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Speaker 1: When you pull up to game night, Ay, all new Camri,
Speaker 1: but it's actually Bingo.
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Speaker 4: Hey, Daniel, what's the difference between a physicist and an astronomer?
Speaker 1: Oh? I feel like this is a trap.
Speaker 4: I know it seems like a simple question.
Speaker 1: It's a constant debate we have in faculty meetings in
Speaker 1: the Department of Physics and Astronomy. Where do we draw
Speaker 1: the arbitrary dotted line.
Speaker 4: Like, are all astronomers physicists or are some physicists astronomers?
Speaker 4: How does it work?
Speaker 1: I feel like any answer I give here is can
Speaker 1: generate a lot of angry.
Speaker 4: Emails physicists or astronomers.
Speaker 1: A lot of astronomers think of themselves as physicists first
Speaker 1: applied to questions of astronomy, but also a lot of
Speaker 1: astronomers think of themselves as a very different breed of
Speaker 1: scientists who tackle problems differently and think about things differently
Speaker 1: than physicists do.
Speaker 4: All right, that wasn't so hard.
Speaker 1: It was my best non answer.
Speaker 4: All right, may actually just ask non questions in the future.
Speaker 1: Welcome to our non podcast.
Speaker 4: Jorge. I'm a cartoonist and the author of Oliver's Great
Speaker 4: Big Universe.
Speaker 1: Hi, I'm Daniel. I'm a particle physicist and a professor
Speaker 1: at UC Irvine. Though I'm no longer sure what those
Speaker 1: categories even mean.
Speaker 4: You don't know what you are? Are you having like
Speaker 4: an identity crisis?
Speaker 1: Yes? Yes, and yes? I mean if everything's particles, then
Speaker 1: isn't everybody a particle physicist?
Speaker 5: Well?
Speaker 4: Not everything's a particle?
Speaker 1: Right, then we're all field physicists, I suppose.
Speaker 4: Like what's dark energy? Dark energy is not necessarily a particle.
Speaker 1: Yet nobody knows. Maybe dark energy is a particle we
Speaker 1: don't know.
Speaker 4: In fact, isn't particles in arbitrary name or a term like?
Speaker 4: Isn't everything just energy? In the end, maybe you should
Speaker 4: just all be energist.
Speaker 1: Yeah, if you ask ten particle physicists what is a particle,
Speaker 1: you'll get ten different answers.
Speaker 4: Well, if you guys can't even agree, then you know
Speaker 4: what's the point.
Speaker 1: The point is that names and words are how we communicate,
Speaker 1: though it's probably best if we do assign meaning to
Speaker 1: them first.
Speaker 4: Maybe should you just all do science with sign language
Speaker 4: or like charades.
Speaker 1: Let's just give up on language and use math. Right,
Speaker 1: that's just so much more crisp.
Speaker 4: I think charades is not just more fun, but also
Speaker 4: maybe a little bit easier. You would have a whole
Speaker 4: conferences where the presentations are just signists getting up there
Speaker 4: and and miming their papers.
Speaker 1: Is that supposed to increase clarity or just hilarity.
Speaker 4: Well, hopefully it'll increase clarity and also hilarity. But anyways,
Speaker 4: welcome to our podcast. Daniel and Jorge Explain the Universe
Speaker 4: a production of iHeartRadio.
Speaker 1: A podcast that does try to pump both clarity and
Speaker 1: hilarity into your brain. We hope that the universe is
Speaker 1: one that we can understand, that we could take it
Speaker 1: apart into little bits that follow some fundamental rules, then
Speaker 1: we can weave it back together into all the amazing
Speaker 1: and beautiful emergent phenomena that we enjoy, from ourselves, to
Speaker 1: our planets, to our solar system, to everything beyond, and
Speaker 1: explain all of it to you with a little bit
Speaker 1: of Dad Joe hilarity sprinkled on top.
Speaker 4: Yeah, Because whether you're a physicist and astronomer, a cartoonists
Speaker 4: and energiesst or a dad, we all live in this
Speaker 4: universe and we all look out there and we wonder
Speaker 4: how things work, why are things the way they are?
Speaker 4: And can you cerde math?
Speaker 1: Nobody wonders that, man, Nobody wonders that that's done. In
Speaker 1: the top one thousand questions, humans.
Speaker 4: Ask how do you know? Nobody wonders that, Daniel, do
Speaker 4: you have scientific proof or data to back up your claim?
Speaker 1: I do have some data. Yes, I cannot rule it
Speaker 1: out entirely, but over the many tens of thousands of
Speaker 1: questions I get from listeners, I've never gotten that one,
Speaker 1: which means it's not in the top one thousand questions.
Speaker 1: I can confidently say that.
Speaker 4: I see, but you can't say that. Nobody wonders that.
Speaker 1: No, you're right, that was too strong. You wonder that apparently,
Speaker 1: and you're people. So the exception proves the rule.
Speaker 4: I'm sure the situation has come up, like somewhere in
Speaker 4: the history of math, at some point some people needed
Speaker 4: to communicate some calculation or result and they couldn't talk
Speaker 4: for some reason.
Speaker 1: Maybe in Italian universities, you know, hand gestures are much
Speaker 1: more important in communicating these abstract ideas.
Speaker 4: Maybe that's why their equations have so much possessed.
Speaker 1: Yes, exactly, whether we're Italian or not, or using charades
Speaker 1: or symbols or language, we are trying to make sense
Speaker 1: of the universe, and part of that involves categorizing it,
Speaker 1: saying this is one kind of thing, this is another
Speaker 1: kind of thing, whether that means distinguishing between particles and fields,
Speaker 1: or between living things and not living things, or planets
Speaker 1: and dwarf planets. Putting things in boxes is just one
Speaker 1: way the humans make sense of the universe, defining kinds
Speaker 1: of things and applying those labels willy nilly.
Speaker 4: Yeah, and we are trying to make sense of the
Speaker 4: whole universe, not just the little things that we're made
Speaker 4: out of, then that things are made out of, but everything,
Speaker 4: all the huge amazing phenomena that are happening out there,
Speaker 4: the flying planets, the swirling galaxies, and the ginormous galaxy clusters.
Speaker 1: And we'd love to study all that in great detail,
Speaker 1: but most of it is very far away, and so
Speaker 1: far our technological eyeballs aren't powerful enough to really resolve
Speaker 1: all the details. So if we want to get down
Speaker 1: to the astronomical nitty gritty, we're best off studying our
Speaker 1: own backyard, looking in our solar system to understand how
Speaker 1: did it form, what's in it, what kinds of stuff
Speaker 1: are out there swirling around in our neighborhood. And over
Speaker 1: the last few hundred years, we've come to a pretty
Speaker 1: good understanding of what's there and where it's going.
Speaker 4: Yeah, we live in a pretty busy neighborhood full of planets,
Speaker 4: asteroid comets, raining satellites from failed rockets, and so there's
Speaker 4: a lot for us to see in our very near vicinity.
