Daniel and Kelly’s Extraordinary Universe - Did Jupiter once have a different orbit?

Episode Date: April 6, 2021

Daniel and guest host Kelly Weinersmith explore the dramatic story of Jupiter's wandering orbits Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener fo...r privacy information.

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Starting point is 00:01:04 I was diagnosed with cancer on Friday and cancer free the next Friday. No chemo, no radiation, none of that. On a recent episode of Culture Raises Us podcast, I sat down with Warren Campbell, Grammy-winning producer, pastor, and music executive to talk about the beats, the business, and the legacy behind some of the biggest names in gospel, R&B, and hip-hop. Professionally, I started at Death World Records. From Mary Mary to Jennifer Hudson, We get into the soul of the music and the purpose that drives it. Listen to Culture raises us on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. The U.S. Open is here, and on my podcast, Good Game with Sarah Spain.
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Starting point is 00:02:01 Brought to you by Novartis, founding partner of IHart Women's Sports Network. Hey, Kelly, how do you feel about moving? It always seems like it's going to be exciting, but it's always a drag. I know, right? It's like there's always one more box of stuff. Yeah, and by mathematical induction, that means we all have infinite stuff.
Starting point is 00:02:30 I totally checks out. I mean, I have like infinite back pain from my last move. Sometimes I wish I had a mobile home so that I wouldn't have to pack everything up every time. That is a genius solution. I mean, you move more stuff, but you do less work because you take your whole house with you. Exactly. I wonder if it scales. Ooh, I'm thinking like mobile neighborhoods, mobile cities, maybe like mobile
Starting point is 00:02:53 planets. Earth is just one big mobile home. Man, I didn't realize we lived in a cosmic trailer park. Hi, I'm Daniel. I'm a particle physicist, and I once moved across the Atlantic 11 times in four years. Seriously? Seriously. This was when I was a junior professor and just getting started at the Large Hadron Collider
Starting point is 00:03:31 and teaching on the West Coast of the United States. So we actually had a house in France and a house in California and we had to go back and forth and back and forth and back and forth and back and forth and back and forth. It almost drove my family crazy. Oh my gosh. Did you have kids at that point?
Starting point is 00:03:45 We had two young children, one of whom was born in Switzerland. Oh my goodness. I know. It's amazing. I think I'm not divorced. It is. It is.
Starting point is 00:03:54 I shouldn't have said it is so quickly. But, well, I'm Kelly Weiner-Smith, and I'm a parasitologist, and it's amazing that I'm not divorced also because I moved my husband four times during my Ph.D. To different states. But, you know, I used to think that was bad. And now I'm going to go downstairs and tell Zach later how easy he has it. So thank you for that. That's good.
Starting point is 00:04:13 That's my goal is to make other marriages look good. We appreciate it. Well, welcome to the podcast, Daniel and Jorge, explain the universe in which we talk about all the crazy and amazing things that we find out there in the universe, moving here and there, taking our brains from the tiniest little particles down to the quantum realm to the vast planets of the outer solar system and all the way to superclusters. Our goal is to embrace everything we know and that we don't know and explain all of it to you. And as you might have guessed today on the program, Jorge is not here.
Starting point is 00:04:47 So we have our fabulous guest host, Kelly Wienersmith, joining us to talk to talk about all these things and ask good questions. Hey, Daniel, I'm excited to be back. I had fun last time. Awesome. Great. Well, thanks very much for joining us. So we started off joking about moving houses and moving planets. But this is something I think is actually really interesting, is thinking about how the planets in our solar system got where they are and whether or not they have ever moved. I personally love this question because it's one of those questions that, like,
Starting point is 00:05:17 the fact that we have anything that even vaguely resembles an answer makes me sort of proud to be a human? Like, how can we even think about these sorts of questions and collect data to answer these questions? It just seems so mind-blowing to begin with. The fact that we have any answers, even preliminary answers, blows my mind. Well, I think it's super fascinating that we even know to ask these questions, right? Like, you look at the solar system, and we have the planets, and they don't seem to be changing from year to year. We have thousands of years of astronomical records. And so it seems sort of stable. So it's sort of absurd even to ask, like, could the planets have ever been in another configuration?
Starting point is 00:05:54 Could the solar system have looked different? It's like very natural to think, oh, things are going around the sun. They've been going around the sun. Of course, they were always in the same orientation. But something that's happened over the last just couple of decades is that we've had a chance to glimpse other solar systems. For thousands of years, we've only ever seen ours. We had like one example.
Starting point is 00:06:16 Now we're seeing lots and lots of other solar systems. And this gives us a clue that solar systems can look different and that there might be a lot of activity that they're actually quite volatile. That is super exciting. So for our sample size for these, like how many solar systems can we see in enough detail where we can like count all of the planets and get a bit of a sense for what those planets are like. Are we talking hundreds, thousands, millions? How big is our data set here? It's exciting because it's growing so rapidly. Like the first exoplanets were discovered just a few decades ago.
Starting point is 00:06:45 And now we have thousands, not yet millions. someday astronomers will get to play with a data set of millions of solar systems and ask really detailed questions. But we have thousands of solar systems that we can look at and we see weird stuff in those solar systems that we don't see in our solar system. And that makes us wonder like, wait a second, are those solar systems weird or is our solar system weird? I need to know the answer. And so today on the podcast, we'll be asking the question. has our solar system look different. In particular, did Jupiter once have a different orbit?
Starting point is 00:07:24 And that's a pretty huge question, right? Because Jupiter is like the biggest planet out there. So where it goes has a big impact. From one point of view, you could imagine it's basically the only planet. Other than the sun, Jupiter has like 99% of all the mass in the solar system. Everything else is basically a detail compared to Jupiter. So, yeah, it's a big deal. If Jupiter had been in a different place, everything would be different.
