Rogue Planets & Exomoons with David Kipping

0:00So Chuck, love me some David Kippen. Yes. When you get some escape word, comes down from Colombia. From Colombia. Catches us up on all the cool stars out there. And I've got to tell you, you're not supposed to say it, but he's a very good looking. Coming up on Star Talk. No. Ha ha ha ha ha ha ha ha ha. Welcome to Star Talk. Your place in the universe where science and pop culture collide. Star Talk begins right now. This is Star Talk. Neil deGrasse Tyson, your personal astrophysicist. Got with me. Check. Nice. What's up, Neil? Check it, baby. Hey. All right. This will be a cosmic query. Oh, OK. Good. One of our favorite people. Yeah. That's right. The boy band of astrophysic. A boy band of one. Ha ha ha. Ha ha. Throb no doubt. No. We have the one. Keep being, David, welcome back to Star Talk. I died to say the introduction, but I will take it.

1:01Thank you. Very kind. I have to announce that you're based in Columbia University, which is up the street a couple of miles. And you skateboarded here. Because even a skateboard, what do you call the thing with the single wheel? Oh, that's a unicycle. That's right. That's right. It is a unicycle. OK. Yeah, literally. Yes. Yes. Hoverboard style. Yes. So you are a associate professor of astronomy up in Columbia. That's where I got my PhD at Columbia University. And you are the host of Cool World podcast. Cool World's YouTube show and a podcast. Yes. Cool world. The same name. Cool world. I always find people get confused. I say, I want to even want to just have a YouTube channel. And I'd say, I'd describe people. They're like, oh, so tell me about your podcast. I'm like, no, no, that's a different podcast. This is a different thing. It's a different mind-mind. Yes.

2:02Yes. We have a main, why do you like these mini documentaries about space and universe and things I'm working on? And then we have the podcast. So it's the Cool World podcast and YouTube channel. You got it. There you go. So you study exoplanet. That's right. Yeah. Let's check we were rising through 6,000 of these things in the catalog, pushing 7,000. I've stopped counting it. This point. I'm old enough to remember when they were none. Right. Back in the day. Well, they were there. But we got to get right to it. We're a planet. We're presumably an exoplanet to aliens orbiting some other star. Right. Yeah. Absolutely. But we have a moon. So what's this I hear that an exo moon was recently discovered? Yeah. There was in the news recently, CD35, a load of letters B. Just call it CD35B for short. And CD is it the name of the catalog that came from? That's the catalog.

3:02I've no idea what the CD is supposed to sound for. But that's the boilerplate name going around. And what's interesting about this object is it's a brown dwarf. Okay. The orbits a M dwarf star. And around that brown dwarf, they see evidence for a companion. And the question is, is that a moon or is that a planet? So a brown dwarf, again, is a not quite a star, a little too massive to be a planet. So this is an object which is in between the mass of say 13 Jupiter masses to about 80. And 80 is the point where you have enough mass for hydrogen fusion. For hydrogen fusion. So you can shine like a star. But below that, you can actually still have enough mass for deuterium fusion to occur. But there's hardly any deuteriums. It's not very efficient. So you're like a reality star. You're on that CT. I was big on Bravo for a while. So you know that people, the people who story-branded us get kind of edgy about that kind of stuff

4:02because they're like, no, no, it's not a failed star. It's an over-achieving planet. Right? It depends how you, how you feel. How are you supposed to say? I'm going to tell you to, I'd rather be Jupiter. I'd rather be Jupiter. I'd rather be Jupiter. That's right. Just trying to plan it instead of the over-achieving, not quite a star. Do you have a red-blooded star, an almost star, not quite a star, too much to be a planet thing, right? And that's not weird to have a brown dwarf orbiting a star. No, I'm not. So this is the first time we found basically a triple system, an object orbiting an object, orbiting the object where two of them are not stars. Well, not quite because we know of binary stars, which are... Right. Not saying this, but two of them are not stars. You said two of them are not stars. Yes. It sort of depends on how you think of the brown dwarf, because some might say the brown dwarf and the star is kind of a binary star system. Yeah. Yeah, but you can't, you just eliminated that possibility.

5:03Right. By degrading it to a not quite star, over-achieving planet. So did it make the news because we don't really know what to call it? It's not that it was some major astrophysical and bit of enlightenment. Is it just who ordered this kind of thing? I think it's a bit of both. I mean, first off, there is an object, almost identical to this one that we discovered before. It's like HD 206, something or other. That's a very similar configuration. They use a different method to find it and they're not as confident. So they say this is a candidate object around a brown dwarf or a star. The authors of this paper are much more confident. This is legit. This is definitely something that... So who's lead author on this? Kevin Hoy, there's a Chilean group. And they're using the VLT to come submissions. And they're able to measure the wobble, the Doppler wobble of the subject. And that's where they get this evidence for. But if you go, if you turn to the IU definitions, they're actually pretty clear. And they say that there's things upon it. Anything in all of it for brown dwarf is a plan according to those definitions.

6:04Now, we can argue about those definitions, but it's... Oh, so it doesn't then say, suppose the brown dwarf is worrying something else. Does that anything about it? It says no matter how... It says actually specifically no matter how it formed, what it's doing, what it's color it is, whatever it is. If it's between 13, 18 Jupiter masses, it's a brown dwarf. And anything in all of that, again, doesn't really matter. It's always a plan. Wait, but suppose I have a binary brown dwarf orbiting the main star. You can't call that a plan. No, then it's a binary brown dwarf. Yeah. Because they actually do have a... It's a footnote of if it's more than less than one of a 25 mass ratio. Then it's a binary. So this object is one over 37 mass ratio. So that's a great... So there's a moon category right there. Planet category. I'd say... There is no moon category in the IU definition. The IU says there's no word, moon, or satellite anywhere in this document. So that's why we need to go to here. Yeah, I think so. Yeah. We should bring the Pluto haters back, because they know how to... They know how to get things done.