Speaker 1: And while the truth is that the Solar system is
Speaker 1: filled with a huge spectrum of stuff, from tiny cosmic
Speaker 1: dust to huge gas giants to the Sun itself, we
Speaker 1: do like to impose categories on it. And as the
Speaker 1: decades and centuries go by, we keep discovering things that
Speaker 1: lie at the edge of those boundaries that challenge our
Speaker 1: definitions for what is what, Pluto of course being a
Speaker 1: famous example. But as our telescopes get more powerful, we
Speaker 1: keep discovering things in the wrong places or at the
Speaker 1: edge of these definitions that make us wonder, really, where
Speaker 1: do we draw these dotted lines?
Speaker 4: And so to be on the podcast will be tackling
Speaker 4: the question are there comments in the asteroid belt? Now?
Speaker 4: How many pop do you think wonder about this question?
Speaker 5: Day?
Speaker 4: Of your tens of thousands of emails, how many have
Speaker 4: asked this particular question.
Speaker 1: This particular question in this phrasing zero.
Speaker 4: So you're saying the same amount of people that wonder
Speaker 4: if there are comments in the asteroid belt? Also probably
Speaker 4: perhaps wonder if you can cherate now.
Speaker 1: If that was your metric, Yes, but there are a
Speaker 1: lot of questions in the vicinity of this wondering about
Speaker 1: like what's the difference between commets and asteroids? Or why
Speaker 1: do we have comments out there and asteroids over here?
Speaker 1: So I think people are curious about, like what's out
Speaker 1: there in the Solar system? Why do we give them
Speaker 1: these labels? And is it really so neat and crisp.
Speaker 4: This is an interesting question, and so let's dig into it.
Speaker 4: And as usually, we were wondering how many out there
Speaker 4: had thought about this question of whether there are comets
Speaker 4: in the asteroid belt.
Speaker 1: Thanks very much to everybody who contributes their voice to
Speaker 1: this segment of the podcast. Really appreciate your responses. If
Speaker 1: you'd like to hear yourself on a future episode, please
Speaker 1: don't be shy. Write to me too, questions at Danielandjorge
Speaker 1: dot com.
Speaker 4: So think about it for a second. Cast your mind
Speaker 4: out there into the far reaches of our solar system
Speaker 4: and wonder if there are comets in the asteroid belt.
Speaker 4: Here's what people had to say.
Speaker 6: I mean, sure, why not? Maybe they also pass through
Speaker 6: the asteroid belt from time to time. And I always
Speaker 6: thought astroid belt was what's mainly in that wage, not
Speaker 6: what's the only thing in that region.
Speaker 7: I don't have a very good idea the definition of
Speaker 7: a comment versus an asteroid. But I think it has
Speaker 7: to do with amount of ice in the structure. So
Speaker 7: if that is the definition, I can imagine sure there
Speaker 7: might be something that falls under that definition in the
Speaker 7: asteroid belt.
Speaker 1: No comment in the asteroid belt, just asteroids. Comments are
Speaker 1: out a lot further.
Speaker 5: I think another sort of way to distinguish comets from
Speaker 5: asteroids is that asteroids are well in the asteroid belt
Speaker 5: and comets can come from a couple different places. Long
Speaker 5: period comets come from the Oort Cloud, but then there
Speaker 5: are shorter period comets than that. Now, if we have
Speaker 5: a dirty snowball in the asteroid belt, which I believe
Speaker 5: there are, some of these bodies that have been discovered,
Speaker 5: are they correctly labeled as comets?
Speaker 1: Are not commets? I anser are made up ice. I
Speaker 1: think if they were that close they probably melt.
Speaker 8: I think comets coming in at a high rate of
Speaker 8: speed from the Oort Cloud are unlikely to get caught
Speaker 8: up in the asteroid belt.
Speaker 4: Comet might be more about composition than trajectory. I mean
Speaker 4: that if it has more ice than rock, it might
Speaker 4: be a comet.
Speaker 9: I can never remember the difference between asteroids and commets.
Speaker 9: I mean, surely there's a good acronym or something else
Speaker 9: there to remember the difference. But I have to say
Speaker 9: that there's no comets in the asteroid belt because asteroids
Speaker 9: become comets after they and through the atmosphere.
Speaker 10: So there are short period comets, and I think there
Speaker 10: are some that operate closer to the Sun, kind of
Speaker 10: in that asteroid belt range, but being within the ice
Speaker 10: line like most of its quote unquote life, I don't
Speaker 10: really see how they can be long lived.
Speaker 11: I think comets are heavenly bodies which have eccentric orbits
Speaker 11: around the Sun, so they don't fit in nicely with
Speaker 11: the other better behaved inhabitants of the Solar System. So
Speaker 11: although comets may pass through the asteroid belt, I don't
Speaker 11: think they can remain there permanently.
Speaker 12: I think that the asteroid belt is far enough out
Speaker 12: so that comets could remain frozen, and I guess the
Speaker 12: asteroid belt does have a lot of its own gravities,
Speaker 12: so it could capture comets if it was lucky.
Speaker 8: I think there might be a few transient comets in
Speaker 8: the asteroid belt, but I don't think that there would
Speaker 8: be much chance for comets to persist in that kind
Speaker 8: of orbit because of exposure to the wind and the
Speaker 8: interaction of the gravity of Jupiter disrupting either the orbit
Speaker 8: or the structure of those comets.
Speaker 13: Guess there could be comets, but yeah, usually commas have
Speaker 13: a large orbit, a very large orbit in detail.
Speaker 8: That wouldn't be the case if it was found in
Speaker 8: the asteroid belt.
Speaker 4: So yeah, pretty wide range of answers here. I guess
Speaker 4: there's only two options, yes or.
Speaker 1: No, or there could be this is a trick question,
Speaker 1: or let's answer in charades, right.
Speaker 4: What made you think of this question? Why are there
Speaker 4: commets in the asteroid belt? Is this something that astronomers
Speaker 4: have been wondering about.
Speaker 1: I've been thinking about this kind of question for a
Speaker 1: while because I find the whole labeling of stuff in
Speaker 1: the Solar System to be kind of ridiculous and arbitrary.
Speaker 1: You know, we're just humans putting dotted lines on a
Speaker 1: smooth spectrum of different kind of stuff that's out there.
Speaker 1: But also it is interesting because when you invent categories,
Speaker 1: then you can wonder about things and the boundaries or
Speaker 1: things across the boundaries. And then I read a paper
Speaker 1: about people who were finding weird stuff in the asteroids
Speaker 1: that didn't belong there.
Speaker 4: All right, well, let's dig into it, Daniel, I guess
Speaker 4: the question is, but comets and asteroids, what's the difference
Speaker 4: between the two?
