Daniel and Kelly’s Extraordinary Universe - Are there planets without a star?

Episode Date: February 11, 2020

Do rogue planets exist? Could they support life? Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

This is an I-Heart podcast. December 29th, 1975, LaGuardia Airport. The holiday rush, parents hauling luggage, kids gripping their new Christmas toys. Then, everything changed. There's been a bombing at the TWA terminal. Just a chaotic, chaotic scene. In its wake, a new kind of enemy emerged, terrorism. Listen to the new season of Law and Order Criminal Justice System

On the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. My boyfriend's professor is way too friendly, and now I'm seriously suspicious. Wait a minute, Sam. Maybe her boyfriend's just looking for extra credit. Well, Dakota, luckily, it's back to school week on the OK Storytime podcast, so we'll find out soon. This person writes, my boyfriend's been hanging out with his young professor a lot. He doesn't think it's a problem, but I don't trust her. Now he's insisting we get to know each other, but I just want or gone. Hold up. Isn't that against school policy? That seems inappropriate.

Maybe find out how it ends by listening to the OK Storytime podcast and the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. In sitcoms, when someone has a problem, they just blurt it out and move on. Well, I lost my job and my parakeet is missing. How is your day? But the real world is different. Managing life's challenges can be overwhelming. So, what do we do? We get support. The Huntsman Mental Health Institute and the Ad Council have mental health resources available for you at loveyourmindday.org. That's loveyourmindtay.org.

See how much further you can go when you take care of your mental health. Hey, Daniel, did you ever want to be an astronaut? Well, yes, but I didn't because I'm terrified of the day. danger and the adventure. A little bit scary? Yeah, I'm not ready to travel in space until it's safe and routine. Yeah, it is pretty dark and scary out there, but isn't that kind of the point of space exploration to sort of go out there and discover and find new things, hiding in the darkness?

Yeah, and I want other people to go out there, take those risks, and then I can just read about it in the newspaper. Hi, I'm Jorge. I'm a cartoonist and the creator of Ph.D. Comics. Hi, I'm Daniel Weitzen. I'm a particle physicist and I'm a stay-at-home adventurer of the mind. Couch Explorer. I like to explore this vast universe from the comfort of my office. Welcome to our podcast, Daniel and Jorge, Explain the Universe, a production of IHeart Radio. In which we take you on an exploration of all the amazing,

crazy bonkers, beautiful, nasty, crazy, weird things in this universe. Did I say crazy twice? That's because the universe is that crazy. It's double crazy. I feel like the things we're learning in science every year, every decade, every generation are crazier than the things we learned before. It's not just that we're learning more, but the stuff we're revealing is just more bonkers than anything we could have imagined.

Don't you feel that way? Well, do you think it's crazier than what we thought it was before? You know, is it crazier than Greek gods and Norse mythology? Well, I think it's maybe less creative, but it's definitely crazier. Every generation has had to absorb ideas, which were very difficult to swallow, because it completely conflict with our view of the world. You know, the universe is expanding. There is no sense of location and time.

You know, things are fundamentally random. Space curves, like, these are hard things to get your mind around, and they get harder and harder as we discover them. Yeah, we are not the center of the universe, and the universe is not like what we see around where we are. Yeah, and every time we look out into space, we discover new stuff, weird stuff. Places we thought were empty turned out to be filled

with interesting, fascinating, weird kinds of matter. Yeah, because that's kind of the history of humanity and science, right? Like, we look around and we assume that the whole universe is kind of like where we're at, right? We thought the world was flat because everything seems flat around us. And we thought that the Earth was the center of the universe because everything seems to prevail around us. But then as we learn more, we learned that there are more and more different things out there.

We keep learning that the assumptions we make, that the generalizations we make about what we learn here, cannot be applied everywhere. And that's the exciting part. That's the moment of discovery. When you realize, oh, I thought the universe was this way, it turns out it's actually totally different in a way I never imagined. We are intellectually maturing as a species by discovering our universe and coming to grips with it.

And it's not always the way we liked it, but it turns out to be quite fascinating. Today on the program we'll be tackling one such idea that, you know, maybe a lot of people even today think is true. But actually it turns out to be much more complex than that. That's right. The darkness out there is more filled with interesting stuff and rocks than you could have ever imagined. Yeah, stuff that's out there hiding in the darkness. Other worlds out there looking at ours and wondering, what would it be like to be so close to a nice, warm, toasty star?

Yeah, so today on the program, we'll be tackling the question. Are there planets without stars? And not just movie stars, right? We're talking about, are there places in the universe and don't have a sun or a star near them? I like the one you ask, though, like, are there planets out there with only B and C list actors? That's right.

Where everyone only has five seconds of fame. You can only be in one movie and then your career is over. It's like term limits for Hollywood actors. I like that. That's great. Wouldn't that be great if we got rid of celebrity culture in our society? Yeah, well, that won't appeal to any of our celebrity listeners, you know? So, hey, Brad Pitt, don't worry.