Starting point is 00:07:46 And so as usual, I was curious whether people had this in their minds. Like, have people imagined the possibility that Jupiter could be in a different place? Is that something people have thought about, have heard about? So I went out there to the wilds of the Internet. And I asked people, hey, do you know the answer to this tough physics question that astronomers are struggling over? Use no preparation, no Googling aloud. Just tell me off the top of your head. what people had to say.
Starting point is 00:08:12 I guess no. There were impacts of, I guess, asteroids and or comets. And maybe even bigger objects in the past. So I think the orbit of Jupiter was a different one, 2 billion years ago. No, I think it was, but I think it used to be a lot closer. and then it moved out through collisions and near collisions. I think Jupiter used to be in a different orbit. I know Uranus rotates about its axis in a way that's sideways compared to the other planets.
Starting point is 00:08:55 What I'm not sure of what I think happened is that Uranus and Jupiter collided at some point. I suspect that Jupiter has been in its current orbit for quite some time. speaking on the scale of the formation of our solar system, but I would not at all be surprised if it had moved around somewhat during the early formation period of our solar system. I would say yes. Well, nothing is permanent, so I guess it's, at the origin, it was part of the sun or giant cloud of gas. But to me, well, it's quite stable orbits. and I don't see why it changed except for minor changes such as
Starting point is 00:09:43 a collision with other objects, but I would say yes. No, no. Jupiter at some point was heading towards the sun but it kind of got locked in by Saturn
Starting point is 00:10:04 probably in interaction with Saturn or something like that. I don't know 100% now you coughed me of guard here. I don't think that Jupiter has always been in its current orbit. I think it formed much closer to the sun. And as it migrated out into the solar system, it cleared a lot of the debris and comets and asteroids and dust
Starting point is 00:10:28 and everything out of its way and made things a little bit more stable here in the inner solar system. So life could form. but I don't think that it started out where it currently is. I'm going to say no, but I guess being it's so big, it could well have picked up a lot of stuff through its time, and as it picks up more stuff, gets impacted, and I guess its gravitational forces would interact with other planets and stuff around,
Starting point is 00:10:56 so therefore it'd get knocked off and moved off its orbit quite regularly, maybe. I think almost certainly no. I think the current model of how those solar, system was formed, actually relies on Jupiter migrating inward, closer to the sun, and then further away. I believe Jupiter has moved from its original orbit. I think the original orbit was closer to the sun. All right. Wow. Those are some great answers from our listeners. When you heard that this was even a question that people were thinking about, did you have a like, oh my gosh, moment? Or did it just seem like an obvious question for you to be asking.
Starting point is 00:11:39 I had an oh my gosh moment and a hope because I thought, ooh, that would be super cool if Jupiter wasn't always in its current orbit. Because one of the fun things for me in science is revealing surprises, right? If you ask a question and then the answer is, oh, yeah, it's kind of boring. Jupiter's always been there. That's not nearly as fun as, oh my gosh, it turns out there's a crazy history here and we have revealed it. Like you were saying earlier, it's incredible that we could like by gathering small, clues left by these crazy cosmic events actually reconstruct something that happened billions of
Starting point is 00:12:12 years ago. It's like solving a billion-year-old murder mystery. As a biologist, every once in a while we will have discussions about what makes humans different than other animals. And clearly being able to think about questions like this is one of those things that, like, certainly we're the only species who's wondering that on our planet. Exactly. So it's super fun. And I was really hoping that the answer would be something crazy. So it's pretty interesting to learn about. And I've also really been enjoying following this exil planet discovery, seeing these other solar systems, these other like potential homes for aliens where life could be really different because the planets are so different from ours. We're sort of like trapped in this colloquial way of thinking that our kinds of planets
Starting point is 00:12:56 are the kinds of planets. You have like small rocky planets in the inner solar system and big gas giants and the outside. But now it's possible to imagine other kinds of scenarios. So is our configuration a typical configuration? It turns out it's not. When we look at other solar systems, we see something really weird. First of all, we see that most solar systems have a lot more planets very close to their star. Like between Mercury and the Sun, there's basically nothing. But in other solar systems, there are lots of planets packed in there. And in particular, we find these things called hot Jupiters, not hot because they're like, you know, big on Instagram or they're really curvy, hot because they're really close to the sun.
Starting point is 00:13:38 Like, we find these planets and other solar systems that are really big, like Jupiter size and gas planets, but they orbit the star in just like hours or days and like a fraction of the distance between the sun and Mercury. So that's a really weird phenomenon to see. Shouldn't they like suck each other into each other pretty quickly? What's the good physics word for that? How do they stay separated if they're both huge and attracting each other and are so close? No, suck each other in is exactly the right physics word to use.
Starting point is 00:14:07 And that's exactly the question people are asking. They're like, hold on a second. How do you get such a big planet so close to the sun? Can it last very long? Are we seeing something just before it dies or can that be a stable configuration? And the models suggest that they can't have been born that close to the sun and they can't last there very long. And that's the clue that got everybody. talking and thinking about whether planets are moving because they suspect that these hot
Starting point is 00:14:32 Jupiters form further out and then get sucked in. And so we're witnessing sort of like the end of the life cycle of these planets before they either get torn apart or pulled in. And that's a clue that like solar systems are volatile. There is stuff going on. It's not just everybody sedately driving in their lane for billions of years. Huh. Is Jupiter going to get sucked into our sun? Not before the sun explodes, right? Are you worried about Jupiter? Have you like invested in real estate on Jupiter? Well, you know, I was thinking about it. We've been reading about space settlements, but no, obviously not. Nobody's going to go live on Jupiter. But maybe it's moons. I once read a fantastic series in science fiction novels about a civilization in the upper clouds of Jupiter.
