Habitable Worlds, Super-Earths, & Evaporating Planets with Anjali Tripathi

Is Earth going to evaporate? Neil deGrasse Tyson and comedian Chuck Nice learn about exoplanet discovery, planetary evaporation, biosignatures and technosignatures with astrophysicist Anjali Tripathi.

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:00Neil deGrasse Tyson?

  Coming up on StarTalk, we've got a Cosmic Queries edition all about exoplanets. I've got with me one of the world's experts on that subject, Anjali Tripathy. Welcome to StarTalk. We're gonna find out where she came from, where she's been, and where she's going in this world of not only exoplanets, but also as a citizen scientist, serving two presidents. Coming up on StarTalk. Welcome to StarTalk, 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.

• 0:43Neil deGrasse Tyson?

  Today is another Cosmic Queries, ever-popular format, if that is, on the subject of exoplanets. Chuck?

• 0:53Chuck Nice?

  Yeah.

• 0:54Neil deGrasse Tyson?

  My co-host, how you feeling, Chuck?

• 0:55Chuck Nice?

  I'm feeling great, man.

• 0:56Neil deGrasse Tyson?

  Feeling good about the exoplanet?

• 0:58Chuck Nice?

  Exoplanets are always fodder for great thought, because now we know that there are millions and millions of them. They're everywhere.

• 1:08Neil deGrasse Tyson?

  I don't know if the catalog has quite hit that yet.

• 1:11Chuck Nice?

  We went from four. They're like, maybe there's four.

• 1:15Neil deGrasse Tyson?

  So, I know a little bit about exoplanets, but if we're gonna really go in with the Cosmic Queries, we're bringing the big guns.

• 1:22Chuck Nice?

  Yeah.

• 1:23Neil deGrasse Tyson?

  Okay? So, we combed the landscape, and we found Anjali Tripathy. Anjali, welcome to StarTalk.

• 1:31Speaker 02

  Thank you so much, so excited to be here.

• 1:33Neil deGrasse Tyson?

  Excellent, excellent. You, in your professional life, not only did original work on exoplanets, you also found yourself, either on purpose or otherwise, at the intersection between science and society. So, I want to get to that in just a minute. Right now, you're a research associate at NASA's JPL.

• 1:52Chuck Nice?

  Lovely.

• 1:53Neil deGrasse Tyson?

  Which Chuck stands for what?

• 1:54Chuck Nice?

  Um, I believe Judy Poulsen lingerie.

• 1:58Neil deGrasse Tyson?

  That's right.

• 2:00Chuck Nice?

  Judy Poulsen's lingerie. It's all the rage now.

• 2:03Speaker 02

  That's usually classified, why'd you let that one out?

• 2:06Neil deGrasse Tyson?

  That was classified information.

• 2:07Chuck Nice?

  Yeah. Another awesome Jet Propulsion Labs.

• 2:10Neil deGrasse Tyson?

  The Jet Propulsion Labs in Pasadena, California.

• 2:13Chuck Nice?

  California.

• 2:14Neil deGrasse Tyson?

  Yes. And it's not only a branch of NASA, they collaborate. And are basically on the campus of Caltech, right?

• 2:21Speaker 02

  I am a Caltech employee.

• 2:22Neil deGrasse Tyson?

  Right, right. So who signs your checks? Is it Caltech?

• 2:24Speaker 02

  It is Caltech.

• 2:25Neil deGrasse Tyson?

  Wow. Okay, there it is. But you still have NASA overlords.

• 2:29Speaker 02

  I do.

• 2:29Neil deGrasse Tyson?

  I'm pretty sure you do. You know who we had on StarTalk just when she just started? Right. Was the director of JPL, who is Lori Leshen. Lori Leshen. She and I served on a commission to study the future of NASA. Wow. We were both appointed by President George W. Bush. Nice. And she went on to great things.

• 2:52Neil deGrasse Tyson?

  And you, um...

• 2:53Speaker 02

  You got stuck with me. I'm so sorry. I'm so sorry.

• 2:57Neil deGrasse Tyson?

  What a shame. But you can dig the Lori Leshen episode out of our archives. That was fun. Right. I wanted to get to her before NASA got to her. Because NASA, they want to over-control the interviews. But she and I go way back. Right. So there was an interval where, let's just rock and roll this. Exactly. Just say what you think, think what you feel. Yeah. Well, you're not going to be able to do that with Anjali because NASA is still controlling her. Sorry.

• 3:23Speaker 02

  I have the NASA handcuffs on.

• 3:24Neil deGrasse Tyson?

  Okay, no, no. We'll figure something out here. So, at JPL, what are your primary concerns?

• 3:31Speaker 02

  I like thinking about what can we see from space, right? So what can you see when you look up at exoplanets and other worlds? And also looking down here on Earth, and how can you improve life here on it?

• 3:41Neil deGrasse Tyson?

  You know, people, when they think of space exploration, they don't always think that from space you can see Earth as a planet. Exactly. And monitor what's going on, and how we doing, you know? So this seems to be a really important feature of what NASA can deliver the public. Yeah.

• 3:58Speaker 02

  Something folks always get wrong. You ask them, what's our most studied planet at NASA? And they go Mars, and you go, wrong. And you think, it's Earth, and nobody realizes that.

• 4:06Neil deGrasse Tyson?

  Exactly. So you still have roots back where you got your PhD?

• 4:09Speaker 02

  I do, yeah. I'm a research associate at the Harvard Smithsonian Center for Astrophysics.

• 4:14Neil deGrasse Tyson?

  Okay, all right. So tell me, before we get back into exoplanets, because that's where we got all the questions are based on them. Yes, they are. Just, the science and society part of your life.

• 4:26Neil deGrasse Tyson?

  How did that begin?

• 4:27Speaker 02

  So, being a valley girl, you know, we had an earthquake in the 90s and I had to move out of my house for a year. And the people who come on TV, for those of you who've had the pleasure of earthquakes, it's a seismologist who comes and tells you what's gonna happen. And I thought, scientists can come and tell you what's gonna happen next and sort of save things? I wanna do that. And then I learned that seismology and geophysics and physics are important, but they don't save the world in the same way. And so, thinking about how you can find connections between science and sort of-

• 4:53Neil deGrasse Tyson?

  You know why they don't save the world? Because they'll only bring the geology on after the earthquake. After the earthquake. Not just before the earthquake, after the earthquake.

• 5:04Chuck Nice?

  It's true.

• 5:05Neil deGrasse Tyson?

  Okay, they saving nobody.

• 5:06Chuck Nice?

  It's a doggone shame, because like, when do we really need them? We just got some readings in. That's when we need them.

• 5:13Speaker 02

  Whereas with the genres, we're like, that eclipse, get ready, it's coming in six months.

• 5:18Neil deGrasse Tyson?

  Okay, it's a total predictive powers.

• 5:20Speaker 02

  Yeah.

• 5:21Neil deGrasse Tyson?

  Alright, so now what? So, okay, so the urge doesn't make the reality, so what happened?

• 5:25Speaker 02

  I mean, I was lucky enough, I went and served in two administrations. President Obama brought me in as a White House fellow.

• 5:30Neil deGrasse Tyson?

  She was lucky. That was just luck.

• 5:32Chuck Nice?

  I was gonna say-

• 5:33Neil deGrasse Tyson?

  That was just luck.

• 5:34Speaker 02

  I mean, I don't like to talk about the bribes.

• 5:35Chuck Nice?