You can still come on the program. No, apparently it works. If you speak badly about so many, they'll want to come on our show, then. That's true. That's true. To defend themselves, maybe, to grab any kind of publicity they can. That's true. Stay tuned for our episode in which science fiction authors come on the show and respond to our critiques.

And when we're thinking about the broad universe, you know, you are used to thinking about your planet as having one very important feature, which is the sun. And every time you think about a planet, you imagine, well, Well, planets form around stars, right? And so it's a bit mind-bending to imagine that the universe might be different. Yeah, a lot of people might be surprised to learn that not every planet out there is centered around the star. You may be shocked to discover that rogue planets are not that rare, that the universe may be chalk filled with these floating dark bodies. Yeah, and that's the official physics name for them, right?

Like a planet without a star, it's officially called a rogue planet. Yes, but you will not be surprised to discover there is some controversy about what exactly gets called a rogue planet. Oh, wow, physicists arguing about what to name something? That's so rare. Not only arguing about whether something is a good name, but like what exactly falls into this category. You know the whole Pluto like, is it a planet, is it not a planet thing? That's this same controversy writ large. Interesting. Because I guess everything is sort of being pulled by every star in the universe. So technically there isn't a planet that's not being pulled by a star.

I like that. You're sort of saying every planet is part of a some solar system, even if it's sort of distant from its star. Right. Well, technically, right? Don't all solar systems sort of overlap with each other technically because the force of gravity is infinite, has infinite reach? Yeah, that's true. The force of gravity is infinite. But at some point, the force of gravity from these stars, is basically negligible, and there's essentially no effect on these planets, and they're more affected by the... Negligible. Yeah, negligible. They're more affected by the mass of the galaxy. So I think the distinction is, are you orbiting a star, or are you orbiting the center of a galaxy? All right. Well, I was a little surprised to find out that there are rogue planets out there, and that there are apparently not just a few of them. But we were wondering how many people out there

knew this same fact that there are planets out there in space without stars. So I walked around campus of UC Irvine and I asked folks what they thought and if they had a guess for how many rogue planets there might be in the universe. So think about it for a second. How many planets out there in the universe would you guess are out there floating without a star?

Here's what people had to say. I have no clue how many there are. My guess understanding from what I think I know is that they're by one way or another or something flying by, they end up ejected from the star that they're orbiting. I have not. Do you think those exist?

Sure, why not? I don't think so. I can't imagine that that would be not true. Okay, so you think there's like a lot or just like ten? I would have no idea how to give a number. I would actually have to say probably a lot just because gravity is so you can get a star really close to another set of planets

and then it throws them off in space, so probably a lot. Probably? I think so. You think there's like seven or like a billion? Oh, geez. Well, in a big universe, I don't know if we could count. No. Do you think every planet has a start?

I think so. Ah, interesting. Pretty good mix of reactions. Yeah, a lot of open minds. I love the people who say the universe is so big, you can never say no. You can never say that something doesn't exist. I think that's a great attitude. I see.

Because technically in an infinite universe, anything can happen, right? And anything is happening. Yeah, in an infinite universe, everything that can happen eventually will happen and is happening somewhere. So it's a good attitude. Now, we don't know the universe is infinite, but it's definitely pretty big. Right. Somewhere out there, there's a version of this podcast in which you and I

are the A-list celebrities. That's not this version? What are you saying? I don't get it. Hold on a second. I'm confused. I think we run out of letters. We're the triple Z celebrities. That's right. We're the triple A. We're triple A

celebrities, which sounds good, but really it's probably welcome to the minor league of podcast folks yeah so um but people seem sort of skeptical I mean some people said yes but it sort of seemed like yes probably but it's probably not very common

that's right and it's immediately a fascinating question it's the kind of thing you might not ever think about you think oh well planets of course they form around stars and that's reasonable because stars form from the gravitational collapse of stuff and planets do the same thing and so you should imagine

they form together, they're probably associated with each other, you probably don't ever think that there are dark bodies floating out there in between the stars. But as soon as somebody suggested to you, then you have to wonder, well, do we know? How do we know? Have we looked? Could we see them? And immediately is a question you need to know the answer to. Yeah, because if it's a lot, then that would be pretty interesting, I guess, or dangerous? Because what if one of them hits us? Yeah, it's a little bit dangerous, but also it just changes sort of your your view of the universe. I mean, what if there are more rogue planets out there than non-rogue planets?

Then your whole view of like, what is a planet has to all of a sudden change from, oh, they're all around stars to, well, my sense of a planet is unusual, is atypical. Oh, I see. It could be that our kind of planet is the minority. Yeah, exactly. Just like we discovered that our kind of matter is a small fraction of all the matter in the universe. All of a sudden things we thought were typical are now weird.

It'd be like discovering there are more continents out there. Yeah, or you know, you grow up and your family eats dinner a certain way, and then you go to a friend's house, you discover, oh, man, my family's weird. We don't use utensils at home or whatever it is, you know. It's maturing in that same way. Right. It's expanding your horizon and your idea of the universe. And that's why this is such a fun opportunity to learn something new about the universe.

