Speaker 1: Hey, Kelly, how do you feel about moving? It always
Speaker 1: seems like it's going to be exciting, but it's always
Speaker 1: a drag. No. Right, It's like there's always one more
Speaker 1: box of stuff, and by mathematical induction, that means we
Speaker 1: all have infinite totally checks out. I mean I have
Speaker 1: like infinite back pain from my last move. Sometimes I
Speaker 1: wish I had a mobile home so that I wouldn't
Speaker 1: have to pack everything up every time. That is a
Speaker 1: genius solution. I mean, you move more stuff, but you
Speaker 1: do less work because you take your whole house with
Speaker 1: you exactly. I wonder if it's scales. I'm thinking like
Speaker 1: mobile neighborhoods, mobile cities, maybe like mobile planets. Earth is
Speaker 1: just one big mobile home. Man, I didn't realize we
Speaker 1: lived in a cosmic trailer park. I'm Daniel, I'm a
Speaker 1: particle physicist, and I once moved across the Atlantic eleven
Speaker 1: times in four years. Seriously, seriously. This was when I
Speaker 1: was a junior professor and just getting started at the
Speaker 1: Large Hadron Collider and teaching on the West coast of
Speaker 1: the United States. So we actually had a house in
Speaker 1: France and a house in California, and we had to
Speaker 1: go back and forth and back and forth, and back
Speaker 1: and forth and back and forth and back and forth.
Speaker 1: It almost drove my family crazy. Oh my gosh, did
Speaker 1: you have kids at that point? We had two young children,
Speaker 1: one of the whom was born in Switzerland. Oh my goodness.
Speaker 1: I know. It's amazing I'm not divorced. It is. It is.
Speaker 1: I shouldn't have said it is so quickly, but well,
Speaker 1: I'm Kelly Wiener Smith and I'm a parasitologist, and it's
Speaker 1: amazing that I'm not divorced. Also because I moved my
Speaker 1: husband four times during my PhD to different states. But
Speaker 1: you know, I used to think that was bad. And
Speaker 1: now I'm going to go downstairs and tell Zack later
Speaker 1: how easy he has it. So thank you for that.
Speaker 1: That's good. That's my goal is to make other marriages
Speaker 1: look good. We appreciate it. Well. Welcome to the podcast
Speaker 1: Daniel and Jorge Explain the Universe, in which we talk
Speaker 1: about all the crazy and amazing things that we find
Speaker 1: out there in the universe, moving here and there, taking
Speaker 1: our brains from the tiniest little particles down to the
Speaker 1: quantum realm to the vast planets of the outer Solar
Speaker 1: system and all the way to super clusters. Our goal
Speaker 1: is to embrace everything we know and that we don't
Speaker 1: know and explain all of it to you. And as
Speaker 1: you might have guests today on the program, Jorge is
Speaker 1: not here, so we have our fabulous guest host, Kelly
Speaker 1: Weener Smith joining us to talk about all these things
Speaker 1: and ask good questions. Hey, Daniel, I'm excited to be back.
Speaker 1: I had fun lost time. Awesome, great, well, thanks very
Speaker 1: much for joining us. So we started off joking about
Speaker 1: moving houses and moving planets. But this is something I
Speaker 1: think is actually really interesting, is thinking about how the
Speaker 1: planets in our solar system got where they are and
Speaker 1: whether or not they have ever moved. I personally love
Speaker 1: this question because it's one of those questions that, like
Speaker 1: the fact that we have anything that even vaguely resembles
Speaker 1: an answer, makes me sort of proud to be a human. Like,
Speaker 1: how can we even think about these sorts of questions
Speaker 1: and collect data to answer these questions. It just seems
Speaker 1: so mind blowing to begin with the fact that we
Speaker 1: have any answers, even preliminary answers, blows my mind. Well,
Speaker 1: I think it's super fascinating that we even know to
Speaker 1: ask these questions, right, Like, you look at the Solar
Speaker 1: system and we have the planets, and they don't seem
Speaker 1: to be changing from year to year. We have thousands
Speaker 1: of years of astronomical records and so it seems sort
Speaker 1: of stable. So it's sort of absurd even to ask, like,
Speaker 1: could the planets have ever been in another configuration? Could
Speaker 1: the solar system have looked different? It's like very natural
Speaker 1: to think, oh, things are going around the Sun. They've
Speaker 1: been going around the Sun. Of course they were always
Speaker 1: in the same orientation. But something that's happened over the
Speaker 1: last just couple of decades is that we've had a
Speaker 1: chance to glimpse other solar systems. For thousands of years,
Speaker 1: we've only ever seen ours. We had like one example.
Speaker 1: Now we're seeing lots and lots of other solar systems,
Speaker 1: and this gives us a clue that solar systems can
Speaker 1: look different and that there might be a lot of activity,
Speaker 1: that they're actually quite volatile. That is super exciting. So
Speaker 1: for our sample size for these like how many solar
Speaker 1: systems can we see in enough detail where we can
Speaker 1: like count all of the planets and get a bit
Speaker 1: of a sense for what those planets are, like, are
Speaker 1: we talking hundreds, thousands, millions? How big is our data
Speaker 1: set here? It's exciting because it's growing so rapidly, Like
Speaker 1: the first exoplanets were discovered just a few decades ago,
Speaker 1: and now we have thousands, not yet millions. Someday astronomers
Speaker 1: will get to play with the datas that have millions
Speaker 1: of solar systems and ask really detailed questions. But we
Speaker 1: have thousands of solar systems that we can look at
Speaker 1: and we see weird stuff in those solar systems that
Speaker 1: we don't see in our solar system and that makes
Speaker 1: us wonder, like, wait a second, are those solar systems weird?
Speaker 1: Or is our Solar system weird? I need to know
Speaker 1: the answer, And so today on the podcast will be
Speaker 1: asking the question has our Solar system look different? In particular,
Speaker 1: did Jupiter ones have a different orbit? And that's a
Speaker 1: pretty huge question, right because Jupiter is like the biggest
Speaker 1: planet out there, so where it goes has a big impact.
