Daniel and Kelly’s Extraordinary Universe - Did the Earth ever have a ring?

Episode Date: February 13, 2025

Daniel and Kelly talk about whether the Universe ever put a ring on the EarthSee 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 on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. Every case that is a cold case that has DNA. Right now in a backlog will be identified in our lifetime. On the new podcast, America's Crime Lab, every case has a story to tell. And the DNA holds the truth. He never thought he was going to get caught. And I just looked at my computer screen. I was just like, ah, gotcha.

This technology is already solving so many cases. Listen to America's Crime Lab on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. I'm Dr. Scott Barry Kaufman, host of the Psychology Podcast. Here's a clip from an upcoming conversation about how to be a better you. When you think about emotion regulation, you're not going to choose an adaptive strategy, which is more effortful to use unless you think there's a good outcome. Avoidance is easier. Ignoring is easier.

Denials is easier. Complex problem solving. Takes effort. Listen to the psychology podcast on the Iheart radio app, Apple Podcasts, or wherever you get your podcasts. The message you often hear about space is that it's vast and empty. The earth and even the sun are these tiny dots and a huge, ocean of black space. That's all true, but it gives you the wrong idea about our cosmic neighborhood. It suggests that the Earth is isolated, alone, not affected by our neighbors,

not in danger. The truth is actually the opposite. Space is vast, but gravity is also very patient. There are a lot of big, dark rocks out there that could get tugged by gravity towards the Earth and then dramatically affect our way of life, both positively or negatively. They They could of course smash into us and cause an extinction event, but then they could also create new snazzy bling around our planet. So today we're going to dig deep into the history of Earth within our cosmic neighborhood, understand the gravitational dance between all of these objects, and ask the question about whether there was ever a time when the universe put a ring on the Earth.

So just in time for Valentine's Day, we're getting cosmically romantic and asking, did Earth ever have a ring? Welcome to Daniel and Kelly's Extraordinary Universe. Hello, I'm Kelly Wienersmith. I'm a parasitologist, and I stopped wearing rings because I got fish guts stuck in my ring too many times and decided it was too gross. Oh, isn't that romantic, though? Fish guts in a ring? You got a weird sense of romance, Daniel. I'm trying to resonate with a biology.

Hi, I'm Daniel. I'm a particle physicist, and I bought my wedding rings for $2 on Telegraph Avenue in Berkeley. I was going to ask you. Are you and Katrina ring people or not ring people? We have rings, which we feel sentimental about, but we're not people who are into expensive, fancy stuff. So, like, her engagement ring has a piece of amber in it. I designed the ring myself. There's no, like, crazy diamond in there.

And we didn't want to spend a lot of money on crazy rings. So we just walked down Telegraph Avenue and found a guy who made silver rings and bought him for a couple of bucks. You designed a ring with Amber and got it for two bucks? Oh, no. The engagement ring, I had a friend make. So that was more than $2. But, yes, I designed it myself.

It has a bunch of Danish runes in it and stuff and a piece of amber in the middle. Aw, that's great. How about you? What's your guy's ring story? Can I tell you about our engagement? story really quick. Oh, yes. Does it involve fish guts? No, no, the rest of our life involves fish guts. But no, our engagement story. So Zach is like not a super sentimental guy. And so like a couple months earlier, I had said to him like, hey, you know, we've been together for a year.

Do you think you could ever see yourself marrying me? Because if so, let's keep going. But if not, let's like cut our losses and just be like this was fun. And so his response, and this is amazing, his response was, I think you're really nice. Wow. Which I thought was him being like, like, I don't want to answer this question because it's going to be uncomfortable, but like, that's not what I was looking for, right? And so I thought to myself like, okay, in a couple more months, I'm going to ask him this again. And if I don't get a better answer, it's over. But so Zach thought, well, you marry the person who you think is really nice. So he thought he had said like, yeah, I could marry you one day. And he thought after that conversation that it was

locked in and that he didn't even really need to ask. That was like the most positive thing he could think of saying. I think you're really nice. No, he's not a super sentimental guy. So it was Pie Day, March 14th. And he gave me a little card with a pie on it that said, don't open until, what are the extended digits of pie? So 314 is the date. And then it's 159. Okay, yeah. So don't open until 159. And I thought it was going to be a poem about how like I eat too much pie because he writes like weird poems. And I forgot about it. And so later in the day, it was like 4 p.m. And he was in the restroom and I reached into my pocket and I was like oh I've got this card in my pocket and it's after 159 so I can open it and it said something to the effect of like you get frustrated because I forgot our anniversary but if we got engaged on pie day that's a date I'd always remember oh my gosh and so he came out of the bathroom and I was like are you asking me to marry you and so I'll note that he forgot when 159 passed so he wasn't worried about the answer he knew what the answer was going to be and I love that there's a bathroom visit in the middle of this story that's very Kelly and Zach Exactly. Very scatological. And so I was like, wait, so are we engaged now? And all he said was, well, you weren't supposed to read it while I was on the sh-der.

Anyway, he didn't have a ring. He didn't have anything. We're not very sentimental. So anyway, we went out, we got a ring. I got fish guts in it, so I stopped wearing it because while I was doing dissections, it kept getting in the way. I got him a ring. And when we were walking around Rice University, our daughter was playing with it. And I was like, Zach, and she was like, two. I was like, Zach, she's going to drop it. You're going to lose your wedding ring. You probably shouldn't let her play with it. And we got back into the car and he sat down and he goes, uh, oh. And anyway, so he lost his ring and I don't wear mine because of fish guts. And we are not super sentimental. But, you know, it's been almost 20 years since we've been together.

