StarTalk Radio - Cosmic Queries – Life on Other Planets with Aomawa Shields

Episode Date: July 11, 2023

If scientists discovered that we are not alone, what would they do with that information? Neil deGrasse Tyson and Chuck Nice learn about the search for life, habitability around M stars and more with ...astrophysics professor and author Aomawa Shields. NOTE: StarTalk+ Patrons can listen to this entire episode commercial-free here: https://startalkmedia.com/show/cosmic-queries-life-on-other-planets-with-aomawa-shields/Thanks to our Patrons Pepper Horton, annie brown, Lance Cardwell, Natalie waugh, firestorm960, and Daryl Spencerfor supporting us this week.Photo Credit: Original ESO/M. Kornmesser  (+ background position from original change by Nagualdesign), CC BY 4.0, via Wikimedia Commons Subscribe to SiriusXM Podcasts+ on Apple Podcasts to listen to new episodes ad-free and a whole week early.

Transcript
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Starting point is 00:00:00 Coming up on Star Talk, we speak with my friend and colleague Aomua Shields. She's an associate professor of astronomy specializing in astrobiology at UC Irvine. And we talk about the search for life on planets that are already known to exist in orbit around their host stars. We're going to learn what M stars are. We're going to find out what the color of the star has to do with what life might be like on a planet's surface that orbits it. And we'll also take questions, cosmic queries from our Patreon members. All that and more coming right up. Welcome to StarTalk.
Starting point is 00:00:41 Your place in the universe where science and pop culture collide. StarTalk begins right now. This is StarTalk. Neil deGrasse Tyson here, your personal astrophysicist. I got Chuck Nice with me. Chuck. Yes. Doing it again. Doing it again.
Starting point is 00:01:03 The universe is nonstop. That's right. And it is continually... Is it really, though, Neil? Is it really? Yes. Doing it again. Doing it again. The universe is nonstop. That's right. And it is continually. Is it really though, Neil? Is it really? Yes. Does it? I mean, seriously, can we say with certitude that the universe does not stop?
Starting point is 00:01:16 I mean. If there's anything in the universe that doesn't stop, it's the universe itself. There you go. Bam. Okay. I'm going to see your statement and raise you entropy. Bam. Okay. I'm gonna see your statement and raise you entropy. Today we're talking about life on other planets. Yes. Life on other planets. And we've got a friend and colleague of mine, Aomawa Shields. So she's an astrophysicist and more specifically an
Starting point is 00:01:44 astrobiologist, which is kind of a new field. New in the last few decades. I'm old enough to call that new. Also on the landscape of science communication, she's there and she's a force. She's an associate professor in the Department of Physics and Astronomy at UC Irvine and founder of Rising Star Girls, a program dedicated to helping girls discover the universe. I know. Watch out.
Starting point is 00:02:11 Also a trained actor. What? I know. Wait a minute. I know. I know. Wait a second. Wait, wait.
Starting point is 00:02:18 But I'm not done. Oh, go ahead. Until I'm done. All right? Now she's got a new book out. Okay. Now you can react. Okay.
Starting point is 00:02:27 What? And she's got a new book, Life on Other Planets, a memoir of finding my place in the universe. Whoa. And that comes out in the middle of 2023.
Starting point is 00:02:43 Welcome back to StarTalk. I think we've had you on before, haven't we? You have. Thank you. It's wonderful to be back. Last time we were talking about terraforming Mars, and now we get to talk about more life on other planets, places where there actually could be life,
Starting point is 00:02:57 although maybe Mars. I don't know. Yeah, plus I want to get to the bottom of what it means to have a book tell a life on other planets, and now you call it a memoir. Chuck, I think she's an alien. Okay, that's what I'm saying. How was the trip?
Starting point is 00:03:13 I have a lot to share. I have a lot of information now. Yes. So we'll get to your book a little later, but let me just, can you update us on where are we in the search for life in the universe? Because you focus on the habitability of exoplanets and in multi-planet systems, what climate might be on those planets. So what are you doing when you go to work each day? Yes. So my team's work starts after the planets have actually been found.
Starting point is 00:03:48 So it's hard enough, as you know, to find a planet around another star. Although we are going like gangbusters. We're approaching 6,000 planets. That's right. So, yeah. And that's the tiniest fraction of our own galaxy. Never mind the fact that we have 100 billion plus galaxies in this universe. But yeah, we've got close to 6,000 now that we've found. And so, well, we don't really
Starting point is 00:04:12 know anything about how habitable they might be, whether they might have water on their surfaces, which is what we define as habitable, because we know all life on earth needs water. Everything from the tallest, largest elephant to the smallest, teeniest microbe needs water. But you just confessed that you're completely biased. You're not just looking for life. You're looking for earth life. That is true. That is true. And this is why- Okay. I want you to fess up just right here and now. Thank you. Show your cards. Okay, go.