Speaker 1: Yes, So these are two human constructed, arbitrary definitions that
Speaker 1: are mostly historical and don't really represent like our best
Speaker 1: understanding of what's out there in the Solar System. If
Speaker 1: you were going to start today, you probably wouldn't come
Speaker 1: up with the same definitions. But you know, science is
Speaker 1: a human endeavor, which means we need to understand the
Speaker 1: words scientists use when they talk to each other, even
Speaker 1: if it's imprecise or historical or ridiculous. So what do
Speaker 1: we mean by an asteroid and what do we mean
Speaker 1: by a comet? So an asteroid is basically like a
Speaker 1: mini planet. Right, there's this complicated definition of a planet
Speaker 1: as an object in the Solar System that's orbiting the Sun,
Speaker 1: is big enough to be mostly round and has cleared
Speaker 1: its own path. An asteroid is like that, except that
Speaker 1: it's not necessarily big enough to be round, and it
Speaker 1: hasn't cleared its own path. So it's like a mini chunky,
Speaker 1: funky shaped planet that doesn't have its own parking space.
Speaker 4: But is there like a size range, like can you
Speaker 4: have an asteroid the size of a marble or does
Speaker 4: that count as something else?
Speaker 1: Technically, there's no minimum size for an asteroid, so like
Speaker 1: a dust grain technically is an asteroid. Practically that's very,
Speaker 1: very difficult to see those things, you know, of course,
Speaker 1: unless they land on Earth, in which case they're no
Speaker 1: longer an asteroid. We can't really detect them in the
Speaker 1: asteroid belt unless they're very shiny or large, or some
Speaker 1: combination of them. So the range of asteroids that we've discovered,
Speaker 1: like in the asteroid belt, goes from things like down
Speaker 1: to one meter across all the way up to things
Speaker 1: like five hundred kilometers across. So there's an incredible range
Speaker 1: of stuff in the asteroid belt that we call asteroids.
Speaker 1: We give them all the same name.
Speaker 4: But I guess there's one common thread, which is that
Speaker 4: it needs to be some kind of solid material, right,
Speaker 4: Like a cloud of gas doesn't count as an asteroid, right.
Speaker 1: Yeah, that's right, needs to hold itself together.
Speaker 4: So it has to be solid, and it has to
Speaker 4: be in space. Is that about the definition of an asteroid?
Speaker 4: Something solid floating in space that's not round.
Speaker 1: And it has to be orbiting the Sun. It's a
Speaker 1: rocky object that orbits the Sun and doesn't qualify as
Speaker 1: being a planet or a comet.
Speaker 4: But I guess, why does it need to be orbiting
Speaker 4: the Sun? Can't you have an asteroid other than space
Speaker 4: by itself? Like what do you call those?
Speaker 1: Well, if it's not orbiting the Sun and it's orbiting
Speaker 1: like the Earth, then you'd call it a moon. If
Speaker 1: it's not orbiting the Sun and it's not really orbiting anything,
Speaker 1: it's just like floating in the galaxy, then it's not
Speaker 1: an asteroid. It's just a rock.
Speaker 4: Is that the official astronomy definition? It's just a space rock?
Speaker 4: Are you sure we don't want to anger any astronomers.
Speaker 1: Now, it's definitely don't. And you know, I'm in a
Speaker 1: department of physics and astronomy, and that doesn't make me
Speaker 1: an astronomer, even though I'm technically a professor of physics
Speaker 1: and astronomy, and I don't want to speak for the astronomers,
Speaker 1: but that is my understanding. If it's out there in
Speaker 1: interstellar space, you could call it an interstellar asteroid. I
Speaker 1: suppose the problem is we haven't like discovered or seen
Speaker 1: many of those. You know, we have had a couple
Speaker 1: of interstellar objects come, but those who think are interstellar
Speaker 1: comets not interstellar asteroids. So yeah, that's a whole new frontier.
Speaker 4: Yeah, like like in Star Wars when they run into
Speaker 4: like an asteroid field, are they taken not calling it
Speaker 4: the right thing?
Speaker 5: Well?
Speaker 1: I think those are usually near a stars. They're probably
Speaker 1: are orbiting a star.
Speaker 4: I don't know, they never show the star.
Speaker 1: That's what I'm always thinking about when they're dodging asteroids.
Speaker 1: Where's the star that makes us an asteroid and not
Speaker 1: a rock?
Speaker 4: Excuse me? Excuse me, I don't see the sun actually,
Speaker 4: all right, So an asteroid is by definition a rock
Speaker 4: that's orbiting the sun. Basically, Yeah, it has to be solid, right,
Speaker 4: or like a solid object that's orbiting the sun.
Speaker 1: Yeah, And your point there about it being solid is crucial.
Speaker 1: Asteroids are rocky objects, meaning they're made of rock and
Speaker 1: metal in this kind kind of stuff, and that's going
Speaker 1: to help us distinguish them from their cousin the comet.
Speaker 4: Gosh, well, how do you define a rock?
Speaker 1: A rock is something made it mostly out of silica.
Speaker 1: You know, the chemical composition of these things tells you
Speaker 1: what it is. If it's a blob of iron, then
Speaker 1: it's metal. You know, if it's a this is all chemistry. Man,
Speaker 1: it's well beyond me. Don't ask me to do chemistry.
Speaker 4: Joined the Department of Physics, Astronomy and chemistry.
Speaker 1: No, never, never, My son is into chemistry.
Speaker 4: Yeah, I guess, I guess all those professors just don't
Speaker 4: have the chemistry.
Speaker 1: I don't have chemistry with those professors, that's for sure. No.
Speaker 1: I respect chemistry, I respect chemists, but I'm not that
Speaker 1: in the history of asteroids is kind of fascinating because,
Speaker 1: you know, we use these words, but for a long time,
Speaker 1: people didn't really distinguish between planets and asteroids, and the
Speaker 1: word planet was used very broadly, like the moon was
Speaker 1: a planet for a while before we invented the concept
Speaker 1: of a moon. So these things change with time. It's
Speaker 1: possible to redefine what is a planet or an asteroid.
Speaker 1: Maybe in five hundred years, honors will have totally different
Speaker 1: words for these things, or use the same words in
Speaker 1: a different way.
Speaker 4: Who knows, yeah, or maybe they'll use the same like
Speaker 4: charade gesture.
Speaker 1: That's exactly when we transition fully to charade science, then.
Speaker 4: We're I wonder if in the future we transition to
Speaker 4: like telepathy, you know, then you don't need words, you
Speaker 4: can just transfer thoughts.
Speaker 1: All right, Well, if we're playing charades and your clue
Speaker 1: was asteroid, what motions would you use to describe it?
Speaker 4: Oh, that's totally easy, Dan, I would do this, so
Speaker 4: he totally conveys what asteroid means.
Speaker 1: Okay, that's a funny way to duck the question. But seriously,
Speaker 1: can you describe what an asteroid gesture would be?
Speaker 4: I just did, all right, but I feel like we're
Speaker 4: getting a little bit uh delled.
Speaker 1: Well, then let's go back to the history of asteroids,
Speaker 1: because I also think it's fascinating when we knew there
Speaker 1: were lots of asteroids, Like, as our technology developed to
Speaker 1: be able to see these things, right, we can see smaller,
Speaker 1: smaller ones. Then we discovered more, and it's this incredible
Speaker 1: sort of explosion of discovery.