All right, so let's get into it, Daniel. What exactly is a rogue planet? Right. So let's begin with technical, definitional stuff that we could argue about easily for half an hour. Right. And very importantly, is there a first rogue planet called Rogue One? Well, the movie rights for that one have already been locked up, unfortunately. Right, yeah. Well, they're definitely not making a sequel of that one. I mean, we should start with Rogue 2. I liked it. I liked it. But, you know, Rogue 2's agent is not exactly getting a lot of traction in Hollywood.

it. But a rogue planet is a planet that's not orbiting a star. And you said earlier, and you were right, that every planet feels the gravity from every star in the galaxy. But you have to look at its motion. Like the motion of the Earth is that we are orbiting our star. We are moving around our star. But if we were a rogue planet, then our primary motion would just be around the center of the galaxy. We'd be the same category as the stars. Like our star orbits the center of the galaxy. It's a planet that's not sort of trapped by the gravitational well or pool of a star. Yeah, we like to think of a solar system as an object because it's gravitationally bound, that the dominant gravitational force on every object in the solar system is the sun.

So it's like the sun has its own little neighborhood in which its gravity is more powerful than any other gravity. Or I guess maybe not just that it's more powerful, but it's powerful enough to do. to sort of trap things in its vicinity. Yeah, it's a stable state. It doesn't let it go. Exactly. But, you know, the galaxy is big, and there are a lot of stars,

but they're not that many. And so there's a lot of room out there between stars. Remember, we are, you know, light years away from the nearest star, which makes a huge amount of space for stuff to be floating between the stars. Oh, I see. So there's a lot of room for you to be out there

without falling into the, you know, the trap of the gravitational pool of a star. Yeah, if you map the Milky Way onto Earth, for example, you know, you'd have like one house here in Los Angeles and another house like in Kansas, another house like in New York City, and there'd be a lot of room between those. That you could rogue around it. Yeah, you could have a rogue cabin in the woods and never have to get close to anybody. And I guess more importantly, you could be so far away from my house and your house in Kansas that you wouldn't feel the need to sort of go visit. Yeah, and you could largely ignore them. You know,

Those stars would just be other slightly more bright stars in the sky. You wouldn't feel their gravitational pull strongly enough to get sucked into one of them. All right. So then what's the definition then, that it's a planet, meaning like a ball of stuff? Is that what it means? What is exactly a planet? Yeah, well, that's where it gets tricky, right? These are either things that were formed in other solar systems and then ejected,

or you could also think about stars that never sort of got started, like failed stars. You know, what if a star never sort of turns on because it's not big enough to burn? Is that a rogue planet or is that a failed star? It's a heated debate in astronomy. But both of those things are out there. Well, in a way, isn't Jupiter also kind of a failed star? Like, it could have been a star, but it wasn't. Yeah.

And if Jupiter had formed far enough away from the sun on its own, If it was like the center of its own little gravitational neighborhood, we would call it a sub-brown-dwarf star. But because it formed around our star, we call it a planet. And so there's a lot of energy spent in astronomy arguing about these names and definitions and... Wait, you're saying that if Jupiter wasn't in our solar system, if it was out there, it would be considered a star, even though it's not burning. Yeah, there's a whole category of stars called brown dwarfs and sub-brown dwarfs that are just not big enough to ignite fusion and to burn. and to glow. But why still call them a star?

If they're not ignited and burning. See what I meant? People have strong feelings about this. Like you do, apparently. Uh-huh. In your mind, you think if it's got to be burning to be a star, right? Well, other people think, oh, you know, it's a failed star. That's a kind of star.

All right. So that's kind of the definition. It's a ball of stuff, or maybe the definition is kind of fuzzy. But generally speaking, a rogue planet is a ball of stuff. It could be gas, too, right? Rocks or gas or, you know, it's compressed. matter, kind of, just to make it different than a cloud. And it's floating out there in space, not in the orbit of a star, whatever that could mean.

That's right. It's a dense blob of stuff primarily orbiting the center of the galaxy instead of orbiting another star. All right. Let's get into how we can see them, even though it's dark out there in space and how many there are out there in the universe. But first, let's take a quick break. December 29th, 1975, LaGuardia Airport. The holiday rush, parents hauling luggage, kids gripping their new Christmas toys.

Then, at 6.33 p.m., everything changed. There's been a bombing at the TWA terminal. Apparently, the explosion actually impelled metal. glad. The injured were being loaded into ambulances, just a chaotic, chaotic scene. In its wake, a new kind of enemy emerged, and it was here to stay. Terrorism. Law and Order Criminal Justice System is back.

In Season 2, we're turning our focus to a threat that hides in plain sight. That's harder to predict and even harder to stop. Listen to the new season of Law and Order Criminal Justice System on the IHRour. Art Radio app, Apple Podcasts, or wherever you get your podcasts. My boyfriend's professor is way too friendly, and now I'm seriously suspicious. Wait a minute, Sam, maybe her boyfriend's just looking for extra credit. Well, Dakota, it's back to school week on the OK Storytime podcast, so we'll find out soon. This person writes, my boyfriend has been hanging out with his young professor a lot.