Starting point is 00:04:43 Very true. And this is why the field of astrobiology is so important, because there are astrobiologists like me who are looking for planets that might be warm enough for liquid water on the surface, but not too warm. And there are also astrobiologists whose job it is to ask the question, what about life as we do not know it? What about non-Earth-like life? Could life use something else besides water or something else besides carbon in its backbone?
Starting point is 00:05:12 So that's really important. We can't be so Earth-focused that we miss discovering life because of that. Because I've seen some missions, they're looking for Earth-like planets around sun-like stars. You can't get more sort of biased than that, it seems. True, true. And sun-like stars are not the majority of the stars in our galaxy. The majority of the stars in our galaxy are actually much cooler, smaller, and redder than the sun. So that brings up…
Starting point is 00:05:42 That sounds to me like we should be looking there. I have spent a lot of my career focusing on that, right? These M stars, these small stars. M, so we're a G star, sun is a G star. Yeah. So with OBA of GKM. So M is like the coldest star category we have. So why would you think- Pretty cold. We know of some even cooler ones now, like L's and T's, but then there's been some controversy. Are those really stars? Are we getting so cool
Starting point is 00:06:12 that we're in the like brown dwarf regime? And just to be clear, when an astrophysicist refers to a cool star, we're talking a few thousand degrees. That's right. It's still really hot. Not Robert Downey Jr. You'd still be incinerated. Yeah, it's still really hot. Not Robert Downey Jr. You'll still be incinerated.
Starting point is 00:06:27 Yeah, it's all relative. All right. So how do you modify your search for life around an M dwarf star? Yeah. If you know it's not as warm as the sun. So what happens to the habitable zone and other sort of properties that you're seeking. So if we want to look for a planet that could be what we call this habitable zone or the Goldilocks zone because it's not too close to its star, not too far away, so it's not too hot, not too cold, we have to look much closer to an M star than we would to around
Starting point is 00:07:02 a sun-like star in the same way that if you're, you know, say you're on the beach and you're crowding around a little campfire, you're going to have to stand much closer to that campfire to get the same amount of heat as you would if that campfire was a bonfire. But the same principle exists when we talk about these cool stars versus the hotter stars. So we're really close. It just redraws your habitable zone. That's right. That's all it does.
Starting point is 00:07:27 Yeah, so it smushes it closer up. And there's some interesting things that can happen when a planet is orbiting that close into its star. There's forces at work. There's tides. The planet pushes on the star. The star pushes on the planet. And the planet's rotation period can get slowed
Starting point is 00:07:45 down and maybe even to the extreme case where there's one permanent day side and the other side, it's always night. And we call that situation synchronous rotation. It's like this extreme case of tidal locking. And it's literally always day on the day side, always night on the night side. And my team- That can't be good for life.
Starting point is 00:08:10 People have thought that it would be really bad. Not if you want to nap. Right, yeah. So how are you going to put life on a planet like that? Or maybe you just have like a work side of the planet and a party side of the planet. Oh, I like that. Let's go life on the night side. So I get it. You don't wait for night
Starting point is 00:08:27 to come. Yeah, you go tonight. You go tonight. Oh, Chuck. It's like, yo, what you doing later? Yo, I'm going over the night, bro. And we're about, we're going to top it up crazy like. And all right, you know, it works. So that's, that has been a big concern. However, fresh off the presses, my team actually has some new work that shows that you could have life along the Terminator. Dun-dun-dun-dun-dun-dun-dun-dun-dun-dun.
Starting point is 00:09:00 The dividing line between the day and the night side. That's what we call the Terminator. Look at that. So temperature-wise, if it's always night and you're just never facing anything, that would be like a super cold part of the planet, right? Yeah. Right. And then if there was daytime, that'd be warm.
Starting point is 00:09:18 That would be a super hot place, right? So there's got to be a spot that's just right. Right. Okay. And it's funny. The just just right spot you call the terminator right so much more much more amenable much more neutral than our our pop fiction schwarzenegger terminator but i can't help i cannot help we coined this term terminator habitable and that's the name of our paper and But I can't help, I cannot help. We coined this term Terminator Habitable and that's the name of our paper
Starting point is 00:09:47 and like you can't not think about it. You are so dabbly comfortable. Very comfortable. It's like a warm bath. So before we continue, let me, if I may,
Starting point is 00:10:00 I will give a brief tutorial on how stars got the letter classifications. Please. So, you go back 120 years, we're getting data on stars that are not just pictures of them, but spectra. And we don't know what spectra are yet because quantum physics wasn't yet discovered. But we knew some spectra look like others, and you can put them on a continuum that transitioned from one kind of spectrum to another. And so we did that. And we lettered them A, B, C, D, E, F, G, H, I, G, the L, M, N, O, P. Okay. Then quantum physics
Starting point is 00:10:38 came around and we said, yo, there are reasons why the spectra look this way, and it's not what you're thinking. And it had to do with the temperature of the star. And it turns out these features can duplicate between being too cool to have a feature and too warm to have that same feature. By the time we shuffled these letters into a temperature sequence, A, B, C, D, E, F, G became O, B, A, F, G, K,
Starting point is 00:11:06 M. And why didn't we just re-letter them, which I think we should have at the time? Yeah. But we didn't. So we have this artifact. Could have gone with numbers. Pretty simple. Yeah, because now we get to confuse astronomy students the world over
Starting point is 00:11:22 year after year. Forever and ever and ever. Every year I get that question. So O stars are hot. B stars are next hottest. O, B, A, G. We're G star. And then each category is split into 10 other subcategories.