Speaker 1: From one point of view, you could imagine it's basically
Speaker 1: the only planet other than the Sun. Jupiter has like
Speaker 1: of all the mass in the Solar system. Everything else
Speaker 1: is basically a detail compared to Jupiter. So yeah, it's
Speaker 1: a big deal. If Jupiter had been in a different place,
Speaker 1: everything would be different, and so as usual, I was
Speaker 1: curious whether people had this in their minds, like, have
Speaker 1: people imagine the possibility that Jupiter could be in a
Speaker 1: different place? Is that something people have thought about, have
Speaker 1: heard about? So I went out there to the wilds
Speaker 1: of the Internet and I asked people, Hey, do you
Speaker 1: know the answer to this tough physics question that astronomers
Speaker 1: are struggling over. Use no preparation, no googling allowed, Just
Speaker 1: tell me off the top of your head. Here's what
Speaker 1: people had to say. I guess No, there were impacts
Speaker 1: off I guess asteroids and or comets, and I may
Speaker 1: be even bigger objects in the past. So I think
Speaker 1: the orbit of Jupiter was a different one two beion
Speaker 1: years ago. No, I think it was, but I think
Speaker 1: it used to be a lot closer and then it
Speaker 1: moved out through collisions and the collisions, I think Jupiter
Speaker 1: used to be in a different orbit. I know Uranus
Speaker 1: rotates about its access in a way that sideways compared
Speaker 1: to the other planets. Well, I'm not sure if what
Speaker 1: I think happened, is that Uranus and Jupiter collies at
Speaker 1: some point. I suspect that Jupiter has been in its
Speaker 1: current orbit for quite some time, speaking on you know,
Speaker 1: the scale of the formation of our Solar system, but
Speaker 1: I would not at all be surprised if it had
Speaker 1: moved around somewhat during the early formation period of our
Speaker 1: solar system. Would say, yes, well, nothing is permanent, so
Speaker 1: I guess it's at the origin it was part of
Speaker 1: the the Sun or giant cloud of gas. But to me, well,
Speaker 1: it's quite stable orbits, and I don't see why each change,
Speaker 1: except for minor changes such as a collision with that
Speaker 1: other objects. But I would say yes, no, no, Um.
Speaker 1: Jupiter at some point was sitting towards the Sun, but
Speaker 1: it's kinda got locked in by Saturn, probably interaction with
Speaker 1: settled um, something like that. I don't know, you caught me.
Speaker 1: I'll guard here. I don't think that Jupiter has always
Speaker 1: been in its current orbit. I think it formed much
Speaker 1: closer to the Sun, and as it migrated out into
Speaker 1: the Solar System, it cleared a lot of the debris
Speaker 1: and comets and asteroids and dust and everything out of
Speaker 1: its way um and made things a little bit more
Speaker 1: stable here in the inner Solar system, so life could form.
Speaker 1: But I don't think that it started out where it
Speaker 1: currently is. Somebody say no, but I guess, being it's
Speaker 1: so big, it could well have picked up a lot
Speaker 1: of stuff through its time, and as it um, you know,
Speaker 1: it picks up more stuff gets impacted, and I guess
Speaker 1: it's gravitational forces would interact with other planets and stuff around,
Speaker 1: so therefore it get knocked off and moved off its
Speaker 1: little but quite regularly. Maybe, I think almost certainly no. UM.
Speaker 1: I think the current model of how those those system
Speaker 1: was formed UM actually relies on Jupiter migrating inward closer
Speaker 1: to the Sun and then further away. I believe Jupiter
Speaker 1: has moved from its original orbit. I think the original
Speaker 1: orbit was closer to the Sun. All right, Wow, those
Speaker 1: are some great answers from our listeners. When you heard
Speaker 1: that this was even a question that people were thinking about,
Speaker 1: did you have a like, oh my gosh moment or
Speaker 1: did it just seem like an obvious question for you
Speaker 1: to be asking. I had an oh my gosh moment
Speaker 1: and a hope because I thought, oh, that would be
Speaker 1: super cool if Jupiter wasn't always in its current orbit.
Speaker 1: Because one of the fun things for me in science
Speaker 1: is revealing surprises. Right If you ask a question and
Speaker 1: then the answer is yeah, it's kind of boring Jupiter
Speaker 1: has always been there. That's not nearly as fun as
Speaker 1: Oh my gosh, it turns out there's a crazy history
Speaker 1: here and we have revealed it. Like you were saying earlier,
Speaker 1: it's incredible that we could, like by gathering small lose
Speaker 1: left by these crazy cosmic events, actually reconstruct something that
Speaker 1: happened billions of years ago. It's like solving a billion
Speaker 1: year old murder mystery. As a biologist, every once in
Speaker 1: a while we will have discussions about like what makes
Speaker 1: humans different than other animals, And you know, clearly being
Speaker 1: able to think about questions like this is one of
Speaker 1: those things that like, certainly we're the only species who's
Speaker 1: wondering that on our planet exactly. So it's super fun.
Speaker 1: And I was really hoping that the answer would be
Speaker 1: something crazy. So it's pretty interesting to learn about. And
Speaker 1: I've also really been enjoying following this Excel planet discovery
Speaker 1: seeing these other solar systems, these other like potential homes
Speaker 1: for aliens where life could be really different because the
Speaker 1: planets are so different from ours. You know, we're sort
Speaker 1: of like trapped in this colloquial way of thinking that
Speaker 1: our kinds of planets are the kinds of planets you have,
Speaker 1: like small rocky planets and the inner Solar system and
Speaker 1: big gas giants and the outside and now it's possible
Speaker 1: to imagine other kinds of areas. So is our configuration
Speaker 1: a typical configuration. It turns out it's not. When we
Speaker 1: look at other solar systems, we see something really weird.
Speaker 1: First of all, we see that most solar systems have
Speaker 1: a lot more planets very close to their star, Like
Speaker 1: between Mercury and the Sun there's basically nothing, But in
Speaker 1: other solar systems there are lots of planets packed in there.
Speaker 1: And in particular, we find these things called hot jupiters.
Speaker 1: Not hot because they're like you know, big on Instagram
Speaker 1: or they're really curvy, hot because they're really close to
Speaker 1: the Sun. Like, we find these planets in other solar
Speaker 1: systems that are really big, like Jupiter size and gas planets,
Speaker 1: but they orbit the star in just like hours or days,
Speaker 1: and like a fraction of the distance between the Sun
Speaker 1: and mercury. So that's a really weird phenomenon to see.
Speaker 1: Shouldn't they like suck each other into each other pretty quickly?
Speaker 1: What's the good physics word for that? How do they
Speaker 1: stay separated if they're both huge and attracting each other
Speaker 1: and are so close now, suck each other in is
Speaker 1: exactly they're all right physics word to use, And that's
Speaker 1: exactly the question people are asking. They're like, hold on
Speaker 1: a second, how do you get such a big planet
Speaker 1: so close to the Sun? Can it last very long?
Speaker 1: Are we seeing something just before it dies? Or can
Speaker 1: that be a stable configuration? And the models suggests that
Speaker 1: they can't have been born that close to the Sun
Speaker 1: and they can't last there very long. And that's the
Speaker 1: clue that got everybody talking and thinking about whether planets
Speaker 1: are moving, because they suspect that these hot jupiters form
Speaker 1: further out and then get sucked in, and so we're
Speaker 1: witnessing sort of like the end of the life cycle
Speaker 1: of these planets before they either get torn apart or
Speaker 1: pulled in. And that's a clue that, like solar systems
Speaker 1: are volatile, there is stuff going on. It's not just
Speaker 1: everybody sedately driving in their lane for billions of years?