  I served in two administrations. That's funny. I used to serve at Wendy's. I was Wendy's manager. And I served for-

• 5:48Neil deGrasse Tyson?

  For two tours of duty.

• 5:50Chuck Nice?

  Two tours of duty.

• 5:51Neil deGrasse Tyson?

  Wait, so who was your-

• 5:52Speaker 02

  Thank you for your service.

• 5:53Neil deGrasse Tyson?

  So who was your first president?

• 5:57Speaker 02

  Uh, well, I mean, I was born a while ago, lady doesn't reveal her age, but of the two administrations-

• 6:02Neil deGrasse Tyson?

  We're gonna triangulate on that if you give us enough information.

• 6:04Speaker 02

  Uh, President Obama.

• 6:05Neil deGrasse Tyson?

  President Obama, okay. And so, what, in what capacity were you serving in the White House?

• 6:10Speaker 02

  I came in serving at the US Department of Agriculture, thinking about climate change. You know, it doesn't matter why your soil is dry, you gotta get things to grow.

• 6:17Chuck Nice?

  That's right.

• 6:18Neil deGrasse Tyson?

  Is there a relationship between the Department of Agriculture and the Environmental Protection Agency?

• 6:22Speaker 02

  I mean, so I was working on food waste, right? Which is something that both care about, right?

• 6:26Neil deGrasse Tyson?

  Big deal.

• 6:27Speaker 02

  Because, I mean, you know, your apple that you don't eat turns into methane, greenhouse gas, right?

• 6:31Neil deGrasse Tyson?

  Yes, without a doubt.

• 6:32Speaker 02

  So.

• 6:33Neil deGrasse Tyson?

  So how does the Obama administration- Connect you to agriculture. What is that pathway?

• 6:39Speaker 02

  Uh, you know, where else would you put an astrophysicist in government?

• 6:42Neil deGrasse Tyson?

  What was your, what you, what was your title?

• 6:44Speaker 02

  I was a White House fellow.

• 6:45Neil deGrasse Tyson?

  Oh, you didn't say that. Okay. A White House fellow. And so you have these science fellows at the White House.

• 6:52Speaker 02

  So the White House fellows are actually, I was the only scientist, right?

• 6:55Neil deGrasse Tyson?

  I didn't know that.

• 6:55Speaker 02

  Yeah, so it's a group about sixteen in my class, right? So one of them is now a Congresswoman. We've got all kinds of folks from the military and business and law. The idea is you go and you serve a cabinet secretary as a senior advisor.

• 7:08Neil deGrasse Tyson?

  Because the cabinet reports to the president. So this is still a White House thing.

• 7:11Speaker 02

  Exactly.

• 7:12Neil deGrasse Tyson?

  So the Secretary of Agriculture then became your...

• 7:14Speaker 02

  Exactly, right.

• 7:15Chuck Nice?

  Who reports to the president and you were working with them.

• 7:18Neil deGrasse Tyson?

  So I'm, I'm intrigued by the fact that you get a PhD studying exoplanets. So you're thinking about planets, looking at them from afar.

• 7:27Chuck Nice?

  Right.

• 7:28Neil deGrasse Tyson?

  And then Earth and agriculture becomes Earth that you're thinking about from afar. So what kind of NASA or astronomical insights can you offer to the Department of Agriculture?

• 7:39Speaker 02

  Well, I mean, I want it to be more down to earth, let's be honest, right? And the idea is just that, you know, you can see so much more from satellites than you can with a guy...

• 7:48Neil deGrasse Tyson?

  Walking around with a mule.

• 7:49Chuck Nice?

  Right.

• 7:50Speaker 02

  They offered to send me to estimator school where they said you're going to walk a certain number of paces in a cornfield, pick the second ear of corn you see and count the diameter and across. And that's how we estimate the crop yields in America. We still to this day don't use satellite technology for the government predictions on crop yields.

• 8:06Neil deGrasse Tyson?

  Which is green acres?

• 8:07Chuck Nice?

  That's crazy.

• 8:10Neil deGrasse Tyson?

  You got Arnold the Pig predicting the weather, like what?

• 8:12Chuck Nice?

  Hey, man, uh, so how big is your corn?

• 8:16Chuck Nice?

  Like, that's crazy.

• 8:17Speaker 02

  It's quantitative. You count, you know? But I mean, it's one of those things that it's really useful for all the companies that come in because then it's calibrated ground truth, right?

• 8:26Chuck Nice?

  I mean, in a way that makes sense. Yeah. So now, but, but isn't it much better to look at, because you can see from space? You can actually see soil conditions, you can see the crop yields themselves. There are, I mean, how dry it is, you can see, you know, there's so much more information you can get from looking down from above. So, what's going on with that?

• 8:52Speaker 02

  I mean, and to your question, right? There is tons of NASA data that looks at the soil moisture, it looks at sort of the different vegetation, and that's all publicly available, both to the agriculture department and anybody else.

• 9:03Neil deGrasse Tyson?

  And to the person pacing cornfields.

• 9:05Chuck Nice?

  Right.

• 9:06Neil deGrasse Tyson?

  It's available to them.

• 9:07Chuck Nice?

  Right.

• 9:07Neil deGrasse Tyson?

  But maybe they need a job.

• 9:09Chuck Nice?

  Exactly.

• 9:10Neil deGrasse Tyson?

  Farmer needs a job. I don't know. So, no, so I'm intrigued by this. So, okay, so that was a tour of duty. It went across the administrations.

• 9:17Speaker 02

  That's right.

• 9:18Neil deGrasse Tyson?

  And, but then you ended up, you told me offline, you ended up at the Office of Science and Technology Policy, which is the executive branch that oversees the budget for science in the United States.

• 9:28Chuck Nice?

  Wow.

• 9:28Speaker 02

  For science, yeah.

• 9:29Neil deGrasse Tyson?

  For science, right. And so what were you doing there?

• 9:31Speaker 02

  Writing about, hey, what are we investing in? What are the people and the programs? And I figured that we added the word "American" in front of everything we want to do, so we wanted "American health," right?

• 9:41Neil deGrasse Tyson?

  Not just health.

• 9:42Speaker 02

  American health.

• 9:43Chuck Nice?

  That was smart.

• 9:44Neil deGrasse Tyson?

  Yeah.

• 9:45Speaker 02

  Yeah.

• 9:45Chuck Nice?

  I mean, that is brilliant, because when you look at America, Merka, you should have made it that, instead of American.

• 9:53Neil deGrasse Tyson?

  You've got to spell it right. Apostrophe M U R I C A.

• 9:57Chuck Nice?

  Merka.

• 9:59Speaker 02

  They didn't teach me that one in my spelling classes, you know.

• 10:02Neil deGrasse Tyson?

  Okay, so that was clever. And so now, more people across the aisle can take ownership of it.

• 10:07Chuck Nice?

  Right.

• 10:07Speaker 02

  That's right. Yeah, no, I mean, it was, I will say, coming in to a new administration, it's kind of crazy. Your hard drives get wiped, everything is gone, you're starting fresh a little bit. And lots of opportunity to learn. So whether you wanted me to have that opportunity or not, but I think, you know, we did some good stuff.

• 10:23Neil deGrasse Tyson?

  But would you have normally been discarded between administrations?

• 10:27Speaker 02

  No.

• 10:27Neil deGrasse Tyson?

  How did, oh, how did you stay on?

• 10:29Speaker 02

  So, White House fellows have a one-year appointment that's fixed. And so, started August of 2016, went to August of 2017.

• 10:35Neil deGrasse Tyson?