Starting point is 00:11:36 Okay, zero through nine. So we are the G2. Oh. Okay, Arabic numeral two. Okay. And we divided them by what's called luminosity class like how big are you
Starting point is 00:11:48 and so we have classes 1 through 5 or 4 or 3 yeah 5 and so we are G Roman numeral 2 I've got G Arabic numeral 2 Roman numeral 5 you tell that to an astrophysicist they know exactly what kind of star you're talking about.
Starting point is 00:12:05 G25. That's what it is. Sounds like something that rappers fly to their next concert in. Summit. G25, baby. So, Alomar,
Starting point is 00:12:19 tell me, what did you need to do to model a terminator habitability? What kind of calculations were necessary there? Yes. And I have to give a shout out to my postdoc, Anna Lobo, who's spearheaded this work. And, you know, we had to ask that question, as I write in the book, that having this question, could these planets even exist?
Starting point is 00:12:42 It's the first place to start for any scientist or any curious person. That helps. Before you invent life on a planet, make sure that kind of planet exists. Could actually exist. And the first thing we had to do, we're using models, climate models that are normally used to predict the climate on Earth. So they're the same models that have been used to predict the effects of climate change into the 2100s. The reason why we know that climate change is real and that it's going to
Starting point is 00:13:12 continue unless we do something is in part because we're using these models to forecast those effects. But what we're doing... And these models, so all you have to do is change some of the... They probably have knobs you can turn. That's right. Where everything else, because the physics would just be the physics, but the rotation ray and the sun's energy entering the system. These are knobs, right? These are knobs that we can turn. I didn't know these were general climate models. Fascinating. That's right.
Starting point is 00:13:39 So we are changing the spectrum of the host star, right? Changing the spectrum of the host star, right? How its energy, its light is distributed across the whole spectrum is going to be different depending on the temperature of the star, the type of star. We're changing the shape of its orbit, how much atmosphere, like what its atmospheric composition is, because we don't know those things for Earth-sized planets. We have no information about the type of atmospheres they might have or their surfaces. And understanding the effects on climate of different types of atmospheres is going to help us understand which of these nearly 6,000 planets we want to prioritize and look at
Starting point is 00:14:19 with next large generation telescopes to find out if there really is life there. So, you know, wow. So this is a beautiful example of the cross-pollination between two otherwise very different disciplines. Yes. You're going to climate science, folks. They don't care about exoplanets. They just care about Earth.
Starting point is 00:14:38 I know, and I'm on a personal crusade to change that. Because it's true. Like, this is, it's so interdisciplinary. We're using atmospheric science, climate science, astronomy, geology in some cases, glaciology, because I'm all about ice
Starting point is 00:14:52 and different types of ices. And different types of ices interact with different types of light depending on the type of ice. There's more than just water ice. We're looking at CO2 ice and other ice. So different ice would reflect
Starting point is 00:15:04 their sunlight differently. Differently. From other ice. So different ice would reflect their sunlight differently. Differently. From other kinds of surfaces and would change how much energy enters the system. That's right. Did I say that right? That's exactly right. I'm Joel Cherico, and I make pottery. You can see my pottery on my website, CosmicMugs.com.
Starting point is 00:15:31 Cosmic Mugs, art that lets you taste the universe every day. And I support StarTalk on Patreon. This is StarTalk with Neil deGrasse Tyson. Tyson. So, Aomawa, tell me, how does all this fold into this book that you just wrote? I'm so excited for this book. This has been a dream of mine for a long time. And as you know, I was an astronomer, then I changed and studied acting, And then I came back and finished my PhD and became a professional astronomer and a professor. And for the longest time, I was trying to reconcile these two things that I loved, acting and astronomy. And I thought that they couldn't coexist.