He doesn't think it's a problem, but I don't trust her. Now, he's insisting we get to know each other, but I just want her gone. Now hold up, isn't that against school policy? That sounds totally inappropriate. Well, according to this person, this is her boyfriend's former professor and they're the same age. It's even more likely that they're cheating. He insists there's nothing between them. I mean, do you believe him?

Well, he's certainly trying to get this person to believe him because he now wants them both to meet. So, do we find out if this person's boyfriend really cheated with his professor or not? To hear the explosive finale, listen to the OK Storytime podcast on the IHeart Radio app, Apple Podcasts, or wherever you get your podcast. I'm Dr. Joy Harden Bradford, and in session 421 of therapy for black girls, I sit down with Dr. Athea and Billy Shaka to explore how our hair connects to our identity, mental health, and the ways we heal. Because I think hair is a complex language system, right, in terms of it can tell how old you are, your marital status, where you're from, you're a spiritual belief. But I think with social media, there's like a hyperfixation and observation of our hair, right? that this is sometimes the first thing someone sees when we make a post or a reel

is how our hair is styled. We talk about the important role hairstylists play in our community, the pressure to always look put together and how breaking up with perfection can actually free us. Plus, if you're someone who gets anxious about flying, don't miss session

418 with Dr. Angela Neil Barnett, where we dive into managing flight anxiety. Listen to therapy for black girls on the iHeart radio app, Apple Podcasts, or wherever you get your podcast. All right, Daniel, there are floating planets out there in the universe, in our galaxy, that don't have a star.

They're called rogue planets, and there might be a lot of them. So, first of all, I guess, how do we even see them if they're not burning bright and they're not near a star for them to shine? How do we know they're there? It's tricky, right? These are dark objects. They are not shining. They're not emitting light. And as you say, they're not close enough to any star to reflect light like exoplanets are. So it's not easy to spot them, which is why for a long time we didn't even know that they existed. But there are two ways to see them. One is you get really lucky and one is close enough that we can see them in the infrared. Remember, these things are not burning, so they're not shining visible light. But they still have some. heat to them. And everything in the universe that has a temperature also radiates some energy, usually in the infrared. And so it's sort of glowing in the infrared. And we have infrared telescopes. I see. Because we, I think we're used to thinking of like asteroids

and things out there in spaces being cold. But you could have, for example, like the Earth is kind of warm by itself. The Earth is kind of warm. And even if we were 10 or 50 Kelvin, and I want to give props to the person out there who wrote in to remind me that it's not degrees Kelvin, it's just Kelvin. But even if we were just 10 or 50 Kelvin, we would still radiate. Everything that's above absolute zero radiates some energy. It's called black body radiation. Oh, I see.

It sort of shines in the infrared. Yeah. And there's a telescope called the Wise Telescope, W-I-S-E, which is really good at seeing this stuff and is really good in the infrared. And so if it's close enough that you can spot them directly with the Wise telescope, but it has to be pretty close. So like if our sun suddenly went out and there was no more light in our solar system,

you could still maybe see the Earth and all the other planets. Yeah, you could precisely. And we do this to study other solar systems. We look at them in the visible light and we also look at them in the infrared to try to get a glimpse for like, what is the stuff out there that's not glowing?

It's still there. It's giving off different kinds of radiation. So we have lots of different ways of looking at the sky, the infrared, x-ray, radio. So these are all just different kinds of light, though. They're all just different parts of the electromagnetic spectrum, but different things out there glow in different parts of these spectrum. So the most direct way is to look for them in the infrared,

but they'd have to be really close by. Oh, I see. Because otherwise it would be too faint to see them. Yeah, because these things are small and pretty faint, and so they're pretty hard to spot. The best way to see these things is to look for a little star eclipse. What? Well, if you have a big, dark object somewhere out there in the universe,

and it passes between you and a star, then what happens? It blocks the light from that star momentarily. Like a one-time eclipse. Yes, like a one-time eclipse. One-time-ever, yeah. And so you can see these things if you very carefully watch all the stars in the sky and wait for a blip. But there's something really fascinating because you might expect that like a star eclipse

would dim the star, that it would go out for a minute and then come back, right? That's you'd expect. But there's this really weird gravitational effect. If the rogue planet or whatever it is, alien ship is big enough, then it has a gravitational lensing effect. It acts like a big lens in space. Because remember, gravity is the bending of space. So gravity can change the direction of light.

It won't just block the light. They'll bend the light. I mean, that sort of happens here on Earth, too, when there's an eclipse, right? Doesn't the light sort of go around the moon when it's blocking the sun a little bit? It does a little bit, yeah. And in this case, it could actually enhance the strength of that star because it acts like a lens. It gathers more light and it focuses it all on the earth.

