But plants, animals, fungi, those are all things which largely have evolved in the context of already pretty rich ecosystem of other organisms. And they're highly dependent on those other organisms to make their living. I mean, plants you might be able to get away with in the sense that they are mostly

self-sustaining photoautrophic organisms that are growing on light, water, and minerals. but even plants are really specialized on growing on land. Like plants are basically, you know, we talk about, oh, the invasion of land. Really, it's the invasion of air from a marine algae that was the difficult part for plants. So I think you could probably, if I was going to throw anything in there that was larger and more complicated, it would be something like a seaweed, right? Because they're phototrophic. They're getting their energy from the sun and minerals.

There are many mutualistic interactions that they have with other organisms, but I'm sure you could find something which doesn't depend on those and can grow azinically. And then once you have macro-algae growing, they create a habitat for many different organisms. Lots of animals, for example. So if I thought about this more, maybe what, you know what I would do? I'm not sure how you'd ship this around the universe, but have ever seen those fully enclosed little ecosystems that have some algae and some shrimp?

I think they're Hawaiian, and they can live in a completely enclosed sealed glass sphere for for decades where that, you know, basically you have this nice balance between the oxygen that's produced by the algae and the food that's created and the shrimp which consume it and create carbon oxide, which the algae use. It's pretty cool. So something like that, maybe some small invertebrate, which is mostly grazer on algae or even eating things that might, the single psychology, which grow on the surface of macroalgae and macroalgae and maybe try to get that established. I don't know about just throwing it into a sterolotion, but if there was a way to sort of, you know, have an incubator where you have a near-shore environment or a pond, something a little bit less

big than subject to planetary scale weather. So is this an idea which excites you? You're like, ooh, this would be really fun to see what happens or something that terrifies you, the idea of, you know, polluting the galaxy with our kind of life. You know, is it wonderful to imagine showing up on this planet and having like intelligent shrimp swimming in kelp forests that we see? you know, long times ago. It's more exciting than terrifying for the simple reason that while we don't really know

what the extent of independently evolved life on other planets is, it seems like the amount of planets that exist vastly outstrips the amount of independent origins of life, certainly complex life. And so it doesn't seem to me that planets with liquid water are necessarily a super limiting resource in our universe. And so the opportunity to see how life would evolve given replays of the tape, right, to see how it would independently go about colonizing a planet, diversifying. I mean, you could, it would be, it's a once in a lifetime opportunity to see how something which starts over reconstitutes itself, how a biosphere reconstitutes itself.

So you want to turn the entire galaxy into your own lab, basically? I mean, you know. I wouldn't say no. That's the exciting part. But I would say you'd have to be very, you know, very confident that there wasn't already existing life on that planet before you went about doing this. I mean, if it truly was sterile, that I don't think that there's a huge amount of downside. But a lot of that depends on how confident you are, that it really is a sterile. And, you know, that being said, if this planet's sterile, and it's been sterile, presumably, for quite a long time, despite being habitable, you know, billions of years, it seems unlikely that it would all of a sudden not become sterile in the near future anyway. So I don't know what you're giving up.

All right. Well, thanks very much for sharing your excitement and your insights with us. Really appreciate your time. Yeah, it's a pleasure. And, of course, I checked in with Katrina to see how much she agreed with Will. So then if microbes are so hardy, if we wanted to seed an exoplanet with life, can we just send anything we want, or do they need to be carefully chosen? I think diversity would be a better strategy than like carefully choosing just one strategy. So I think you would be better off, you'd be more likely to succeed by gathering up microbes from a lot of different environments

and then sending as many different strategies out there. So you'd get to roll the dice a lot more times. But I think you would want to pick from environments that are already harsh and potentially similar to the place that you're trying to bring the microbes to so that they would already be adapted. But yeah, if I had to pick between, like, you know, one lab evolving a perfect bug

versus just like sampling all of Earth's environments, I would vote Earth's environments. So I think Will's answer your question is that it would take a lot longer than 50 million years to get from microbes to redwoods and dinosaurs and grocery stores. So I am not going to be shopping at the Brown Dwarf grocery store. That's a bummer. No, but your great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great. Great grandkids might be able to have dinosaur steaks for dinner. Thank goodness. The future is good.