Starting point is 00:15:11 I think it was called Bio of a Space Tyrant. Man, I loved those books when I was a teenager. It was so, like, fantastically imagined. So I hope that one day humans do get to live on Jupiter, and I hope that we get to keep Jupiter because I like it. I mean, Jupiter is pretty. For all the press that like Mars gets recently, Jupiter is a gorgeous planet. So maybe we should start by thinking about our solar system and understanding what we know about Jupiter, like where it was made, how it got formed, and that can give us a clue for like why people think there might have been crazy stuff going on in our solar system at the very beginning of time.
Starting point is 00:15:47 All right. So tell me about how Jupiter got to be where it is. Yeah, so we think Jupiter was probably born out in the outer solar system. There's this point in the solar system called the Iceland. line, where beyond that, it's cold enough for ice to form and to stay melted and basically be like a rock that you can use in building planetary cores. And it's about like three and a half AU, where remember, AU is at one astronomical units, the distance between the sun and the Earth.
Starting point is 00:16:15 So three and a half times the radius of the Earth, beyond that is the ice line. Some people call it the snow line. And out there, it's easier to make big planets because there's ice available to add to your core. So we think that the way the solar system started, obviously you have a big blob of gas and dust and some shockwave comes through it and you get the spark that begins the formation of the whole solar system, which basically means the sun. But the sun is gathered together a huge amount of gas and it has around it a big swirling disk. And that's the disc that's going to provide the material that forms all of the planets. Now out past the snow line, there's also ice in there. So the
Starting point is 00:16:57 ice and the rock and the dust gather together to make these protoplanetary cores, they start pulling themselves together, and that sort of seeds the planets. And so we ended up with, what, four planets out past the ice line? Is that pretty common? Like that number and like the size of our planets? Does that match up with what we see in other solar systems? We don't know the answer to that yet. We haven't seen enough. But also remember that we can see a bunch of solar systems, but we're not that great at seeing all of them and there's certain kinds of solar systems that are easier to see. It's easier to see big planets that are closer to their sun because they block more of the sun's light. The way we see these exoplanets is that they block the light of their sun or they tug gravitationally on the
Starting point is 00:17:41 sun. So big planets are easier to see. Close up planets are easier to see. So far out planets harder to spot. Far out small planets harder to spot. Does that mean that like super slow moving things. We probably don't have good data on yet because we wouldn't have had a chance to see them pass in front of the sun or tug it as it moves around to the side. That's exactly right. Yeah. We have to watch these things cross their sun. And so basically it's best if you can see them pass a few times. So you can see like a regular interval. So the equivalent of several of their years. But if their years take like, you know, a hundred earth years to go around, then we're not going to have had time to see it. So slow moving things, small things, things far from their
Starting point is 00:18:21 sun are harder to see. So that's a long way of saying we don't have an unbiased picture of what's going on in these other solar systems. And we have to try to play this game of wondering like, well, if we see only one of them, do we imagine that there are a thousand? Or if we only see two of those, do we imagine there are a hundred? We have to estimate like how good we are seeing them so we can like invert that and imagine what's actually there that we're missing. But there's a lot that we're missing still. Interesting. Yeah, it's really fascinating. And so that's why we focus on our solar system because it's here, it's relevant, and it's one that we can study in great detail. But those other solar systems do give us a lot of clues. Back to Jupiter, we think that it must
Starting point is 00:18:58 have had to form in the outer solar system because that's basically only place to make these big gas giants. I mean, you need enough ice and enough rock to pull together to make this big core to grab a bunch of gas. Remember, everything in the solar system is competing with the sun. In the inner solar system, there's not that much gas left because the sun has slurped it all up. So to make a gas giant, you really have to be far enough away from the sun to get any of the gas, and you have to be past the snow line so you can have ice accumulate in your core and get big enough that you can grab some of the gas before all spirals into the sun anyway. Okay, so Jupiter was formed in the outer solar system, and it's still in the outer
Starting point is 00:19:40 solar system. So after the break, let's talk about why we think it moved. 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. Ambulance is just a chaotic, chaotic scene.
Starting point is 00:20:22 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 we're you get your podcasts. I'm Dr. Joy Harden-Brandford, and in session 421 of therapy for black girls, I sit down with
Starting point is 00:21:00 Dr. Othia 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 hyper fixation 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 communities, the pressure to always look put together, and how breaking up with perfection can actually free us. Plus, if you're someone
Starting point is 00:21:39 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 IHeartRadio app, Apple Podcasts, or wherever you get your podcast. Get fired up, y'all. Season two of Good Game with Sarah Spain is underway. We just welcomed one of my favorite people and an incomparable soccer icon, Megan Rapino, to the show, and we had a blast.
Starting point is 00:22:06 We talked about her recent 40th birthday celebrations, co-hosting a podcast with her fiancé Sue Bird, watching former teammates retire and more. Never a dull moment. with Pino. Take a listen. What do you miss the most about being a pro athlete? The final. The final. And the locker room.
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Starting point is 00:22:50 on the Iheart radio app, Apple Podcasts, or wherever you get your podcasts. Presented by Capital One, founding partner of IHeart Women's Sports. I'm Dr. Scott Barry Kaufman, host of the psychology podcast. Here's a clip from an upcoming conversation about exploring human potential. I was going to schools to try to teach kids these skills and I get eye rolling from teachers
Starting point is 00:23:12 or I get students who would be like It's easier to punch someone in the face. When you think about emotion regulation, like, you're not going to choose an adaptive strategy which is more effortful to use unless you think there's a good outcome as a result of it, if it's going to be beneficial to you. Because it's easy to say, like, go you, go blank yourself, right? It's easy.