So what actually happens when you get a micro-lensing event, they call it, is that the star gets brighter. Not just darker, or like darker and lighter. Yeah, it actually gets brighter. It gets enhanced, right? It gets amplified by this micro-lensing. And so the very center of it is blocked out, but you're gathering light from nearby and focusing it onto the earth.

You actually get more of the star light. when it goes by. It's an eclipse that makes the star look brighter. Yeah, precisely. It's really fun. And the telescope that sees these things has a really awesome name. It's called the Ogle telescope, O-G-L-E. I'm not making this up, not making it up.

I thought it was already too much to have a Weiss telescope, W-I-S-E. But this one, they want to look at things called the Ogle. If you want to sit on the couch and ogle the universe, and you do it using the optical gravitational, lensing experiment, Ogle. Wow. You guys probably pop some champagne when you came up with that name. So those are the two ways you can see them. You can see them either through microlensing or anti-eclipsis or directly through the infrared. And so what do we know about them?

Do we know, are they sort of round like our planets necessarily? Or do they look like giant asteroids? Or what do we expect them to look like? Yeah, we expect that they're mostly round because anything that's big enough, gravity will make it round. You know, gravity is powerful, and if you got a bit that's sticking out, eventually it's going to roll down. And so you have something that's big enough to have strong gravity, it's going to get round. Oh, I see. And you expect these to be big, right? I guess if you're calling them planets, there's a certain size associated with that name, isn't there? Like Pluto got demoted because it wasn't big enough. Yeah, but the really

amazing part is that probably there's a whole spectrum of sizes, from like things bigger than Jupiter, down to Earth-sized things, down to just rocks. And the number is probably inversely proportional to the size. So there are a certain number of Jupiter-sized ones, and they're probably more Earth-sized ones, and then probably like a zillion times more just rocks out there. But at some point they're just called rocks. You wouldn't call them planets, right? At some point, they're called planets and then dwarf planets and then, yeah, just comets or rocks or dust, right? And, you know, some of these things have come through our solar system. Remember, Omuamua?

And the comet that came through in December of 2019, these are just rocks from other solar system that flew through our solar system. Wow, there are Jupiter-sized planets out there just floating in space, not being bound to any star, just doing their own thing? And that was the question. When people first thought about this, they thought, are they? they out there, let's go look for them. And so they started using these two approaches. And what they found sort of boggled the mind. Right. They found more than they expected. Yeah, they found that there's something like around one Jupiter-sized rogue planet for every star in the Milky Way. So there's hundreds of millions of these Jupiter-sized rogue planets out there. Yeah, more like

100 billion. Oh, wow. Yeah, because it's about 100 billion stars in the Milky Way. And a few years ago there was a really exciting result. Some people said that there might be like two to four Jupiter-sized rogue planets out there for every single star. So like hundreds of billions. And everybody was like, reacted just the way you did. Like, what? And then another experiment did some measurements and they came back to said, everybody calmed down. It looks like there's probably just about one Jupiter-sized rogue planet. And I was like, that's still crazy. I mean, I was thinking like there might be 10 in the whole galaxy. Turns out there's billions. and billions of these things.

And those are the Jupiter-sized ones. The Milky Way is littered with these. Yeah, they're everywhere. And as you go down the mass scale, right, like Earth-sized planets, there might be 10 or even 100 times as many. Wow. It's just traffic out there. It's pretty messy.

Space is littered with stuff being thrown around. Nobody's cleaned up, right? We formed all these solar systems and all the leftover bits are just still out there. But, you know, it gets more and more uncertain. As the size of the object we're talking about gets smaller, it's harder to see. And so we've seen fewer of them, so we're making more of an extrapolation with more uncertainty. We're in early days of understanding this, and in 5, 10, 50 years, we'll have a much better handle on it. But right now it's pretty uncertain.

Are they going to keep on floating out there, or will all of these planets eventually kind of fall into a star? Think about what happens when a big Jupiter-sized planet approaches a star. it's not that easy to fall into orbit. Remember, orbit requires being in the right location, having the right direction, and the right velocity. Much more likely is that you come into a solar system and you just sort of like mess it up. Below through it.

Yeah, you perturb the gravitational, the nice, cozy gravitational orbits of everybody that's been there for billions of years and you make more rogue planets. Like, you come in and you bust up a family. If a Jupiter-sized planet came into our solar system, we would probably lose a planet or two. Well, I hope it's not Earth.

They can take Pluto, Neptune. You know, we don't even care about those. Wow, they haven't even arrived yet, and you're already at the negotiating table offering up our neighbors. Yeah. What has Uranus done for me lately? Oh, come on. Oh, come on.

It's comic fodder. Uranus, really? I would give away Neptune first. Oh, I see. It's less funny. I see. You want a planet around, you can make fun of it. Yeah, exactly.