  Oh, you started at the end of the Obama administration.

• 10:36Speaker 02

  I did.

• 10:37Neil deGrasse Tyson?

  Oh, so you cross over.

• 10:37Chuck Nice?

  You were, you were a part of the transition.

• 10:39Speaker 02

  I was, yeah.

• 10:40Neil deGrasse Tyson?

  Okay, very cool. So, at the time, you told me, again, offline, that you knew I was on a Pentagon board at the time. How did you know about that?

• 10:48Speaker 02

  Because I go into five-sided buildings, I can handle that, not just four-sided ones.

• 10:52Neil deGrasse Tyson?

  Okay, right on. You need to go five, how, hey, how many five-sided buildings do you know?

• 10:57Chuck Nice?

  I don't know, because I work at the Heidestad.

• 11:01Chuck Nice?

  Okay. That's top secret.

• 11:05Speaker 02

  Why do you think the telescopes have these hexagonal mirrors, right?

• 11:08Chuck Nice?

  Yeah.

• 11:09Neil deGrasse Tyson?

  Yeah, the mirror segments of JBL. Exactly.

• 11:12Chuck Nice?

  That's right.

• 11:13Neil deGrasse Tyson?

  So that's a top secret nobody knows about except for you.

• 11:15Chuck Nice?

  There you go. That's right. You know where we came up with that idea? At the Hexagon.

• 11:21Chuck Nice?

  Not the Pentagon.

• 11:26Neil deGrasse Tyson?

  Okay, what's your most recent published paper? Was it about climate change?

• 11:30Speaker 02

  Yeah, we just wrote a paper together about sea level rise and how you can use satellite data to actually do better job of preparing coastal cities.

• 11:38Chuck Nice?

  Excellent.

• 11:39Speaker 02

  Right, yeah.

• 11:40Chuck Nice?

  Which is only where like most, everybody lives.

• 11:43Neil deGrasse Tyson?

  Every major city is on a coast. On a body of water. And so.

• 11:49Speaker 02

  What can satellites do for you?

• 11:50Neil deGrasse Tyson?

  Okay, but again, it sounds like the seismologist. It's like, here's what to do when the water knocks at your door. Rather, is there preventative?

• 12:01Speaker 02

  No, so this is all about how cities can look at glaciers in Antarctica and Greenland melting now to prepare for what's happening in the future, right? Rather than waiting for the level to actually rise, that you have some early warning.

• 12:15Neil deGrasse Tyson?

  Oh, so you can make predictions.

• 12:17Speaker 02

  Yeah, exactly.

• 12:18Neil deGrasse Tyson?

  Got it.

• 12:18Chuck Nice?

  That's amazing.

• 12:19Neil deGrasse Tyson?

  Got it. And plus, I'm not thinking about Antarctica or Greenland.

• 12:22Speaker 02

  Exactly.

• 12:23Neil deGrasse Tyson?

  When I don't live near them.

• 12:24Chuck Nice?

  Right.

• 12:24Neil deGrasse Tyson?

  But their water doesn't carry passports, right? Their water molecules will go wherever it goes.

• 12:29Chuck Nice?

  Yes, exactly.

• 12:30Neil deGrasse Tyson?

  Right? So let's get back to exoplanets.

• 12:31Speaker 02

  Absolutely.

• 12:32Neil deGrasse Tyson?

  So, so your work for your PhD was what?

• 12:36Speaker 02

  Thinking about how planets form and how they evolve over time.

• 12:38Neil deGrasse Tyson?

  Oh, formation of exoplanets, good. Somebody had to make them.

• 12:41Chuck Nice?

  That's right.

• 12:42Neil deGrasse Tyson?

  They're not just born whole.

• 12:43Chuck Nice?

  No, exactly.

• 12:44Neil deGrasse Tyson?

  Okay. So Chuck, you got questions for?

• 12:46Chuck Nice?

  We have them right here.

• 12:47Neil deGrasse Tyson?

  Let's do it.

• 12:47Chuck Nice?

  You want to jump right into this?

• 12:49Neil deGrasse Tyson?

  Let's do it.

• 12:49Chuck Nice?

  All right, I love this first one. This is Manchelle Hicks. And Manchelle says, hi, Dr. Tyson, hi, Anjali. Planets are evaporating?

• 13:02Chuck Nice?

  That's it. That's all that it says.

• 13:03Speaker 02

  I mean, Montreal's got it down. Planets are evaporating.

• 13:06Chuck Nice?

  Right.

• 13:06Speaker 02

  I mean, we got the Earth, we got exoplanets, right? Because you've got all this gas that we call the atmosphere that's trying to stick to the planet by gravity. But sometimes you got the heat from that star that's enough that it just pulls it off.

• 13:18Chuck Nice?

  Well, we're losing, what, helium and what's the other thing?

• 13:21Speaker 02

  Hydrogen?

• 13:22Chuck Nice?

  Hydrogen and helium on a daily basis.

• 13:24Speaker 02

  Hourly, minutes, seconds, yeah.

• 13:26Chuck Nice?

  Wow.

• 13:26Neil deGrasse Tyson?

  Okay, but not so fast that I should worry about it and make a thing of it. But, but if there's stars that get brighter, more luminous, and they're gas-rich planets. So they, how about those big Jupiters that are orbiting close to their star? Are they evaporating?

• 13:43Speaker 02

  Yeah, these planets, right, that we call hot Jupiters because they're so close in.

• 13:46Chuck Nice?

  Right.

• 13:46Speaker 02

  Right? And especially since they've always got one side and often facing the stars, the same side.

• 13:51Neil deGrasse Tyson?

  Because they're tightly locked.

• 13:52Speaker 02

  Exactly.

• 13:52Neil deGrasse Tyson?

  Like, the moon is tightly locked to us.

• 13:54Chuck Nice?

  Right.

• 13:54Neil deGrasse Tyson?

  If you get close to a massive source of gravity, it's gonna lock you and only look at one side, just as we did to the moon. The moon is trying to do that to us. Did you know that?

• 14:03Chuck Nice?

  Yeah, just lead us down the wrong path.

• 14:05Neil deGrasse Tyson?

  It's just trying to...

• 14:06Speaker 02

  A new path.

• 14:07Chuck Nice?

  A new...

• 14:08Neil deGrasse Tyson?

  I don't know about that. Yeah, don't value judge the path.

• 14:10Chuck Nice?

  Yeah.

• 14:11Neil deGrasse Tyson?

  It's just, it's just the orbital mechanics of it.

• 14:13Speaker 02

  Come on, did we go over here?

• 14:14Chuck Nice?

  Why you're well...

• 14:15Neil deGrasse Tyson?

  It's, it's, I'm just saying.

• 14:16Speaker 02

  Go over here.

• 14:17Neil deGrasse Tyson?

  So the moon is trying to slow us down, so we only show the same face to it. Yeah, that's why we throw in leap seconds every now and then to make up for that. But, you know, so...

• 14:25Chuck Nice?

  So wait a minute, with the evaporation, because I'm concerned about Earth, to be honest, uh, what's gonna happen first? Well, our atmosphere, which I understand from Neil, is like thinner than the skin of an apple. Okay? It's thinner than the skin of apple. Will that evaporate before the sun expands and kills us all? Or what's gonna happen first?

• 14:47Speaker 02

  All right, Chuck, don't worry about it. Don't worry about it. A lot of things that'll scare you with this isn't one of them, right? So the idea is that you will have this atmospheric escape is what they call it, because your atmosphere is literally escaping the planet, happening more and more in the future as the sun gets brighter. But it's not all gonna go away before then, so you're, you're safe.