Starting point is 00:16:17 I thought I had to choose. And when I would share with people those two loves, I got a lot of like, what? This is so strange. Why? How? And I think I internalized that and tried to figure it out. And it was funny because when I stopped figuring it out, these incredible miracles got to happen where I saw how they can really coexist, like hosting a science TV show, which I could never have planned on my own. Eventually going back to grad school in part because of your suggestion and being put in touch with you and your mentorship. And also I had applied to the Astronaut Canada program and had not reached the next level. It was like everything was saying, go back, get your PhD. And I finally became willing to listen. And so the book really is
Starting point is 00:17:06 about that whole journey. It's about why I fell in love with the stars and the night sky and why I fell in love with acting and this whole edge that I carried for a long time of like feeling like I was an astronomer or a scientist around actors, feeling like I was an actor around scientists, and eventually coming into full acceptance of this non-traditional background that I had and how it could really make me a better scientist and a better communicator because of it. It's about the whole journey. First of all, that's beautiful, what you just said, because
Starting point is 00:17:45 it's a reconciliation of self, which I think is always a wonderful, wonderful thing that anyone has ever... You could be a counselor. You could be like a therapist. Yeah, if you want to mess up your life. But...
Starting point is 00:18:04 No, I think if you're in love, if you have these loves, you know, I think if you have these loves, I too had sort of secondary pathways, but none as significant in my life as your acting was. But I just did little things. I doodled and I liked calligraphy when I should have been doing other things. But now when I sign my books, I use a calligraphic pen. And the people who receive the book,
Starting point is 00:18:24 they appreciate it that much. With little things like that, I use a calligraphic pen. And the people who received the book, they appreciated that much. It was little things like that. You find a way to fold it in, your life and the lives of others are much more enriched. So I'm so glad that you pursued what you love rather than what people thought you should be doing. Thank you. I have to say, I still remember. And you're going to find out. You probably read parts of it already.
Starting point is 00:18:43 But if not, you'll see later. You're in the book. I'm in the book i'm in the book okay i write a minute wait a minute am i am i in the book you're gonna have to read it to find out and you're in the book and you're in the book there are a lot of people who are in the book but like i write about that moment when I first met you in person at the AAS, the American Astronomical Society. That's our professional conference for those who don't know what AAS means. And we sat on some umbrella chairs or whatever, and people were walking by like, is that who we think it is? Is that Neil deGrasse Tyson? And, you know, and you were just there. And I think I like started to cry at one point
Starting point is 00:19:30 because I had, you know, we'd been talking about my background and how I had, you know, I had, there were ups and downs. I had struggled academically because my head was not in the place, like my heart and my head were not in the same place. You know?
Starting point is 00:19:44 You know, it's funny because I cried when I met Neil too. But that's because he was standing on my foot the whole time he was talking to me. And he's a big guy. I'm telling you, he's a large man. It was not pleasant. Wait, almost. Plus, it didn't help matters that you also married an actor. Isn't that right?
Starting point is 00:20:06 If I remember correctly? Is that correct? I did, yes. And he is 100% actor. He doesn't have the, like, my actor, scientist, engineer, architect. Distraction. He's 100% actor, although he does enjoy those, like, Doomsday, Nat Geo shows or, like, Super Volcano. Okay, yeah, yeah.
Starting point is 00:20:25 That's in us. He's a lot. But what I'm saying is that that would have been a force that would have been supportive of your acting, correct? I mean, I presume. Absolutely.
Starting point is 00:20:33 We met in acting grad school. He was my classmate. Oh, okay. So at UCLA. You were becoming a real actor. She said acting grad school. Yes. Okay.
Starting point is 00:20:42 Listen. Yeah, I. That's the real stuff. Yeah. That's the real stuff. Yeah. That's when you're just like, you know how people say, well, I'm going to be an actor and they're like,
Starting point is 00:20:51 well, you're never going to get a job. When you say, I'm going to acting grad school, they'll be like, oh, you're getting a job. That's what we hoped and expected.
Starting point is 00:21:02 That wasn't always the case. But yes, I wanted to study it in the same way that I studied astronomy. I, you know, and, and, and that was so much fun. You know, I, after, so I had left the PhD program that I was struggling academically in and I had a old white male professor tell me to consider other career options and, you know, and I internalized that and, um, and left. And, you know, and I internalized that and left. And, you know, when I got to acting grad school, it was like I was free. I felt so light. But it wasn't like it was easier compared to astronomy grad school. It was harder in a different way. And I write about this. It was like, it didn't, it wasn't necessarily about the brain cells working overtime.
Starting point is 00:21:49 It was about dredging up my emotions and feelings and childhood experiences and like bringing it all up. You know, that I needed to use it to embody these different characters. Summoning it on command. Yeah. Summoning it on command. Yeah. It's got to be real. It's got to be real.