Starting point is 00:23:32 It's easy to just drink the extra beer. It's easy to ignore, to suppress, seeing a colleague who's bothering you and just, like, walk the other way. Avoidance is easier. Ignoring is easier. Denials is easier. drinking is easier, yelling, screaming is easy. Complex problem solving, meditating, you know, takes effort.
Starting point is 00:23:52 Listen to the psychology podcast on the IHeartRadio app, Apple Podcasts, or wherever you get your podcasts. Okay, so, Jupiter is where we would expect it to be, given how we expect it to be, given how we expect that it formed. So why would we suspect that it had moved at any point? Yeah, it seems at first like it might be a simple story, right? Jupiter had to form somewhere in the neighborhood where it is today. And so the simplest explanation is, well, maybe it just formed there and stayed there. Why do we imagine it ever took a tour in the inner solar system? And the reason is that the inner solar system looks weird. Like we can't explain the inner solar system in that picture. Our models of how the solar system came together, we run a bunch of like simulation
Starting point is 00:24:42 and try to explain how we got Venus and Earth and Mars. None of the models that we run actually match up with what we see. How are they different? Well, in particular, Mars is really weird. Like, Mars is a nice little planet, but it's really small. Like, Mars is like 10% of the mass of the Earth. That's a really small planet. And in all our models of the solar system, Mars should be a lot bigger.
Starting point is 00:25:07 Like, as you get further out from the sun, there's more material available because the sun hasn't stolen at all. And so you expect a planet forming around there to be like about the size of the Earth or even bigger. You know, as you go to the outer solar system, things get bigger, right? So why is Mars so tiny? Why is it so little? So as you get farther out in the solar system, things should get bigger, but Jupiter is the biggest and it's not the most far out. So why is Saturn smaller than Jupiter then? Oh yeah, that's a great question. There's a whole other fun story about how Saturn Jupiter may be switching locations and the whole dance of Uranus and Neptune that they might have done, but you're right, there's a balance there because you want to be far enough
Starting point is 00:25:44 away from the sun so it doesn't steal all the material, but as you get even further away from the sun, you run out of material also, right? Obviously, there aren't like super giant planets twice as far away as Jupiter. And so there's something of like a peak location there. Jupiter's probably sitting right there in the spot where you can make the biggest planet. But the question remains like, why is Mars so little? What happened to make Mars so tiny? And it's not just Mars. Like, the asteroid belt is also kind of weird. Like we don't really understand how it formed the way it did. Again, we run these models that start from just the gas cloud and you don't get an asteroid
Starting point is 00:26:19 belt that looks the way it does. Specifically, our asteroid belt is weird because it has both like rocky objects. It seemed like they came from the inner solar system. Plus, they have a bunch of icy objects, the kinds of things you would find like in the Kuiper belt or deeper further out in the solar system. So there are these like pieces of evidence. You were talking earlier about like how good. we possibly find clues about things that happened so long ago.
Starting point is 00:26:42 Like, these are the things that have puzzled scientists for a long time. So is the asteroid belt inside the ice line or on the Jupiter side of the ice line? Yeah, the asteroid belt is really weird, actually. Part of it is inside the ice line, the part that's like closer to Mars. Remember, it sits between Mars and Jupiter, but it also extends kind of far out. And part of it actually is in orbit with Jupiter. Like, it's not all between Mars and Jupiter. There's these big blobs of asteroids that are in Jupiter's orbit just sort of like rotated away from them.
Starting point is 00:27:13 Like, you know, 30 degrees around to 30 degrees the other direction. And stuff is sort of like sloshing back and forth. So some of it's definitely out there past the ice line and can stay frozen and some of it's a little bit closer in. Huh. Interesting. Yeah. And so we have these mysteries. And I love that this is like the way we do science. You know, we say, well, we think we understand how the solar system works, but let's double check. Let's run a bunch of models and see if what we get matches up with what we actually expected.
Starting point is 00:27:43 And when you see those weird deviations, when you see something that doesn't make sense, that's when you know you might have found something. So it's like when your model doesn't work is a potential discovery moment. And isn't that how we figured out, how humans figured out that was it Neptune was out there? Something was not working mathematically. So there had to be another planet out there. Exactly. Yeah.
Starting point is 00:28:03 There's all these times when something hasn't quite worked, just like you're saying, orbits of the planets don't quite make sense. And that's been a clue as to like a huge discovery. But it always makes me think about like all the other times when your model doesn't work. And it's just because like you have a bug or you did something stupid, you know, and you can't be like, oh my gosh, maybe I've discovered something fantastic. Sort of frustrating part of science. Yeah, usually for me it's just a bug. But I'll keep pulling out hope. We have that experience all the time at the large Hadron Collider because we're always on the lookout for something unexplained, something new.
Starting point is 00:28:36 something weird, some new particle that we've just created, or a mini black hole or something, and it might be evidenced by some deviation in the data compared to what we expect. But we see that all the time, especially young students make mistakes, and they see something weird and like, oh my gosh, did I discover something? Like, yeah, well, you discovered that you don't know how to run this program correctly. You discovered that you're missing a bracket, but. Yeah, exactly. You discovered that bugs are easy to insert in programs.
Starting point is 00:29:04 But also, you don't want to squash their enthusiasm, right? It's wonderful to see this in young scientists to imagine that they could be the ones making some discovery. This could be a historic moment. So I like to tell them stories like this because it does actually happen sometimes, right? Sometimes we run these models and we see something weird and it means something real about the universe. Awesome. We can all keep our fingers crossed that we'll have those amazing moments where it's not you not being smart enough. It's actually the universe revealing herself to you.
Starting point is 00:29:31 And so we're trying to understand like how our solar system got to be weird the way it is. why don't we have a bunch of other planets close to the star? Why is Mars so small? Why is the asteroid belt the way it is this weird mix of rocky and icy objects? So we've taken clues from these other solar systems that have big planets really close to their star. One idea initially was like maybe Jupiter was formed close to the sun and then like drifted out. And along the way sort of messed up things in the solar system. But you just told us that it needed to be out there where there's ice in order to form.