Some planet has to be the butt of all of our jokes. So, okay, so it's not likely, because if they're already floating out there, you know, careening through space, it's unlikely for them to stop at any particular star. They'll just kind of bounce around from solar system to solar system. It is possible. It's possible for our star to capture a new planet. And people wonder about the history of our solar system, you know, like some of our planets have weird orbits. Is it possible they were captured? but if you just shoot a planet at a star

most of the trajectories will lead to it just being like whipped around and shot out into space and probably losing some of its planets. I guess then that gets us to the question of how these planets even formed if they are not in a solar system and they were probably

they can be captured by a solar system where did they even come from? So let's tackle that question but first let's take a quick break. December 29th, 1975, LaGuardia Airport. The holiday rush, parents hauling luggage, kids gripping their new Christmas toys. Then, at 6.33 p.m., everything changed. There's been a bombing at the TWA terminal.

Apparently, the explosion actually impelled metal, glass. The injured were being loaded into ambulances, just a chaotic, chaotic scene. In its wake, a new kind of enemy emerged, and it was here to stay. Terrorism. Law and Order Criminal Justice System is back. In Season 2, we're turning our focus to a threat that hides in plain sight. That's harder to predict and even harder to stop. Listen to the new season of Law and Order Criminal Justice System on the IHeart Radio app.

Apple Podcasts or wherever you get your podcasts. My boyfriend's professor is way too friendly, and now I'm seriously suspicious. Wait a minute, Sam. Maybe her boyfriend's just looking for extra credit. Well, Dakota, it's back to school week on the OK Storytime podcast, so we'll find out soon. This person writes,

My boyfriend has been hanging out with his young professor a lot. He doesn't think it's a problem, but I don't trust her. Now, he's insisting we get to know each other, but I just want her gone. Now, hold up. Isn't that against school podcast? Well, see, that sounds totally inappropriate. Well, according to this person, this is her boyfriend's former professor and they're the same age. And it's even more likely that they're cheating.

He insists there's nothing between them. I mean, do you believe him? Well, he's certainly trying to get this person to believe him because he now wants them both to meet. So, do we find out if this person's boyfriend really cheated with his professor or not? To hear the explosive finale, listen to the OK Storytime podcast on the IHeart Radio app, Apple Podcasts, or wherever you get your podcast. I'm Dr. Joy Harden-Brand-Brandt. And in session 421 of therapy for black girls, I sit down with Dr. Athea and Billy Shaka to explore how our hair connects to our identity, mental health, and the ways we heal.

Because I think hair is a complex language system, right? In terms of it can tell how old you are, your marital status, where you're from, you're a spiritual belief. But I think with social media, there's like a hyperfixation and observation of our hair, right? That this is sometimes the first thing someone sees when we make a post. or a reel. It's how our hair is styled.

We talk about the important role hairstylists play in our community, the pressure to always look put together, and how breaking up with perfection can actually free us. Plus, if you're someone who gets anxious about flying, don't miss session 418 with Dr. Angela Neil Barnett, where we dive into managing flight anxiety.

Listen to therapy for black girls on the IHeart Radio app, Apple Podcasts, or wherever you get your podcast. All right, so where do rogue planets come from? Is there like a rogue planet factory somewhere? Is there a rogue nation of planets where all of these planets go rogue from their rogue nation? Well, it depends on how you define a rogue planet. There's a big population of them that were probably formed around a star.

Just like Earth and Jupiter and all of our planets, they were part of some big cloud of gas and dust and rocks which coalesced to form a star and planets. But remember, that's not like organized. Nobody planned our solar system. And so in the early days of our solar system, stuff was pretty chaotic. It's not like everybody had cleared it up and say, everybody in this lane become Earth and everybody over here. You had stuff sort of bouncing around more, it was more disorganized. And so stuff got ejected. So some planets that were formed in the early days of our solar system probably got ejected and now out there is real planets.

We have a lost brother out there or sister? Yeah, we almost certainly do. Almost certainly. It's a fun question to ask like what fraction of planets end up in stable orbits and what fraction get ejected? And, you know, we're looking at our solar system billions of years in. It's basically after everything has settled down. You know, in our solar system, people think, for example, like Saturn and Jupiter might

have once had different orbits. They might have been in a different order. I see, because we had more things. Yeah, and that there was a third planet, another icy giant, which got ejected from the solar system. Like, you look at the organization of our solar system for clues, and you're like, this looks weird. You know, it would make more sense if this crazy thing happened, and that's how we ended up with this configuration of our planets. Oh, interesting. That's right, because the solar system didn't always look like the solar system. No, and remember Earth had a massive collision with like a planet-sized object

which led to the formation of the moon. Where did that thing come from? Well, probably our solar system. And so now it's been obliterated. Okay, so that's one way you can create a rogue planet out there in space is it's born in a solar system along with other planets,

but then the other planets sort of get together and kind of vote that planet out. That's right. Planet Survivor. But, you know, from that planet's point of view, they're probably like, I never wanted to be in a solar system anyway. So much more exciting out here in the backwoods. I see.

It's much cooler out here. It is much cooler out there. And it could also be, as we talked about earlier, that something comes by and perturbs a nice stable solar system. Like a black hole comes near a solar system and perturbs it and sucks out some of the planets or even just, you know, another passing rogue planet. So solar systems are not that stable. So those are rogue orphan planets, I guess you could call them. Then you can also have, like, true rogue planets. or like independently form rogue planets.