Starting point is 00:22:04 Yeah. Wow. So you stitch this, you've made a tapestry of your life with your professional ambitions in this book. So it's part memoir, part advice column? Is that fair? Yeah, there's a little bit of, there's certainly, it's all spoken for the most part in the first person. Like, this is what I did. This is what helped me make my life better and reconcile these different parts of myself. And I hope that I'm writing it
Starting point is 00:22:31 for the people that have that question of like, is it too late? There's that part of me that I never could bring up into my life. But it's always been there. Like I say in the book, when you leave a dream behind, it never dies. It's like sitting on the side of the road and eventually it'll catch up. And that's what happened for me. And the whole message of the book is that it's not too late and that if there's no role model that's doing what you want to do, you can be your own role model. Yeah, that's right. want to do, you can be your own role model. Yeah, yeah, that's right. And in fact, if you always needed a role model, you would only ever do things that other people did before you. But sometimes
Starting point is 00:23:10 you have to trailblaze. And like you just said, if you become your own role model, that's harder, of course, and you got to figure things out on the fly. But if and when you succeed, then people say, of course, that's what I always wanted to do. Those who come behind you. So just congratulations on that. Thank you. It's fantastic. Well, Chuck, let's get to some queries.
Starting point is 00:23:32 All right. Why not? Especially tuned for this visit. Absolutely. These are questions from our Patreon members? Patreon patrons. Yes. For a paltry, almost insignificant $5 a month.
Starting point is 00:23:49 All right. This is Mike Parker. And Mike Parker says, hello, Dr. Shields. Mike Parker here from Richmond, Virginia. If life does exist in our solar system, which planet or moon do you think offers the most promising location? I love it. In fact, give me the top three cases in order. Oh, my gosh.
Starting point is 00:24:11 Not just one. Okay. This is a fantastic question. Thank you for asking it. Europa, which is Jupiter, a moon of Jupiter, would be my top. Even though there's a lot of buzz right now around Saturn's moon Enceladus, which would be my number two, the next one. Saturn's moon Enceladus has geysers, geysers of liquid water that are shooting out from its south pole. And there was a recent.
Starting point is 00:24:37 Can't argue with geysers. And apparently all of the basic elements of life are there. There you go. Geysers lead to geezers. Geysers lead to geezers. Geysers lead to geezers. Chuck, I don't think that's how language works. Okay. And then, gosh, number three.
Starting point is 00:24:55 Okay, and third one. Give me a third one. I'm thinking. I mean, I'm skeptical about Mars. Mars, under surface Mars, where you know there might be some liquid water and aquifers. I'll be your third option. I was about to say that, but I'm skeptical.
Starting point is 00:25:17 Or it could be Mars might have fossilized life. Okay. So the life was there. It's no longer there, but that still counts because it ain't here. It ain't here. If we can prove that it was there, it still counts as life
Starting point is 00:25:31 because it was there. True. And we have so much. I'll give you that. And there's so much evidence of liquid water on the surface at some point. At one point.
Starting point is 00:25:40 Yeah. All right. Excellent. Excellent question there. Yes. Nice question. Keep it going, Chuck. Mike Parker, way to go. All right. Excellent. Excellent question there. Yes. Nice question, Mike Parker.
Starting point is 00:25:45 Way to go. All right, here we go. This is Sherry Caruso. And Sherry Caruso says, Hello, Dr. Shields. Do the ideal conditions for life on extrasolar planets depend on the star itself? Or are the requirements the same no matter what? Also, thank you. Thank you for Rising Star Girls. I am registering my niece. You are an inspiration,
Starting point is 00:26:15 Sherry from San Diego. Thank you so much, Sherry, for asking that question. And can't wait to see your niece in Rising Star Girls workshops. Rising Star Girls hosts summer, we host annual virtual workshops during the summer for middle school girls of color. And that means ages 10 to 14 or 15, roughly. No one is turned away. It's virtual? And they're virtual. So we have girls from all over the country, and we even have girls participate from other countries too. And we're ramping up to do even more. We also host educator webinars where we show educators how to use the activities in our handbook with girls in their own communities all over the world. in their own communities all over the world.
Starting point is 00:27:05 So, and back to your question, the ingredient we, the primary ingredients for life are liquid water or a liquid, which on our planet is water. And as we know, we can't just look for water, but that's like, that's our first order thing. We're looking for some liquid that life can use to make the stuff it needs to carry out its chemical processes and reactions. Some kind of energy source, whether it's the sun, the star, or chemical energy, like life that lives in the deep ocean around these hydrothermal vents, has no access access to sunlight and yet there's life there.
Starting point is 00:27:45 So it's using the chemistry of rocks and heat from the core of the earth. And I add there that when I was taught biology, it was only assumed that life could thrive. It was assumed that life could only use sunlight because we hadn't discovered the life at the bottom of the ocean yet. So they had to broaden the definition. Not that light depends on the sun, but life depends on an energy source. So I like this, that that's now folded into that definition. Okay, so keep going. And then the last one is the basic building blocks of life.
Starting point is 00:28:17 And some kind of environment for life to make its, to carry out its metabolic processes and to use. So we think of this like it needs sulfur or phosphorus or oxygen or nitrogen or carbon. These are like the basic elements of life. The organic chemistry. Yeah, the organics. Organics, energy source, and liquid. So all of those things are what we look for when we're looking for a planet that could be habitable.