Speaker 1: Is Jupiter going to get sucked into our Sun? Not
Speaker 1: before the Sun explodes? Right? Are you worried about Jupiter?
Speaker 1: Have you invested in real estate on Jupiter? Well, you know,
Speaker 1: I was thinking about it. We've been reading about space settlements,
Speaker 1: but no, obviously not nobody's gonna go live on Jupiter.
Speaker 1: But maybe it's moons. I went to read I fantastic
Speaker 1: series and science fiction novels about a civilization in the
Speaker 1: upper clouds of Jupiter. I think it was called Bio
Speaker 1: of a Space Tyrant Man. I loved those books when
Speaker 1: I was a teenager. It was so like fantastically imagined.
Speaker 1: So I hope that one day humans do get to
Speaker 1: live on Jupiter, and I hope that we get to
Speaker 1: keep Jupiter because I like it. I mean, Jupiter is pretty.
Speaker 1: For all the press that like Mars gets recently, Jupiter
Speaker 1: is a gorgeous planet. So maybe we should start by
Speaker 1: thinking about our solar system and understanding of what we
Speaker 1: know about Jupiter, like where it was made, how it
Speaker 1: got formed, and that can give us a clue for
Speaker 1: like why people think there might have been crazy stuff
Speaker 1: going on in our solar system. At the very beginning
Speaker 1: of time. Alright, so tell me about how Jupiter got
Speaker 1: to be where it is. Yes, so we think Jupiter
Speaker 1: is probably born out in the outer Solar system. There's
Speaker 1: this point in the Solar system called the ice line,
Speaker 1: where beyond that it's cold enough for ice to form
Speaker 1: and to stay melted and basically be like a rock
Speaker 1: that you can use and building planetary cores. And it's
Speaker 1: about like three and a half AU. Will remember a
Speaker 1: U isn't one astronomical units the distance between the Sun
Speaker 1: and the Earth, So three and a half times the
Speaker 1: radius of the Earth. Beyond that is the ice line,
Speaker 1: or some people call it the snow line, and out
Speaker 1: there it's easier to make big planets because there's ice
Speaker 1: available to add to your core. So we think that
Speaker 1: the way the Solar system started obviously, have a big
Speaker 1: blob of gas and dust and some shock wave comes
Speaker 1: through it and you get the spark that begins the
Speaker 1: formation of the whole Solar system, which basically means the Sun.
Speaker 1: But the Sun has gathered together a huge amount of
Speaker 1: gas and it has around it a big swirling disk,
Speaker 1: and that's the disc that's going to provide the material
Speaker 1: that forms all of the planets now out past the
Speaker 1: snow line, there's also ice in there. So the ice
Speaker 1: and the rock and the dust gathered together to make
Speaker 1: these protoplanetary cores. They start pulling themselves together and that
Speaker 1: sort of seeds the planets. And so we ended up
Speaker 1: with what four planets out past the ice line? Is
Speaker 1: that pretty common? Like that number and like the size
Speaker 1: of our planets does that match up with what we
Speaker 1: see in other solar systems. We don't know the answer
Speaker 1: to that yet, we haven't seen enough. But also remember
Speaker 1: that we can see a bunch of solar systems, but
Speaker 1: we're not that great at seeing all of them. And
Speaker 1: there's certain kinds of solar systems that are easier to see.
Speaker 1: Like it's easier to see big planets that are closer
Speaker 1: to their Sun because they block more of the Sun's light.
Speaker 1: The way we see these exoplanets is that they block
Speaker 1: the light of their Sun or they tug gravitationally on
Speaker 1: the Sun. So big planets are easier to see. Close
Speaker 1: up planets are easier to see, so far out planets
Speaker 1: harder to spot. Far out small planets harder to spot.
Speaker 1: Does that mean that like super slow moving things we
Speaker 1: probably don't have good data on yet because we wouldn't
Speaker 1: have had a chance to see them pass in front
Speaker 1: of the sun or tug it as it moves around
Speaker 1: to the side. That's exactly right, Yeah, we have to
Speaker 1: watch these things cross their sun, and so basically it's
Speaker 1: best if you can see and pass a few times
Speaker 1: so you can see like a regular interval, so the
Speaker 1: equivalent of several of their years. But if their years
Speaker 1: take like, you know, a hundred earth years to go around,
Speaker 1: then we're not going to have had time to see it.
Speaker 1: So slow moving things, small things, things far from their
Speaker 1: son are harder to see. So that's a long way
Speaker 1: of saying we don't have an unbiased picture of what's
Speaker 1: going on in these other solar systems. And we have
Speaker 1: to try to play this game of wondering, like, well,
Speaker 1: if we see only one of them, do we imagine
Speaker 1: that there are a thousand? Or if we only see
Speaker 1: two of those, do we imagine there are a hundred.
Speaker 1: We have to estimate like how good we are seeing them,
Speaker 1: so we can like invert that and imagine what's actually
Speaker 1: there that we're missing. But there's a lot that we're missing.
Speaker 1: Still interesting Yeah, it's really fascinating. And so that's why
Speaker 1: we focus on our solar system because it's here, it's relevant,
Speaker 1: and it's one that we can study in great detail.
Speaker 1: But those other solar systems do give us a lot
Speaker 1: of clues. Back to jo Butter, we think that it
Speaker 1: must have had to form and the outer Solar System
Speaker 1: because that's basically the only place to make these big
Speaker 1: gas giants. I mean, you need now of ice and
Speaker 1: enough rock to pull together to make this big core
Speaker 1: to grab a bunch of gas. Remember, everything in the
Speaker 1: Solar system is competing with the Sun. In the inner
Speaker 1: Solar system, is not that much gas left because the
Speaker 1: Sun has slurped it all up. So to make a
Speaker 1: gas giant, really have to be far enough away from
Speaker 1: the Sun to get any of the gas, and you
Speaker 1: have to be past the snow line, so you can
Speaker 1: have ice accumulated in your core and get big enough
Speaker 1: that you can grab some of the gas before all
Speaker 1: spirals into the Sun. Anyway, Okay, so Jupiter was formed
Speaker 1: in the outer Solar System and it's still in the
Speaker 1: outer Solar system. So after the break, let's talk about
Speaker 1: why we think it moved. Okay, so Jupiter is where
Speaker 1: we would expect it to be, given how we expect
Speaker 1: that it formed, So why would we suspect that it
Speaker 1: had moved at any point. Yeah, it seems at first
Speaker 1: like it might be a simple story. Right, Jupiter had
Speaker 1: to form somewhere in the neighborhood where it is today,
Speaker 1: and so the simplest explanation is, well, maybe it just
Speaker 1: formed there and stayed there. Why do we imagine it
Speaker 1: ever took a tour in the inner Solar System? And
Speaker 1: the reason is that the inner Solar System looks weird,
Speaker 1: like we can't explain the Inner Solar System in that picture.