Starting point is 00:30:05 could it have possibly formed near the earth? People spent a while trying to cook up these models and wondering, like, maybe there's a way to have a hot Jupiter that survives, or maybe there's a way to form a planet really close to the star. Maybe there are other methods. So, you know, this idea of how you form a Jupiter is sort of one model, but there are other models. There's like, you know, gravitational instabilities that maybe stuff smashed together
Starting point is 00:30:28 to make like an unusually large object, which then, like, gathered together a bunch of stuff. And people have been working on these things and trying to put them, together. And, you know, this is the kind of creativity that's inspired by basically a mystery. But it doesn't seem to really be working. Like, there's just not enough gas and not enough mass close to the star. And also, it's just too warm. Like, a lot of this stuff, if you did happen to form a big object, would get blown apart by the sun. The sun just, like, boil the gas off of that planet. And it also probably just, like, pull it apart by the tidal forces. Remember,
Starting point is 00:31:02 the sun has a lot of gravity and it tugs on everything. thing. But if you're a really big object, it's going to tug on the part of you that's closer to the star more than it tugs on the part of you that's far from the star. And that's effectively the same thing as trying to pull you apart. And that's why, for example, you get close to a black hole, you won't survive because you'll get pulled apart by the relative difference in the gravity at your feet and at your head. It's called spaghettiification. One of the best physics words out there. And so now imagine like making a big gas giant. You've accomplished the impossible. You formed a gas giant close to your star. What's going to happen, the star pretty
Starting point is 00:31:40 quickly is going to spaghettify Jupiter. And like, that's a lot of spaghetti. I'm there for that. I love spaghetti. So are people still work on that question or have scientists pretty much decided like, okay, this is not the answer. There's always somebody still working on that question. There are people out there who think that it might have been possible to make a Jupiter close to the star and they're working on their models. And in that line of thinking, they're hoping that you've made this Jupiter close to the star and that it's somehow we don't know how then drifted out to the outer solar system and in doing so has perturbed the asteroid belt and in doing so has like stolen a lot of the material that might have made Mars but I don't think that it's a mainstream idea I mean there's
Starting point is 00:32:22 somebody out there you know smoking banana peels and thinking about it and I encourage that and that kind of creativity is wonderful and you know diversity of ideas is also very very important for the scientific method. But I don't think the leading idea is that you form a hot Jupiter close to the sun and that it then drifts out into the outer solar system. Okay. So it started in the outer solar system and then it went on a cool vacation towards the sun and decided it preferred skiing. Yeah. And so we don't think that this idea of it starting in the inner solar system and moving out makes much sense. And another clue is that when we look at these other solar systems, the ones that have hot Jupiters and we wonder, like, how are they made and how could that survive?
Starting point is 00:33:09 There's some evidence that what we're looking at are really young solar systems, solar systems that haven't been around for very long. And so one explanation for how hot Jupiters even exist is that they're transient, that they're going to be absorbed by the star, that we're seeing them before they get spaghettified and sucked in and basically just become part of the star. Because we don't tend to see hot Jupiters in older solar systems. Ah, so it started in the outer solar system. It got sucked in, and we are seeing it at a point where it is sort of in the process of soon to be absorbed by the sun. Is that right? That's the leading explanation for why we are seeing hot Jupiters in other solar systems. But, you know, of course, that doesn't answer the question of our solar system, because we don't have a hot Jupiter, right? But we still have to explain what happened in the inner solar system. So we have Jupiter starting in the outer solar system. We think that makes more sense. We don't have it currently in. the inner solar system. So then there's this question of like, well, how could it have perturbed things in the inner solar system? You know, it's sort of like got an alibi. It's like,
Starting point is 00:34:10 I was born here and I'm still here. Why are you looking at me? Right. Okay. So the progress we've made so far is that there's an explanation that we don't think is right. So let's try another explanation and see if we can maybe solve some of the problems with what's happening with Mars and the asteroid belt after we take a 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.
Starting point is 00:34:56 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.
Starting point is 00:35:25 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. I'm Dr. Joy Harden-Brandford, and in session 421 of Therapy for Black Girls, I sit down with Dr. Ophia 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?
Starting point is 00:35:54 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 hyper fixation 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,
Starting point is 00:36:16 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 Neal-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. Get fired up, y'all. Season two of Good Game with Sarah Spain is underway. We just welcomed one of my favorite people and an incomparable soccer icon, Megan Rapino, to the show.
Starting point is 00:36:49 And we had a blast. We talked about her recent 40th birthday celebrations, co-hosting a podcast with her fiancé Sue Bird, watching former teammates retire and more. Never a dull moment with Pino. Take a listen. What do you miss the most about being a pro athlete? The final. The final. And the locker room.
Starting point is 00:37:08 I really, really, like, you just, you can't replicate. You can't get back. Showing up to the locker room every morning just to shit talk. We've got more incredible guests like the legendary Candace Parker and college superstar A.Z. Fudd. I mean, seriously, y'all. The guest list is absolutely stacked for season two. And, you know, we're always going to keep you up to speed on all the news and happenings around the women's sports world as well.
Starting point is 00:37:32 So make sure you listen to Good Game with Sarah Spain on the IHart Radio app, Apple Podcasts, or wherever you get your podcasts. Presented by Capital One, founding partner of IHeart Women's Sports. I'm Dr. Scott Barry Kaufman, host of the Psychology Podcast. Here's a clip from an upcoming conversation about exploring human potential. I was going to schools to try to teach kids these skills, and I get eye rolling from teachers or I get students who would be like, it's easier to punch someone in the face. When you think about emotion regulation, like, you're not going to choose an adaptive strategy
Starting point is 00:38:06 which is more effortful to use unless you think there's a good outcome as a result of it if it's going to be beneficial to you. Because it's easy to say like, like go you, go blank yourself, right? It's easy. It's easy to just drink the extra beer. It's easy to ignore, to suppress, seeing a colleague who's bothering you and just like walk the other way. Avoidance is easier.