Starting point is 00:28:49 And the part that I am really focused on is where could the climate be suitable for water to not freeze, not evaporate away, but to stay in liquid form somewhere on that surface. away, but to stay in liquid form somewhere on that surface. And so this can be affected by the type of star, as you bring up in your question. Because this starlight can be different depending on the temperature of the star, how that starlight interacts with the surface of the planet, the various atmospheric molecules on that planet, that can influence the planet's climate. So it does depend on the star. But those three ingredients are the main ingredients that we think any kind of planet would need to host life, to keep life going for a long time.
Starting point is 00:29:41 Now you just made me think of a question that I've, if it's a dumb question, just let me know. There are no dumb questions. That is not true. You have not heard me ask questions. When people say there's no dumb questions, I'm like, just wait. No, but so are there different stars
Starting point is 00:29:58 that give off different colors and can look like our star is white? Are there different stars that give off different colors and can those different colors actually affect the development of light? I mean, of life? That is the complete opposite of a dumb question. That is a fantastic question. So yeah, I'm not going to believe anything you say now. Okay. It's not a dumb question. It just popped in my head. So when it just pops in my head, I'm like, maybe that's a dumb ass question. Never, never.
Starting point is 00:30:27 So yes, different stars have different colors. And if you are fortunate enough to live someplace where you don't have a lot of light pollution, if you go out on your porch or your stoop and look up, you'll see this. You'll see this in action that all of the stars don't all look the same. Some of them look white. Some of them look yellow. Some look a little orange or a little red. And if they're twinkling, that's a pretty good bet that that's a star. If it's not twinkling, then you can be more convinced that it's a planet. There's a lot more stuff between us and a star than there is between us and a planet in our own solar system. And so there's a lot more atmospheric distortion
Starting point is 00:31:11 and turbulence, and that's what we see as twinkling. But anyway, yes, the colors are real, and that has to do with the temperature of the star and how much light it's emitting. to do with the temperature of the star and how much light it's emitting. And that light, again, that's going to, if there's a planet around that star and just about every star in our galaxy has a planet around it, may not be in the habitable zone, but just about every star has a planet, then that planet, if it's got an atmosphere, if it's got a surface, that light is going to be shining down on that planet. And how much light is in what region of the spectrum, the color of that light is definitely going to influence how it interacts with what's on that planet and the weather, the temperature, the climate of that planet. So you have one of the most complicated
Starting point is 00:32:02 problems to solve out there, it seems to me. Because it's not just light shining on the planet, it's like, how does the chemistry of the atmosphere interact with the light that's shining down on the planet? Does it get absorbed? Does it get readmitted? Is it reflected? And then if it reaches the surface, then you got to worry about the surface. And somewhere in there, maybe there's light. It's so true. It sounds like a really hard problem. It is a really hard problem. Because those same cool stars that, you know, comprise 70% of all stars in the galaxy, those M stars, they're really awesome because they're so numerous.
Starting point is 00:32:34 And there's a lot of advantages to looking for life around those stars. But there's some disadvantages too. They have really long phases where they send out a lot of x-ray and UV radiation shooting towards the surface. And we know the reason why we wear sunscreen is that UV radiation is not good for biology. And so it could be that, you know, life could only exist at the bottom of the ocean
Starting point is 00:33:01 on those planets. It really- Where you're protected from the UV. Where you're protected. Water is a good UV absorber. Yeah. All right. Okay, cool.
Starting point is 00:33:09 Super cool. All right, keep it coming. All right, here we go. This is Omar Marcellino. And Omar says, hello, Dr. Tyson. Hello, Chuck and Dr. Shields. Omar here from Dallas, Texas. Dr. Shields, given your unique journey through the cosmos of astronomy and theater,
Starting point is 00:33:38 two fields that are often mentioned never in the same sentence, let alone in the same career, you have boldly gone where few have gone before and leading the way and ensuring others from diverse backgrounds can do the same through your work with your rising star girls. In your perspective, how could this universe of diverse talent and experiences propel us further into the final frontier? How do you think incorporating a spectrum of perspectives in astronomy could accelerate our interstellar mission to understand and reach other worlds?
Starting point is 00:34:14 Whoa. Now, wait a minute. Is your husband named Omar? Is it about to be? No, I'm kidding. That was an excellently written question and recited. So, yeah, I'm going to say, Omar, you want to read this book. Oh, look at that.
Starting point is 00:34:36 This has got the whole journey in there, pretty much everything. I see what you did there. And go to risingstargirls.org because you'll see we're not just teaching these girls astronomy and astrobiology. We're not just saying, hey, there's stars out there. There's galaxies. These are the names of it. They get to write a poem about what they're learning. They get to design their own exoplanet and make choices about how many stars it orbits.