7:04Yeah. We got it down. Yeah. Okay, so is it something to be excited about? I don't know, it's just something to add to the catalog. I think it's definitely an exotic object. I look for examines, as you know. And for me, the reason why I do it is because I want to understand how common is the Earth-Moon system, how common is the Moon's right? Do you have to like, how common is us, like our backyard? You know, where do we come from? And this object, as cool as it is, doesn't really speak to anything familiar to that, which we have in the solar system. So it's an exotic object. That's the rub right there. I love it. It does fit. The way you originally described it, it's very exotic. Yes, yeah, that's what makes it. Which is cool. I love you, it makes it exciting. But I also want to understand our story. Right. Yeah. How did this Chilean group discover this examune? I think this brown dwarf was already known, and they were able to separate the light from the brown dwarf and the star using a chronograph, and then they were able to measure the Doppler shifts of the light from that brown dwarf. Wow. So it's kind of similar to how we discovered the first exoplanet, around 51 Pegasy B,

8:06that was just a star by itself, and we saw the Dopolines, here it's harder because you've got two sources of light. So you have to do that separation first, and then you can actually look for things around the brown dwarf. Wow. So but they had to know to think to do that in the first place. Yeah. Yeah. It's not easy work. Right. So now you recently submitted for publication a paper that explores life on exoplanets, but that's quite the cottage industry. It's not a few months go by before another result. We found some chemistry in the atmosphere that means there's life from the surface because you can't see the surface. Right. It's too small, too distant, too dim, right? But the chemistry pops out. So what are you, how are you adding to that conversation? You know, I was just frustrated as someone interested in the search for alien life that we keep seeing so many false stars. Right. So you've had, you go away back when I was a kid, I remember Bill Clinton's done the White House law and talking about the Alan Hill's meteor. Yes. As evidence for life. And of course that evaporated. We've had recently K-18B, this evidence of dye methyl sulfide that everyone got excited about could be life.

9:06And again, it's been challenged and we had Venucine phosphine. So we just seem to have like time and time again. Dymethyl sulfide and it's also dye methyl dye sulfide, right? I think there were two. Yes. Well, the original claim is just DMS, but now they think there's not as well. So on Earth, right? Phytoplankton. Okay. The boys that do photosynthesis, the basis of everything here, the basis of everything. Right. They're the ones that give us these dye methyl sulfides. Yeah. And so if you could find that on another planet, it's possible. And that's that's headline making. That's really cool. So has that been retracted? That discovery? It's not been retracted, but other authors have come up with other ways you could plausibly expect to have this atmosphere without necessarily life being involved. And you want to, you want a strong result. Yeah. So this is kind of a frustration to have. That every, it seems like over and over again, someone sees something which looks like evidence of life. And then six months later, a theorist comes along and says, oh, by the way, I think of a way of doing that without life involved. And that doesn't make them right. Doesn't make them right.

10:07So have you found a way to make an airtight argument here? Well, I tried to point out two things. One is that as we plan these new observatories, like the Habitall Worlds Observatory, which will be the success, hopefully, to James Webb, another multi-billion dollar telescope we're planning right now, we have to confront the reality of this epistemic problem that will be persistent, I think, for generations to come. And I suggest that one strategy could be, kind of what we do in YouTube space, of AB testing. So instead of just looking at a bunch of things and saying, how often do I detect dimethylsulfide? How often do I detect a biosignature? Split your group into two categories. And accept that there will be some number of confounders in these two groups. But hopefully, you can design these two groups which the confounderate is the same, but the life rate is somehow different. If you can do that, I'm not saying it's easy to do that. But if you can do that, you can solve this problem cleanly, statistically. And that's kind of the whole premise of my paper

11:07that we need to think about the strategy, not just the technology, but really how we even approach this question. Hmm. So is that similar to, because I remember back during the, was it the challenge your disaster? Any disaster, they bring all the evidence and then come up with a conclusion. What I always think they should do is, they should bring in only half the evidence and see what you conclude. Oh, yeah, yeah. And then you add to it and see if the conclusion remains. Yeah, if the last bit of evidence is what tips it, that it means most of the evidence wasn't really pointing to that result. Yeah. And in science, you want the more evidence to align with what your thoughts were, otherwise go home. Right. Yeah. Right. Yeah, I mean, in statistics, we call that cross-finalization. Cross-finalization, okay? When you block out some of the data, you deal with your fits on the data you have, and then you uncover your hand and ask, which one actually works? And that's like the true discriminatory test of which one is okay. That's cool, man.

12:07This will be a way to keep people on notice. I think it's important. It's the question we all care about, right? I think it's where there's life out there. And I just want to get an answer before I die, right? I hope the A to S, C, C, is an amazing innovation of science. Yeah, I'm going to get it done before I die. Before I die. Right. Don't worry, when you die, you'll, Jesus will tell you how the answer is. Okay? Does it not have to worry? It'll be right there. I Space Fact. If Earth rotated once in 90 minutes, rather than in 24 hours, the centrifugal force of that rotation would render everyone on the equator weightless. If you like that fact, you can find 4,999 more in lost in space, 5,000 facts to help navigate the universe.