• 15:05Chuck Nice?

  Okay, so...

• 15:06Speaker 02

  You're good.

• 15:06Neil deGrasse Tyson?

  We'll be falling around the surface of the Earth trying to breathe.

• 15:09Chuck Nice?

  Right, stay low, like you're in a fire.

• 15:13Chuck Nice?

  Stop dropping roll, just so you can breathe.

• 15:15Speaker 02

  Well, I think you're gonna wanna, you know, go up towards the poles or something like that. The equator's not gonna look so hot.

• 15:20Neil deGrasse Tyson?

  Oh.

• 15:20Speaker 02

  Or maybe it is gonna look so hot.

• 15:22Chuck Nice?

  Yeah, that's the problem.

• 15:22Neil deGrasse Tyson?

  Okay. But you already got this planned out. You have to join a Santa Claus.

• 15:39Chuck Nice?

  All right, what else you got, Charlie? All right, here, this is TJ Show, who says, "Hi, TJ here from Winnipeg, Canada."

• 15:46Neil deGrasse Tyson?

  He does not have that in there.

• 15:47Chuck Nice?

  No, they don't. Okay.

• 15:51Chuck Nice?

  They do not.

• 15:52Neil deGrasse Tyson?

  Okay.

• 15:52Chuck Nice?

  Okay. It says, "Thanks for taking my question. Hello, Dr. Tyson, Dr. Pathy, and Lord Nice. Longtime listener and new Patreon here. My question's about intelligent life. If there are roughly 10 million unique organisms on Earth, 99% of all species that have ever existed are extinct, and we are only the, the only intelligent species out of all of that? Questionable, let me say. Questionable."

• 16:16Neil deGrasse Tyson?

  Big assumption.

• 16:17Chuck Nice?

  Big assumption. Then doesn't that mean that the likelihood of there being intelligent life on a newly discovered habitable world is about one in a billion?

• 16:27Neil deGrasse Tyson?

  Oh, I like that.

• 16:28Chuck Nice?

  Okay, so there you go.

• 16:29Neil deGrasse Tyson?

  He's fast, fast back, and he have a little math there.

• 16:31Chuck Nice?

  Have a little math there, so he says, yeah. So, and then he goes on, "Our galaxy might be teeming with life, but intelligent life could be extremely rare."

• 16:40Neil deGrasse Tyson?

  So let me, let me recast that in another way. So if you have a dark, if you have all the, so his Earth, is this one branch of vertebrates coming out of fish

• 16:48Chuck Nice?

  Right.

• 16:48Neil deGrasse Tyson?

  that became great apes.

• 16:50Chuck Nice?

  Right.

• 16:50Neil deGrasse Tyson?

  Okay. I've known some apes, but not all of them were great.

• 16:52Chuck Nice?

  Well, no, some of them were just not so great apes.

• 16:55Neil deGrasse Tyson?

  So, and one thin branch of that are the humans. Anything could have stopped that.

• 17:00Chuck Nice?

  Right.

• 17:00Neil deGrasse Tyson?

  The asteroid not taking out the dinosaurs would have disrupted the mammals from ever even, quote, ascending to where we are. Just, just sheer luck.

• 17:09Chuck Nice?

  Exactly.

• 17:09Neil deGrasse Tyson?

  Okay, bad luck dinosaur. So... If this is just one branch out of the tens of millions of life forms, if you have tens of millions of Earths, close your eyes and throw a dart. Really? Most of them will just have life like we got here.

• 17:24Chuck Nice?

  Just life, but it will not be developed.

• 17:27Neil deGrasse Tyson?

  So react to that place.

• 17:29Speaker 02

  I'm just saying, I'm not smart enough to know what else is out there in the universe, and certainly not the numbers of that. So I think, you know, if we're being honest, do we know if there's life out there? I don't know. Do I hope there's life out there? Heck, yeah. Do I hope it's intelligent? Heck, yeah, but the number's one in a billion?

• 17:45Chuck Nice?

  Let's take the intelligence out.

• 17:47Speaker 02

  Okay.

• 17:48Chuck Nice?

  Now, the fact is.

• 17:49Neil deGrasse Tyson?

  It's already out.

• 17:51Chuck Nice?

  Let's factor that out. What is the likelihood of just life? I don't care if it's single-celled life. I don't care if it's just, you know, like, you know, some type of bacteria, amoebas, whatever. What is the likelihood of that happening, seeing as how, you know, the same building blocks that we have here are everywhere?

• 18:13Neil deGrasse Tyson?

  Yeah, plus it happened pretty quickly on Earth.

• 18:14Chuck Nice?

  Yeah, yeah. I mean, we're only 4.5 billion years old, and we got to the life part pretty damn quickly.

• 18:19Speaker 02

  I mean, there's planets everywhere, right? Like, every star has planets. And so if you think about, we've got so many planets, so many balls of rock are probably amongst those planets. Chances are good you had the conditions for life, right? And you know, water, some energy. Those things seem like they're out there. So I think the chances are good. But again, one in a billion? I don't know if it's that slim.

• 18:38Neil deGrasse Tyson?

  Yeah, plus, we're not even limited to rocky planets anymore, because there's some, there's some good moons.

• 18:42Speaker 02

  There are some great moons. There's that habitable world, right? Not just the habitable planets.

• 18:46Chuck Nice?

  Habitable worlds, not just planets.

• 18:47Neil deGrasse Tyson?

  Yeah, yeah, world. Forget planet, non-planet. Yeah, have world.

• 18:52Chuck Nice?

  And then, yeah, yeah, yeah. I mean, like, even, even like a ice, well, what would be like an ice world, like, Enceladus?

• 18:58Speaker 02

  Yeah, you got that water underneath, right?

• 19:00Chuck Nice?

  Yeah, but that could happen, right? Like, okay.

• 19:02Neil deGrasse Tyson?

  Totally happen.

• 19:03Chuck Nice?

  All right, here we go. This is Dylan, and Dylan says, "Greetings, everyone from Flagstaff, Arizona. I'm taking undergraduate astrophysics courses and learning about spectro- spectroscopy." Thank you.

• 19:16Neil deGrasse Tyson?

  Spectroscopy.

• 19:16Chuck Nice?

  Spectroscopy. I can't, God, it always gets me. "And other amazing methods of how to find and characterize planets, what has been the best method so far to find planets, and what possible new methods are being brought up?"

• 19:32Neil deGrasse Tyson?

  So let me, let me focus that down and have you tell us. We're now using spectroscopy to study the atmospheres of these planets. So what's coming out of that?

• 19:40Speaker 02

  I mean, it's amazing that when you get just the right configuration, that you've got the star and the planet passes in front of it and you're looking at that, some of the light goes through that atmosphere of that planet from the star and gets to us. And so we can actually see some of those chemicals in that atmosphere.

• 19:54Chuck Nice?

  It's amazing.

• 19:54Speaker 02

  So we see all.

• 19:55Neil deGrasse Tyson?

  So the chemicals are disrupting, really, the clean path of light from the star. And that disruption shows up in the spectrum.

• 20:02Speaker 02

  They were like putting their fingers on there, getting those fingerprints.

• 20:05Neil deGrasse Tyson?

  So what are you looking for?

• 20:06Speaker 02

  So we've seen carbon dioxide with the James Webb Space Telescope, which is pretty cool, right? First time we've seen that on another exoplanet.

• 20:12Neil deGrasse Tyson?

  All right. Okay, what else?