Starting point is 00:38:24 Ignoring is easier. Denials is easier. Drinking is easier. yelling, screaming is easy. Complex problem solving, meditating, you know, takes effort. Listen to the psychology podcast on the IHartRadio app, Apple Podcasts, or wherever you get your podcasts. Okay, so we feel pretty confident that Jupiter started in the outer solar system, and it didn't start in the inner solar system and then move out.
Starting point is 00:38:58 So if it started in the outer solar system and it's still there now, does that mean at some point Jupiter sort of toyed with the idea of a summer vacation and then decided it preferred the cold and went back to go skiing? Did it come to the sun and then leave? I know this is that moment in the murder mystery where you're like, hmm, this person was home all evening. Hold on a second. Do we actually have a way to account for all their whereabouts? Could they have snuck out and committed the murder and then come back in time? How fast are those trains? We can't leave Jupiter in the outer solar system for its whole history, but now we have a
Starting point is 00:39:32 crazier idea, which is maybe Jupiter did trend into the inner solar system, just like all those other hot Jupiters were seeing in other solar systems, but that it stopped and it turned around and it went back out to the outer solar system. So this is called the Grand TAC hypothesis, seeing Jupiter's like a sailboat that like sailed into the inner solar system and then sailed back out. This is blowing my mind. So let's break it into two parts, I guess. So how did it get pulled in just through the typical gravity pulled it in?
Starting point is 00:40:05 Yeah, so you have to cast your mind back to the very, very early days of the solar system. Solar system we think is about four or five billion years old. And we're talking about things that happen in the first few million years. You shouldn't be imagining a bunch of planets around a star. You should be imagining a star and then a huge disk of gas and dust. And then inside that gas and dusk were forming planets, but they're not like clear. They're not like totally separated. If you were doing astronomy back then, you would have had a really hard time seeing any planets
Starting point is 00:40:34 because there's so much gas and dust everywhere. So the beginning of the story in the first few million years is that like proto-Jupiter has formed, but it's not as far out as it is now. It's only like three and a half AU, like right there on the snowline. As we were saying earlier, like the peak place to make a gas giant is just past where things freeze. so you can gather ice and rocks and dust, but not so far out that things are getting dilute. So Jupiter forms there, and then it drifts into the inner solar system. And so you're asking, like, what makes that happen?
Starting point is 00:41:06 Is it just the sun's gravity? And, you know, anything can orbit stably. The sun obviously has a lot of gravity, but the reason, like, the Earth is not falling into the sun right now is that we have a lot of speed. We're in a stable orbit. So we think Jupiter probably was in a stable orbit, but remember, it wasn't on its own. it's still surrounded by a lot of gas and dust that hasn't gotten pulled into any planet. So the idea is that it interacted with that gas and dust, which basically slowed it down
Starting point is 00:41:33 and started falling in towards the sun. That must have been very scary for Jupiter. I know it's like this inextricable fall, right? You know that you're like rolling in towards this huge burning ball of plasma. And there's basically nothing you can do about it. So very dramatic moment. And these gases eventually, you know, spiraled in and they fell in. into the sun. And Jupiter was spiraling it also. And so the idea is that it passed through the
Starting point is 00:41:59 inner solar system. And along the way, it gobbled up a lot of material, which eventually would have otherwise led to a larger Mars. How far in did it go? Did it get like Earth close or just Mars close? Not quite Earth close. We think that it came into like about one and a half a new. And that's why we still have Earth at a pretty reasonable size because Jupiter came in and it either like gobbled up the material to make Mars or scattered it and threw it into the sun. But the things in the inner solar system were a bit more protected. Okay, so part of Jupiter should have been in Mars. It's like those twins, you know, where like one of them eats the other one and you still have like a jaw or whatever inside the body of the adult. Those are the craziest stories. I don't think
Starting point is 00:42:43 they're actually eating the other one. But yes, I know where you're going with that. What? You don't believe in the evil twin theory that twins can eat each other in the womb? I was reading about this the other day. And I think it's the like absorb eating suggests a bit more intention than I think is actually happening in there. You know, I'm going to use that next time I eat my kids cookies. I'm like, I didn't eat your cookies. I just absorbed them. And Kelly, the biologist, she tells me that's different. And then your children remind you that you are not a fetus. You're a grown man who can make decisions. And so, you know, let them know that they can call me if they need. back up. All right. I'll give them your number. Anyway, so Jupiter's out there like
Starting point is 00:43:21 unintentionally absorbing the materials that Mars would have needed to get larger and scattering a bunch of other stuff. And so it came into about one and a half AU. And that actually explains a lot about what's going on in our inner solar system. That's why there are no like other rocky planets after Mars. We think there might have also been other planets out there that were forming that Jupiter just like nudged into the sun. So why did it nudge them into the sun as opposed to pulling it into Jupiter? Yeah, we don't know. It could have been either fate, right?
Starting point is 00:43:52 This is very chaotic. And so it depends exactly on how big they were and how they were aligned. And so the fate of these planets could be like fall into the sun or get absorbed by Jupiter or even get tossed out of the solar system entirely. Like Jupiter is a big bully, right? It's so much bigger than Earth and Mars and it comes in. And it doesn't take very much to really disrupt the inner. solar system.