Speaker 1: Our models of how the Solar System came together. We
Speaker 1: run a bunch of like simulations and try to explain
Speaker 1: how we got Venus and Earth and Mars. None of
Speaker 1: the models that we run actually match up with what
Speaker 1: we see. How are they different? Well, in particular, Mars
Speaker 1: is really weird, Like Mars is a nice little planet,
Speaker 1: but it's really small, Like Mars is like ten percent
Speaker 1: of the mass of the Earth. That's a really small planet.
Speaker 1: And in all our models of the Solar System, Mars
Speaker 1: should be a lot bigger, like as you get further
Speaker 1: out from the Sun, there's more material available because the
Speaker 1: Sun hasn't stolen at all, and so you expect a
Speaker 1: planet forming around there to be like about the size
Speaker 1: of the Earth or even bigger. You know, as you
Speaker 1: go to the outer Solar System, things get bigger, right,
Speaker 1: So why is Mars so tiny? Why is it so little?
Speaker 1: So as you get farther out in the Solar System,
Speaker 1: things should get bigger. But Jupiter is the biggest and
Speaker 1: it's not the most far out, So why is Saturn
Speaker 1: smaller than Jupiter? Then? Oh, yeah, that's a great question.
Speaker 1: There's a whole other fun story about a sounder Jupiter,
Speaker 1: maybe switching locations and the whole dance of Uranus and
Speaker 1: Neptune that they might have done. But you're right, there's
Speaker 1: a balance there because you want to be far enough
Speaker 1: away from the Sun so it doesn't steal all the material,
Speaker 1: but as you get even further away from the Sun
Speaker 1: you run out of material also, right, Obviously there aren't
Speaker 1: like super giant planets twice as far away as Jupiter,
Speaker 1: and so this is something of like a peak location there.
Speaker 1: Jupiter is probably sitting right there in the spot where
Speaker 1: you can make the biggest planet. But the question remains
Speaker 1: like why is Mars so a little what happened to
Speaker 1: make Mars so tiny? And it's not just Mars? Like
Speaker 1: the asteroid belt is also kind of weird, like we
Speaker 1: don't really understand how it formed the way it did. Again,
Speaker 1: we run these model let's start from just the gas cloud,
Speaker 1: and you don't get an asteroid belt that looks the
Speaker 1: way it does. Specifically, our asteroid belt is weird because
Speaker 1: it has both like rocky objects that seems like they
Speaker 1: came from the inner Solar System. Plus they have a
Speaker 1: bunch of icy objects, the kinds of things you would
Speaker 1: find like in the Kuiper Belt or deeper further out
Speaker 1: in the Solar system. So there're these like pieces of
Speaker 1: evidence you were talking earlier about like how could we
Speaker 1: possibly find clues about things that happened so long ago?
Speaker 1: Like these are the things that have puzzled scientists for
Speaker 1: a long time. So is the asteroid belt inside the
Speaker 1: ice line or on the Jupiter side of the ice line? Yeah,
Speaker 1: the asteroid belt is really weird. Actually part of his
Speaker 1: inside the ice line, the part that's like closer to Mars,
Speaker 1: remember it sits between Mars and Jupiter. But it also
Speaker 1: extends kind of far out, and part of it actually
Speaker 1: is in orbit with Jupiter. Like it's not all between
Speaker 1: Mars and Jupiter. There's these big blobs of asteroids that
Speaker 1: are in Jupiter's orbit just sort of like rotated away
Speaker 1: from them, like you know, thirty degrees around the thirty
Speaker 1: degrees the other direction, and stuff is sort of like
Speaker 1: sloshing back and forth. So some of it's definitely out
Speaker 1: there past the ice line and can stay frozen, and
Speaker 1: some of it's a little bit closer. Interest. Yeah, and
Speaker 1: so we have these mysteries, and I love that. This
Speaker 1: is like the way we do science. You know, we say, well,
Speaker 1: we think we understand how the solar system works, but
Speaker 1: let's double check. Let's run a bunch of models and
Speaker 1: see if what we get matches up with what we
Speaker 1: actually expected. And when you see those weird deviations, when
Speaker 1: you see something that doesn't make sense, that's when you
Speaker 1: know you might have found something. So it's like when
Speaker 1: your model doesn't work is a potential discovery moment. It
Speaker 1: isn't that how we figured out how humans figured out
Speaker 1: that was it? Neptune was out there, something was not
Speaker 1: working mathematically, so there had to be another planet out
Speaker 1: there exactly. Yeah, there's all these times when something hasn't
Speaker 1: quite worked, just like you're saying, the orbits of the
Speaker 1: planets don't quite make sense, and that's been a clue.
Speaker 1: Is to like a huge discovery, but always makes me
Speaker 1: think about like all the other times when your model
Speaker 1: doesn't work and it just because like you have a
Speaker 1: bug where you did something stupid, you know, and you
Speaker 1: can't be like, oh my gosh, maybe I've discovered something fantastic.
Speaker 1: Sort of frustrating part of science. Yeah, usually for me,
Speaker 1: it's just a bug, but I'll keep all me out hope.
Speaker 1: We have that experience all the time. It's a large
Speaker 1: hage on collider because we're always on the lookout for
Speaker 1: something unexplained, something new, something weird, some new particle that
Speaker 1: we've just created, or mini black hole or something, and
Speaker 1: it might be evidenced by some deviation in the data
Speaker 1: compared to what we expect. But we see that all
Speaker 1: the time, especially young students make mistakes and they see
Speaker 1: something weird, like oh my gosh, did I discover something
Speaker 1: like yeah, well, you discovered that you don't know how
Speaker 1: to run this program correctly. You discovered that you're missing
Speaker 1: a bracket. But yeah, exactly, you discovered that bugs are
Speaker 1: easy to insert in programs, but you also you don't
Speaker 1: want to squash their enthusiasm. Right, It's wonderful to see
Speaker 1: this in young scientists, to imagine that they could be
Speaker 1: the ones making some discovering this could be a historic moment.
Speaker 1: So I like to tell them stories like this, because
Speaker 1: it does act really happens sometimes, Right, Sometimes we run
Speaker 1: these models and we see something weird and it means
Speaker 1: something real about the universe. Awesome. We can all keep
Speaker 1: our fingers across the will have those amazing moments where
Speaker 1: it's not you not being smart enough, it's actually the
Speaker 1: universe revealing herself to you. And so we're trying to understand,
Speaker 1: like how our solar system got to be weird the
Speaker 1: way it is. Why don't we have a bunch of
Speaker 1: other planets close to the star? Why is mar so small?
Speaker 1: Why is the asteroid belt the way it is? This
Speaker 1: weird mix of rocky and icy objects. So we've taken
Speaker 1: clues from these other solar systems that have big planets
Speaker 1: really close to their stars. One idea initially was like
Speaker 1: maybe Jupiters formed close to the Sun. And then like
Speaker 1: drifted out and along the way sort of messed up
Speaker 1: things in the Solar system. But you just told us
Speaker 1: that it needed to be out there where there's ice
Speaker 1: in order to form. Could it have possibly formed near
Speaker 1: the Earth? So people spend a while trying to cook
Speaker 1: up these models and wondering like maybe there's a way
Speaker 1: to have a hot jupiter that survives, or maybe there's
Speaker 1: a way to form a planet really close to the star.