• 20:13Speaker 02

  Uh, right, all kinds of other compounds, right? You get water, right?

• 20:17Neil deGrasse Tyson?

  Okay, sure, water molecule, yeah.

• 20:18Speaker 02

  Right, and you got some good things in there. And so all kinds of configurations of oxygen and carbon and hydrogen that you're thinking about.

• 20:25Neil deGrasse Tyson?

  Methane.

• 20:26Speaker 02

  Methane is pretty great, right?

• 20:27Neil deGrasse Tyson?

  You get methane there too? Have you seen it yet?

• 20:29Speaker 02

  There is methane about on the planets, yeah.

• 20:30Neil deGrasse Tyson?

  Okay, okay. That would be evidence of?

• 20:33Chuck Nice?

  Of farts.

• 20:34Speaker 02

  It can be, it can be.

• 20:36Neil deGrasse Tyson?

  All right, keep going.

• 20:36Chuck Nice?

  That is so cool. This is, uh, Cesar.

• 20:39Neil deGrasse Tyson?

  By the way, just to bring closure to that, to say that the boring, obvious fact, so many of these planets were discovered.

• 20:46Speaker 02

  Exactly.

• 20:47Neil deGrasse Tyson?

  Were discovered just by their spectra.

• 20:49Speaker 02

  Right, and by transits, right? That you looked at the light and you saw it blinking? And that's just because something kept going around at that light of the star.

• 20:56Chuck Nice?

  And a transit is the planet going in front of the star's light, blocking the star's light.

• 21:00Speaker 02

  It's just like when we have eclipses where you block out the whole face of the star, but here it's just a fraction of it, right? So we talk about.

• 21:05Neil deGrasse Tyson?

  Yeah, in fact, solar eclipses are really transits.

• 21:09Speaker 02

  Yes. We talked about the transits of Mercury and Venus.

• 21:12Neil deGrasse Tyson?

  Yeah, yeah, yeah, yes. Mercury transit, Venus transit, it's a moon transit.

• 21:16Chuck Nice?

  That's right.

• 21:17Neil deGrasse Tyson?

  And an eclipse technically, astronomically, is just object moving into the shadow of another object.

• 21:24Chuck Nice?

  Okay.

• 21:24Neil deGrasse Tyson?

  So a total solar eclipse, really, we shouldn't use the term eclipse, but we do.

• 21:28Chuck Nice?

  All right, nice. Uh, this is Cesar Erno, who says, hello, Dr. Tyson, Dr. Tropi. Is the James Webb Space Telescope used to look for exoplanets.

• 21:40Speaker 02

  Heck, yeah.

• 21:41Chuck Nice?

  Okay, so why don't we just zoom in on some exoplanets and get high quality?

• 21:45Neil deGrasse Tyson?

  She works for NASA, she said, heck, yes.

• 21:47Chuck Nice?

  Heck, yeah.

• 21:47Neil deGrasse Tyson?

  Heck.

• 21:48Chuck Nice?

  We heard that.

• 21:49Neil deGrasse Tyson?

  No, let me hear it real. You're in New York City, you're in Manhattan, say that right.

• 21:54Chuck Nice?

  [bleep] Yeah!

• 21:57Chuck Nice?

  I'm so sorry. I'm so sorry.

• 21:59Neil deGrasse Tyson?

  Chuck wins that.

• 22:00Chuck Nice?

  I'm sorry.

• 22:03Chuck Nice?

  That was just too New York, I couldn't.

• 22:04Neil deGrasse Tyson?

  That's a long bleep on that one.

• 22:07Speaker 02

  No, I think if I had the T-shirt, instead of "I love New York", it would be "I love GWST", right? For the exoplanets.

• 22:13Neil deGrasse Tyson?

  Oh, yeah.

• 22:14Speaker 02

  James Webb's space telescope.

• 22:15Neil deGrasse Tyson?

  So, the... So, I thought it would only be looking closer at exoplanets we've already discovered. Is it... Is there a discovery mode?

• 22:22Speaker 02

  There are discoveries too, yeah.

• 22:23Neil deGrasse Tyson?

  How does it do that?

• 22:24Speaker 02

  I mean, it actually captures pictures where you see that there's planets in the frame.

• 22:29Neil deGrasse Tyson?

  Without knowing that in advance?

• 22:30Speaker 02

  Yeah, yeah.

• 22:31Chuck Nice?

  So, he said, "Why don't we just zoom in and get some high-quality images?"

• 22:34Neil deGrasse Tyson?

  That's what it's doing.

• 22:34Chuck Nice?

  And that's exactly what GWST is doing.

• 22:37Neil deGrasse Tyson?

  Wait, wait, so you see the whole star and you see the planet?

• 22:41Speaker 02

  You get... You get a hint of the planet being there.

• 22:44Neil deGrasse Tyson?

  A hint of the planet.

• 22:44Speaker 02

  You get a little, little dip of tea, right? Dip of planets. But I mean to, you know...

• 22:48Neil deGrasse Tyson?

  Wait, wait, can GWST block the light of the bright star?

• 22:54Speaker 02

  There is no coronagraph on GWST.

• 22:55Neil deGrasse Tyson?

  Coronagraph.

• 22:56Speaker 02

  Right, so a coronagraph is the part that, you know, it's like sunglasses for your telescope to block out the light.

• 23:01Chuck Nice?

  Got you.

• 23:02Speaker 02

  But, you know, the question of can we zoom in on planets there? You know, James Webb is looking at different patches of the sky. And if there are planets in there, that's great. But it can't look at just any part of the sky and say, "Zooming in deeper and deeper", because planets don't give off a lot of light. They're just reflecting their starlight, which is so faint that you don't see it most of the time.

• 23:21Chuck Nice?

  Yeah, got you.

• 23:22Neil deGrasse Tyson?

  Alright.

• 23:22Chuck Nice?

  Got you. Alright, this is Gavin Bamber, who says, "Hello from North Vancouver, where plant life flourishes", and he's not lying. That's a...

• 23:31Neil deGrasse Tyson?

  Northern Vancouver.

• 23:32Chuck Nice?

  Ooh, it's so green up there.

• 23:34Neil deGrasse Tyson?

  Really?

• 23:34Chuck Nice?

  Oh, you can go green-blind up there. It's crazy. It's crazy. He says, "Once we find plant or animal life on other planets, uh, oh, will we be able to eat it? Or can we tell if we're able to eat it? Or for tuck, will we be able to smoke it?"

• 23:49Speaker 02

  Well, that's a question from you.

• 23:50Chuck Nice?

  Yeah.

• 23:50Neil deGrasse Tyson?

  Wait, wait, did he say that?

• 23:52Chuck Nice?

  Yes, he did.

• 23:52Neil deGrasse Tyson?

  No, he didn't.

• 23:53Chuck Nice?

  Yeah, I swear to God. He said, "Or for tuck, will we be able to smoke it?"

• 23:57Neil deGrasse Tyson?

  Okay, so let me ask that... Ask this. So, can we only... I don't have biology, you know? Um, but can we process organic matter that has a different DNA from us? Like, our DNA is right-handed, like it spirals this way.

• 24:14Speaker 02

  Yep.

• 24:15Neil deGrasse Tyson?

  Uh, like clockwise looking up.

• 24:17Chuck Nice?

  A double human.

• 24:17Neil deGrasse Tyson?

  Yeah, but in principle, you can have DNA doing the other direction.

• 24:20Chuck Nice?

  Right.

• 24:21Neil deGrasse Tyson?