So it's working out. So Zach's ring is somewhere on the campus of Rice University. Or some undergrad plays drinking games with it or something. I don't know. I don't know where it ended up. We never found. it. All right, right. Students, if you see a ring on campus, send it to Kelly. Yeah, I'll take all the random rings that get lost on campus. All right, well, I've gotten us off topic. Your story was

lovely. Mine was hopefully good for a laugh. But today we're talking about whether or not Earth ever had a ring, which is a fun question to think about. It is fun to think about because it makes us think about the deep past and how we think of the Earth as a certain way and having the moon and the sky looks a certain way and the solar system's arranged a certain way. We imagine it's always been that way or for billions of years. But it turns out that on a cosmic time scale, the solar system has a very chaotic history and things used to look quite a bit different. So it's really fun for me to like go deep into the past and learn about how the solar system used to be quite different, how life on earth could have been different. You could have looked up at the sky

and seeing different stuff out there. And I got to say when you sent me this idea for a podcast, podcast episode topic, it had not been on my radar at all that Earth could have ever had a ring. So I'm excited about hearing the answer to this. So I was wondering if folks out there had considered the possibility of whether Earth had ever had a ring. So I sent this question to our intrepid volunteers. Thank you very much to everybody who plays along. If you would like to hear your voice answering questions on the podcast, please don't be shy. We would love to have you as part of the chorus. Write to us to questions at danielandkelly.org. And we will set you up. In the meantime, think about it for a minute. Do you think Earth could have ever had a ring?

Here's what our listeners had to say. A big meteorite smashed into the earth. All the debris shot up into space. The Earth did have a ring with the material that eventually coalesced into the moon. Yes, it did have a ring and it still does. Maybe it did, like, with all the rocks flying around it right at the beginning when it was being formed, They might have had like a ring of rocks around it. And maybe when the ice aid happens, then there could have been a ring of life around it when there was the ice save.

I don't really think that could have happened. Say yes, that Earth probably had a ring when the moon was born. As bodies coalesced and started to form into planetoids and eventually planets, there would have been rings. Earth might have had a ring after the collision with Theta. If you're referring to a persistent ring system akin to Saturn's, then that's more of a complex question open to interpretation. The ejecta from that collision temporarily formed a ring.

There is a chance that there be some sort of ring during its creation. It no longer has a ring because it is divorced. Middle Earth did, and it was a big freaking deal. Is that one of the theories or hypotheses behind where the moon came from? When a Mars-sized object collided with Earth. Do bears poop in the woods? Do tacos taste better on Tuesdays? Does Tom Cruise love to sprint like a maniac in every one of his movies?

Yes. Yes, the Earth had a ring. But I do know that some Liberace had wings. During the formation of the moon? No. I mean, Saturn offered, but long-distance relationships just never work out. When a proto-planet hit it. To form the moon. While the moon was being formed. I really don't know, but I imagine not since the moon has been there.

That was an amazing mix of like serious good. serious, good answers and some really clever, not answers. I think Tom Cruise does sprint in every movie he's in. I think that's true. Every movie I can think of. Did he sprint in Jerry McGuire? He must have. There must have been a reason to sprint.

Somebody check the footage. Okay. Let us know. And I was a little surprised, though, because I shouldn't have been that most people went to the sort of early formation of the Earth, the impact with a proto-planet that formed the moon and thinking about how that might have been a ring. as well. And that's a totally reasonable answer. That's not what I was going for for today's episode. Well, I think probably it would help to know how rings are formed in general. So I'm

guessing you're going to tell us that today. But let's start even earlier. So like what are rings? I guess I realized, well, I was thinking about this question. Like, you know, the moon orbits in a ring, but that's not a ring. How continuous does the line need to be before you have a satellite versus a ring? Yeah. So it's astronomy, which means where you're going to do our best to draw arbitrary dotted lines between continuous concepts that really exist on a spectrum. But you know, some things we call moons, some things we call rings. What's the difference?

How many tiny moons does it take before you start calling it a ring? Typically we call something a ring if it's composed of solid materials such as dust or moonlets, but it's not in one single object. So, you know, basically there's a spectrum between like, you have one single object, you call that a moon. If you break that moon up into little rocks, you could call those moonlets, or you could say if they're fine enough, you could call it a ring. But if you had two objects as big as the moon that somehow didn't run into each other, would that be a ring? Does Mars have a ring? Or does it just have two moons? Mars has two moons. So I think there isn't a very crisp distinction. I couldn't

find a crisp distinction online. I don't think like the astronomers have had a meeting arguing about this yet. Nature doesn't care about our criteria and our categories. But I think one thing that is important for a ring is that it's basically in a plane. So, you know, a swarm of objects surrounding a planet, you wouldn't call that a ring if it's like in a sphere. If it's orbiting every direction and completely surrounding the planet with little rocks, that isn't a ring. One distinguishing feature of a ring is that it does orbit in a plane, right? The like the vertical motion relative to the ring is small compared to the motion around the planet. Does it happen that you get junk like all around a planet or does it always end up in the same plane as a ring?

Yeah, great question. You can get junk around a planet, but that's sort of temporary. That's not a very stable situation because gravity will eventually pull it down together into a plane. There's a reason that planets have rings and not swarms of stuff. And there's a reason that moons typically form in a single plane around a planet, which aligns with the planet's spin usually. And it's the same reason why the planets all spin in the same plane as their motion around the sun, which aligns with the rotation of the sun. And the reason is angular momentum. Gravity would like to pull everything down together into a little dot.

What resists that? Well, sometimes it's like structural integrity. The Earth doesn't collapse into a black hole because it's solid, right? And the rocks resist being crushed. But there's another factor there, which is the Earth is spinning. And the spinning of the earth sort of fluffs it up a little bit and makes it larger. So like the Earth's radius from the core to the surface is larger at the equator because it's spinning. And if the Earth was softer like pizza dough, it would get flatter and flatter as that spinning resists gravity.