13:12Latest collaboration between StarTalk and National Geographic Books. Lost in Space is now available for pre-order, wherever books are sold. This is a Cosmic Queries. You have a huge fan base out there among our followers. So, Chuck, you got it lined up? I have them right here. Okay. So, you haven't seen these questions, right? They're coming right out of the blue for you. Cool. Good for, yeah, that makes three of us. Good. These are our Patreon supporters who have given us $5 a month, right? Which qualifies you to be able to submit your query. Here we go. This is Andorra Klomp, who says, dear Dr. Kippling, Dr. Tyson Lorde Nice. Kippling. Kippling, sorry.

14:12Dear Dice said Kippling. Oh, I made you quite literary, didn't I? Kippling. And what's your name? What's your name? What's your name? I'm a male boy. Anyway, dear Dr. Kippling, Dr. Tyson Lorde Nice. LHS 1140B has a confirmed atmosphere. 48 light years away. If microbial life lives there under ice or in its ocean, what would be the very first sign we would detect from this distance greeting from Rotterdam, the Netherlands. And so if I remember from the news, 1140 is a rocky planet, right? Well, we're not sure. That's a good question. We're actually not sure. Oh, really? So it's probably almost certainly not rocky to be honest with you. Not really. Okay. It's about five and a half earth masses. All right. But it's 1.7 Earth radii. Okay. So when you do the math, that gives you a density. There's actually similar stuff of the earth.

15:12Sounds like it. But that's why the news was rocky planet found. Right. So you might think that's rocky. But the problem with that is, is that that's compressed density. Right. There's 1.7 Earth radii. It's squeezing all that self-gravity. So if you kind of relaxed it, it means that the stuff that it's made of must be lighter than rock. It can't just be pure rock. It can't have squeezed in that way. Correct. So it's probably some rock and then something on top. Like a big envelope of gas or maybe an ocean or something in between like ice or something. So something is confounding those blunt calculations and confusing how to interpret what. I mean, it's a challenge because we have nothing in the solar system to point her and say, oh, that's what it must be. That's the problem. There you go. Right. Solar system is not a thing. It's in between earth and Neptune. It's okay. And we just don't really know what it is. That's what it is. Does it nullify the inquiry here? If it wasn't in? No, it is. It's at the right distance from its star, potentially for liquid water. If it is. Goldy luck zone. If it has water. Yep. It's in the Goldlux zone.

16:13And it's small. So it seems like it would be potentially possible that could have had water delivery. It's not a gas giant. So if it has life on it, which I think is possible, it's not an Earth-like planet. I want to be clear about that. It's not an Earth-like planet. But it could still have life, nevertheless. And then maybe we could look for things like phytoplankton, like this dimethyl sulfide signature that we talked about earlier. Yeah. We could have oxygen. You could look for methane. You could have some of these gases. But then it kind of comes back to that original question of like, well, then how are you sure that if you see methane, that really is life. So that's just an unsolved question. So here's what I want to know. All right. Just hasn't really nothing to do with this. Just because you said something that triggered me. Yeah. All right. When it's Goldy luck zone, right? Yeah. The star that creates the Goldy luck zone. You said the right distance. Does that distance change on the size of the star and the age of the star? And do stars burn cooler when they get older,

17:16increasing or decreasing the Goldy luck zone? Yes, yes and no. Is the short answer to three questions? Oh, wow. So go. So that was easy. Yeah, I wasn't tracking it to be that efficient in my reply. No, yeah, all stars. This is actually an M dwarf. It says a small star. I'm not sure if it's exact mass, but it's less than half the mass of the sun. So that's why it has this red dim light. That's why it's in the LHS catalog because it's nearby. And but it's not it's not a visible star. It's not an A-Kid eye star. You can't see it with an A-Kid eye. So I have to take telescopes to detect it. But it is nearby. The star because it's less luminous than the sun means this Goldy luck zone is much closer. And yeah, as it ages. And importantly, for these cooler stars, cooler, this is thousands of degrees, the Goldy luck zone is not only closer, it's narrower. Okay. Okay. Okay. So the harder stars get bigger Goldy luck zones. Right. So these are in the statistics of Goldy luck's planets, this matters. Okay. Yeah, of course. Yeah.

18:16Okay. And I'll just finish that point. As it ages, the Goldy luck zone must be moved out, usually for main secret stars. So it should, as the sun is increasing luminosity, was about 30% less luminous, four billion years ago than it is today. I think that's what it feels like. So that means the Goldy luck zone is moving out. Right. We used to be on the outredge of the Goldy luck zone. And now the Earth is on the inner edge. Which is why we're so sensitive to CO2, right? If it wasn't, if we were two billion years ago, we could have probably polluted a lot more, not worried about it. But because we're on the inner edge of the outred zone now, we have to kind of worry about this a bit more. Yeah. A lot more. No, no, yeah. Wow. We'll go back four billion years. Yeah. Yeah. Either one. That's that, right? Yeah, let's go on. Here we go. This is Alejandro Guardado. He says, he says, Hello, Dr. Tyson, Lauren Nice, and Dr. Kipping. Alejandro here from Washington State. Hello, or should I say, Hola.

19:17That is not what you're there. I know it's not. That's what you're saying. That's not what you're saying. That's not what you're saying. Oh, God. Okay. He says this. Let me start messing around. He said this. I was sorry. I got it agreed. That's what Alejandro could say. Oh, yeah. If he don't sound like that, he should take some lessons. I just see him sitting around drinking an espresso with Antonio Bendini. Yeah. That's your mind, bro. All right, here we go. This is what he says. My question is, in our search for life in the universe, why does it matter if aliens are intelligent? Should the search for intelligent life be simplified to just life with a simplification lead to less fear in our society about aliens and lead to advances in the search? Thank you for always keeping me curious. NASA in the day used to have interest in the search for life. Okay. Which included the search for intelligent life.