Starting point is 00:44:15 Hmm. Okay. And so how does this describe what happened or does this help explain what happened with the asteroid belt? Yeah. So it actually all really fits together beautifully because to explain the asteroid belt, you need Jupiter to get back out to where it was, right? The asteroid belt has rocky stuff in it from the inner solar system, but also icy stuff
Starting point is 00:44:36 from the outer solar system. And so if you could somehow turn Jupiter around, right, we've seen all these other solar systems also that these big gas giants sometimes fall slowly in towards the star and we think that in most cases probably they just end up inside the star. They didn't happen in our case. So we need Jupiter and move somehow to the outer solar system. And in doing so, we think that it will have disrupted the asteroid belt and also disrupted the Kuiper belt and like pulled some of those objects towards the inner solar system. So that the asteroid belt then has like a weird mixture of these like further out objects and these inner objects.
Starting point is 00:45:12 And that's why we see these like icy objects and rocky objects in our asteroid belt. If we can get Jupiter to go in and then come back out. That's fascinating. So now how you told us that Jupiter probably slowed down and that's what caused it to get pulled in. So for Jupiter to go back out again, what is required for that? Does it have to start speeding up and then also kind of get nudged? Why did it leave? Well, Jupiter, we think, probably was saved by its friend Saturn, because Saturn has the same fate, right?
Starting point is 00:45:45 Saturn, also a big gas giant, also probably surrounded by big swarming clouds of gas, getting slowed down, drifting in towards the inner solar system. So imagine Jupiter like the big brother and then Saturn like the younger sister or the younger brother following in behind it, having sort of the same fate and seeing what's happening to Jupiter. But the calculations suggest that it's possible that as these two things get close to the inner solar system, that they then start tugging on each other and that their gravitational interaction makes this weird resonance where they're pushing on each other and they're passing around the sun, they're tugging on each other in the same way. So they do this like weird dance. Like imagine two people spinning and both letting go and they get flown out of the inner solar
Starting point is 00:46:27 system. I know it's crazy. It's like Saturn like dove in after Jupiter and saved them both, right? They could have ended very badly. Yeah, there's got to be a buddy comedy that could be written about this or something. That's wild. Exactly. And so that's maybe the story that Jupiter started in the outer solar system, got tugged in as it got slowed down by all this gas, and then got saved by Saturn.
Starting point is 00:46:51 And that would explain why Mars is so small. And it would explain why the asteroid belt has the weird composition that it does have. And so is that the only explanation we have for how Jupiter? got thrown back out again, or is that just the top explanation right now? That's the top explanation. And we don't think that it's very unlikely. I mean, we think that in most cases, when you have a big gas giant that falls towards your star, it ends in the way you would expect that it falls towards the star and gets gobbled up. And so in most solar systems that have basically a Jupiter, we think that it doesn't last for very long. So that means that our solar system
Starting point is 00:47:27 is probably weird, right? That we're unusual for keeping this big gas giant and having it back in the outer solar system in a stable way. After all the gas and dust have cleared out, now Jupiter can go back out to the past the ice line and hang out for billions of years. That would suggest that the reason we're weird is because we also have a Saturn. So do other solar systems without hot Jupiters also have a Saturn equivalent? Yeah, great question. I don't think we know the answer to that because these planets are much harder to spot. We're talking about things five, six, seven, A.U that only passed their sun every few years, right? Like, if you were observing our solar system from really far away, Jupiter and Saturn would not
Starting point is 00:48:09 be that easy to spot because while they're pretty big, they're also really far away from the sun, and it takes them years and years to orbit. So you would have to be watching our solar system for a long time with a really good telescope before you discovered Jupiter and Saturn. So that's not something that we're really sort of good at knowing about other solar systems yet. So far, we mostly know what's going on in the inner solar system for big, fast-moving planets around their star. So astronomers have like incredible job security because we're going to need to watch for hundreds of years to get these data. And surely the government's going to pay for all of that. Exactly. Yeah. It's incredible what we have learned so far.
Starting point is 00:48:46 You know, we've learned so much about how our solar system is weird to compare to the other solar systems that's out there. And that's sort of like cool. Like, hey, our solar system is awesome and special. It's also a little bit disheartening because if you believe in aliens or you want to believe in aliens and you want to think that there are lots of opportunities for life out there, it makes the story a little bit harder because to have a solar system like ours and a planet like ours, you need this sort of special thing to happen, this dance of the two gas giants to clear out the inner solar system and then also save themselves and be in the
Starting point is 00:49:22 solar system. You know, we think that Jupiter probably protects the Earth from a lot of sort of incoming bombardment because it's so big. It's like hoovering up all the comets and other stuff. So it's a special configuration we have. You've kind of bummed me out. You know, at the beginning of this conversation when we were talking about how big our data set is, I was thinking, all right, that's got to be good for the Drake equation. You know, we're like adding all of these possible solar systems that might have Earth-like planets. But now what you're telling me is probably a lot of the ones that are out there don't have Earth-like planets. And now I'm kind of bummed.
Starting point is 00:49:57 Yeah, a little bit. And we've been excited to find what we thought were Earth-like planets in these other solar systems. One's about the right radius, about the right distance from the star. But what we don't know is if they really have the right composition to be in Earth. You know, it might be that Jupiter came through the inner solar system and it cleared out a lot of gas, et cetera, et cetera. And so we ended up with a planet just the right combination of stuff.
Starting point is 00:50:20 to have life. If Jupiter hadn't come through the inner solar system, Earth might have been a little bit bigger and there might have been more gas. So we might have ended up with a very different composition. You can imagine like a super earth that's like choked in hydrogen instead of having the atmosphere that we have. You know the way like Venus is just like choked in CO2. It's very oppressive. And so it might be that a lot of the planets we're seeing in these other solar systems are not actually sort of habitable in the way that we would hope for. They're not really copies of Earth. They might have the right size roughly and being roughly the right position, but that doesn't mean they have the same conditions as Earth. Man, we're lucky. Oh, we're special.