But the spinning only resists gravity along the plane, right? So if you have like the Earth spin axis, the spinning helps resist gravity, helps keep Earth fluffed out along the plane of that spin. So the axis is perpendicular to the plane. But it doesn't prevent things from collapsing to the plane. So now imagine you have a big swarm of stuff that's swirling around the earth. Gravity can pull it down into that plane, making a disk. But the spinning keeps gravity from pulling it down into the earth necessarily. That's why a big swarm of stuff would collapse into a plane.

And it's the same reason why the whole solar system has collapsed into a plane. The original blob of gas and dust that formed our solar system collapsed due to gravity, but didn't collapse as far along that plane because everything is spinning. It keeps stuff from falling all the way in. So if you had a speck around the Earth, not around like the plane where you get the ring, would it get thrown out or pulled in or either? Yeah. So say, for example, Earth has a big ring.

And now you add a rock in a random orientation to the earth. What's going to happen to it? Well, it has a lot of velocity, so it's not going to fall to the earth. It's going to be an orbit. But it's going to get gravitated towards the ring. The ring is going to pull it in. And so while it's going to maintain an orbit because of its speed, that orbit's going to shift until it joins the ring.

The ring, because of its gravity, is going to pull that new rock into it. So gravity pulls things together, but it can't overcome angular momentum. Okay. And are rings always at the equator of the thing that they're orbiting around? And if the thing is at a tilt, that's why it doesn't look like it's straight around. So like Saturn is at a tilt, and that's why its rings are kind of tilty? Yes, great question. And it depends a little bit on the formation.

And this is actually a question people have about how rings form. Like if the ring formed from the original blob of stuff that made the planet, and one of the theories for how rings formed is you have a big blob of stuff, And some of it collapses into a planet and some of it doesn't because it's moving too fast and it stays outside and forms a ring. Then it all comes from the initial blob of stuff that's spinning and then you expect it to have the same spin on the same plane, basically be around the equator of the planet. But another theory is that these rings come from the outside. You have a planet that forms. It's already spinning and hard and compact.

And now some material comes from the outside and is captured by the planet into a ring. That will collapse on its own, but its axis doesn't have to align with the edge. axis of the planet. Gravity will pull it down into a single ring and it will orbit around its spin axis. It doesn't have to align with the planet. There's nothing the planet can do to change its spin axis because angular momentum is conserved. All right. Is there anything else we need to know about how rings are formed? Are we all now experts? Another thing to think about is the difference between the formation of moons and rings. Like why do some planets and rings and some of them have moons and some of them have both. You know, why doesn't gravity always pull a ring together into a

moon, right? You can imagine like a string of little moonlets orbiting together in a circle around the planet. Why doesn't gravity always pull those together? It can do that without violating angular momentum. And the answer there is tidal forces. Usually when we think about the solar system, we're thinking about gravity as just like here you have a rock and there you have a rock and there's gravity between them and they're pulling on each other. But gravity is a little bit more complex than that if your rocks are not just point objects. If they're just points, then you can just think about the gravity on the objects. But if it's big, then you have one side that's closer and another side that's further. And gravity depends on distance. So gravity is going to

pull on the closer part harder than it's pulling on the further part. And that's true always. So for example, if you're an astronaut and you're in space and you're doing, you know, an EV or whatever, the earth is pulling on your feet harder than it's pulling on your head. You might think, no big deal, but those are relative forces. You can think of it as pulling on your feet harder than your head, or equivalently, you can think the earth is trying to pull your head off of your body, because that's really what it's doing, right? It's pulling on one side harder than the other side.

It's trying to tear you apart. And normally your neck is strong enough that the earth's not going to decapitate you, but if you were close to a very powerful body like a black hole, then those are the those tidal forces are powerful enough to pull you apart. That's what spaghettification is. And so planets pull on things. The Earth, for example, is tugging on the moon. It's trying to squeeze the moon into a football.

It's trying to pull rocks off the surface of the moon that's closer to it. I can imagine how that pulling over time would start to like pull off pieces and results in a ring. So does that mean that a lot of the rings around planets are moons that just got kind of crushed? And then why didn't our moon end up succumbing to that pressure? It depends on distance. It also depends on structural integrity what your moon is made out of. But basically, if a moon gets too close to a planet, the tidal forces will pull it apart.

If the moon is far enough away, then the structural integrity of the moon is more powerful than the tidal forces. It'll stay together. So if you look at all the planets in the solar system, you notice that it's usually rings on the inside and moons on the outside. And you can calculate this sort of dividing line. It's called the Roche limit. Things that are closer than the Roche limit, the tidal forces will part. Probably pull it apart. Things that are further, things will coalesce into a moon.

The self-gravity will pull it together, and then the structural forces will hold it. Is it an interplay between distance and size, or is it just size? Or distance size and what you're made out of? Like a chunk of metal would be harder to pull apart than something else? It's mostly distance from the planet and what you're made out of. So, for example, there's a different roche limit for a blob of water than there is for like a moon made of diamond, which would be much harder to pull apart. But for like a typical rock, you can calculate these distances.

For the moon, for example, if it came within 10,000 kilometers of the surface of the Earth, it would be pulled apart. Its orbit is safely outside that. It's like 390,000 kilometers. So it's well past the Roche limit. And, you know, the sun has a Roche limit. If a planet gets too close to the sun, it would get pulled apart by its tidal forces. So, for example, if the Earth came within almost a million kilometers of the sun, it would get pulled apart. We're like 150 million kilometers, so we're in no danger.