Speaker 4: But how do we see them? Like you sort of
Speaker 4: can't see asteroids with the naked eye, can you? Or
Speaker 4: sometimes if they like catch the sun.
Speaker 1: Technically, I don't see why you couldn't have photons hit
Speaker 1: an asteroid and then hit your eye, but enough of
Speaker 1: them for you to spot it and identify it seems
Speaker 1: very challenging. So asteroids are usually seen through telescopes just
Speaker 1: because you know, the aperture is larger and you're gathering
Speaker 1: more light and so it's basically a bigger eyeball.
Speaker 4: So is that how they discover them? Like they were
Speaker 4: looking through a telescope and they saw a bunch of
Speaker 4: these They probably looked like pinpoint stars, but they were
Speaker 4: probably moving faster than the regular stars.
Speaker 1: Exactly the same way that planets move across the field
Speaker 1: of the stars, which is how you know that they're closer, right,
Speaker 1: And that's why sort of planets and asteroids were called
Speaker 1: the same thing for a long time before we distinguished
Speaker 1: between them somewhat arbitrarily. And you know, until one hundred
Speaker 1: and fifty years ago, we thought there were six ish planets,
Speaker 1: and we thought there were about ten astraids. Like eighteen
Speaker 1: forty nine, we knew about ten different asteroids, and then
Speaker 1: as technology improved, that number grew to be one hundred
Speaker 1: twenty years later, to a thousand about one hundred years ago,
Speaker 1: And now we know about more than a million individual
Speaker 1: asteroids that can be tracked, and we have these telescopes
Speaker 1: that look at these things, of course, because we're concerned
Speaker 1: about whether one of them might eventually hit the Earth,
Speaker 1: and NASA is tracking all of these things. And as
Speaker 1: you say it, they don't glow, but they do reflect
Speaker 1: the Sun, and so when the conditions line up for
Speaker 1: like photons from the Sun to hit the asteroid and
Speaker 1: then reflect back into the telescope aperture, that's when we
Speaker 1: see it. But a lot of these things are invisible
Speaker 1: for long fractions of their flight around the Sun.
Speaker 4: Now, what was the technological advance that it allows us
Speaker 4: to see so many? Like you, we just got bigger
Speaker 4: telescopes and we're more sensitive. They could see dimmer things,
Speaker 4: or we could maybe zoom with more presition into certain
Speaker 4: parts of the sky.
Speaker 1: Yea. It's a combination of more telescopes and bigger telescopes.
Speaker 1: So a lot of this is limited by glass technology.
Speaker 1: Can you make lenses that are big and smooth and
Speaker 1: free of aberrations and so like Galileo's original telescopes are
Speaker 1: pretty bad, right, and limited by the size of the
Speaker 1: telescope you could make because the glass you could grind
Speaker 1: and have it to be smooth and not create distortions
Speaker 1: was pretty small. But then people got a lot better
Speaker 1: at that about one hundred and fifty years ago, and
Speaker 1: things exploded from there, and then we also just built
Speaker 1: more of them. And now, of course we have dedicated
Speaker 1: space telescopes just out there looking for.
Speaker 4: These things millionnasteras. That's pretty wild. I mean, if you
Speaker 4: could see the way these telescopes could see, you would
Speaker 4: see the night sky basically like shifting all the time, right, moving, swirling, spinning.
Speaker 1: Yeah, it's much more dynamic than you imagine. There's a
Speaker 1: lot of stuff out there. There's also an inflection point
Speaker 1: in sort of the history of astronomy in the mid
Speaker 1: nineties when Jupiter was hit by a comet. Comet Shoemaker
Speaker 1: Levee broke up as it entered the inner Solar System,
Speaker 1: whipped around the Sun, and then each of the twenty
Speaker 1: six or so pieces slammed into Jupiter, creating huge fireballs
Speaker 1: the size of the Earth. And that's made people wake
Speaker 1: up to the idea that like, wow, you know, asteroids
Speaker 1: of comets really could hit the Earth. This is potentially
Speaker 1: an existential threat. And NASA has really been investing in
Speaker 1: tracking near Earth objects ever since that moment. Comet Shoemaker Levee.
Speaker 1: That's one reason why we went from like seeing some
Speaker 1: of the asteroids to like, let's be serious about this,
Speaker 1: folks and make a solid catalog of all the biggest ones.
Speaker 4: Okay, so that's asteroids, and most asteroids are in the
Speaker 4: asteroid belt, right, or there's a couple of belts around
Speaker 4: the Solar System.
Speaker 1: Yeah, asteroids are mostly in the asteroid belt, which is
Speaker 1: between Mars and Jupiter. And that's not an accident, right.
Speaker 1: The reason we have asteroids is basically because of Jupiter.
Speaker 1: Jupiter has a huge fraction of the mass of the
Speaker 1: Solar System that's not in the Sun. Like the Sun
Speaker 1: is ninety nine percent of the mass Solar System, and
Speaker 1: Jupiter is almost three times the mass of everything else
Speaker 1: in the Solar System combined, including like Saturn and Neptune
Speaker 1: and Urinous. So it's a big massive thing and it's gravity.
Speaker 4: Wait what so like seventy percent of the non Sun
Speaker 4: mass in the Solar System is Jupiter.
Speaker 1: Yeah, Jupiter is a big hog.
Speaker 4: You know, I'm not sure we should be shaming Jupiter, Daniel.
Speaker 1: You're taking big hog to be pejorative. I meant that
Speaker 1: as a compliment, like, hey, good job, Jupiter, congrats.
Speaker 4: I don't know, I guess it was your tone.
Speaker 1: Okay, Hey, Jupiter is a big hog has that. But
Speaker 1: you know, this is a gravitational runaway effect at work.
Speaker 1: You have a huge cloud of gas and dust that
Speaker 1: forms the Solar System. Somewhere in there is an initial
Speaker 1: density that causes the collapse that's going to turn into
Speaker 1: the Sun. But if somewhere else in that nearby cloud
Speaker 1: also has a little spot of density, then it can
Speaker 1: form its own little runaway effect to gobble up some
Speaker 1: of that gas and dust before it falls into the Sun.
Speaker 1: And that's what Jupiter did.
Speaker 4: Now, Jupiter is mostly made out of gas, So I
Speaker 4: wonder why got so much of the gas in the
Speaker 4: Solar system? Like, did it some of it just blow
Speaker 4: away when the Sun ignited or what and it just
Speaker 4: happened to gather around Jupiter.
Speaker 1: Yeah, there's a lot of controversy about that. Where gas
Speaker 1: giants form. Do they mostly form in the outer Solar
Speaker 1: System and then transition inward? Do they form in the
Speaker 1: inner Solar System? We see a lot of gas giants
Speaker 1: in exoplanet systems that are near their Sun, but we
Speaker 1: think probably these gas giants form farther away because further
Speaker 1: away from the Sun. Number one, the gas isn't being
Speaker 1: blown away by the radiation of the Sun. And number two,
Speaker 1: there's ice there, which helps these planets accrete more quickly.