Okay, so as you may have been able to pick up throughout the course of the conversation, I have some concerns about this. idea, though I do find it interesting. So should we do it? Let's end on that. So how about in our solar system? What do you think? Should we ever do this? I think it's a hard question in general, but I think that in our solar system, it's pretty clear. Like, yes, it'd be nice to be able to live on Ganymede or on I.O. But if we just send our microbes and spray them all over the solar system in the hopes of eventually having a biome that could support us, we're ruining our chance to answer a much deeper, more important question, right? Like, how hard is it for life to start? Could life have started in other places in the solar system independently? Or maybe

life in the solar system actually did start only one place, but not on Earth and then came to Earth. If we sprayed bacteria and microbes all over our solar system, we couldn't answer these questions. We'll have polluted our backyard. And I think those questions are more important than grocery stores on I. I think many people would disagree with you, especially when it comes to Mars, because of course, if we're going to settle Mars, we are going to be seeding Mars with all kinds of stuff.

And depending on how soon we do that, that might be before we even know for sure if Mars has life on it or not. So this is, you know, something that could possibly happen in our lifetime. But do you think that the ethical questions become or have a little clearer answers if we're talking about other solar systems?

Well, I'm going to get back to Mars, actually, because as a world-famed skeptic on the possibility of settling Mars, I have to ask you, do you think it's possible to settle Mars and not polluted? Like, could we set up some sort of barrier where we have like a Earth region on Mars and somehow avoid contaminating the rest of the planet? Or is that impossible? I'm not very optimistic that we could do that. So, you know, Mars has dustworms that blow dust all over the planet.

And, you know, I think there are microbes that, you know, even if you said like, okay, no humans are allowed to, you know, cross this line and half the planet is going to be pristine, I think our microbes over time would sort of blow around the planet. And, you know, if there's no microbes there there already, then maybe that's not so bad. Although the microbes will start changing, you know, like the chemistry of the environment. And that might make some scientists sad who wanted to study Mars and it's like preserved states. So, you know, there's a lot of tradeoffs you need to make when you're thinking about what to do with another planet. Yeah, it really does seem like we have to decide, is Mars a scientific preserve or is it a resource to be exploited? Yeah, and then the difficult

thing is, you know, if the U.S. decides one thing or in China decides another or Russia decides another, like can you get the whole global community to agree on what we're going to use Mars for? And I guess we'll see. Yeah, and not just governments, right? Accentric zillionaires can start their own Mars colony outside of any jurisdiction, right? There are no laws on Mars as far as I'm aware. Nope, no, no, nope, nope. So if, if, if, if Musk wanted to go to Mars, he would still have to, like, get a permit through the FAA and he would have to, like, essentially get approval from the U.S. government. And when you're out in space, you are still the responsibility of some government. So Musk would still be the United States's responsibility. They should be telling him what he can

or cannot do out there. So, you know, the outer space treaty is international. law that is supposed to apply to when humans go out into space as well. But, you know, is Musk going to listen? That's a different question entirely. And what would be the implications if he doesn't listen? Who knows? Because, you know, the U.S. could say no more. You're going to throw him in Mars jail. That's right. I mean, so the U.S. does have some leverage. They could say we're not sending any more resupply ships until you guys, you know, get your axe cleaned up. But, yeah, who knows what Musk will do when he gets there? Yeah. So it's a tricky question here in our solar system. In terms of other solar systems, I think it's related, but for me, the balance

tips a little bit in the other direction. Like, there are so many planets out there, I'm fairly confident we could find some that have no life on them, that we could use as experiments, or we could use to seed edible biomes for the very future of humanity. Seems to me to be too restrictive to say we can't explore or we can't experiment anywhere in the galaxy. Yeah, I think if you could absolutely convince me that we definitely knew what to look for and could absolutely determine that a planet was sterile, you know, the evolutionary biologist in me would love to see what happens if you, you know, drop microbes and then come back, you know, six billion years later. What do you have there? That sounds fascinating.

It would be difficult for you to convince me that it was definitely a sterile planet and we weren't going to be, especially when it's, you know, in a different solar system. But if you could convince me of that, then I would certainly be interested in seeing this experiment run, not just because I love food so much, but because I think there'd be interesting science. Yeah, because it would be a huge tragedy if there really was like alien life on that planet. And then we sent our microbes and it like wiped them out. What if we showed up and there were like fossils of a dead civilization that we had killed with our equivalent of smallpox? Oh, that would be awful.

And also from like a science perspective, like losing all of the data on like when life actually pops up independently and the direction that that took as opposed to, you know, what does our life do when you put it somewhere else? I think it's much more interesting to see what happens when life. pops up somewhere else on its own and then what happens to it. But yes, so many levels of it being super sad if it turns out we're messing up what's happening on some other planet. Yeah. If that happens, we should get thrown in space jail. Yes.