Speaker 1: Maybe there are other methods. So you know, this idea
Speaker 1: of how you form a jupiter is sort of one model,
Speaker 1: but there are other models. There's like, you know, gravitational
Speaker 1: instabilities that maybe stuff smashed together to make like an
Speaker 1: unusually large object, which then like gathered together a bunch
Speaker 1: of stuff. And people have been working on these things
Speaker 1: and trying to put them together, and you know, this
Speaker 1: is the kind of creativity that's inspired by basically a mystery.
Speaker 1: But it doesn't seem to really be working, Like there's
Speaker 1: just not enough gas and not enough mass close to
Speaker 1: the star, and also it's just too warm, Like a
Speaker 1: lot of this stuff, if you did happen to form
Speaker 1: a big object, would get blown apart by the sun.
Speaker 1: The Sun just like boil the gas off of that planet.
Speaker 1: And it also probably just like holding apart by the
Speaker 1: tidal forces. Remember that the Sun has a lot of
Speaker 1: gravity and it tugs on everything. But if you're a
Speaker 1: really big object, it's going to tug on the part
Speaker 1: of you that's closer to the star more than it
Speaker 1: tugs on the part of you that's far from the star.
Speaker 1: And that's effectively the same thing as trying to pull
Speaker 1: you apart. And that's why, for example, you get close
Speaker 1: to a black hole, you won't survive, because you'll get
Speaker 1: pulled apart by the relative difference in the gravity at
Speaker 1: your feet and at your head. It's called spaghettification, one
Speaker 1: of the best physics words out there. And so now
Speaker 1: imagine like making a big gas giant. You've accomplished the impossible.
Speaker 1: You've formed a gas giant close to your star. What's
Speaker 1: going to happen The star pretty quickly is going to
Speaker 1: spaghettify Jupiter. And like, that's a lot of spaghetti. I'm
Speaker 1: there for that. I love spaghetti. So are people still
Speaker 1: work on that question or have scientists pretty much decided like, okay,
Speaker 1: this is not the answer. There's always somebody is still
Speaker 1: working on that question. Right. There are people out there
Speaker 1: who think that it might have been possible to make
Speaker 1: a Jupiter close to the star, and they're working on
Speaker 1: their models, and in that line of thinking, they're hoping
Speaker 1: that you've made this jupiter close to the star and
Speaker 1: that it's somehow we don't know how, then drifted out
Speaker 1: to the outer Solar System and in doing so has
Speaker 1: perturbed the asteroid belt and in doing so has like
Speaker 1: stolen a lot of the material that might have made Mars.
Speaker 1: But I don't think that it's a mainstream idea. I mean,
Speaker 1: there's always somebody out there, you know, smoking a banana,
Speaker 1: appeals and thinking about it. And I encourage that, and
Speaker 1: that kind of creativity is wonderful, and you know, diversity
Speaker 1: of ideas is also very very important for the scientific method.
Speaker 1: But I don't think the leading idea is that you
Speaker 1: form a hot jupiter close to the Sun and that
Speaker 1: it then drifts out into the outer Solar system. Okay,
Speaker 1: so it started in the outer Solar System and then
Speaker 1: it went on a cool vacation towards the Sun and
Speaker 1: decided it preferred skiing. Yeah, And so we don't think
Speaker 1: that this idea of it's starting an inner solar system
Speaker 1: and moving out makes much sense. And another clue is
Speaker 1: that when we look at these other solar systems, the
Speaker 1: ones that have hot jupiters, and we wonder, like, how
Speaker 1: are they made and how could that survive? There's some
Speaker 1: evidence that we're looking at our really young solar systems,
Speaker 1: solo systems that haven't been around for very long. And
Speaker 1: so one explanation for how hot jupiters even exist is
Speaker 1: that they're transient, that they're gonna be absorbed by the
Speaker 1: star that we're seeing them before they get spaghettified and
Speaker 1: sucked in and basically just become part of the star.
Speaker 1: Because we don't tend to see hot jupiters in older
Speaker 1: solar systems. Ah, so it started in the outer solar system,
Speaker 1: it got sucked in, and we are seeing it at
Speaker 1: a point where it is sort of in the process
Speaker 1: of soon to be absorbed by the sun. Is that right?
Speaker 1: That's the leading explanation for why we are seeing hot
Speaker 1: jupiters in other solar systems. But you know, of course
Speaker 1: that doesn't answer the question of our solar system because
Speaker 1: we don't have a hot Jupiter, right, But we still
Speaker 1: have to explain what happened in the inner Solar System.
Speaker 1: So we have Jupiter starting in the outer Solar System,
Speaker 1: we think that makes more sense. We don't have it
Speaker 1: currently in the Inner Solar System. So then there's this
Speaker 1: question of like, well, how could it have perturbed things
Speaker 1: in the inner Solar System? You know, it's sort of
Speaker 1: like got an alibi. It's like I was born here
Speaker 1: and I'm still here. Why are you looking at me? Right? Okay,
Speaker 1: So the progress we've made so far are is that
Speaker 1: there's an explanation that we don't think is right. So
Speaker 1: let's try another explanation and see if we can maybe
Speaker 1: solve some of the problems with what's happening with Mars
Speaker 1: and the asteroid belt after we take a break. Okay,
Speaker 1: So we feel pretty confident that Jupiter started in the
Speaker 1: outer Solar System and it didn't start in the Inner
Speaker 1: Solar System and then move out. So if it started
Speaker 1: in the outer Solar System and it's still there, now,
Speaker 1: does that mean at some point Jupiter sort of toyed
Speaker 1: with the idea of a summer vacation and then decided
Speaker 1: it preferred the cold and went back to go skiing.
Speaker 1: Did it come to the Sun and then leave. I know,
Speaker 1: this is that moment in the Murder mystery where you're like,
Speaker 1: this person was home all evening. Hold on a second
Speaker 1: to actually have a way to account for all their whereabouts.
Speaker 1: Could they have snuck out and committed the murder and
Speaker 1: then come back in time? How fast are those trains?
Speaker 1: We can't leave Jupiter in the outer Solar System for
Speaker 1: its whole history. But now we have a crazier idea,
Speaker 1: which is maybe Jupiter did trend into the inner Solar
Speaker 1: System just like all those other hot jupiters were seeing
Speaker 1: in other solar systems, but that it stopped and it
Speaker 1: turned around and it went back out to the outer
Speaker 1: Solar system. So this is called the Grand Tach hypothesis.
Speaker 1: Seeing Jupiter's like a sailboat that like sailed into the
Speaker 1: inner Solar System and then sailed back out. This is
Speaker 1: blowing my mind. So let's break it into two parts.