Speaker 1: There's like more stuff to gather. So we think that
Speaker 1: Jupiter became so big because it's so close to that
Speaker 1: snow line, you know, where ice and frozen vapor can
Speaker 1: still exist. It helps these planets a creek quickly. And
Speaker 1: then we think it's probably a complicated history of Jupiter
Speaker 1: moving in towards the Sun and then getting pulled back
Speaker 1: out by a now missing gas giant which was ejected
Speaker 1: in that interaction. So the whole formation of Jupiter is
Speaker 1: a really fascinating and complex topic.
Speaker 4: All right, Well, let's dig into where else in the
Speaker 4: Solar System you might find asteroids, and then we'll dig
Speaker 4: into comments and whether there are any in the asteroid belt.
Speaker 4: So we'll get to that, but first let's take a
Speaker 4: quick break.
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Speaker 4: Where we're talking about asteroids, commets and belts and the
Speaker 4: fact that Jupiter needs a really big built And the
Speaker 4: question is are there commets in the asteroid belt. So
Speaker 4: we've been talking about asteroids what they are, and you
Speaker 4: said they're mostly in the asteroid built but can you
Speaker 4: find them anywhere else in the Solar System.
Speaker 1: You can find them also in Jupiter's orbit. So there's
Speaker 1: a big blob of asteroids ahead of Jupiter in its
Speaker 1: orbit and another one behind Jupiter in its orbit. They're
Speaker 1: like leading and trailing Jupiter. These are called the Greeks
Speaker 1: and the Trojans, and these are just like big clumps
Speaker 1: of rock that are in Jupiter's orbit. So you know, technically,
Speaker 1: did Jupiter really clear its orbit? Is Jupiter even a planet? Well?
Speaker 4: I mean is if these things are orbiting Jupiter, then
Speaker 4: they're not asteroids, right, No.
Speaker 1: These things are orbiting the Sun in the same orbit
Speaker 1: as Jupiter. Oh yeah, And all of this is just
Speaker 1: dominated by Jupiter's gravity. Like, why don't the rocks in
Speaker 1: the asteroid belt come together to make another planet the
Speaker 1: way they did for Earth or for Mercury, or even
Speaker 1: for Mars. The answer is Jupiter's gravity distorts it, It
Speaker 1: pulls it apart, it shreds things. These are all tidal
Speaker 1: for do you put in gravity so strongly if you
Speaker 1: try to pull these things together, It's gravity would tug
Speaker 1: on one side harder than the tug's on another side
Speaker 1: and pull it apart. So it sort of like mixes
Speaker 1: it up. It's I got a big spoon, and it
Speaker 1: keeps stirring up the asteroid belt and keeping it from
Speaker 1: coalescing into something WOA.
Speaker 4: It just disrupts the formation of any planets in that
Speaker 4: sort of neighborhood exactly. Do we have any asteroids out
Speaker 4: there beyond the gas giants?
Speaker 1: There are definitely rocks further out in the Solar System,
Speaker 1: because remember any big rocky object that's not a planet
Speaker 1: or a dwarf planet is technically an asteroid. There's some
Speaker 1: fuzziness there because past Neptune there's a huge number of
Speaker 1: these objects we called dwarf planets, which are like sort
Speaker 1: of larger enough to be called a planet, maybe by
Speaker 1: havn't cleared their own path right, like Pluto and Sharon,
Speaker 1: for example. And so the distinction between dwarf planet and
Speaker 1: asteroid out there and the edges of the Solar System
Speaker 1: is pretty fuzzy.
Speaker 4: You have to ask an astronomer Okay, So then the
Speaker 4: question was are there comets in the astory belt? And
Speaker 4: now how do you define what a comet is?
Speaker 1: Yeah? So your comment earlier about asteroids that they have
Speaker 1: to be solid was really on point because one of
Speaker 1: the crucial ways we define a comet is very similar
Speaker 1: to the way we define an asteroid. An asteroid is
Speaker 1: a rocky object that orbits the sun. A comet is
Speaker 1: an icy and dusty object that orbits the sun.
Speaker 13: Icy.
Speaker 4: So it's made out of ice. But isn't ice technically
Speaker 4: a mineral, which means it's a rock? Right?
Speaker 1: Yeah, there's a distinction here. Ice is not like a silicate, right,
Speaker 1: It doesn't have the same chemical composition as these things
Speaker 1: we call it rocks.
Speaker 4: Excuse me, Daniel, excuse me. I believe. I believe that
Speaker 4: the definition of a rock is like a composite of minerals, right,
Speaker 4: and ice is a mineral. So wouldn't ice be a rock?
Speaker 4: Or is this something that would be have to be
Speaker 4: decided in a death match between geologists and astronomer.
Speaker 1: Yeah, and I think some chemists need to be involved
Speaker 1: in that conversation. But in terms of the Solar system,
Speaker 1: we distinguish between ice and other kinds of rock or rocks,
Speaker 1: depending on whether you're gonna call ice.
Speaker 4: A rock and so ice. How do you define ice?
Speaker 4: Does it need to be water or can it be
Speaker 4: other liquids?
Speaker 1: There's several categories there. First of all, water ice has
Speaker 1: lots of different chemical forms, so it's not just the
Speaker 1: kind of ice that we see on Earth. There's like
Speaker 1: ice and ice three, and ice seven and ice nine,
Speaker 1: all sorts of complicated water chemistry to give you solid
Speaker 1: forms of ice that we don't often see on Earth
Speaker 1: because it's a very different pressure environment out there in
Speaker 1: the outer Solar System. But also you know, things like methane.
Speaker 1: If that's frozen, they call that ice. A lot of
Speaker 1: the ice that's out there is water ice, but there
Speaker 1: are also other kinds of ices.
Speaker 4: Gosh, I have so many netpicky questions, Daniel. I mean, like,
Speaker 4: if you heat up a rock, it'll melt, so it's liquid.
Speaker 4: So really a rock is just frozen liquid rock.
Speaker 1: Yes, a rock is frozen liquid rock. But lots of
Speaker 1: sot our frozen liquids.
Speaker 4: Right, how do you define what an ice is?
Speaker 1: There's an arbitrary dotted line, you know, it's just historical.
Speaker 1: Some crystals we call ices. Some crystals we call rocks.
Speaker 1: And that's, frankly, is my whole problem with chemistry. All
Speaker 1: of chemistry is like this, just like draw dotted lines
Speaker 1: between stuff because some dude one hundred and fifty years
Speaker 1: ago thought that made sense. We're sticking to it.
Speaker 4: Well, it sounds like it's not just chemistry, it's physics, astronomy.
Speaker 4: Why are you tying chemist under the bus.
Speaker 1: We're definitely guilty of that in physics and in astronomy,
Speaker 1: and especially in this situation naming things in the solar system.