Yeah. Except, you know, we will have long since been dead because it will take so long to get the microbes there. But so I guess our whole species would have to get thrown into space jail. Yeah, exactly. I think it's an interesting question, even if we never do it, right? Even if we don't actually do this, it's fun to imagine, Like, how would it work?

What technology would you need? Is it even possible? To me, it's fascinating that we're not actually that far from this kind of technology. Like solar sails, we could build that. Magnetic brakes, probably that would work. Capsules of ocean water, which might survive the transit from here to there. That's not implausible. Like, this sort of science fictiony scenario could be reality in the not far future.

Yeah, we live in exciting times with exciting possibilities. I hope we make the right choices. Since we're talking about some big moral choices, I ask Katrina about the should we side of this question. And how would you feel if an alien payload arrived with their microbes, hoping to seed our world with their bugs? Would you feel invaded or intrigued? I mean, obviously intrigued, but how would I handle that? I hope you're listening to that, aliens. Yeah, and CDC.

I hope the CDC is not listening to that. one too much, actually. But I mean, you would definitely want to do that kind of work in a very careful environment. And we do know how to work with pathogens. It's never perfect, though. I mean, that's a whole other conversation. But, you know, I don't love hearing that there's smallpox in a freezer somewhere. And it's just one mistake away from getting into contact with humanity again. And so not knowing what the health impact or the environmental climate impact of a new set of microbes would be, I would definitely want to tread lightly. But I'd be super intrigued. Oh my gosh, that's a dream to like get to figure out how on earth they, how on wherever they

came from, they do their metabolisms and copy themselves. And I mean, that would be fascinating. I hope you feel like you've made the right choice in listening to me and Kelly talk about this question for the last hour. And I hope that you learn something. Not just about whether not Kelly is likely to chop you up, but whether future humanity could and should send microbes to other planets. I was the scary co-host this time. Usually that's your job. Exactly. Now I know what it feels like. Oh my gosh. I'm quivering my boots and I'm glad we're across the country from each other. Thanks very much for joining us, even though you threatened to slice me into pieces. Thanks very much for having me and for being a good sport when the tables

returns. All right. Thanks for listening, everyone. Tune in next time. Thanks for listening. And remember that Daniel and Jorge Explain the Universe is a production of I-Heart Radio. For more podcasts from I-Heart Radio, visit the I-Heart Radio app, Apple Podcasts, or wherever you listen to your favorite shows. Get fired up, y'all.

Season two of Good Game with Sarah Spain is underway. We just welcomed one of my favorite people, an incomparable soccer icon, Megan Rapino, to the show. And we had a blast. Take a listen. Sue and I were, like, riding the lime bikes the other day. And we're like, we're like, we. People ride bikes because it's... We got more incredible guests like Megan in store, plus news of the day and more.

So make sure you listen to Good Game with Sarah Spain on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. Brought to you by Novartis, founding partner of IHeart Women's Sports Network. Tune in to All the Smoke Podcast, where Matt and Stacks sit down with former first lady, Michelle Obama. Folks find it hard to hate up close. And when you get to know people and you're sitting in their kitchen tables and they're talking, like we're talking. You know, you hear our story, how we grew up, how Barack grew up. And you get a chance for people to unpack and get beyond race. All the Smoke featuring Michelle Obama. To hear this podcast and more, open your free iHeartRadio app. Search all the smoke and listen now.

Have you ever wished for a change but weren't sure how to make it? Maybe you felt stuck in a job, a place, or even a relationship. I'm Emily Tish Sussman and on she pivots. I dive into the inspiring pivots of women who have taken big leaps in their lives and careers. I'm Gretchen Whitmer, Jody Sweetie. Monica Patton, Elaine Welteroff. Learn how to get comfortable pivoting because your life is going to be full of them. Listen to these women and more on She Pivots, now on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts.

Culture eats strategy for breakfast, right? On a recent episode of Culture Raises Us, I was joined by Belisha Butterfield, media founder, political strategist, and tech powerhouse. for a powerful conversation on storytelling, impact, and the intersections of culture and leadership. I am a free black woman. From the Obama White House to Google to the Grammys, Valicia's Journey is a masterclass in shifting culture and using your voice to spark change. Listen to Culture raises us on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts.

Why are TSA rules so confusing? You got a hood of you. I'll take it all! I'm Mani. I'm Noah. This is Devin. And we're best friends and journalists with a new podcast called No. No Such Thing, where we get to the bottom of questions like that. Why are you screaming?

I can't expect what to do. Now, if the rule was the same, go off on me. I deserve it. You know, lock him up. Listen to No Such Thing on the IHeart Radio app, Apple Podcasts, or wherever you get your podcast. No such thing. This is an IHeart podcast.