Speaker 1: I guess, So, how did it get pulled in? Just
Speaker 1: through the typical gravity pulled it in? Yeah, so you
Speaker 1: have to cast your mind back to the very very
Speaker 1: early days of the Solar system. Solar system we think
Speaker 1: is about four or five billion years old and we're
Speaker 1: talking about things that happened in the first few million years.
Speaker 1: You shouldn't be imagining a bunch of planets around the star.
Speaker 1: You should be imagining a star and then a huge
Speaker 1: disc of gas and dust, and then inside that gas
Speaker 1: and dusk, we're forming planets. But they're not like clear,
Speaker 1: they're not like totally separated. If you were doing astronomy
Speaker 1: back then, you would have a really hard time seeing
Speaker 1: any planets because there's so much gas and dust everywhere.
Speaker 1: So the beginning of the story in the first few
Speaker 1: million years is that, like proto Jupiter has formed, but
Speaker 1: it's not as far out as it is now. It's
Speaker 1: only like three and a half au like right there
Speaker 1: on the snow line. As we were saying earlier, like
Speaker 1: the peak place to make a gas giant is just
Speaker 1: pass where things freeze, so you can gather ice and
Speaker 1: rocks and dust, but not so far out that things
Speaker 1: are getting dilute. So Jubiter forms there and then it
Speaker 1: drifts into the inner Solar system. As you're asking, like
Speaker 1: what makes that happen, it's it just the Sun's gravity,
Speaker 1: and you know anything can orbit stable. The Sun obviously
Speaker 1: has a lot of gravity, but The reason, like the
Speaker 1: Earth is not falling into the Sun right now is
Speaker 1: that we have a lot of speed. We're in a
Speaker 1: stable orbit. So we think Jupiter probably wasn't a stable orbit.
Speaker 1: But remember it wasn't on its own. It's still surrounded
Speaker 1: by a lot of gas and us that hasn't gotten
Speaker 1: pulled into any planet. So the idea is that it
Speaker 1: interacted with that gas and dust, which basically slowed it
Speaker 1: down and started falling in towards the Sun. That must
Speaker 1: have been very scary for Jupiter. I know, it's like
Speaker 1: this inextricable fall, right, you know that you're like rolling
Speaker 1: in towards this huge burning ball of plasma and there's
Speaker 1: basically nothing you can do about it. So very dramatic moment.
Speaker 1: And these gases eventually, you know, spiraled in and they
Speaker 1: fell into the Sun, and Jupiter was spiraling and also
Speaker 1: and so the idea is that it passed through the
Speaker 1: inner Solar System and along the way it gobbled up
Speaker 1: a lot of material which eventually would have otherwise led
Speaker 1: to a larger Mars. How far in did it go?
Speaker 1: Did it get like Earth close or just Mars close,
Speaker 1: not quite Earth close. We think that it came into
Speaker 1: like about one and a half a you. And that's
Speaker 1: why we still have Earth as a pretty reasonable size,
Speaker 1: because Jupiter came in and it either like gobbled up
Speaker 1: the material to make ours or scattered it and threw
Speaker 1: it into the sun. But these things in the inner
Speaker 1: Solar system were a bit more protected. Okay, so part
Speaker 1: of Jupiter should have been in Mars. It's like those twins,
Speaker 1: you know, where like one of them eat the other
Speaker 1: one and you still have like a jaw or whatever
Speaker 1: inside the body of the adult. Those are the craziest stories.
Speaker 1: I don't think they're actually eating the other one, but yes,
Speaker 1: I know where you're going with that. Well, you don't
Speaker 1: believe in the evil twin theory that twins can eat
Speaker 1: each other in the roomb. I was reading about this
Speaker 1: the other day, and I think it's they like absorb
Speaker 1: eating suggests a bit more intention that I think is
Speaker 1: actually happening in there. You know, I'm going to use
Speaker 1: that next time I eat my kids cookies. I'm like,
Speaker 1: I didn't eat your cookies, I just absorbed them. And
Speaker 1: Kelly the biologist, she tells me that's different. And then
Speaker 1: your children remind you that you are not a fetus.
Speaker 1: You're a grown man. You can make decisions, and so
Speaker 1: you know, let them know that they can call me
Speaker 1: if they need back up. All right, I'll give them
Speaker 1: your number. Anyways, So Jupiter's out there like unintentionally absorbing
Speaker 1: the materials that Mars would have needed to get larger
Speaker 1: and scattering a bunch of other stuff, and so it
Speaker 1: came into about one and a half a U. And
Speaker 1: that actually explains a lot about what's going on in
Speaker 1: our inner Solar system. That's why there are no like
Speaker 1: other rocky planets after Mars. We think there might have
Speaker 1: also been other planets out there that were forming that
Speaker 1: Jupiter just like nudged into the Sun. So why did
Speaker 1: it nudge them into the Sun as opposed to pulling
Speaker 1: it into Jupiter. Yeah, we don't know. It could have
Speaker 1: been either fate, right, this is very chaotic, and so
Speaker 1: it depends exactly on how big they were and how
Speaker 1: they were aligned, and so the fate of these planets
Speaker 1: could be like fall into the Sun or get absorbed
Speaker 1: by Jupiter, or even get tossed out of the Solar
Speaker 1: system entirely. Like Jupiter is a big bully, right, It's
Speaker 1: so much bigger than Earth and Mars, and it comes
Speaker 1: in and it doesn't take very much to really disrupt
Speaker 1: the inner Solar System. Okay, so how does this describe
Speaker 1: what happened or does this help explain what happened with
Speaker 1: the asteroid belt. Yeah, so it actually all really fits
Speaker 1: together beautifully, because to explain the after oid belt, you
Speaker 1: need Jupiter to get back out to where it was. Right.
Speaker 1: The asteroid belt has rocky stuff in it from the
Speaker 1: inner Solar System, but also I see stuff from the
Speaker 1: outer Solar System, and so if you could somehow turn
Speaker 1: Jupiter around, right, we've seen all these other solar systems.
Speaker 1: Also that these big gas giants sometimes fall slowly in
Speaker 1: towards the star, and we think that in most cases
Speaker 1: probably they just end up inside the star. They didn't
Speaker 1: happen in our case. So we need Jupiter move somehow
Speaker 1: to the outer Solar System, and in doing so we
Speaker 1: think that it will have disrupted the asteroid belt and
Speaker 1: also disrupted the Kuiper Belt, like pulled some of those
Speaker 1: objects towards the inner Solar System, so that the asteroid
Speaker 1: belt then has like a weird mixture of these like
Speaker 1: further out objects and these inner objects. And that's why
Speaker 1: we see these like icy objects and rocky objects in
Speaker 1: our asteroid belt. If we can get Jupiter to go
Speaker 1: in and then come back out, that's fascinating. So now,
Speaker 1: how you told us that Jupiter probably slowed down own
Speaker 1: and that's what caused it to get pulled in. So
Speaker 1: for Jupiter to go back out again, what is required
Speaker 1: for that? Doesn't have to start speeding up and then
Speaker 1: also kind of get nudged. Why did it leave? Well, Jupiter,
Speaker 1: we think probably was saved by its friend Saturn, because
Speaker 1: Saturn has the same fate, right, Saturn, also a big
Speaker 1: gas giant, also probably surrounded by big swarming clouds of gas,
Speaker 1: getting slowed down drifting in towards the Inner Solar System.