Starting point is 00:35:03 And if there's life there, and if there's not, why not? They get to write their own constellation myths. They get to calculate the distance from the Earth to different solar system bodies and units of themselves. So we're doing this all to develop a personal connection between these girls and the universe of which they're an integral part. So we're processing what they learn through a creative arts-based lens. And I wanted to bring it back to Rising Star Girls because that's really, my journey has been epitomized by this program of like, they're not these, the arts and the sciences are not as disparate as many people might think. In both cases, it's about the story, right?
Starting point is 00:35:50 Everything has a story. Planets, stars, they all live, right? And they die. And there's a story of their becoming, and there's a story of their evolution, and there's a story of their deaths, right then there's a story of their deaths, right? Except planets don't have mother issues. Right.
Starting point is 00:36:09 Later in life. That's right. There's certain stories they're not going to tell. I'm pretty sure. Yeah, the stories are different, but there's a journey. There are stories nonetheless. There are stories, right? There are stories nonetheless.
Starting point is 00:36:21 Or the stories of humans on the stage or on the screen, right? Looking to live, as one of my method acting teachers used to say, right? Trying to find happiness and fulfillment. So there's that whole science and the arts. And in fact, not only are they not as disparate as we might think, but they actually, interweaving them is the key, in my mind, to answering your question, is to creating imaginative thinkers and enlightened scientists and enlightened artists, for that matter, realizing that these disciplines can fuel each other, can be used to elevate our core understanding of the human experience and the universal experience. So that would be my best way to answer that really exciting question. Can I add to that, as a minimum, in a day when only men did science, it means half the population of the world,
Starting point is 00:37:20 half the intellectual capital of our species was not at the table at the time anyone is thinking about how the universe works. So the extent to which you can extend that to have 100% of our species have access to, whether they choose it, that's another question. But if they don't have access to it, then you can ensure that we're getting the best minds who want to actually think about our past, present, and future in the universe. And right now, that is not the case.
Starting point is 00:37:49 That is absolutely not the case. Physically, it was half. Percentage-wise, it was way more than that. What? It was half of the mass and less than half the actual brain power. There you go. I get it. Yeah, and we want these girls to claim ownership of what they're learning.
Starting point is 00:38:15 You know, to know that they matter, that they're an integral part of this universe. That, you know, just in the same way that if we were to look at the Milky Way galaxy through one type of light, just visible light, you'd see this thin line with a bunch of dark clouds in it. And you'd think there was nothing there. If you looked towards the center of the Milky Way galaxy, that swath of space that some of us can see if we go out in the desert. If you just thought that that was the only... some of us can see if we go out in the desert, if you just thought that that was the only- Some of us can see. Yeah. Remaining 3% of the population of the world.
Starting point is 00:38:51 Where there's no extra light pollution, right? If we thought there was nothing there, we'd miss out on so much information about this galaxy. But if we looked at the infrared, we see so much going on, right? Nevermind UV and gamma, there's so much more, right, to the galaxy than meets the eye. So too is there so much more to these girls than meets the eye. And we want them to have that ownership of that star, that planet, that galaxy that they're studying so that when they continue on and the heavy math comes in,
Starting point is 00:39:25 they'd be less likely to leave the field because they think, oh, you know, I didn't get that question right on that test. I didn't know. Someone told me that, you know, I shouldn't be here. Right. Just knowing that they, there's a connection that they have between what they're learning and who they are that we hope will really help them stay. Cool. All right, let's see if we can slip in two more questions, Chuck.
Starting point is 00:39:49 All right, well, here's one from Carrie Manaberg. And Carrie says, Hi, Dr. Shields. Is there any scientific evidence that life on Earth came here from an interaction with a comet or asteroid that had biological foundation chemicals? Ooh. Ooh, this is a popular question within the astrobiology community.
Starting point is 00:40:07 I believe the term for this is panspermia. Yes. Right? That something comes in from elsewhere and like seeds us. Seeds us. Yeah. Yeah. I mean, of course it's possible. I don't think it's being given very much funding, to be honest, in terms of exploration of this topic. But it certainly has been discussed within astrobiology communities. Okay. Okay. All right. Okay.
Starting point is 00:40:41 This is Jason. He says, hello, Dr. Shields. Do you have any personal moral quandaries about science moving forward? Or is pretty much just forget morals and let's just see how far we can go. Now, I don't know if Jason is making an indictment of any sort or not.