20:18Okay. And then it ended up in the sites of William Proxmeyer for the Golden Fleece Award, which was given to agencies who do research on public money for things that he judges is a waste of money. Golden Fleece. Okay. And so NASA in the search for intelligent life he viewed that exercise as completely beyond the pale. And so NASA, in response, separated the search for life, which is of interest to everyone biologist and everybody from the search for intelligent life. Mm-hmm. And in that separation, forfeited the search for intelligent life and that was picked up by SETI. Right. SETI is the whole SETI institute, which is privately supported. Yes. And so kind of in response to this, they are two separately funded activities. Now, if someone in your on your exoplanet waves to you, you don't have any problem with that. Yeah. But that's not what you're after. You're looking for any kind of life at all.

21:20I think, I mean, I would especially be interested in life that was technological. I try to avoid the word intelligent because we may not even have intelligent life here. That's the ultimate. That's the ultimate. Of course, yeah. Of course, yeah. But technological life, I think, is something we could look for. And it's pretty interesting if that's out there. Mm-hmm. And it does answer a different question because it's one thing to say, okay, a planet has some kind of life, microbial life. But what if in the evolutionary chain that gets from there to something like us, there is a, what we call a great filter. Some point, which is a bottleneck, which makes it incredibly unlikely that the animals ever develop past a certain point or something. So if we discover technological life, then it would prove that, oh, there is no filter. It's just a smooth track all the way. And it would make the so-called Fermi paradox even more puzzling. So what you're suggesting is just one other example, which show that however narrow that bottleneck is, it's not so narrow, it would have only produced one example of technology in the universe. Right. So if you have another example, one independent example of either life or technology

22:23would be enough to say, let's pay, universes don't it twice, it is completely independently. And life has been on earth for three and a half billion years. Right. For two and a half of those three and a half billion, it was just single solid organism. Right. So if you're throwing a dart at planets with life, and if earth is any measure of that, you're probably going to hit a planet with microorganisms. Right. More likely to do that. Some of their dark statistics on this. But okay. And would one sign of technology be smog? It could. I mean, that'd be the problem. One of the, if that was, I think the advantage, the beauty of a techno signature is that some of them, not all of them, not smog could be unambiguous. Right. If you get, in like in the film, contact, where it's really fast has the headphones on and gets the transmission. And you can unpack it and there's this engineering plan of how to build a machine. There's no way that's random chance. Someone's engineered that.

23:24Exactly. Whereas if we detect a gas, so that would be, that would be slam dunk. There's definitely aliens. If you detect dimethyl sulfide and exoplamosphate, people are going to argue about that for years and decades to come. So that's the advantage of tech signatures. It can be because they're not going to argue over engineering companies. Exactly. Like if they send you akea directions, it's a done deal. How to put together your table. Exactly. Right. And then at the end of the directions, it says, don't worry if there are pieces left over. Oh, wow, that's really cool. And I love that technical, they have technical life. That's the way the technology goes. All right. Here we go. Larry Chan says, I'm Larry Chan from NYC and I'm a science fiction writer. Once humanity travels to other star systems, planets will most likely be named after the gods of ancient times. For example, Tiroa and Catacul, were native American gods.

24:26After the list of gods reaches its limit, how would we name exoplanets? I suggest naming them after characters of classical literature. For example, Ahab, the madhatter, Tom Sawyer, Alice Lodell, I love that. And there's no shortage of those names. Those names. Right. You know, we had a similar challenge when asteroids were discovered. Yeah. They are there. Well, there's at least 10, all right. And they were initially named. Well, the first asteroids we thought were planets. So the name, after Roman gods, as are the other planets. And then we discovered there's some other category of object. But there was an urge to name them after feminized versions of people. So there's an asteroid, not called Mozart, but Mozart Tia. Okay. So that was a little bit, because it was the, the feminine would be the diminutive variant of a planet name.

25:26Got you. Because they're asteroids, right. So then you quickly run out of names, although there's still a lot of names. I mean, there's a lot of names. People named me after their pet. There's an asteroid Santa. People love observing that on New Year's Eve. Right. Okay. A friend of mine did that, and he showed me the data. Okay. Just kind of. That's cool. When you have nerd friends, that's the kind of stuff we do. Yeah, it's just a bedroom, right. I kind of think we should just call them GPS coordinates. You know, just like, you give me a number, and then I know exactly where to go. I'm weird to go and talk about. To go and look at it. Because if you give me a name like, go to a Relia, so sometimes I will, I don't know anything about that star, just from that name. I'd like to get some information about the star. So there was some from the name. As you may know, the moons of Uranus that are all named for fictional characters and Shakespearean literature. Okay. Of which there are plenty enough to get you going. Yeah. Yeah. So another thing, they wanted to name largely successfully initially. All of the asteroids whose orbit cross Earth orbit, which puts us at risk,

26:27the named after evil gods. That's awesome. Yes. Now that makes sense. Yes. So one of them is a poffis. Right. The Egyptian god of death. The night. Yes. And there are plenty of, you know, in the polyseistic realms, there's no shortage of these. Well, there is a shortage because there's hundreds of thousands of asteroids that will do this. So that's the problem. But you go to literature, you got a Sauron. You go to Sauron. That's what I'll be doing. That's all right. Yeah. Yeah. Yeah. I love that. Well, hey, hey, there you go. Yeah, but I think David is right. At some point, the coordinate on the sky is uniquely identifies it. Right. And you know what we can do? Because we went amateur astronomer at all. As a kid. No, no, no. At a high level. Yeah. That was a pretty high level amateur astronomer. So we, there are a lot of objects discovered by an amateur would later get a catalog designation. But then you would carry both names. Yeah.