  The chemistry shouldn't matter.

• 24:23Chuck Nice?

  Right.

• 24:23Neil deGrasse Tyson?

  Alright, except we don't.

• 24:25Chuck Nice?

  And all those people's skin is on the inside of their body.

• 24:29Chuck Nice?

  All their organs are on the outside. They are so messy looking.

• 24:33Neil deGrasse Tyson?

  So what is the scholarship on just the digestibility of life forms that are not native to Earth?

• 24:39Speaker 02

  A researcher doesn't eat and tell, Neil.

• 24:42Neil deGrasse Tyson?

  A researcher doesn't eat and tell?

• 24:45Neil deGrasse Tyson?

  I don't know why that got me.

• 24:48Speaker 02

  But I mean, I would say, you know, would you want to though, right? Because I mean, there's so many things that you're like, oh, that cheese doesn't look quite right. I don't know if I want to eat that. Now you're going, I just found this out there. I foraged for some while.

• 24:58Neil deGrasse Tyson?

  Yeah, yeah, yeah. There's a whole lot of stuff on Earth you know not to eat. Now you're that desperate to eat aliens?

• 25:04Speaker 02

  Fred, I'm just saying, would you want to?

• 25:15Speaker 03

  Hi, I'm Chris Cohen from Hallworth, New Jersey, and I support StarTalk on Patreon. Please enjoy this episode of StarTalk Radio with your and my favorite personal astrophysicist, Neil deGrasse Tyson.

• 25:35Chuck Nice?

  So this is Daniel L. Thompson, who says, howdy, Dr. Tyson, Dr. Tripathi, and Sir Nice. And that's Lord Nice. He says...

• 25:43Neil deGrasse Tyson?

  Lord is above, sir.

• 25:44Chuck Nice?

  Lord, exactly.

• 25:45Neil deGrasse Tyson?

  Yeah, Lord is totally above, sir.

• 25:46Chuck Nice?

  Why would you demote me? He goes, I'm Daniel from high school in the AFJR ROTC, Junior Air Force Reserve Officer Training Corps. Good for you, buddy.

• 25:59Neil deGrasse Tyson?

  Nice.

• 25:59Chuck Nice?

  Um, he says, for potential habitable planets, has there been a minimum and maximum size or density to define what would be survivable for humans to live?

• 26:11Neil deGrasse Tyson?

  I like that.

• 26:11Chuck Nice?

  Uh, yeah. And P.S. Chuck, you're welcome for the easy name. Well, thank you, Daniel. But you can't take credit. I'm gonna thank your parents for that.

• 26:20Chuck Nice?

  But anyway, is there, I mean, I suppose planet sizes, the pressure, atmospheric pressure, or gas, planets, whatever, all those things would have a-

• 26:29Neil deGrasse Tyson?

  There was a movie, The Space Between Us, where someone grew up on Mars. An astronaut got pregnant on the night before the launch.

• 26:36Chuck Nice?

  Yeah.

• 26:37Neil deGrasse Tyson?

  And it takes nine months to get to Mars.

• 26:38Chuck Nice?

  Right.

• 26:39Neil deGrasse Tyson?

  And NASA had to hide that information. So she gave birth on Mars and no one knew about it. And then the kid came back to Earth and was like, huh.

• 26:47Chuck Nice?

  That's pretty cool.

• 26:48Neil deGrasse Tyson?

  He had a hard time breathing.

• 26:49Chuck Nice?

  Yeah.

• 26:50Neil deGrasse Tyson?

  And, you know, all the things he was used to on Mars.

• 26:52Chuck Nice?

  On Mars.

• 26:52Neil deGrasse Tyson?

  His muscles couldn't handle it. But he was still alive, it didn't kill him. So do you have any thoughts on survivability of low or high gravity?

• 26:59Speaker 02

  I mean, I'm a big fan of Earth, right? So like, looking for planets like Earth, because, you know, I like being able to jump up and down, rather than Jupiter out on it and jump up. Where are you going next, right?

• 27:09Neil deGrasse Tyson?

  Right, right.

• 27:10Speaker 02

  And, you know, having that nice solid surface. So, you know, something sort of the size of Earth is nice and cozy. We seem to do okay.

• 27:16Neil deGrasse Tyson?

  Oh, actually, your point is if it's much more massive than Earth, it's not a rocky planet. It's gaseous.

• 27:20Speaker 02

  You're getting gaseous.

• 27:21Neil deGrasse Tyson?

  Because it kept all of its gas.

• 27:22Speaker 02

  Right, yeah.

• 27:22Neil deGrasse Tyson?

  Okay, so that's out, the upper end of that's out.

• 27:24Speaker 02

  Upper end's out. I don't know how low we can go, right? Because we've got moons that are possibly good places to live, right?

• 27:30Neil deGrasse Tyson?

  Well, our moon is one-sixth gravity.

• 27:32Chuck Nice?

  Right.

• 27:32Neil deGrasse Tyson?

  Right, so that's not gonna kill you.

• 27:34Speaker 02

  It's not gonna kill you, you're gonna get some help.

• 27:36Neil deGrasse Tyson?

  But you don't wanna get used to it and then come back to Earth.

• 27:38Chuck Nice?

  Yeah, I mean, three generations later, you know, you have the bone density of a marshmallow.

• 27:43Speaker 02

  But you've got the space suit, right? That, you know, it's a souvenir, right? All I got was this lousy space suit, right? When I came.

• 27:51Speaker 02

  You're not gonna be bound for my souvenir shop anymore, so now you're gonna... All right, it's okay. So, I mean, I think, you know, down on the lower end, it's hard to say how low you can go. It is interesting, though, that when we look out at exoplanets, we find some where there are these little planets that actually end up just getting evaporated away. So instead of their atmospheres being all that evaporates, you've got just like crumbly planet going off into space.

• 28:11Neil deGrasse Tyson?

  Wow.

• 28:12Speaker 02

  Right? So you got the wrong conditions there. So it's not just the size of the planets, it's how close it is to the- Star and everything else it's feeling, so.

• 28:18Neil deGrasse Tyson?

  It probably feels tidal forces that'll disrupt structurally too.

• 28:22Speaker 02

  Yeah.

• 28:22Neil deGrasse Tyson?

  Okay, but when they say super Earths, we've heard this.

• 28:25Speaker 02

  That's right.

• 28:25Neil deGrasse Tyson?

  Among exoplanets, super, how, how big is super?

• 28:28Speaker 02

  Bigger than Earth, smaller than Neptune, right? It's not like anything we've got in the solar system, so you think like, ah, it's in between.

• 28:34Neil deGrasse Tyson?

  So you might be twice your gravity, something like that.

• 28:37Speaker 02

  Could do, right, we talk about it in terms of the radius of it, so how's the size of it? Because the super Earth, right, it could have a surface, it could be a little bit more puffy.

• 28:46Neil deGrasse Tyson?

  Okay, but so how big a radius compared to Earth if it's a super Earth?

• 28:49Speaker 02

  Depends on your definition, right, it's a few times.

• 28:51Neil deGrasse Tyson?

  A few times, yeah, okay. A few times, but that's pretty big.

• 28:54Speaker 02

  That's pretty big, right?

• 28:55Neil deGrasse Tyson?

  Normally, when people think of, oh, it's twice the size, but if you can range 10 and 100 times bigger. Yeah. A factor of two is just friendly, you know? Exactly.

• 29:03Speaker 02

  I mean, we have a poster that we made of people skydiving on a super Earth, because they thought, oh, that'd be fun, right?