Feral planets, maybe we can say. Yeah, native planets. These are the ones that you were saying don't really count as a star, and they're called sub-brown dwarf stars. And they're just clumps of matter that started to form together, but didn't get enough to form enough gravitational pressure

that you would get hydrogen fusion at the core of it. And so you never start to burn. Right, because you could just have dust out there, and gas and just have it, if there's nothing around it, it'll just come together as a clump. It will come together as a clump. Eventually, gravity wins, right? Gravity is so weak, but so patient. And it just pulls this stuff together, whatever you started with. And, you know, you might wonder, like, how does that start? And that's a whole other fascinating topic. People think they're at these clouds of gas and dust and maybe like a supernova shockwave passes through it and that triggers the

coalescing. Anyway, we'll talk about that in another episode. But whatever, you got around you forms into a blob and if it's not bright enough to burn into a star then it becomes to ignite to start fusion

right that's what you need yeah yeah because you know if you just have a rock out there it's not enough to start fusion you need enough mass that the gravity

sort of takes over and you start that star and then it's basically a sub brown dwarf star oh man I'm just gonna pass judgment right now Daniel I don't think

they should be called stars all right just calling him sub brown dwarves or something So would you call them a rogue planet then? Yeah, right? An independent planet or, yeah, why not?

Is there an argument against calling them a rogue planet? Well, some people think that, you know, a planet is something that formed around a star. And so that a rogue planet, I think the generally acceptable term is that a rogue planet is something was around a star and then got lost. It went rogue. You can't be born rogue in astronomy, apparently. I see. If by planet you mean something that forms around a star, then the thing. Technically, something that doesn't form with it around a star is not a planet.

But this is all semantics, right? This is just what people decided to call this thing. So they can have words that they communicate with and all mean the same thing. Or maybe they just like arguing about this stuff at meetings. That's probably true also. Or maybe what you mean by star is just like celestial objects, then this could be sort of a non-shining star. Yeah.

And these things sort of go the same way as the rogue planets. That is, when it comes to stars, we know more about bigger stars because they burn bright and we can see them. It's hard to spot brown dwarfs and sub-brown dwarfs because they don't shine like stars. We think that the number of these things grows very quickly, though, as you dial down the mass of the object, from bright star to sub-brown dwarf to just dark little blob. So there's a lot more sub-brown dwarfs out there than there are burning stars. There are more failed stars than stars. Is that what you're saying? Big surprise, right?

There are more waiters than celebrities in Hollywood. Wow, the analogies just keep on rewarding us here. It turns out what we've learned here in Los Angeles does apply to the rest of the universe in this one case. L.A. is the center of the universe, obviously. It is taught us something about... It's a template. It's a template for the rest of the universe. That is terrifying. That is terrifying.

All right, cool. So it's pretty interesting to know, to understand, to have a sense that there are. are giant planets out there floating in space without a home, you know? They're just cruising through space, like a, like a spaceship, I guess. Yeah, and you have to wonder, like, what would it be like to stand on the surface of that planet? It would be perpetual night. You'd have no seasons. You could do a lot of great astronomy, right, because you have no sun to interfere with your telescopes. You could have a walk around that planet, go all the way around, and you would only see the night sky with stars in it. Yeah, but you could stay up all night long every night.

you would never get a sunburn that's right that industry that industry would just not take off yeah good for astronomers bad for Procter & Gamble yeah and also makers of swimsuits probably because you know

it'd be pretty cold right we rely on our sun not just for sunlight but also for the warmth and it provides something like 99.97% of the energy on the surface of the earth comes directly from the sun. Really? But aren't there planets

in our solar system that are like super hot by themselves or is it also from the sun? There are like Venus is super hot but all that energy comes from the sun and the reason it's super hot is it has these thick clouds that trap that energy.

So all the surface energy from all the planets in our solar system is almost all from the sun. But that's front on the surface if you wanted to live on the surface and have a view of the night sky. But technically could you

In one of these rogue planets, could you, like, evolve life inside of it where it is warm? You might, because as you say, the core of our planet is warm, and that's not from the sun. That's from the gravitational pressure, right? The Earth is also being squeezed and melt the rock and from the radioactive decays that are happening inside that rock that radiates a little bit of energy. And so there is, you know, there are hotspots underground. And so if you were on one of these rogue planets, say, for example, the Earth went rogue, right? what would happen? Well, the oceans, not good, right?

You throw away all your sunscreen, sorry about that. And the oceans would freeze, and the atmosphere would, like, turn to snow and just, like, accumulate on the surface of the earth, which would be crazy. But if you go down deep enough, there would still be warmth. And so there might be enough energy sort of bubbling up through the crust to keep, like, a layer of water melted. Oh, interesting. You could have, like, underground oceans.