But this is the distinguishing feature between rings and moons, basically how far you are from the surface of the planet. You know, now, anytime we discuss something that's named after someone, and I'm guessing the Roche limit is named after Roche, I find myself wanting to have Kathy Johnson back because I want to be like, Kathy, did Roche really come up with this? Or who was he building on? What were people thinking at the time? She should just always give us the background on everything, because she's wonderful.

Yeah, and science is a human story. which means that every time you learn a little bit of knowledge, there's a fascinating, probably tortured history for how we figure that out and how it was named after this person and whether that person was actually a jerk and if their paper was full of mistakes and whether they deserve the credit for that or not. Human history is always fascinating. Every time you lift up the rug, you find really interesting stuff under there. Everyone should check out if you missed it,

our episode on Maxwell's Equation, to hear Kathy's amazing history and also to make you feel better if you're not good at math. because neither was Faraday or Maxwell apparently Maxwell was good at math he just wasn't good at keeping track of minus signs but hey who is anyway he got away with a lot of mistakes yes all right that's true I have fewer published math errors than Maxwell there you go you should feel good about that you should get a plaque to put over your desk

maybe just a t-shirt there you go that's right fewer mistakes than Maxwell it's got to be a pretty niche audience for that t-shirt Okay. All right, well, we're all missing Kathy right now, but there's nothing we can do about it at the moment. So let's take a break to think about how great Kathy is. And when we come back,

we'll talk about what those rings tend to be made of. 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 two, 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.

Well, 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. 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. A foot washed up a shoe with some bones in it.

They had no idea who it was. Most everything was burned up pretty good from the fire that not a whole lot was salvageable. These are the coldest of cold cases. But everything is about to change. Every case that is a cold case that has DNA. Right now in a backlog will be identified in our lifetime. A small lab in Texas is cracking the code on DNA. Using new scientific tools,

they're finding clues in evidence so tiny you might just miss it. He never thought he was going to get caught. And I just looked at my computer screen. I was just like, ah, gotcha. On America's crime lab, we'll learn about victims and survivors. and you'll meet the team behind the scenes at Othrum, the Houston Lab that takes on the most hopeless cases to finally solve the unsolvable.

Listen to America's Crime Lab on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. Hola, it's HoneyGerman, and my podcast, Grasasas Come Again, is back. This season, we're going even deeper into the world of music and entertainment with raw and honest conversations

with some of your favorite Latin artists and celebrities. You didn't have to audition? No, I didn't audition. I haven't audition in, like, over 25 years. Oh, wow. That's a real G-talk right there. Oh, yeah. We've got some of the biggest actors, musicians,

content creators, and culture shifters, sharing their real stories of failure and success. You were destined to be a start. We talk all about what's viral and trending with a little bit of chisement, a lot of laughs, and those amazing vibras you've come to expect. And, of course, we'll explore deeper times.

dealing with identity, struggles, and all the issues affecting our Latin community. You feel like you get a little whitewash because you have to do the code switching? I won't say whitewash because at the end of the day, you know, I'm me. Yeah. But the whole pretending and code, you know, it takes a toll on you. Listen to the new season of Grasasas Come Again as part of My Cultura Podcast Network on the IHartRadio app, Apple Podcasts, or wherever you get your podcast. All right. So based on our earlier conversation, I'm guessing that a lot of rings are made out of, you know, like moons that got crushed. So probably, you know, rocks and metal and stuff. What else do we get out there? Yeah. So the rings tend to be made out of the same stuff that the solar system is made out of. So the inner solar system, it's mostly rocky because, you know, the solar system, well, it starts out mostly gas. But all that gas gets gobbled up by the sun. And any gas left over in the inner solar system got blacked.

blasted out of it by the sun's radiation. So you don't have a whole lot of gas left in the inner solar system. The rings closer to the sun are going to be rockier. Further out, you're more distant from the sun so you can have things like water crystals and out past what we call the frost line where water isn't vaporized by the sun. You have ice. And so, for example, beyond Jupiter, there's a lot of ice in those rings. So you don't get any ice in rings between the sun and Jupiter, but Jupiter outwards.

you can get ice in rings, is that right? Yeah, exactly. Okay. And so we have some pretty spectacular ring systems in the solar system, right? And one of the first ever to be seen was Saturn's. This is one of the first things actually that Galileo saw through his telescope on those cold Italian nights in the early 1600s are the rings of Saturn, which of, you know, anybody who's used to telescope in their backyard knows that this is an amazing thing to see.

I can't imagine being the first one to see that must have been just absolutely mind-blowing. Right, right. To me, it's always exciting where you can resolve any feature on these objects in the night sky. Like you look at the moon and you can see things on the surface, that's super cool because it's not just like a point and seeing the rings of Saturn is the same way. You're like, I'm seeing something that's really out there. I don't know about you, but when I look at the night sky, it's just too easy to think of it as like a screen with dots on it. But when you can resolve features on something, then suddenly I'm transported to this mode where I understand I'm looking across an incredibly vast. ocean of nothingness to huge objects that are incredibly distant.

You know, it's so difficult for your mind to really put yourself in that vast 3D space. But on a clear night when you can see the rings of Saturn or the moons of Jupiter, I feel like it's easier to visualize yourself in this vast space rather than thinking of it as a screen. Part of me feels like this is cheating, but I love those apps on my iPhone where you look up at the night sky and it tells you like, that's Saturn, that's Venus. And, like, to me, I get all philosophical when I get that extra detail. It makes me feel like I'm more of a small spec than if I just look out. Like you said, it's almost like you've got a sheet with little pinpricks in it and lights coming through.