Starting point is 00:40:59 That's a very specific question. It's starting out with the premise that all scientists are immoral. Yeah, basically. But I think I know what he means. but that's a very specific question. It's starting out with the premise that all scientists are immoral. That's kind of- Yeah, basically. But I think I know what he means. It's like scientists want to discover. What if you and you too, Neil,
Starting point is 00:41:13 had the opportunity to make a discovery that would enlighten, but there was a larger chance that it would destroy? Would you still expose that discovery? That's a moral quandary. Yeah, this is an important question. This harkens back to the last episode
Starting point is 00:41:38 that I was fortunate enough to be on with you, where we talked about terraforming and we talked about some of the moral and ethical implications of that question of, is it okay to terraform another planet or terraform Mars? I do think that as scientists, ethics must be key. So I don't subscribe to the view that, you know, science and discovery at all costs. There's a piece that I've written for upcoming a periodical that's like, why do this? Why look for life elsewhere? Why spend billions of dollars doing all of this? And is that object, Oumuamua, that first interstellar object, you know, is that, you know, is it really
Starting point is 00:42:25 an alien's craft or is it, you know, is it just, can it be explained by regular, you know, regular scientific method? I think what it comes down to is if we go, and I'm talking about this in the context of the search for life elsewhere, there's all sorts of other genetics and questions about cloning and all of that that have their own ethical implications. But from my part of the sphere on that question, if we were to discover that we are not alone, what would we do with that information? What would we do with that information? Would we have to go and visit? Or could we stay on our planet and know that we're not alone and let that information inform how we think and feel
Starting point is 00:43:13 and move throughout the world? Or would we need to go? And if we would need to go and visit, could we just go and visit and then come back home? Or would we need to stay? And if we needed to stay, could we just stay and not try to conquer? Or would we have to go the way that,
Starting point is 00:43:35 and emulate what was done on our planet with Columbus and Magellan and all the rest and the implications of that, right? That led to genocide. I would hope that we would be able to learn from the lessons of the past and not repeat them. And that really is what I think it all comes back to is hope. You know, I have no clear answer about what other scientists might do, and maybe even what I might do if given the opportunity to go to another world and communicate with other, you know, other species. But I carry with me the hope that I
Starting point is 00:44:12 would want to do whatever we do from a place of love, kindness, inclusivity, and welcome, and welcome and humility, to be honest. So that, I think, is the key. That to be a scientist, I must concede that there is more that out there that can be explained and I can hold on to that humility and allow that to guide, to serve as a North Star for me morally.
Starting point is 00:44:44 So, I believe it. Well, that is beautiful. That's beautiful me morally. So, I'll leave it there. Well, that is beautiful. That's beautiful. As a comedian, let me just say this. That ain't happening. It's not going to happen. That is not what is going to happen. Well, but I got two reactions.
Starting point is 00:44:56 One, how charming it was that you thought we would go find aliens on another planet and that we might exploit them. It's just... Oh, rather than like Independence Day and they're going to come and kill us. Yeah, yeah, yeah. And believe me, if we go see them,
Starting point is 00:45:14 they're not answering the door. They're going to play the role just like we Jehovah's Witnesses or something. They'll be like, they're here. Please, don't let them... We're not... Get away from the window. But that question... Get away from the window. Get away from the window.
Starting point is 00:45:26 I've never had heard anyone talk about an encounter with aliens and talk about we exploiting them. That is like never, I don't know any storyline. If you're thinking of that storyline, that is completely beautiful. That's a beautiful thing.
Starting point is 00:45:41 But of course it mirrors what happened on our planet. I mean, how could I not think of it that way? You know why I think about it? I think if they come here and they do what we do to each other, as we portray in the films, then we're creating them not based on a supposition of how they would behave, but on actual knowledge of how we did behave.
Starting point is 00:46:06 So, in fact, all of the alien movies are mirrors to our culture. Treating it almost like a guidebook or a recipe. Yes, yes. And I couldn't help, you have to publish a paper on the interstellar visitor Amuamua. So we have Aumaua. I know, it's so close to my name. We need that research paper.
Starting point is 00:46:31 I write it. I write in the book. I say, Uumuamua, it sounds like my name. Yeah, that's great. Aumaua studies Amuamua. That's right. But Amuamua is Hawaiian. And Aumaua, does that have some origins?
Starting point is 00:46:44 My parents made it up. They made up vowel sounds. They put together their musicians. They made a chant up. But yeah, that sounds... I went to Hawaii once. They sounded like hippies. They sounded like some leftover hippies right there.
Starting point is 00:46:56 Very nice. Well, at least you weren't named Moon Unit. Okay. Right. Or Moonbeam. Or Pilot Inspector. I mean, come on. That's unfortunate. But yeah, come on. That's unfortunate.
Starting point is 00:47:07 But yeah, Umuamua means messenger from afar arriving first. Yes, the first messenger. Yes. Yeah. Yeah. So, guys, we got to end it there. That's sad. Oh, my gosh.
Starting point is 00:47:20 This is good. This has been fantastic. Thanks for being on and congratulations again. Thank you so much, Neil. And thank you, Chuck. It's great to be here. All right. Chuck, good to have you, man, this is good. This has been fantastic. Thanks for being on and congratulations again. Thank you so much, Neil. And thank you, Chuck. It's great to be here. All right. Chuck, good to have you, man.
Starting point is 00:47:29 Always a pleasure. All right. I'm Neil deGrasse Tyson. You're a personal astrophysicist for StarTalk. As always, I bid you to keep looking up. Bye.

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