Speaker 1: But and I'm really going to catch a lot of
Speaker 1: flak from the chemists out there. I feel like all
Speaker 1: of chemistry is just built on that. Like, if you
Speaker 1: took that away from chemistry, what do you have left?
Speaker 12: Man?
Speaker 1: It's all just exceptions.
Speaker 4: Oh man, he just lost is a bunch of chemists listeners?
Speaker 1: No, man, they're all going to right to me, and
Speaker 1: they're gonna listen carefully through all the next episodes to
Speaker 1: see if I slight chemistry.
Speaker 4: I see they're gonna hate listening. That's the kind of
Speaker 4: fan that we want. Look, as long as they sit
Speaker 4: through the ads, then we don't care or why.
Speaker 1: They're Lovelessen or hate listen, we love you.
Speaker 4: All right, So then what does that leaves about the
Speaker 4: definition of a comet.
Speaker 1: So, according to the arbitrary distinction between ices and rocks,
Speaker 1: comets are made out of ice and asteroids are made
Speaker 1: out of rocks. And one important difference is that if
Speaker 1: you bring something made out of ice into the Inner
Speaker 1: Solar System, it tends to vaporize, Like the Sun is
Speaker 1: capable of turning those ices into vapor and it's not
Speaker 1: capable of doing that with rock. So probably there's some
Speaker 1: distinction there about like the melting point or the vapor
Speaker 1: point of these substances.
Speaker 4: Oh, I see, all right, So now we're getting somewhere.
Speaker 4: It's the sort of scientific If it melts under the
Speaker 4: light of the Sun, then you might call it a comet.
Speaker 4: That's basically the only distinction that sea.
Speaker 1: Yeah, And when you bring these things into the inner
Speaker 1: Solar System, like comets traditionally originate in the Kuiper Belt
Speaker 1: or in the Ort cloud, which you're kind of like
Speaker 1: bands of rocks in the more distant parts of the
Speaker 1: Solar System, much further out than the asteroid belt. When
Speaker 1: you bring them into the inner Solar System, they develop
Speaker 1: tails because the Sun is beginning to vaporize them, they
Speaker 1: get a coma, they have like a little envelope of
Speaker 1: gas around them, and then as they move in towards
Speaker 1: the Solar System, they get tails. And so that's really
Speaker 1: what distinguishes comets from asteroids. Asteroids are just rocks, and
Speaker 1: comets have these little gas clouds and tails because they're
Speaker 1: made out of.
Speaker 4: Ices, all right, and they mostly hang out on the
Speaker 4: outside of the Solar System.
Speaker 1: Right, Yeah, they originate in the Kuiper Belt, which is
Speaker 1: this big collection of rocks, billions and billions of snowballs
Speaker 1: in the distant Solar System, and this is probably the
Speaker 1: origin of short period comets, like you know, years up
Speaker 1: to tens of years. And then we think there's a
Speaker 1: collection of them also much much further out in the
Speaker 1: Ort Cloud, which is like very far out there, much
Speaker 1: further than Pluto. And it's also technically theoretical because we've
Speaker 1: never actually seen the Ork Cloud. We've just like deduced
Speaker 1: its existence from various gravitational calculations and models. And we
Speaker 1: also think that it's the source of long period comets,
Speaker 1: comets with periods you know, again longer than tens or
Speaker 1: hundreds of years, and they could take a very long
Speaker 1: time to fall into the inner Solar System, and out
Speaker 1: there there could be trillions of these.
Speaker 4: Snowballs, and that's in the or cloud. So what's the
Speaker 4: Kuiper belt? Is it asteroids or comets?
Speaker 1: The Kuiper Belt is snowballs, and when they fall into
Speaker 1: the Inner Solar System you call them comets. I think
Speaker 1: you still call them commets when they're in the Kuiper
Speaker 1: Belt before they've fallen in, because technically they are icy
Speaker 1: objects out in the Solar System orbiting the Sun.
Speaker 4: Because they would melt if they got closer to the Sun.
Speaker 4: But doesn't everything melt if you get close enough to
Speaker 4: the Sun?
Speaker 1: Yeah, exactly, And so this distinction between asteroids and comets
Speaker 1: is also a little bit fuzzy. I found a comet
Speaker 1: from an astronomer or the University of Arizona who said, quote,
Speaker 1: everything is a comet. If you brought my couch close
Speaker 1: enough to the Sun, it would start melting and have
Speaker 1: a coma. So like it's just a question of how
Speaker 1: close you get to the Sun. Because you bring an
Speaker 1: asteroid close enough to the Sun, it's to get vaporized.
Speaker 1: Even if it's like a hunk of iron.
Speaker 4: What if it's a hunk of like diamond.
Speaker 1: If you dropped a huge diamond into the sun, it
Speaker 1: would definitely get vaporized.
Speaker 4: Yeah, into the sun.
Speaker 1: If you had a huge diamond and you dropped it
Speaker 1: from the outer solar system and it fell in towards
Speaker 1: the Sun at some point at which it would reach
Speaker 1: its melting point, and you would melt.
Speaker 4: That diamond and become a diamond commet.
Speaker 1: A diamond commet with a cloud of carbon.
Speaker 4: And leave a trail of sparkly melted diamonds.
Speaker 1: Yeah. I think melted diamond is just carbon though, because
Speaker 1: it's only diamond because of the arrangement of those carbon atoms,
Speaker 1: and so once you melted it could it's the same
Speaker 1: as like melted coal. I guess.
Speaker 4: Oh man, now we're getting really confusing.
Speaker 1: Turn chemistry is a mess.
Speaker 4: Is melted chocolate just carbon?
Speaker 12: Then?
Speaker 4: Oh no, are just eating coal when I when I'm
Speaker 4: drinking my hot cocoa.
Speaker 1: That's why putting these names on things is such a mess,
Speaker 1: and we should just use math or charades.
Speaker 4: That's why would you just use charades or speed up
Speaker 4: the telepathy idea?
Speaker 1: And then to make things even more confusing, there's another
Speaker 1: category of stuff that's sort of like a hybrid, these
Speaker 1: things that are actually brilliantly named. They call them centaurs.
Speaker 1: You know. Centaurs are like half horse, half human. These
Speaker 1: things have characteristics of asteroids and characteristics of comets. So
Speaker 1: they're sort of like a comet because they have long
Speaker 1: elliptical orbits the way comets do, and some of them
Speaker 1: have dust comas. But they're kind of like asteroids in
Speaker 1: that they're really large and they're mostly metallic. But they're
Speaker 1: not like asteroids because they leave the asteroid belts and
Speaker 1: they sort of traverse the Solar system the way comets do.
Speaker 1: So these centaurs are sort of like a weird thing
Speaker 1: in the Solar system that blurs the line between asteroid and.
Speaker 4: Comet, meaning like it's a mix of rocks and ice.
Speaker 1: Yeah, exactly, And it sort of moves like a comet,
Speaker 1: and it's the size of an asteroid. These things tend
Speaker 1: to be typically bigger.