It's like easy to not think about it as a vast expanse out there. But anyway, yay for technology. There's an app for that. Well, the rings of Saturn are really incredible because they're so very, they're a bunch of different rings. They're separated. And NASA has given them really creative names. There's the A ring, the B ring, the C ring, you know, goes out to the G ring and the E ring,

which are sort of harder to see with your naked eyes. Some of these things have like a lot of dark organic compounds, so they're not as easy to see. The inner ones have more ice. Like they're just basically a bunch of icy particles spread out in these vast, very flat rings. Who should be naming these, right? You know, so NASA clearly shouldn't be allowed to name things because they're not doing a good job. But, you know, like if you let the internet name them, it would have been like, like ringy McRing face.

What is the right solution here for these amazing celestial objects? I think they should be renamed. That's what I think. Yeah, absolutely. I think they should not be named by scientists. Maybe we should have Jorge on the podcast to suggest names. He was always good at that. Sounds good.

But there are these fascinating gaps between the rings. Like there's the A ring and the B ring. And we've known about these gaps forever. It was Cassini in like the late 1600s who first saw these gaps. And that's why we call that spacecraft that visited Saturn, in the Cassini spacecraft because he was the first one to see them. And these gaps in the rings come from actually the interactions of the ring material with little moons.

You know, so we talked about how like their only moons out past the rings. But if you're small enough, you're going to avoid those tidal forces. You're like basically a big chunk of rock within the ring. Is it really part of the ring? Is it a moonlit? Now we're getting into that murky territory where the dotted lines don't make any sense. But these rings sometimes are called shepherd rings, shepherd moons. because they orbit near the edges of these rings

and they can help keep the material in place. There's these fascinating gravitational interactions between the ring and the moon. Huh. And okay, so the moon is countering Saturn's gravity to keep some of the stuff in the ring in its place. How is the moon clearing its own orbit? Is it gravity pulling anything else

that might have been in a ring in that location? It's pulling it into itself? Yeah, essentially, it's acting like a little shepherd. It helps keep their edge of the ring sharply defined because anything that gets too close gets accreted onto the moon or it can make a near miss and can like get accelerated by the moon

and then deflected back away from the moon like a slingshot back into the ring. That's how it keeps its own like little lane. That's why you get these gaps in the rings. It's really fascinating. But these rings are really, really broad, right? They're like 70,000 kilometers wide, the rings of Saturn. And they're only 20 meters thick.

That's meters. not kilometers. Oh, wow. Yeah, it's the scale of like, if you had a sheet of paper, the sheet of paper would be like a kilometer wide, right? It's incredibly thin compared to the breadth of it. And that's due to angular momentum and gravity. Gravity has done its work to collapse it down to a thin sheet,

but it can't do it in the sort of plane of rotation because of angular momentum. It's kind of amazing that we can see anything that thin from all the way here on Earth. It's because it's reflective. It's the icy particles that make it possible to see it. Oh, okay. All right. So then where did Saturn,

get this ring in the first place? Was Jupiter feeling amorous at some point? You know, the story of Saturn's rings is interesting history. It used to be that people thought this was probably left over from formation of Saturn because it does orbit in the plane of Saturn. And it seemed like, wow, this must have been here for a long time. But Cassini's visits revealed that the rings are quite low mass. You know, there's like less stuff in there than we thought. And it's still very sharp and bright, like the edges of these ice crystals are still very sharp, which isn't consistent with like being there a long time. You know, things tend to get rounded and collisions tend to soften stuff.

A more recent theory is that some moons of Saturn might have collided and left a huge spray of debris, which basically formed into a ring, which might mean that these rings themselves are temporary. It might be that Saturn gathers them back together into moons. We don't quite know because the Roche limit is a little bit fuzzy, you know, the structural integrity if those rings will be there in a hundred million years. Oh, man, and we're not going to be around to know. How do you know? Come on.

We're going to have great, great, great, great, great, great kids making non-sentimental marriage proposals to each other using ice from the rings of Saturn. Wait, your grandkids are going to, are we getting into incestuous stuff? Oh, you mean, mine. I mean, humanity's descendants. I couldn't say enough great, great, greats to get us 100 million years. But are you not optimistic that people will be living in the solar system in 100 million years. I know I'm optimistic.

All right. Somebody will be here to see the new moons of Saturn and to give them a creative name. I hope somebody gets on that much sooner. I don't want to wait for that to happen. And other planets in the solar system have fascinating histories with rings. And like

astronomers think that Mars has gone through several cycles of having rings and moons and rings and moons. Wait, so does that mean that like Bobos and Demos have broken up and come back together multiple times or? Well, we don't know how long Phobos and Demos will last, but we think that Phobos and Demos formed from a ring that was created from a giant impact. So like something hit Mars and then ejected a huge amount of stuff like 10 to the 23 kilograms of stuff into orbit and left this huge debris cloud around Mars, which then collapsed into a ring, which then got gathered together into these small moons.

So is it possible to look at a moon and figure out if it's gathered up ring or not? Like, that's got to be hard. It's not always possible to tell the history, but you can get some clues. Like, for example, Phobos and Demos have very circular orbits, which suggest that you have, like, a lot of stuff which formed a ring and then gathered together, rather than being single objects that were, like, captured as they floated near Mars, which would tend to be, like, more elliptical orbits and not, necessarily in the same plane as Mars. So that suggests that it formed from a ring. Also, you can look at the composition of the stuff. And Phobos and Demos are made of the same stuff as Mars is,

which suggests, like our moon, that it formed due to a giant impact rather than, like, was captured. Sometimes moons can be captured. Some of the moons of Saturn and Jupiter, we think, are just, like, big rocks that floated too close and got gobbled up into the gravitational system of those planets, not yet torn apart. But hit the cosmic lottery and didn't get pulled into the center. Exactly.

And if these things form moons and then they're too close to the planet, like they'll drag. If there's an atmosphere there, they'll drag and then eventually just fall into the planet and so that you can lose your moon. So there's evidence on Mars of several of these cycles like impact, forms a cloud, makes a ring, then makes a little moon, and that moon gets dragged down into the planet and lost. and you start again. So Mars is like a really kind of checkered history with its moons. It's got like a bunch of X's that it's gobbled up.