27:27Right. That was going to say, you have the coordinate as the name and then in parentheses underneath. We're close to it. Close. Tabby star. Yeah. There's Barnard star. Barnard star is another one of these stars that's nearby. And Barnard for study, but it's got a catalog name. So I think that's how you do it. There's a reason to have a name because of its properties or because of who discovered it. You do it. You still need the unambiguous identifier. Okay. Yeah. All right. All right. Hey, well, thanks a lot there. Larry. That was a good question. Okay, let's go to Mary Rose. Mary Rose says, hello to all at StartTalk. This question is coming to you from the tiny island of Malta in the Mediterranean. Oh, I want to be there. Yes. Invite us. What's your name, Ian? Mary Rose. Mary, invite us all. Yes. We'll be right there. Yeah. You got room for a sleepover. Okay. She says, David, what has been the most surprising fine for you so far in the study of Exoplanets? Thank you, Mary Rose.

28:27I love that. Yeah. That's a great question. There are many things we've just covered which lure minds. I think what we kind of expected, I mean, this is a little bit for my time, is that we'd find other solar systems which looked like our solar system. This is the template. Everything would look the same. Of course. And I think the greatest. The Cuberist. But yeah, we are the default. But it turns out we're actually kind of weird. And most solar systems look very different. So I think it's a very like kind of vague answer but to give some examples, mini-net tunes, which we talked about with this LHS, 1140. That's the most common type of planet in the universe. What? And we do not have one. And we don't have one. We don't have one of these. That ain't right. That ain't right. Yeah. That's weird. That ain't right. That's kind of strange. That's not how many is a mini-net tune. It's in between about. What fraction of Neptune's mass would that be? Well, it's in between about two and four times the size of the Earth. So that's about half the size of the Earth. Yeah. So super-Earth. Yeah. Super-Earth. The super-Earth is at the same as a mini-net tune.

29:28We don't know. They have things because people like about the names. Simple as something. You can't call it super-Earth. We don't know. It's rocky. You shouldn't call it the name. But I'm sure you're going to show through this. You don't know. You're the expert here. We don't know. Yeah. I don't know. That's how you know he's good. That's right. That's right. That's right. That's it. Exactly. Okay. But I think that diversity is surprising. There are certain binary planets. Like the Tatooine, like your home star, what was like? George Lucas imagined that. I never understood he was crazy. But we know that that's a very common type of planet. Yeah. Do you think he really knew where did he just think? That's cool. No. No. No. But I do, it's the only science in the world of star wars. That's as good as it goes. Oh my god. Downhill from the top. That's it. It is downhill. That's just awful. Totally downhill from there. Um, that only worked because of the distance to the planet relative to the distance between the stars. Mm-hmm. So that the planet sees two stars.

30:28That's the double sunset. The famous scene is double sunset. Those have to be so close together that the planet thinks they're one source of gravity. Because if they were more separated and the planet is trying to figure out where to go or be it. Or maybe you get a chaotic trajectory. That's the three-body thing, right? It's a three-body problem. That's the three-body problem. You lose the stability. Either falls into one of the planets or escapes. So that one was correctly shown with the two stars setting together. And we can judge what that distance the planet was. So you can create stable orbit that way. So that's the only way they work. So that's good science. And just that we call that a P-type orbit. A P-type orbit. You can have a binary star where they're close together like Tatooine that goes around the two close together on the outside. That's a P-type orbit, planet type. Or you can have the binary stars widely separated and the planet goes around the planet. Oh, that's right. That's the same as a S-type. And that was the S-type. Sublight. Oh, okay. Yeah, that's cool. There you go. But then you don't get two sunsets. Yeah, yeah, yeah. That was cool.

31:28Okay. So here's what I want to know. I read that one of the most common things that we never consider with planets are rogue planets that in the formation of solar systems, so many planets are flung out of the solar system. So stable orbits can be achieved by the rest of the planets, right? Just got out of dodge. Just get out of here. So how common would it be if we were able to see them? Well, we just see planets wandering around like they lost from the home planets. The home is homeless. The homeless, then they became rogue planets. Oh, well, that sounds a lot more bad. It's a little bit more bad. Yeah. It's only none of y'all. Yeah. Wait, so David, the numbers I remember are that our solar system might have started with as many as 30 planets coming down to the eight that we now have. Yeah. So that tells us that maybe there are more rogue planets than there are planets with homes. Right. Yeah. There's a really hot area in Ashrifizuk right now, rogue planets. So you could get a PhD right now doing this.

32:32Oh, right. A hot topic. But you're right. The, it's thought the solar system had more planets. Some of them merged together. It's really thought there was a fifth giant planet. There's a lot of evidence for that. It's actually really difficult to keep Neptune stable unless there was another Neptune-like planet in the solar system in the past. So that's, it's not canonical, but it's widely accepted. There's likely a true there was a fifth giant planet in the solar system in the past that got a GXed out into space. And that's how you keep the solar system stable. So there should be a ton of those. And the Roman space telescope, which is coming up, is going to be. That's a great Roman telescope. Yeah. It's going to be the perfect machine using micro-lensing to detect a whole host of those. So we're expecting thousands of those to be found with Roman telescope. So this is where you have a star in the background. Ideally, to dense starfield, like the center of the galaxy. Of course. And you just watch for any starlight that, that, that's increased, no, no. That it, oh, gets brighter. It gets, that's a cap. That's, okay. Oh, it gets brighter. Why? Because light going on either side of the planet,

33:33you can't see that the rogue planet, of course, because it's nothing's illuminating it. It's in the middle of freaking nowhere. Right. And there's a planet behind it. Pathways of that star is going around the planet. Come back and join, magnifying the brightness of the star itself. Because a sightline would have gone and missed you. Right. This sightline would have missed you. Right. They had bent into your view, adding to the brightness of the object. It's a gravitation of lensing for a rogue planet. But it's, it's only a tiny amount. And it's what we call it, micro lens. Yes. Yeah, yeah. There's enough of a variation in the travel of the light for you to determine that. In that, the, the mean, in terms of the magnification. The magnification. Yeah. It's very small, but Roman's a very precise telescope. Oh, really? The real trick is that these are very rare events. So you'd have to observe millions and millions, even billions of stars simultaneously to have a chance of detecting one per day or so, right? And that's kind of the rate they want to get to. One per day, yeah. That's the power of Roman. It's, I mean, you probably know the number is better than I do. But the field of view is like 10 times Hubble or something.