Speaker 1: To imagine Jupiter like the big brother and then Saturn
Speaker 1: like the younger sister or the younger brother, following in
Speaker 1: behind it, having sort of the same fate and seeing
Speaker 1: what's happening to Jupiter. But the calculations suggests that it's
Speaker 1: possible that as these two things get close to the
Speaker 1: Inner Solar System that they then start tugging on each other,
Speaker 1: and that their gravitational interaction makes this weird resonance where
Speaker 1: they're pushing on each other and they're passing around the Sun.
Speaker 1: They're tugging on each other in the same way. So
Speaker 1: they do this like weird dance. Like imagine two people
Speaker 1: spinning and both letting go and they flown out of
Speaker 1: the inner Solar System. I know, it's crazy. It's like
Speaker 1: Saturn like dove in after Jupiter and saved them both. Right,
Speaker 1: they could have ended very badly. Yeah, there's got to
Speaker 1: be a buddy comedy that could be written about this
Speaker 1: or something that's wild exactly. And so that's maybe the
Speaker 1: story that Jupiter started in the outer Solar system, got
Speaker 1: tugged in as it's got slowed down by all this gas,
Speaker 1: and then got saved by Saturn. And that would explain
Speaker 1: why Mars is so small, and it would explain why
Speaker 1: the asteroid belt has the weird composition that it does have.
Speaker 1: And so is that the only explanation we have for
Speaker 1: how Jupiter got thrown back out again? Or is that
Speaker 1: just the top explanation right now? That's the top explanation.
Speaker 1: And we don't think that it's very likely. I mean
Speaker 1: we think that in most cases, when you have a
Speaker 1: big gas giant that falls towards your star, it ends
Speaker 1: in the way you would expect that it falls towards
Speaker 1: the star and gets gobbled up, And so most solar
Speaker 1: systems that have basically a Jupiter, we think that it
Speaker 1: doesn't last for very long. So that means our solar
Speaker 1: system is probably weird, right, that we're unusual for keeping
Speaker 1: this big gas giant and having it back in the
Speaker 1: outer Solar system in a stable way after all the
Speaker 1: gas and dust have cleared out. Now Jupiter can go
Speaker 1: back out to the past the ice line and hang
Speaker 1: out for billions of years. That would suggest that the
Speaker 1: reason we're weird is because we also have a Saturn.
Speaker 1: So do other solar systems without hot jupiters also have
Speaker 1: a Saturn equivalent? Yeah, great question. I don't think we
Speaker 1: know the answer to that, because these planets are much
Speaker 1: harder to spot, right, We're talking about things five six
Speaker 1: seven a U that only passed their son every few years. Right, Like,
Speaker 1: if you were observing our Solar system from really far away,
Speaker 1: Jupiter and Sounder would not be that easy to spot
Speaker 1: because while they're pretty big, they're also really far away
Speaker 1: from the Sun and it takes them years and years
Speaker 1: to orbit, so you would have to be watching our
Speaker 1: solar system for a long time with a really good
Speaker 1: telescope before you discovered Jupiter and Saturn. So that's not
Speaker 1: something that we're really sort of good at knowing about
Speaker 1: other solar systems. Yet so far, we mostly know what's
Speaker 1: going on in the inner Solar system for big, fast
Speaker 1: moving planets around their star. So astronomers have like incredible
Speaker 1: job security because we're gonna need to watch for hundreds
Speaker 1: of years to get these data and tuarly the government's
Speaker 1: going to pay for all of it, exactly. Yeah, And
Speaker 1: it's incredible what we have learned so far. You know,
Speaker 1: we've learned so much about how our solar system is
Speaker 1: weird to compare to the other solar systems that's out there,
Speaker 1: and that's sort of like cool, like, hey, our solar
Speaker 1: system is awesome and special. It's also a little bit
Speaker 1: disheartening because if you believe in aliens, or you want
Speaker 1: to believe in aliens, and you want to think that
Speaker 1: there are lots of opportunities for life out there, it
Speaker 1: makes the story a little bit harder because to have
Speaker 1: a solar system like ours and a planet like ours,
Speaker 1: you need this sort of special thing to happen, this
Speaker 1: dance of the two gas giants to clear out the
Speaker 1: inner Solar System and then also save themselves and being
Speaker 1: the outer Solar system. You know, we think that Jupiter
Speaker 1: probably protect the Earth from a lot of sort of
Speaker 1: incoming bombardment because it's so big. It's like hoovering up
Speaker 1: all the comets and other stuff. So it's a special
Speaker 1: configuration we have. You've kind of bummed me out. You know.
Speaker 1: At the beginning of this conversation, when we were talking
Speaker 1: about how big our data set is, I was thinking,
Speaker 1: all right, that's got to be good for the Drake equation.
Speaker 1: You know, we're like adding all of these possible solar
Speaker 1: systems that might have earthlike planets. But now what you're
Speaker 1: telling me is probably a lot of the ones that
Speaker 1: are out there don't have earthlike planets. And now I'm
Speaker 1: kind of bummed, yeah, a little bit. And we've been
Speaker 1: excited to find what we thought were earthlike planets in
Speaker 1: these other solar systems, ones about the right radius, about
Speaker 1: the right distance from the star. But what we don't
Speaker 1: know is if they really have the right composition to
Speaker 1: be an Earth. You know, it might be that Jupiter
Speaker 1: came through the Inner Solar System and it cleared out
Speaker 1: a lot of gas, etcetera, etcetera, And so we ended
Speaker 1: up with a planet just the right combination of stuff
Speaker 1: to have life. If Jupiter hadn't come through the Inner
Speaker 1: Solar System, Earth might have been a little bit bigger
Speaker 1: and then might have been more gas, So we might
Speaker 1: have ended up with a very different composition. You can
Speaker 1: imagine like a super Earth that's like choked in hydrogen
Speaker 1: instead of having the atmosphere that we have you other way,
Speaker 1: like Venus is just like choked in CEO two. It's
Speaker 1: very oppressive. And so it might be a lot of
Speaker 1: the planets we're seeing in these other Solar systems are
Speaker 1: not actually sort of habitable in the way that we
Speaker 1: would hope for. They're not really copies of Earth. They
Speaker 1: might have the right size roughly and being roughly the
Speaker 1: right position, but that doesn't mean to have the same
Speaker 1: conditions as Earth. Man, we're lucky. Oh we're special. We're special.