Oh, man. Yet one more reason and not go to Mars, as if I needed one. So it sounds like these transitions are very chaotic and would be dangerous if humans were living on the surface at the time. Oh, yeah. No, you don't want to be around during one of these transitions. You don't want to be around when you have like a huge dust cloud around your planet either because it's going to block a lot of light.

So, you know, the temperature probably plummets on the planet when you have a situation like that. In general, it's probably really fun to watch from far away, but not fun to watch from the surface. And the connection with the dust cloud is because when something plummets, it kicks up a bunch of dust. Is that right? Yeah.

A lot of these are formed from an impact. So either you have something that comes nearby and is torn apart and then you get a cloud of debris, or you get an actual impact on the planet which kicks up huge piles of stuff from the planet, which then coalesces into a ring and then a moon. And so we used to think that Saturn was the only planet, in the solar system that had rings,

but now we've discovered that rings are much more common. So, for example, Jupiter has rings, but we've only known that since 1979 when Voyager went to visit. These things are so faint that you either need to send a probe to see them or have a very powerful space telescope, like Hubble can see the rings of Jupiter now, but otherwise we couldn't see them from Earth. And what are they named?

One, two. I hope we've done better with Jupiter's rings. Maybe alpha, beta, gamma, delta. Yeah, that's a good question. But these rings around Jupiter are very faint because they mostly consist of these little dust particles that come from like tiny meteors hitting the planet's moons and then being vaporized. But this dust also doesn't last very long in the Jovian system because Jupiter is crazy. It has really powerful magnetic fields and these basically pull these rings apart and shepherd them up to the poles. And so a piece of dust can only last in these rings for like a few hundred years or a few thousand years, which means that, like, Jupiter's rings are constantly being degraded and replenished.

Like micrometeers are hitting the moons, which then get vaporized, and then they join the ring, but there's also an outflow. So it's not like a constant structure. It's more like a river of dust that's moving through this sort of like dust cycle around Jupiter. It's probably nice to get some new bling from time to time, you know, out with the old, in-weil. with the new ring. Yeah, maybe you and Zach should get new rings sometime. Yeah, no, he'd just lose them and I would get bug guts in them and it would just not, it wouldn't work for us.

It's all right. Yeah, you know, I'm the same way I lose stuff. I put stuff down. I can't remember it. So I've always been terrified. I was going to lose my ring. So I just never, ever, ever take it off. Like, that's my rule.

Not in the shower. I never take it off because I'm afraid I lose it. Same with my glasses. Like I wear glasses all the time. I actually only need them for reading. Really? But if I ever took them off, they would be gone within a day. So I just wear them all the time because I can't manage it otherwise.

I'm just totally blind without mine. So I never take mine off. But lately, my kids think it's funny to try to pull them off. And I do not think that's funny at all. So we're working on that. I think it's hilarious when mom bumps into stuff in the kitchen. I mean, yeah, I guess so. But then I remind them like, oh, I can't drive you to go get ice cream.

And then they're like, oh, we found your glasses. Like, oh, that was easy. Isn't it wonderful as your kids grow up to be real people? Yeah, I know. They're growing up to be bullies. I'll do better. All right, so we've talked about how Mars maybe had rings. Jupiter, Saturn, definitely have rings.

How about Uranus? She says with glee. You're just desperate to talk about rings around Uranus. I mean, what would an episode be without it? So there are actually uranium rings. The individual particle. in these rings are jet black, like lumps of coal. And we haven't visited close enough or been able to study these enough to know exactly what they're made out of. But they seem like some

kind of carbon or hydrocarbon compounds. They're not very well understood because they're so far out and they're so hard to see because they're black. Like, remember, we can only see stuff that reflects light unless we go and visit. And so jet black stuff out there in the deep, dark solar system, it's very hard to study. I would have so much fun naming things on a Uranus mission, rings and all that. Okay, let's take a break. You think of what you would name Uranus rings if you discovered them. And when we get back, let's talk about whether or not Earth ever had a ring. 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 emerge. And it was here to stay. Terrorism.

Law and order criminal justice system is back. In season two, 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. Well, 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. 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. Hola, it's Honey German, and my podcast, Grasasas Come Again, is back. This season, we're going even deeper into the world of music and entertainment, with raw and honest conversations with some of your favorite Latin artists and celebrities. You didn't have to audition? No, I didn't audition. I haven't auditioned in, like, over 25 years.

Oh, wow. That's a real G-talk right there. Oh, yeah. We've got some of the biggest actors, musicians, content creators, and culture shifters, sharing their real stories of failure and success. You were destined to be a start. We talked all about. what's viral and trending with a little bit of chisement, a lot of laughs, and those amazing vivras you've come to expect.

And of course, we'll explore deeper topics dealing with identity, struggles, and all the issues affecting our Latin community. You feel like you get a little whitewash because you have to do the code switching? I won't say whitewash because at the end of the day, you know, I'm me. But the whole pretending and code, you know, it takes a toll on you. Listen to the new season of Grasasas Come Again as part of my Cultura podcast network on the IHartRadio app, Apple Podcasts, or wherever you get your podcast. A foot washed up a shoe with some bones in it. They had no idea who it was. Most everything was burned up pretty good from the fire that not a whole lot was salvageable.

These are the coldest of cold cases, but everything is about to change. Every case that is a cold case that has DNA right now in a backlog will be identified in our lifetime. A small lab in Texas is cracking the code on DNA, using new scientific tools, they're finding clues in evidence so tiny, you might just miss it. He never thought he was going to get caught. And I just looked at my computer screen. I was just like, ah, gotcha. On America's Crime Lab, we'll learn about victims and survivors.