Starting point is 00:51:02 We're special. I'm going to go with lucky, but maybe life is better if you go with special. So did Jupiter go back to where it came from, or did it end up a little closer or a little farther out than where it was before? It ended up a little farther out. It's like, it wanted to go out in the excerpts. You know, it was born in the suburbs, and it came to the inner city, and then it decided in its retirement, it wanted to live further out. So it started out of three and a half AU, came in probably at about one and a half, and now it's comfortably out around 5.2 AU. I can totally understand how Jupiter feels. I was born in the suburbs and then I moved to a big city and now I live out in the country where nobody else is. So I feel you, Jupiter.
Starting point is 00:51:41 Well, it takes a lot to feel Jupiter. And the story doesn't end there. What we talked about is like the first few million years of the solar system, but there's still a lot of interesting planetary dynamics that need to be explained. Like, we think that maybe Uranus and Neptune switched places at some point and that Jupiter and Saturn may not have sort of ended up where they are now, that it may have taken a little while and they may have also done some later migrations. We're talking like 500 million years after the start of the solar system. So we like to think about the solar system as sort of like, it is what it is and it's been
Starting point is 00:52:15 what it's been. But if you did it like in time lapse over like hundreds of minutes, millions of years, it would seem pretty chaotic. It would seem like, wow, there's really something happening there. So this idea of Jupiter moving in and out, is this like totally accepted by the mainstream? Or is this just sort of a theory that some people ascribe to? How broadly is this idea accepted? Yeah, it's somewhere in between. The astronomers I spoke to think it's like probably the most plausible explanation. But, you know, there's a lot of details still to get right. And our models are just going to keep getting better and better.
Starting point is 00:52:51 And then we could ask more and more detailed questions. And right now the models explain Mars, but as we make those models better, we can ask more specific questions about like, why does Mars have the composition that it does? And why does it get exactly this small and not larger? And maybe as we do those studies, we'll find discrepancies and things that don't work and then we'll need to modify this model. Or maybe there's some other crazy part of this story that we haven't even thought of yet that could be revealed by some little detail that some student uncovers.
Starting point is 00:53:21 So given the gaps in our data sets, which are caused by things that are hard to remove, like really, really slow moving planets, what do you think the chance is that by the time you and I are, you know, retiring, that we'll be able to say like, definitely that's what Jupiter, or, you know, maybe we'll never be able to say definitely. But we feel super confident that that's what Jupiter did. Is this a problem that could get solved soon? or are we looking at decades and decades before we can really get a good answer? Well, that depends, Kelly.
Starting point is 00:53:49 How long until you plan to retire? I'm not sure I'm ever going to retire, but, you know, the average age of a woman in the U.S. when they die is, what, 87 is something like that? So that timescale. I think that our understanding of our solar system and other solar systems is going to be continually revolutionized basically every 10 years for the next 100 years because we are just at the very beginning of understanding how these. things work because we've just started to look and to see these other planets and we're going
Starting point is 00:54:19 to find lots more surprises once we develop telescopes that are better at these things once James Webb launches and teaches us more about cold planets. James Webb is an infrared telescope that can see things that are not just quite as hot that can see like cold disks of protoplanetary formation and actually maybe individual planets that glow in the infrared. So we have a lot more information coming And if the universe holds true to its reputation, it will be filled with surprises that upend our ideas. So probably by the time we retire, people will look back at these ideas as quaint and goofy. And they will have a much more interesting idea, probably filled with dramatic events we haven't even considered. You know, it's a really fascinating time to be alive with the kinds of data that we're able to collect right now.
Starting point is 00:55:06 It really is. It's a kind of time that makes me just want to like live another 10 years because the things we're learning are just blow. our minds, you know, it makes me wonder, like, what would a children's book about the solar system say in a hundred years, right? Like, I would love, I would kill to travel forward in time and steal children's books about science. Well, this suggests that biology needs more funding because we need people to be working on the problem of immortality. Don't give me that. On my campus, we have like 10 times as many biologists as physicists already. All right, all right, fair enough. But I love biologists. Literally, I mean, I'm married to one. So I'm definitely
Starting point is 00:55:42 pro-biology, more funding for all the sciences so we can unravel these amazing mysteries of the universe. There you go. Agreed. All right, something we can agree on. So thank you everybody for joining us on this tour of the early days of our solar system, the dramatic story of Jupiter's visit to the inner solar system and how it might explain everything that we're seeing, all the mysteries about the size of Mars, and the composition of the asteroid belt. Thank you very much for sharing your curiosity with us. And thank you again to Kelly, our wonderful guest host for joining us on today's episode. Thanks for having me on the show and thanks for listening everyone. It was a lot of fun. All right. Tune in next time.
Starting point is 00:56:42 Smokey the bear Then you know why Smokey tells you when he sees you passing through. Remember, please be careful. It's the least that you can do. Because it's what you desire. Don't play with matches. Don't play with fire. After 80 years of learning his wildfire prevention tips,
Starting point is 00:57:11 Smoky Bear lives within us all. Learn more at smokybear.com. And remember, only you can prevent wildfires. Brought to you by the USDA Forest Service, your state forester, and the ad council. Tune in to All the Smoke Podcast, where Matt and Stacks sit down with former first lady, Michelle Obama. Folks find it hard to hate up close.
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Starting point is 00:57:50 Search All the Smoke and listen now. Culture eats strategy for breakfast, right? On a recent episode of Culture Raises Us, I was joined by Belisha Butterfield, Media Founder, Political Strategist, and Tech Powerhouse for a powerful conversation on storytelling, impact, and the intersections of culture and leadership. I am a free black woman. From the Obama White House to Google to the Grammys, Valicia's journey is a masterclass in shifting culture
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