Yeah, you could have underground oceans. The earth would be covered in a layer of ice, but a mile or maybe two miles down, there could still be water, and it might be warm enough to sustain life. Oh, I see. So you would throw out your sunscreen, but not your swimsuit. That's right, take your swimsuit, or maybe your wetsuit, because I don't think it's going to be very warm. But you could find, like, you know, cracks in the Earth's mantle underground where there's geothermal energy. And there is life, the very bottom of the ocean, cluster around these thermal vents. Yeah, and they don't have any sunlight.

that you just live off of the hot water from these vents. They've been planning for this for a long time. Yeah, they're ready for Earth to go rogue. They're the rogue life, right? They're ready to take over when Earth goes rogue. There are the waiting to rise up. But I think what I was saying is that that could happen on one of these rogue planets out there.

I mean, there could be like a giant floating Jupiter out there in space that's actually like a spaceship full of life under the surface. Yeah, and it doesn't have to be that life evolves on a planet and then it goes rogue. I think you're saying, like, could life evolve on a planet when it's rogue? And I think the answer is, yeah, you could have liquid water on a rogue planet

and life could evolve, and it could evolve under, like, a mile of ice and never see the sky, right? It might not even be aware that the universe is larger than its ocean. It would be, like, rogue life. Yeah, and you have to wonder, like, what kind of technology could you evolve?

Like, could you become intelligent? Could you evolve technology? Could you drill out of the ice and then discover that? Imagine what that would be like to be that kind of... I want to read a science fiction novel about life that evolves on a rogue planet and develops the technology, drills out of the ice and then discovers, oh my gosh, the universe is so much bigger than we ever imagined. What a moment, right?

There is a story you and I were talking earlier about the writer, Doug Chang. He has a story, I don't know if you read it, called The Tower of Babel, where that's kind of the plot where they drill through the ceiling of heaven. Oh my gosh, huh? I want to read that story. that sounds awesome. Yeah. All right.

So that's kind of possible is that there are, and there are so many of these rogue planets out there that it probably is, maybe possible that there is life started in one of these rogue planets? Yeah. It's very exciting for the possibility of alien life, which you know I'm a fan of. You know, recently we've learned that there are a huge number of planets around other stars. That was a big moment just in astronomy in general,

but also for us who promote alien life, to realize that there are other places for life in the universe and around other stars. That was exciting. Now we're learning that that's a tiny fraction of all the planets out there and that there's an enormous number of these dark rogue planets. And I think it's more challenging for life to form on a rogue planet. But hey, you got more opportunities also. Right.

There's like a hundred billion rogue planets, the size of Jupiter. Yeah. And maybe 10 to 100 times as many Earth-sized planets out there. Right. Just in our solar system. Just. I mean, just in our galaxy. That would be getting kind of crowded.

Just in our galaxy, yeah. I mean, the galaxy, there's hundreds and hundreds of billions of these, and maybe there are hundreds of billions of galaxies. So who knows, right? There could be a rogue life form out there. My money is that there is. I mean, it just seems so much more likely. It seems so impossible to imagine that nowhere out there on any of these planets has life begun.

There's so many opportunities and so many ways for life. to happen. We haven't even imagined. I would definitely put my money on there being rogue alien life. Can you imagine them bursting out of their shell and be like, whoa, what is this? Even crazier, though, is that like one of these rogue planets could pass by our solar system, you know, within a few AU, you know, just outside the edge of Pluto, and we wouldn't even see it. And they might not even see us. And so we could be like, there could be like cosmic neighbors zooming by, and we're not even paying attention. And maybe. just maybe this happened a few billion years ago

and maybe just maybe an asteroid hit that rogue planet and ejected a piece of rock with life that then landed on Earth. I'm taking it too far. No, I like that theory a lot. It's totally possible. It's possible for life to have originated somewhere else and then come to Earth.

All right. Well, that's pretty interesting to know. It sort of makes you look at space and the night sky differently. You know, in all those places where you only see blackness, there could be planets out there floating and possibly with life.

Yeah, and this life might not be looking back at you. It might be hidden under two miles of ice looking up at the inside of its ocean and wondering what else is out there. Right. That's no interest in being famous like a star. Only because they don't even know it's possible. Once they get a taste of it, though, they're going to go crazy. Oh, no.

Once they discover television, it's all over. Who doesn't want to be a star? All right, well, we hope you enjoyed that. little tour into the blackness of space and what could be out there waiting for us to discover. And as usual, you are in no danger as you sit on your couch or sit in the seat of your car and listen to us, helping you explore the universe. All right. We hope you enjoyed that. See you next time. If you still have a question after listening to all these explanations, please drop us a line.

love to hear from you. You can find us at Facebook, Twitter, and Instagram at Daniel and Jorge, that's one word, or email us at Feedback at Danielandhorpe.com. Thanks for listening, and remember that Daniel and Jorge Explain the Universe is a production of IHeartRadio. For more podcasts from IHeartRadio, visit the IHeartRadio app, Apple Podcasts, or wherever you listen to your favorite shows. December 29th, 1975, LaGuardia Airport. The holiday rush, parents hauling luggage, kids gripping their new Christmas toys. Then, everything changed.

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