• 29:08Neil deGrasse Tyson?

  Yeah.

• 29:11Neil deGrasse Tyson?

  We'd be falling faster.

• 29:12Speaker 02

  I personally don't think it would be fun.

• 29:14Neil deGrasse Tyson?

  A lot fast, yes.

• 29:14Speaker 02

  But our art team thinks it's great.

• 29:16Neil deGrasse Tyson?

  Yeah.

• 29:17Speaker 02

  I think that's great, but, you know, there was also the question in there of the density, right? And I definitely want to be on that ball of rock rather than that ball of gas like Jupiter, because I like having a surface.

• 29:27Neil deGrasse Tyson?

  Like you want to land somewhere, okay?

• 29:28Chuck Nice?

  And, and, yeah, and so, but what if, or could you tell this? Like, when they, when we retrieved, uh, you know, part of the asteroid, right? We were able to do so because we put the, uh, the drill down in a place where we knew it was crumbly rock. So what if we know that it's a super Earth, but it's kind of made of that, kind of that composition of crumbly rock?

• 29:52Speaker 02

  I mean, I would love to get to that point, right? Right now, I'm just like, it weighs this much, it seems this big, eh, divide some numbers.

• 29:57Neil deGrasse Tyson?

  I don't think that's a real thing.

• 29:59Chuck Nice?

  Really?

• 30:00Neil deGrasse Tyson?

  Yeah, because if it's big enough and has a strong enough gravity.

• 30:02Chuck Nice?

  Right.

• 30:03Neil deGrasse Tyson?

  It'll compactify.

• 30:04Chuck Nice?

  Right, it will condense.

• 30:06Neil deGrasse Tyson?

  The problem with the asteroid is they don't have much gravity.

• 30:08Chuck Nice?

  Right.

• 30:08Neil deGrasse Tyson?

  So they're like loosely, they're loose. Plus, it didn't drill, it was a touch and go.

• 30:14Chuck Nice?

  It was, right, it was bang, and then it sucked up.

• 30:16Neil deGrasse Tyson?

  Grabbed whatever.

• 30:17Chuck Nice?

  Whatever came up inside of it, yes.

• 30:19Neil deGrasse Tyson?

  Right, and they were ready for just a couple ounces, and they got to half a pound.

• 30:21Chuck Nice?

  Right.

• 30:22Neil deGrasse Tyson?

  Half a pound, so they were good.

• 30:23Chuck Nice?

  But no, you're, you're right, the gravity makes it, that's, that makes sense.

• 30:27Neil deGrasse Tyson?

  All right, we've got time for like one and a half more questions.

• 30:29Chuck Nice?

  One more, all right, all right, all right, all right. Let me see. Okay, let's go with Andrew Nisker. And Andrew says, hello from Flecherton, Ontario. Can you please explain the different types of biomarker gases? How will the next generation of telescopes enhance our ability to study exoplanets? Guess that's two separate questions, but hey, I'm always looking up, so I have to ask lots of questions.

• 30:54Neil deGrasse Tyson?

  Nice. So picking up on the earlier question, you mentioned, uh, water molecule, uh, methane, and carbon dioxide.

• 31:02Chuck Nice?

  Right.

• 31:02Neil deGrasse Tyson?

  But is there like the greatest hits of what would reveal life on the, on the, on the surface?

• 31:08Speaker 02

  I mean, there's so many different ways that we can search for exoplanets with life, right? Those signatures, right? We call them biosignatures or techno-signatures. We even wanna go a little further afield. And so the fact that, you know, you could look for pollution on a planet.

• 31:21Neil deGrasse Tyson?

  That'd be a techno-signature.

• 31:22Speaker 02

  That, well, depending on how you count it, yeah. Right? But I mean, like you look for chlorofluorocarbons, right? From your, you know, hairspray on your alien world.

• 31:29Neil deGrasse Tyson?

  Okay.

• 31:29Speaker 02

  You know, that would be a slam dunk for life, even though it's not one of the things we've historically always studied.

• 31:34Neil deGrasse Tyson?

  Right.

• 31:35Speaker 02

  These sorts of things. And so, you know, signatures like methane.

• 31:38Neil deGrasse Tyson?

  Wait, so the chlorofluorocarbons, they're idiots.

• 31:42Speaker 02

  But they're idiots we can see, right?

• 31:44Neil deGrasse Tyson?

  No science in technology like that.

• 31:45Chuck Nice?

  Exactly.

• 31:45Neil deGrasse Tyson?

  They're getting rid of their ozone layer.

• 31:47Chuck Nice?

  Which is probably what they're saying about us when they actually see the biomarkers from this planet. Or the techno-markers from this planet.

• 31:54Speaker 02

  Right. I mean, it's like, if you're really smart, would you want people to see you and find you?

• 31:57Neil deGrasse Tyson?

  Right, right, right. So anymore, what's it, phosphate was one of them?

• 32:01Speaker 02

  Uh, so phosphine is something that people have talked about, possibly, no, no, it's all good, it's all good. Uh, being detected possibly in Venus and whether that's a sign of life or something else. There's probably something else there. But I think there are lots of detections of all of these more complicated molecules, right? Where you start putting things together.

• 32:17Neil deGrasse Tyson?

  That would be there only if you have life on the surface.

• 32:20Speaker 02

  That could be caused by life, right? You know, like the chlorofluorocarbons would only be caused by life. But methane could be common from something else.

• 32:27Chuck Nice?

  Something else.

• 32:27Neil deGrasse Tyson?

  Okay. Cause you get, you can get naturally occurring methane.

• 32:30Speaker 02

  Right, yeah.

• 32:30Neil deGrasse Tyson?

  So what about oxygen?

• 32:32Speaker 02

  Oxygen could be there, it can be, I mean.

• 32:33Neil deGrasse Tyson?

  I don't, I don't know how you get oxygen unless somebody's making it, like with plants.

• 32:38Speaker 02

  I mean, like, look at the history of the Earth, right, for billions of years we've existed, and we didn't have this much oxygen all that whole time, right, like, go back in time. So you not only need to look at that planet and just see what it is, but at this particular moment in time.

• 32:51Neil deGrasse Tyson?

  When I saw the original Star Trek, do you, do you remember, then the original Star Trek, no one ever wore a spacesuit.

• 32:56Chuck Nice?

  No.

• 32:57Neil deGrasse Tyson?

  When they went down.

• 32:57Chuck Nice?

  They didn't wear a spacesuit, they never wore a mask.

• 32:59Neil deGrasse Tyson?

  Right, right, well, you know why, because they, they, but they would establish, uh, oxygen, nitrogen atmosphere, Captain, but let's go on down.

• 33:05Chuck Nice?

  It's a Class M planet.

• 33:06Neil deGrasse Tyson?

  Right, right, exactly.

• 33:07Chuck Nice?

  Breathable atmosphere.

• 33:08Neil deGrasse Tyson?

  So I'm thinking, oh, if you just look hard enough, you find other oxygen, nitrogen planets. And then I realized later that you're only getting the oxygen from living matter on the planet. It's not just some random mixture.

• 33:20Chuck Nice?

  Right.

• 33:20Neil deGrasse Tyson?

  In the random assortment of planets. Somebody's making the oxygen, and on Earth it's our plant life.

• 33:25Speaker 02

  But I mean, we can also, you know, when you form a planet, you got all kinds of chemistry going on in there, and things going into the rocks, and so what goes on in your atmosphere, some of that just happens naturally.

• 33:35Chuck Nice?

  Okay.