34:33Yeah. 20 times. Yeah. Wow. That that can boost your statistics. Well, if the star gets brighter and dimmer, how we know it's not the star doing that? Because usually the star repeats that. Whereas a micro lensing event is singular in time. Plus, it has an exact profile. Oh, it would be singular because the planet is on the moon. It's on the moon. It's on the moon. It's on the moon. Oh, class. And the profile of the brightness and the dimming is that you know that in advance because Einstein's had general relativity. So let me ask you Dave. That's wild. David, Earth retains some of its heat of formation. Yeah. And it's got heat from radioactive decay within the crust. If Earth left the solar system, there would still be a source of energy within it. Some life would not care that we no longer have the sun to sustain it. How many of these rogue planets still have energy within them? And therefore might still have life making no reference to the sun? Because life in the bottom of the ocean never seen the sun ever.

35:35Yeah. Anyway, they're all blind. It's possible. I mean, people have speculated about that recently. If you have moons, it's even better. Right? Because moons can have tidal heating. Think about I.O. Right. I.O. is a volcanic world. Yes. Lots of energy there. You wrote for two. Probably has a liquid ocean. It's like a tidal heating. You mean like a subtle stretching and attracting of the... Yes. As multiple moons interact with each other, it causes sometimes the moons to plunge a little bit deep into Jupiter's gravitational field, sometimes a little bit further out. And it's like a squash ball. It kind of gets stretched and squeezed, like a piece of dough. So that's probably what happened in these moons. And so you could have for billions of years life just thriving in between the stars. That is dope. Yes, totally dope. That is unbelievable man. Well, it's totally believable. That's what makes a dope. Wow. Yeah. And in fact, look at the bias thrust upon us by biologist. Right. Saying the sun is the source of all life in the world. The source of most life. Right. But this life doing the backstroke at the bottom of the ocean

36:35that never gets to the general thermal energy. Right. And so it's not that life needs the sun, is that life needs energy. And if you find a way to get the energy, that's why we're looking for life on Europa. Another tidally heated moon of Jupiter. Right. Yeah. Interesting. Okay. Wow, that's so cool man. So what's the difference between Europa and I.O. in the tidal heating? In terms of the map energy. Yeah. Well, I.O. is on the inside. It's closest to you. So it gets the real brunt of it. Europa is, I think number two. Right. So it still gets heated, but not as much as I. Okay. But I was so significant of that. There's volcanoes on it. Yes. Yeah. Right. Yeah. It's liquefied. The raw. You can see it coming out into space. Yeah. From I.O. is crazy. Yeah. Yeah. Cool. Okay. I'm Nicholas Castella and I'm a proud supporter of Star Talk on Patreon. This is Star Talk with Neil deGrasse Tyson.

37:40All right. This is Peter Jacobs and Peter Jacobs says, get out of David. Neil and the, uh, applaudable, laudable, audible, oh my Lordy, Lordy, Lordy, Lorde Nice. What? Yeah. Peter Jacobs here from Mulu-alaba in sunny Queensland, Australia. Okay. I'd like to get me some dimmies. Oh, okay. All right. He says, thinking of the Fermi Pair. That's quite the intro to the, did you make that up when you wrote that? No, this is written. I don't know for such a time. I was just doing the terrible Australian accent. That's all I had to say. Sometimes I don't know what it is. Okay. Okay. Okay. He says, thinking of the Fermi Pair, docs, how close can we get to sag A before ambient radiation from surrounding stars would make life impossible and would pulsars, quasars and colliding black holes sterilize their galaxies.

38:41Oh, wow. So the amount of radiation coming out of a pulsar or a collision. Sagittarius A is the supermassive black hole in the center of the galaxy. Right. And it is a rock and rock and sock in place. Yeah. And other galaxies that's even more severe than ours. In terms of just the flux of high energy radiation. So do you guys think about that's why? Let's soften this just a little bit. Okay. Some stars give off a lot of UV. But like the blue stars, the blue stars and UV is hostile to life. Yes, everything. So are you thinking about life on planets that orbit high mass high temperature stars? Yeah. So I think, but there's a great question. And I think it touched on the idea called the galactic haptal zone. So you can have a haptal zone around the star. But there might also be a haptal zone in our own galaxy. Okay. And that would be a radiation problem for you if you're a little too close to the center. Not necessarily just radiation. It could be a metalicity, the metalicity of the galaxy

39:42change. I don't know what metalicity is. So how the... It's jargon. Now I've got to explain the jargon. Okay. So it's the heavy atomic elements. Basically, in astronomy, anything heavier than hydrogen helium, the two things came out of the big band are a metal. And that's what you're made out of. Primarily, hate that. Oh yeah. Got to go. Everything metal. Is it metal rich? Yeah. If it has, you know, carbon, it's considered a metal. Right. And it can't hate that. So the whole universe is one big headbangers ball. The whole process. A metal man. Okay. So you have the radiation in the center. Yeah. And you need enough heavy elements to make planets. To make planets and people. Yeah. And you need... I mean, when you really look at around such a star, you've seen some of these animations. They've reconstructed the star paths. They're on top of each other. So planets wouldn't even be stable. Yeah. Right. So all of these stars... Yeah, they're like these loop orbits. Yeah. It's what won the Nobel Prize. Right. That the observations confirming the black hole in the center of the galaxy by tracking these orbits