And you'll meet the team behind the scenes at Othrum, the Houston Lab that takes on the most hopeless cases, to finally solve the unsolvable. Listen to America's Crime Lab on the IHeart Radio app, Apple Podcasts, or wherever you get your podcast. All right, so I am going to hope that Earth never has another ring, because I think that would probably result in something catastrophic for the humans living on the planet. And actually, have you ever read Seven Eves by, I think it's Neil Stevenson? I have read Seven Eves and greatly enjoyed it.

It's a fun book. I really want to know more about what bloke. up the ring in that book. It's not a spoiler because it happens in like chapter one. And I thought, oh, this book is going to be about understanding the mystery of what destroyed the moon. But he just basically moves on to like what it's like to live in that system. Never answers a question like, was it an alien attack?

Was it a random impactor? I found that very unsatisfying. I mean, it's a great book otherwise. I kind of appreciated that. I felt like, you know, there's just a lot of things we don't know the answer to. And probably like in a situation like that where you think humanity is in peril. That probably goes to the bottom of your to-do list, like, figuring out the answer to that. But I had some questions about the evolutionary biology stuff there.

No, we're science people. We're curious. You can't, like, give us a huge mystery and then leave it unsolved. That's the point of these books is to inflame your curiosity itch and then scratch it. You can't just inflame it. That's really unfair. I mean, there was a lot of other hard science in that book. No, there definitely was.

If anyone knows Mr. Stevenson, we would love to talk to him on the show. Let us. Yes, absolutely. Please. Mr. Stevenson, come talk to him. to us. We will be very nice. We'll be huge nerds. All right. So let's hope that Earth never has a ring into the future, but let's look into our past. When might we have had a ring? So a lot of the answers from listeners were really insightful. They were thinking about the early formation of the

moon and how that probably got gathered together from a big cloud of stuff, which probably initially formed into a ring. And that's a very insightful answer. I think my only quibble with that would be like, was the Earth really formed at that time? You know, we had the Proto Earth, which then got collided with Thea and formed a huge swirling system which coalesced into the Earth and the Moon simultaneously. So, like, I don't know if that counts as the Earth having a ring because the Earth itself was still forming. But it's true that the Moon was likely a ring of material before it formed a moon. Oh, interesting. But that was over 4 billion years ago, very, very early in the solar system. There was actually another period, much more recently,

only 466 million years ago when scientists think the Earth might have temporarily had a ring system. Oh man, all right, what catastrophic thing happened to make that happen? So what we do know and has been well established is that around 466 million years ago there was a time of heavy bombardment.

It's the Ordovician period of the Earth. And we know from fossil records and from other crazy pieces of evidence we have that there was just a lot of impacts on Earth. Like there are these quarries in Sweden where you dig down to get lines, stone, each layer is older and older. And it's a layer that corresponds to this time period with all these fossil meteorites in it. Like they found these weird green rocks down there. They're

like, what is this? And you find them in this one particular strand. And they dug into them and discovered these are meteorites. You can tell like chemically and also from the shape of these things that they're meteorites. So not just like rocks from Earth. And then they found similar impact sites in other places around the Earth that tells us like, wow, there's a period here where Like the weather was bad on Earth. So is the idea then that there was something that got within the Roche limit and it got broken up into a ring and then it fell all over the planet and that's why there's a lot of it? Yes. So the theory used to be that there was probably some impact between asteroids out in the asteroid belt or near Jupiter or something that created a lot of shrapnel and then the earth basically flew through a cloud of this shrapnel.

That was the original idea. So we know that there was a lot of impacts. You see them all over the planet. There's even evidence of like enhanced seismic and tsunami activity from all this time ago. It's incredible what you can learn from geology, from like seeing these fragments of rock that got broken up and stuck back together in ways you only get from like really cataclysmic tsunamis and seismic events. Anyway, the theory used to be, okay, there's a cloud of stuff that's created far from Earth and the Earth flies through this cloud, which creates all these impacts, right? But a recent study, they analyzed where on the surface these craters were, and they discovered that they were suspiciously all along the equator. That suggested there was time for this thing to form into a ring around the earth.

And probably your description was more accurate that some big thing came pretty close to the earth within its roche limit, was then torn apart into bits, which orbited for a while, formed a ring before the atmosphere dragged it down. into impacts on Earth. Oh, my gosh. And so was there an extinction that happened concurrent with this? There is a moment called the Great Ordovician Biodiversification event. And there was definitely a change in the Earth's temperature. If you look at the temperature records, they call this a global ice house. It's like a big dip in the history of the temperature on Earth.

And so this paper suggests, oh, this could explain that as well, because if you have a huge ring that forms over the equator, it's going to significantly shade the planet. And this is a really hard study to do because if you want to think about where these things land on the earth, you have to know where that land was at the time, right? continents move. And you might be thinking, hold on, didn't Daniel say there were a bunch of fossil meteors that landed in Sweden? And Sweden isn't close to the equator. Yeah, it isn't today, but 466 million years ago it actually was.