Speaker 4: I mean, it moves like a common You never said
Speaker 4: motion was part of the definition.
Speaker 1: Yeah, it's not technically part of the definition, right, But
Speaker 1: comets tend to have these longer elliptical orbits just because
Speaker 1: of where they come from in the Solar System. They
Speaker 1: come from further out, and so they have these longer
Speaker 1: orbits that traverse the path of the giant planets, whereas
Speaker 1: asteroids typically hanging out in the asteroid belt and sometimes
Speaker 1: fall in and so they don't traverse the giant planets.
Speaker 1: So if you have like an asteroid like rock that
Speaker 1: also has a long elliptical orbit, you're like, hmm, it's
Speaker 1: a little comedy. It's a little asteroidy. You know. It's
Speaker 1: sort of like chocolate and peanut butter, which.
Speaker 4: We all know. If you melt it just becomes carbon.
Speaker 1: And if you squeeze it hard enough, it becomes a diamond.
Speaker 4: Yeah, technically a chunky diamond or a smooth diamond.
Speaker 1: Yeah, maybe a creamy diamond.
Speaker 4: Yeah, or me a carrot diamond.
Speaker 1: I like my diamonds nicely salted.
Speaker 4: So these centers are pretty interesting. How big can they get?
Speaker 1: Some of them are pretty big, Like the largest one
Speaker 1: is two hundred and seventy kilometers across, and actually it's
Speaker 1: so big that it has its own rings, like a
Speaker 1: little group of dust and tiny rocks orbiting this centaur.
Speaker 4: Well, and where is that one?
Speaker 1: It orbits in the Solar system out there between Saturn
Speaker 1: and Urinus. So it's a big blob out there, and
Speaker 1: it's sort of weird to be that far out. Why
Speaker 1: isn't it in the asteroid belts? Or if it's that
Speaker 1: far out, why doesn't that have more ice?
Speaker 5: You know?
Speaker 1: You might ask also, well, why do all the objects
Speaker 1: and what we call the asteroid belt, why are they
Speaker 1: mostly rocks and metal and the stuff out there in
Speaker 1: what we call the Kuyper belt in the or cloud,
Speaker 1: why do they have more ices? And that's just distance
Speaker 1: from the sun. If you're further from the Sun, then
Speaker 1: the sun is not bright enough, not hot enough to
Speaker 1: vaporize all that stuff, so you get these ices. And
Speaker 1: that's why comets when they form out there, are icy
Speaker 1: and asteroids are not. The way the Earth is not
Speaker 1: mostly icy, right, And so it's weird to have an
Speaker 1: object that's out there beyond the snow line that doesn't
Speaker 1: have as much snow or ice as everything else.
Speaker 4: And how do we know it's a centaur? Does it
Speaker 4: have a take?
Speaker 1: This one is big enough that it might have its
Speaker 1: own like little atmosphere, right, things that are boiling off
Speaker 1: of it, But we don't know the composition of it
Speaker 1: that well, it's sort of far enough away that it's
Speaker 1: difficult to study, but we do see that it has
Speaker 1: its own ring systems, so we have some information about it.
Speaker 1: But these things are really fascinating because they paint sort
Speaker 1: of a picture of the history of the solar system.
Speaker 1: A lot of this stuff is interesting in the context
Speaker 1: of like, hey, how did we get here? How did
Speaker 1: our solar system end up the way that it is.
Speaker 1: All these things are clues that let us like back
Speaker 1: out that story and figure out how it all got
Speaker 1: arranged to be this way.
Speaker 4: Sok Can we tell what it's made out of with
Speaker 4: our telescopes.
Speaker 1: We can tell a little bit because of the color,
Speaker 1: Like some of these things are a little bluer and
Speaker 1: some of these things are a little redder. That gives
Speaker 1: us a clue as to what they are, because what
Speaker 1: they are determines, you know, what they're reflecting and what
Speaker 1: they're absorbing. So we have some clues about their chemical composition.
Speaker 1: But that's also sort of a mystery. Like some of
Speaker 1: these centaurs are bluer and some of these are redder.
Speaker 1: Some of them look more like asteroids, of them look
Speaker 1: less like asteroids. That's sort of one of the central
Speaker 1: mysteries of centaurs. But none of these things have been
Speaker 1: like photographed up close. A lot of Solar System objects
Speaker 1: have been visited by probes, like we recently had up
Speaker 1: close pictures of Pluto, which is awesome, and most of
Speaker 1: the moons of Saturn and Jupiter have been visited, but
Speaker 1: nobody's ever done a close flyby of a centaur to
Speaker 1: take like crisp photos of its surface and see what
Speaker 1: it's made out of and what that surface looks like.
Speaker 1: It'd be really fascinating.
Speaker 4: But wait, how do we know what they're made out of?
Speaker 1: Ben We don't know for sure. It's just really guesses
Speaker 1: based on the spectrometry looking at the wavelength of light
Speaker 1: that bounces off of it. So we have ideas.
Speaker 4: How do you assume that it has ion it?
Speaker 1: Because they look different from the asteroids, right, They have
Speaker 1: different reflections than asteroids do m All.
Speaker 4: Right, Well, let's get to the question of the episode,
Speaker 4: which is are there comments in the asteroid belt? So
Speaker 4: let's tackle that. But first let's take another quick break.
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Speaker 4: All right, we're talking about comments, asteroids, and centaurs and
Speaker 4: also charades.
Speaker 1: So in your house, who typically wins the games of charades?
Speaker 4: We never play charades.
Speaker 1: What you're such a big proponent on the podcast, but
Speaker 1: you don't practice that at home.
Speaker 4: That's what I'm trying to do, see, Daniel, is bring
Speaker 4: more charates into everyone's homes. So we're tackling today the
Speaker 4: question are there comments in the asteroid belt? Now, Daniel?
Speaker 4: Is the answer yes or no?
Speaker 1: The answer is that there's some weird stuff in the
Speaker 1: asteroid belt that we don't understand. In nineteen ninety six,
Speaker 1: people saw something any asteroid belt that had a coma
Speaker 1: like it has this gas and envelope in it, so
Speaker 1: it looks like it's melting in the presence of the sun.
Speaker 3: Wait.
Speaker 4: Wait, so that the tail of a comet, you call
Speaker 4: it a coma.
Speaker 1: The tail is when it's moving. A coma is like
Speaker 1: the envelope that surrounds It's sort of like a little atmosphere.
Speaker 1: But it's not really an atmosphere because it's not holding
Speaker 1: onto it gravitationally. It's just sort of like off gasing.
Speaker 1: It's like melting. It's the vapor that's coming off as
Speaker 1: the sun is melting it.
Speaker 4: That's the coma, like an aura or like a cloud
Speaker 4: of a vapor around it.
Speaker 1: Yeah, exactly. And then if it's in motion, it's going
Speaker 1: to leave that behind because it's not gravitationally holding onto
Speaker 1: it and generate a tail. So a coma and a
Speaker 1: tail are characteristic signatures of a comet rather than an asteroid.