40:43share the Nobel Prize with our guy, our physics guy, Roger Penrose, who showed early the mathematical rigor of why you would get a black hole in the first place. Interesting. A perfect combination of theory and observation. That's wonderful. There. So there's other parameters. So... Yeah. So you've got a former planet. You've got a... With the red ingredients. Yeah. You've got to have a stable orbit to the right place. And then the radiation environment has to not sterilize you. Right. And obviously if there's lots of stars around and say one and a thousand stars go supernova, then the chances of, if you're in a busy neighborhood, if you're in Manhattan, you'd like to have one of these guys go off at you. So you don't even want to be around another star that blows up right? Yeah. Yeah. Yeah. Okay. Yeah. Cool. That's funny because I read that one of the reasons for life here, where... Yeah. Is the fact that we're in a suburb of the Milky Way galaxy. Yeah. Yeah, I think that's true. And we also don't put... You know, our orbit is more or less circular. It doesn't like have an eccentric but we plunge towards the central cone back out. So we're in a nice neighborhood.

41:46We're about to turn to the way out. We don't have to commute into the center. Yeah. We're in red lines. We're over. You know what I mean? We're in the Carol God and so do you. Milky Way. So we're about two-thirds of the way out. And I hadn't appreciated, yes, we're in a basically circular orbit. Yeah. So we're not... We don't risk changing neighborhoods and surviving the consequences of it. That's right. Yeah. And one full orbit is a couple hundred million years. So that's at our distance. In plenty of times. It's well known but that evolutionarily. Right. That's... It works pretty stable. Yeah. Yeah. That's it. All right. Wow, that's all cool stuff, man. Yeah. Damn. Yeah, you do some cool stuff, man. That's why I think it's called the cool laboratory. Oh, that's right. Yeah. Oh, that's cool laboratory. All right. There we go. This is Mike Landers. He says, hi, Dr. Tyson, Dr. Kipping-Lord Nice. This question comes from San Francisco.

42:49If we eventually detect an unambiguous technosignature or biosignature, do you think it might belong to a civilization that is already extinct by the time the signal reaches us making our first contact essentially an archaeological... Damn. Oh, I like that. Oh, so how far away are your stars? Facetti. Facetti signatures. We... We can search across huge spans of the galaxy. I mean, you can span tens of thousands, even a hundred thousand light years in some extreme cases. So they could easily have more extinct. But your stars, your cool stars... Those did not have far away. So why are signatures? Is things that James Webb are observing and trying to get signs of atmospheres? Those are nearby. So those are tens, 20 light years, 30 light years away. Open that. So if presumably civilization takes so much longer than 30 years to establish that a 30-year delay is not some... It's not major... It's not prohibitive of you... Right, but technosignature doesn't have to be like an active beacon. It could be one of the coolest ideas I've ever heard for a technosignature.

43:50Is the idea of putting shades in space that orbit the sun and they would be artificial transits. So like put a giant triangle in space, like a sheet of aluminium. And as it transits the sun, it would create a very strange eclipse to alien observers. They'd be like, hold on, someone's put a triangle around that thing. That doesn't occur in nature. That's a space to real. So it would... Exactly. You'd be like, that's weird. That shouldn't be there. And that thing would be stable for millions, billions of years long after we're gone. So we could leave a relic that would betray our presence. And you could even have interesting signals. Usually the Easter Island heads. Yeah. The civilization left them there. Right. And it's been argued that you come upon the island and you're looking at you still. Yeah, if you leave some some purposeful relic of the monument... The monuments are a communication from another civilization to us through time. And we too have the opportunity

44:51with a time capsule of some kind to communicate to future civilizations. Perhaps even future... I think the most likely... Wait, Constantine Claire, he's not saying the pyramids were left by aliens. No. Just a jwana. A shaman civilization. Yeah, so left by basically an extinct human civilization. Yes. Ancient Egypt. Yeah, yeah. There's no longer with us. There's like, there's descendants but they're not building pyramids anymore. My provocative claim is that the most likely alien contact we will ever have, not really a contact but a way of them known that we're here is that we could leave something like the voyage like the Gordon record, like the Pioneer plaques. We could leave something like that perhaps on the moon. And maybe in 500 million years from now, another advanced civilization will emerge and discover that on the earth. So it will be a non-human intelligence, not alien, but still non-human that evolves after us and they pick this up and they realize, oh, we are not the only ones to ever develop. But that would imply that there isn't a continual awareness

45:52of a previous civilization. Are you referring to an apocalyptic earth? We all die, civilization disappears and then some other intelligence evolves later and discovers that we're the people to have. But yeah, we fade out maybe, just gradually, there's evolution, you know, species very rarely last longer than a million years. So eventually we change into something else and some other future civilization emerges. I think there's mammal species around a million other species I'm not sure. Yeah, it's rare. There's some, but it's unusual for a species to last that long. So that's what it means. We're not going to be. We don't even have to worry about whether or not we're going to make it until a million years. Come on. So I think that's cool. Alex are a cool way. The whole thing called artifact setty, which is the question ask us should definitely look into. Yeah, all right, here we go. This is, here we go. This is Aiden Rodriguez who says hello, Dr. Tyson Lorde and Nice and Dr. Kipping. Greetings from Panama City, Panama, the country that gave the world the Panama Canal.