• 33:35Neil deGrasse Tyson?

  So you're gonna have to distinguish those.

• 33:37Speaker 02

  That's right.

• 33:38Neil deGrasse Tyson?

  Cases, and that's, so getting the list is one thing, and then you fight about whether it's biological or not.

• 33:43Speaker 02

  Exactly.

• 33:44Neil deGrasse Tyson?

  Yeah, at the conferences, yeah, that's, that's good.

• 33:46Chuck Nice?

  That was a good question.

• 33:47Neil deGrasse Tyson?

  Chuck, time for one half a question.

• 33:48Chuck Nice?

  Oh, my God, let's see, let's go with Captain James Riley, who says, hello, everyone, Texas here. Is there a most common atmospheric composition out there among rocky planets?

• 33:59Neil deGrasse Tyson?

  Like that, that's related to that last question.

• 34:01Chuck Nice?

  Related to the last question.

• 34:02Speaker 02

  I love that question, and I think in the last question, he asked about the telescopes, and I think the answer is, we need more data, right, to answer this, because we haven't been able to tell the atmospheres.

• 34:10Neil deGrasse Tyson?

  I'm not allowing you to cop out and just say, we need more data.

• 34:12Speaker 02

  No, no.

• 34:12Neil deGrasse Tyson?

  You talk to me, give me.

• 34:13Speaker 02

  But I mean, I think that's the thing, is that so many of these things, because if it's a cloudy day, you can't see what's going on underneath, right, you see clouds, you see, like, water vapor up there. Right, so there's so many of these systems where you think, like, hey, I need this new, new telescope.

• 34:25Neil deGrasse Tyson?

  Okay, so of all the planets where we know anything about their atmosphere, is there an emergent common? Uh, list.

• 34:34Speaker 02

  I think it's kind of like the zoo, right? There's some common things, like there's all those things with tails. So there's all those things with oxygen. There's all those things with carbon and methane, right? It's the sort of thing that we haven't seen enough to be able to say this is the most common thing yet. So not yet.

• 34:47Neil deGrasse Tyson?

  So like the zoo, you have animals with tails, animals with four legs. And.

• 34:51Speaker 02

  And things with wings, right? Like it just.

• 34:52Neil deGrasse Tyson?

  Okay, so the blunt. The blunt, you start blunt.

• 34:55Chuck Nice?

  Right.

• 34:56Speaker 02

  I think what it means is we gotta chat more again in a few years and then we can do better.

• 34:59Neil deGrasse Tyson?

  Oh, then we can come back.

• 35:00Speaker 02

  Come back.

• 35:01Neil deGrasse Tyson?

  Well, very cool. By the way, I understand you have a TED Talk?

• 35:04Speaker 02

  I do.

• 35:04Neil deGrasse Tyson?

  Yeah, on.

• 35:05Speaker 02

  On atmospheric escape.

• 35:06Neil deGrasse Tyson?

  Oh, oh, okay.

• 35:07Chuck Nice?

  Okay, well, I'm not watching that.

• 35:09Speaker 02

  Uh.

• 35:10Chuck Nice?

  I'm scared to death.

• 35:11Speaker 02

  But you know that how it ends. You know, you're safe, right? You know how it ends. It's a no problem.

• 35:15Neil deGrasse Tyson?

  Yeah. So you're the first to model the escape of gas from, from atmospheres?

• 35:20Speaker 02

  Uh, doing that in 3D for these planets.

• 35:22Neil deGrasse Tyson?

  3D modeling.

• 35:23Chuck Nice?

  Oh, cool.

• 35:24Neil deGrasse Tyson?

  In the old days, computers weren't fast and we didn't have AI. And so you do like 1D modeling and 2D modeling just to approximate the 3D model because you couldn't calculate it. And then when computers get fast enough, and she comes along, says, I got this 3D.

• 35:37Chuck Nice?

  Boom.

• 35:37Neil deGrasse Tyson?

  All in.

• 35:38Chuck Nice?

  There you go.

• 35:38Neil deGrasse Tyson?

  And it's hard because you're modeling getting gas.

• 35:41Speaker 02

  Right, you're just watching it flow.

• 35:43Neil deGrasse Tyson?

  Yeah, yeah, this, the flow of gas in a computer model, let's not eat.

• 35:46Speaker 02

  It's not let it go, it's let it flow, right?

• 35:48Chuck Nice?

  Right.

• 35:49Neil deGrasse Tyson?

  Okay.

• 35:50Chuck Nice?

  What's it, what's, but yeah, but I mean, what's funny is like, isn't that like, gas is, what's that? As it, gas moves towards entropy, it's just no chaos, right? So what do you?

• 36:00Speaker 02

  Somewhere in between, right? Because it was starting on the planet in the atmosphere and just blowing off into space.

• 36:05Chuck Nice?

  So that's what you're doing. You're going from where it's very more stable and then to its instability.

• 36:10Speaker 02

  There you go.

• 36:11Chuck Nice?

  Okay.

• 36:11Neil deGrasse Tyson?

  All right, we good. All right, Chuck, Chuck is good till the next time.

• 36:16Chuck Nice?

  Yeah, I'm feeling better.

• 36:17Neil deGrasse Tyson?

  I feel a little better.

• 36:18Chuck Nice?

  I'm feeling better.

• 36:19Speaker 02

  You gotta be feeling totally better.

• 36:23Neil deGrasse Tyson?

  So Anjali, thanks for coming up on the Star Talk.

• 36:25Speaker 02

  Thanks for having me.

• 36:26Neil deGrasse Tyson?

  We'll continue to follow your career.

• 36:28Speaker 02

  Appreciate that.

• 36:29Neil deGrasse Tyson?

  Uh, you know, there's still a few more presidents you can work for.

• 36:32Chuck Nice?

  Exactly.

• 36:32Neil deGrasse Tyson?

  You know, don't slouch. You gotta get back in the White House.

• 36:38Speaker 02

  I mean, I'm the Exoplanet Ambassador though, right now, right? So gotta go visit those exoplanets too eventually.

• 36:42Neil deGrasse Tyson?

  You have an ambassador title?

• 36:43Speaker 02

  Oh yeah, no, I'm NASA's Exoplanet Ambassador.

• 36:46Neil deGrasse Tyson?

  Oh, sweet. Oh my god. That's very cool. So, so do you speak at the UN?

• 36:50Speaker 02

  I speak for the State Department.

• 36:51Neil deGrasse Tyson?

  The Galactic UN. Oh, yeah, there you go. So when the aliens come, when they say, "Take me to our leader," I'll say, "We have an ambassador." We have an ambassador, is that good enough? Yeah.

• 37:04Neil deGrasse Tyson?

  No, we say, "We ain't taking you to our leader."

• 37:08Neil deGrasse Tyson?

  The ambassador is gonna be what you're gonna meet. Believe me, yes, it will, it will be a scientist or Taylor Swift.

• 37:15Speaker 02

  The doctor will see you now.

• 37:19Neil deGrasse Tyson?

  All right, well, good luck in your continued career and your ambassadorship. And we'll, we'll want a full update.

• 37:26Speaker 02

  All right, sounds good.

• 37:27Neil deGrasse Tyson?

  As more exoplanets show up and more aliens visit.

• 37:31Speaker 02

  Okay.

• 37:32Neil deGrasse Tyson?

  You'll be first on the list. Nice. All right, good. This has been StarTalk. Neil deGrasse Tyson here, your personal astrophysicist. Chuck, thanks for being there. Always a pleasure. All right, and as always, I did you.