Speaker 1: I'm gonna go with lucky. But maybe life is better
Speaker 1: if you go with special. So did Jupiter go like
Speaker 1: back to where it came from or did it end
Speaker 1: up a little closer a little farther out than where
Speaker 1: it was before. It ended up a little farther out.
Speaker 1: It like it wanted to go out. In the excerpts,
Speaker 1: you know, it was born in the suburbs, and it
Speaker 1: came to the inner city, and then it decided in
Speaker 1: its retirement it wanted to live further out. So it
Speaker 1: started out at three and a half a U. Came
Speaker 1: in and probably about one and a half and now
Speaker 1: it's comfortably out around five point two a U. I
Speaker 1: can totally understand how Jupiter feels. I was born in
Speaker 1: the suburbs and then I moved to a big city
Speaker 1: and now I live out in the country where nobody
Speaker 1: else is. So I feel your Jupiter. Well, it thanks
Speaker 1: a lot to feel Jupiter. And the story doesn't end there.
Speaker 1: What we talked about is like the first few million
Speaker 1: years of the Solar System. But there's still a lot
Speaker 1: of interesting planetary dynamics that need to be explained. Like
Speaker 1: we think that maybe Uranus and Neptune switched places at
Speaker 1: some point, and that Jupiter and Saturn may not have
Speaker 1: sort of ended up where they are now, that it
Speaker 1: may have taken a little while, and they may have
Speaker 1: also done some later migrations we're talking like five hundred
Speaker 1: million years after the start of the Solar system, So
Speaker 1: we like to think about the Solar system is sort
Speaker 1: of like it is what it is, and it's been
Speaker 1: what it's been. But if you did it like in
Speaker 1: time lapse over like hundreds of millions of years, it
Speaker 1: would seem pretty chaotic. It would seem like, wow, there's
Speaker 1: really something happening there. So that this idea of Jupiter
Speaker 1: moving in and out, is this like totally accepted by
Speaker 1: the mainstream or is this just sort of a theory
Speaker 1: that some people ascribe to. How broadly is this idea accepted? Yeah,
Speaker 1: it's somewhere in between. The astronomers I spoke to think
Speaker 1: it's like probably the most plausible explanation. But you know,
Speaker 1: there's a lot of details still to get right, and
Speaker 1: our models are just going to keep getting better and better,
Speaker 1: and then we could ask more and more detailed questions.
Speaker 1: And right now the models explain Mars, but as we
Speaker 1: make those models better, we can ask more specific questions
Speaker 1: about like why does Mars have the composition that it
Speaker 1: does and why does it get exactly this small and
Speaker 1: not larger? And maybe as we do those studies we'll
Speaker 1: find discrepancies and things that don't work, and then we'll
Speaker 1: need to modify this model. Or maybe there's some other
Speaker 1: crazy part of this story that we haven't even thought
Speaker 1: of yet that could be revealed by some little detail
Speaker 1: that some student uncovers. So, given the gaps in our
Speaker 1: data sets, which are caused by things that are hard
Speaker 1: to remove, like really really slow moving planets, what do
Speaker 1: you think the chance is that by the time you
Speaker 1: and I are, you know, retiring, that will be able
Speaker 1: to say, like, definitely, that's what Jupiter. You know, maybe
Speaker 1: we'll never be able to say definitely, but we feel
Speaker 1: super confident that that's what Jupiter did. Is this a
Speaker 1: problem that could get solved soon or are we looking
Speaker 1: at decades and decades before we can really get a
Speaker 1: good answer. Well, that depends, Kelly, how long until you
Speaker 1: plan to retire. I'm not sure I'm ever going to retire.
Speaker 1: But you know, the the average age of a woman
Speaker 1: in the US when they die is what seven seventy
Speaker 1: seven something like that, So that time scale, I think
Speaker 1: that our understanding of our solar system and other solar
Speaker 1: systems is going to be continually revolutionized, basically every ten
Speaker 1: years for the next hundred years, because we are just
Speaker 1: at the very beginning of understanding how these things work,
Speaker 1: because we have just started to look and to see
Speaker 1: these other planets, and we're going to find lots more
Speaker 1: surprises once we developed telescopes that are better at these things.
Speaker 1: Was James web launches and t to us more about
Speaker 1: cold planets. James Webb's an infrared telescope that can see
Speaker 1: things that are not just quite as hot, that can
Speaker 1: see like cold disks of protoplanetary formation and actually maybe
Speaker 1: individual planets that glow in the infrared. So we have
Speaker 1: a lot more information coming, and if the universe holds
Speaker 1: true to its reputation, it will be filled with surprises
Speaker 1: that upend our ideas. So probably by the time we retire,
Speaker 1: people will look back at these ideas as quaint and goofy,
Speaker 1: and then we'll have a much more interesting idea, probably
Speaker 1: filled with dramatic events we haven't even considered. You know,
Speaker 1: it's a really fascinating time to be alive with the
Speaker 1: kind of data that we're able to collect right now,
Speaker 1: It really is. It's a kind of time that makes
Speaker 1: me just want to like live another ten years because
Speaker 1: the things we're learning are just blowing our minds. You know.
Speaker 1: It makes me wonder, like, what would a children's book
Speaker 1: about the Solar system say in a hundred years, right, Like,
Speaker 1: I would love, I would kill to travel forward in
Speaker 1: time and steal children's books about science. Well, this suggests
Speaker 1: that biology needs more funding because we need people to
Speaker 1: be working on the problem of immortality. Don't give me that.
Speaker 1: On my campus, we have like ten times as many
Speaker 1: biologists as businists already. Alright, alright, fair enough, but I
Speaker 1: love biologists literally, I mean, I'm married to one. So
Speaker 1: I'm definitely pro biology. More funding for all the sciences
Speaker 1: so we can unravel these amazing mysteries of the universe.
Speaker 1: There you go, agreed. Alright, something we can agree on.
Speaker 1: So thank you everybody for joining us on this tour
Speaker 1: of the early days of our solar system, the dramatic
Speaker 1: story of Jupiter's visit to the inner Solar System and
Speaker 1: how it might explain everything that we're seeing, all the
Speaker 1: mysteries about the size of Mars and the composition of
Speaker 1: the asteroid belt. Thank you very much for sharing your
Speaker 1: curiosity with us. And thank you again to Kelly, our
Speaker 1: wonderful guest host for joining us on today's episode, Thanks
Speaker 1: for having me on the show, and thanks for listening everyone.
Speaker 1: It was a lot of fun, alright, tune in next time. Yeah,
Speaker 1: thanks for listening, and remember that Daniel and Jorge Explain
Speaker 1: the Universe is a production of I Heart Radio. Or
Speaker 1: more podcast from my heart Radio, visit the I heart
Speaker 1: Radio app, Apple Podcasts, or wherever you listen to your
Speaker 1: favorite shows. H