46:55I've been a fan of you guys for many years and I'm a Patreon supporter now. My question is could life exist on a planet with much stronger gravity than Earth say two or three times stronger. If so, it also would have evolved in an atmosphere with much higher pressure than ours. Thanks so much. Let's keep up the amazing work. Yeah, that's pretty wild. That's a great question. I think the immediate challenge is how would you engineer a planet to have two or three times Earth gravity? No, gravity. Because as you increase the gravity, a planet will naturally accumulate gas around it as it's forming. So you're going to turn to a gas giant basically. Right. So there's even only three times the gravity? I think by three times, yeah. Really? I don't think there's any super Earths with a more than like a 0.71 point. Also, super Earths are just slightly more muscular, but not multiples. Right. I did not know that. Yeah, that's wild. That's why that extreme. Oh, yeah. And at that point, all the fluid that has accreted puts a pressure on the surface. And so the pressure would be super-cute too.

47:56Right. And what, yeah. So the pressure would be high. I mean, it is cool. You could probably have 1.5 times Earth gravity, no problem. And what's interesting, I think, about these things? Because one would weigh 50% more. Unfortunately, I'm just so young. I'm going to be on a Zen bit. Or I hate to. I hate to. Yeah. Just here's the thing. Most of us are already weigh 50% more. So if you want to know what it feels like to be on such a planet, there you are. Yeah. OK. Now, you want to feel like it's back on Earth, lose that one-third your body weight, and then you're back to what it is on Earth. Let me tell you something called about weight, though. Look at what's behind you, the Saturn 5. Yes. Now, if you've made the gravity 1.5 times heavier, that thing's not getting up. Yeah. And so if you think about the rocket equation, the size that thing would have been... Which one does all the time? You think about the rocket equation? Of course, yes. That thing would have to be the size of a pyramid to get up and see. That's how you'd have to lose 99.999999 percent of your mass as fuel. So it's thought that super-eth might be a prison. That civilization might be trapped there. They can never get off them because the gravity is so strong.

48:57They can't have it as a... It's not going to get wormholes. Don't be so... They have to go... Right. For the same natural progression, the same way that we've enjoyed. Maybe there's so much smarter to... Let's do... Little Timmy and preschool just designed a new wormhole. Right. Let's just use that one instead of the other. So no, that it isn't interesting. For given our engineering flight technologies, we would not be able to launch... We'd be stuck. From an Earth that's one and a half. Look at that. You know what else I think about? If we were Venus, you would never know there was a night sky with stars in it. Right. Because Venus is a thick, dense, opaque atmosphere. There's a tarp over Venus. Right. It's a tarp. It's a tarp. So let me end on something that I wanted to even start with. This notion of... Unknown unknowns. Because on Venus, like I'm saying, I know that tarp will prevent anybody from seeing anything about the universe. There'd be no astronomy. No one would have ever thought it up.

49:57Because when you look up, you just see clouds. Okay? So to them, an unknown unknown is... It could be a universe beyond your planet. We don't have that problem here. Is there some unknown unknown that we don't even know? We don't know that puts us in a prison. That another planet freely escapes from. That is a truly frightening thought, Neil. And it reminds me of how in cosmology, cosmologists often take for granted the fact we live now. But were we to emerge 10, maybe 100 billion years in the future, when the universe has expanded so much, you would not see the galaxies. The galaxies will expand beyond our horizon. And so you'd think the Milky Way was the universe, and you would never know all of that, which is out there. I think that's an amazing point of time. The time it will be. Einstein's relativity, that's what anybody thought. To him, the universe was all the stars and the night sky

50:57of our Milky Way galaxy. Right. So have you thought about a missing chapter in our book of the universe that we don't even know is not there? How can you think about that, but you do not know? It's impossible, but it's certainly possible. But we can't imagine what that might be. Okay. That we're just blithering idiots. And I was going to say one thing is for Sora. We're stupid. Thank you, Chuck. So David, how can we find you? Remind us. You can find me on the Cool Words YouTube channel. So it's just cool. Cool Words. Yeah, cool Words. It's just cool, cool Words. And I've also got a pod so you can go to the Cool Words podcast. And that drives your lab, isn't that correct? Yeah. Yeah, yeah. We have a doughnuts like you have your start-up patrons. We have patrons, but all of that money is just used for research, actually. So that's kind of fun that you can pledge your money to go to real discovering, hopefully, as much as you want. As more and more research money is evaporating, God, yeah. That funding model becomes more and more significant. I think so.

51:58Thank you, and it's huge. Yeah. Until the day you get the phone call from somewhere else, hey, we got a lab for you here, which is probably, they're, yeah. And, you know, with that accent, he's like, see a bitch's, no, I'm joking. So, yeah, we already know, we already have colleagues. We've been cherry-pink. Yeah, this is a real problem. You guys better write, you know, reach out to your Congress, people, reach out to your senators, and let them know that you want science funded in this country. Chuck the president. The power of the purse still resides in the Congress and not the executive branch, and that you won't stand by and allow for science to be defunded. Okay. So that's it. Thank you, Chuck. No worries. Are you just smart enough? So true. Funny. You should say that, Neil. That's the name of my special. Oh, which is right here on the, when they start talking YouTube channel, check it out. Chuck my smart enough. It's easy to find. It's right there. All right. All right. So thanks, David.

52:58My pleasure. Thank you. For skateboarding anytime. Anytime. For one wheeling over here. For 40 blocks out. And saving the, saving the planet with your water bottle and your one wheel. He's still exhaling CO2, though. Well, yes. Still work on that. This has been start talk. And cosmic queries. Cool world edition. Ooh, yeah. Until next time, we bid you to keep looking up. Get on the tune. Thanks.