So what they had to do was figure out where are all these craters that you can associate with this time period, which, isn't always easy because sometimes you can date these things very well. Sometimes you can't because the layers they're in. Then they had to rewind the history of the earth to understand where were these craters when the impact actually happened. And so they computed this amazing word. I love this. The paleo latitude, right? Like where on the earth was this when it happened? I love that. That's a good word. So those people should be in charge of naming the rings. We found the people. Yes, exactly. Right? Sometimes you hear. weird in science. You're like, okay, that's well done. Nice. That's nice. And so they did this

calculation. They found all these things. But, you know, we're talking about a handful of things, not like millions of examples. They have like a couple of dozen, maybe three dozen craters that they can definitively pinpoint are from the Ordovician period. And so you might wonder like, well, how do you really know these are within the equator? It's not like they all line up perfectly on the equator. They're sort of like loosely associated with the equator. Their paleo latitude tends to be less than 30 degrees. And so they did a pretty robust statistical analysis. I've read this paper carefully because honestly, I'm kind of skeptical about the ability of lots of folks out there to do statistics in a robust way because not that many people really

understand statistics. And I've been shocked to read papers in other fields, especially biology. Yeah. And be like, I'm pretty sure that statistical analysis is totally wrong. Yeah, but I read this paper. I thought they did a great job. They thought about, like, what are the chances of getting this kind of distribution of paleo latitudes if things actually were evenly spread? And they did some good calculations and some good simulations.

They look, for example, at the distribution of modern impacts and showed that they're much more broadly distributed than these. So they calculate it's very unlikely that these things by random chance just happen to fall along the equator. And that suggests that they probably were in a ring above the earth for a while. This is 466 million years ago. They also looked at some of these rocks, these actual fossil meteors, and they can study the chemical composition of these things and understand how much space radiation they were exposed to. This is super awesome. Yeah. Yeah. Because, you know, there's a lot more radiation out in space than there is here on Earth, because out in space you don't have the

benefit of our atmosphere protecting you. And so like there are all these high speed particles, cosmic rays and solar wind, constantly penetrating it. And that changes the chemical composition of stuff, right? It smashes into the rocks. It degrades some of those isotopes. So you can basically count how long something has been in space by looking at the chemical makeup of a rock.

And it looks like these rocks were not exposed to space for very long, only like a few tens of thousands of years. not millions. And that means that probably they were like on the inside of some large asteroid for many, many, many millions or billions of years, basically protected from the radiation of space, then torn apart by the Earth's tidal forces into a bunch of little rocks, which are not protected by the radiation of space, but only for a few tens of thousands of years before they fell to the surface of the Earth and then protected again. So, you know, they were near the surface of an asteroid out in space, exposed to radiation for only.

only a few tens of thousands of years. So that's also suggestive. None of this is completely conclusive. But, you know, this is like solving a mystery. You have a few clues. You're trying to piece together a story. All this is very circumstantial, but it all points in the same direction. You mentioned that there was like a shrapnel theory.

Wouldn't the shrapnel theory also have something big where most of it was protected by space radiation and then it got broken into pieces and those pieces were exposed to space radiation for a short period of time before Earth hit it? How would you tell the difference between those two options? Yes, a short period of time, but longer. Like if there was a collision out in the asteroid belt that created all this shrapnel, it would take much longer to get to Earth, probably millions of years, not just 10,000. And so that's how they can tell the difference.

Got it. That's very cool. Who was the first author in this study? Let's give them some credit. This sounds awesome. And scientists who understand statistics. Yeah, so this is Andrew Tompkins, Aaron Martin, and Peter Kewood, in a paper in Earth and Planetary Studies in November 2024.

It's really quite readable, even for somebody outside their field. So, congrats on the exciting result and the nicely written paper. And where did you come across this? How did we come to talk about this today? I think a bunch of listeners might have heard press releases about it and sent me an email asking me to explain it. So I put it on my list, and eventually I actually do get to everything on my list, as I promise. But we got a long backlog, so it might take me a while.

But if you are curious about something you've heard about in the news and you'd like for us to break it down and explain it to you, for Kelly to ask me hard questions, for me to ask Kelly naive biology questions, then please send us your questions. We'd love to dig into something you'd like to hear more about. So write us at question. Oh, I always forget our email address. What's our email address, Daniel? Questions at Daniel and Kelly.org. You can write to us and ask us like, what is our email address? Yeah, that's probably not going to be super successful on that one.

But good luck. and we hope to hear from you. Until next time, put a ring on it. That's right. My daughter would be absolutely appalled if I say. So anyway, thanks, everyone. Tune in next time. Daniel and Kelly's Extraordinary Universe is produced by IHeart Radio.

We would love to hear from you. We really would. We want to know what questions you have about this extraordinary universe. We want to know your thoughts on recent shows, suggestions for future shows. If you contact us, we will get back to you. We really mean it. We answer every message.

Email us at Questions at Danielandkelly.org. Or you can find us on social media. We have accounts on X, Instagram, Blue Sky, and on all of those platforms, you can find us at D and K Universe. Don't be shy. Write to us. 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 podcast. 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 her gone. Hold up. Isn't that against school policy? That seems inappropriate. Maybe find out how it ends by listening. listening to the OK Storytime podcast and the iHeart radio app, Apple Podcasts, or wherever you get your podcast. I'm Dr. Scott Barry Kaufman, host of the psychology podcast. Here's a clip from an upcoming conversation about how to be a better you. When you think about emotion regulation, you're not

going to choose an adaptive strategy, which is more effortful to use unless you think there's a good outcome. Avoidance is easier. Ignoring is easier. Denials is easier. Complex problem solving. takes effort. Listen to the psychology podcast on the iHeart radio app, Apple Podcasts, or wherever you get your podcasts. Hi, it's Honey German, and I'm back with season two of my podcast. Grasias, come again. We got you when it comes to the latest in music and entertainment with interviews with

some of your favorite Latin artists and celebrities. You didn't have to audition? No, I didn't audition. I haven't audition in like over 25 years. Oh, wow. That's a real G-talk right there. Oh, yeah. We'll talk about all that's viral and trending.

with a little bit of cheesement and a whole lot of laughs. And of course, the great bevras you've come to expect. Listen to the new season of Dresses Come Again on the IHeart Radio app, Apple Podcast, or wherever you get your podcast. This is an IHeart podcast.