Speaker 1: And in nineteen ninety six people were looking at stuff
Speaker 1: in the asteroid belt and it's like, what's out there,
Speaker 1: what's weird? And they found this one that had a
Speaker 1: coma and a tail, And people were like, well, that's weird.
Speaker 1: But you know, one example is never anything, because you
Speaker 1: can always find one weird thing just necessarily tell you anything.
Speaker 1: But then a few years later they did a systematic
Speaker 1: study this Isaac Newton telescope in the Canary Islands. They
Speaker 1: were watching five hundred and thirty four asteroids specifically looking
Speaker 1: for like a gassy shell around them or whether they
Speaker 1: had a tail, and they found like twenty more of
Speaker 1: these things in the asteroid belt that have comas and tails, Well.
Speaker 4: So does that mean their comments or centaurs.
Speaker 1: That means we don't know what to name these things,
Speaker 1: and maybe we're all wrong about these definitions. After all.
Speaker 1: It means that we don't really understand like how they
Speaker 1: got there, you know. I think question number one is
Speaker 1: like why is there something in the asteroid belt that's
Speaker 1: still melting? You put something there and it's melting, it's
Speaker 1: gonna shrink, so it can't last for very long. But
Speaker 1: we think a lot of these asteroids have been there
Speaker 1: for like billions of years, and so how long have
Speaker 1: these things been in the asteroid belt? And if it's
Speaker 1: only and if it's a recent event, then where did
Speaker 1: they come from? And if it's not a recent event,
Speaker 1: then how they lasted so long? So it's weird to
Speaker 1: see something that you know has got to be short lived.
Speaker 1: So it's weird to see so many things that you
Speaker 1: know have to be short lived, because there's got to
Speaker 1: be some explanation there.
Speaker 4: You're saying they saw a coma or a shell or
Speaker 4: a cloud or a tail, because you can see it
Speaker 4: with the telescope.
Speaker 1: As it passes in front of the Sun. For example,
Speaker 1: you could see the gas around it affecting the light
Speaker 1: as it transits, or you can see the way it
Speaker 1: reflects light differently.
Speaker 4: These are pretty firmly in the asteroid belt or are
Speaker 4: they maybe just cruising through the asteroid belt?
Speaker 1: Oh yeah, great question. Now these are things that are
Speaker 1: part of the asteroid belt, and as they watch them,
Speaker 1: they have stable orbits that can make them be part
Speaker 1: of the asteroid belt. They're not just like happened to
Speaker 1: be comets that were captured on their way into the
Speaker 1: inner Solar System. These things are not transients. They're there
Speaker 1: in the asteroid belt basically to stay. But we don't
Speaker 1: understand where they came from. And these are deep and
Speaker 1: important questions because we want to understand, like where is
Speaker 1: the water in the Solar System? How did it get
Speaker 1: spread out the way that it did? For example, where
Speaker 1: did Earth's water come from? We know that all the
Speaker 1: ice and all the water that originally was involved in
Speaker 1: the formation of our planet got boiled off by the
Speaker 1: Sun in the early history of the Solar System, and
Speaker 1: so it's still an open question of like where did
Speaker 1: the water that's on the surface of the Earth now,
Speaker 1: like where did our oceans come from? Did it come
Speaker 1: from comets hitting the Earth? Did it come from the
Speaker 1: water that's still trapped inside the Earth. These are important
Speaker 1: questions and to answer them, we're going to have to
Speaker 1: understand like where's the water now and what is it?
Speaker 1: All of its history. It's a deep question about our
Speaker 1: origins and the whole history of the Solar System. And
Speaker 1: so whenever you see something weird.
Speaker 4: Like wait, are you saying that maybe, like some of
Speaker 4: these weird objects in the asteroid belt, they came from
Speaker 4: the outer Solar System and then maybe they crashed into
Speaker 4: the asteroid belt.
Speaker 1: It could be absolutely it could be that they were
Speaker 1: comets and they were coming into the asteroid belt and
Speaker 1: they like interfered with something. And people think of the
Speaker 1: asteroid belt the way you described like Star Wars earlier,
Speaker 1: like oh it's heart you got to dodge the asteroids.
Speaker 1: It's very dense. In reality, the asteroid belt is very dilute,
Speaker 1: Like if you flew through the asteroid belt, it'd be
Speaker 1: hard to hit an asteroid. So a random commet flying
Speaker 1: through the asteroid belt is not gonna have a problem
Speaker 1: making it through. But you know, maybe occasionally these things
Speaker 1: do get disturbed, or they get deflected by Jupiter or
Speaker 1: captured effectively somehow, And so it could be that these
Speaker 1: are comets that got waylaid and ended up in the
Speaker 1: asteroid belt. But then you'd need a continuous stream of
Speaker 1: them to keep it populated because they're not gonna last
Speaker 1: very long in the asteroid belt, like the Sun is.
Speaker 4: Gonna fry them even with that far away.
Speaker 1: Yeah, I mean, the fact that they have a gassy
Speaker 1: shell means that they are actively outgassing because they can't
Speaker 1: hold onto that gas. And if you're actively outgassing, you're
Speaker 1: literally melting, you're shrinking. That's not gonna last very long.
Speaker 1: They might have like a rocky core, and that might
Speaker 1: be left over when the Sun is done frying all
Speaker 1: of their ices, but they're definitely not gonna look like
Speaker 1: this for that long. We're talking, you know, millions of years,
Speaker 1: but in the history of the Solar System, that's just
Speaker 1: a blink of an eye.
Speaker 4: I wonder if it could be just like the Earth,
Speaker 4: when the Earth got formed, they had water trapped inside
Speaker 4: of it in the rock. Could these asteroids also have
Speaker 4: water inside of them that's maybe sweating out.
Speaker 1: They certainly might have water inside of them the way
Speaker 1: the Earth does. And you know, if you think about
Speaker 1: water inside the Earth, it's not like there's literally an
Speaker 1: ocean you can go swimming in. It's like the chemical
Speaker 1: composition of the rock includes a lot of water. And
Speaker 1: so in a similar way, you might have water infused
Speaker 1: into the metals and the rocks at the heart of
Speaker 1: these asteroids. But any water ice that the sun is
Speaker 1: capable of frying off got fried off a long time ago,
Speaker 1: because these asteroids have been there for billions of years,
Speaker 1: and so these guys would have to be new, right,
Speaker 1: These new, weird things they spotted in the asteroid belt
Speaker 1: should have arrived fairly recently, if that makes any.
Speaker 4: Sense, all right, Well, so I guess the answer is,
Speaker 4: maybe are there comets in the asteroid There could be.
Speaker 4: There are definitely things that are comedy, right, or that
Speaker 4: have ice in them.
Speaker 1: There's definitely something in the asteroid belt that has ice
Speaker 1: because it's melting. We don't understand what they are or
Speaker 1: where they came from, or what it means about where
Speaker 1: our drinking water came from.
Speaker 4: Or would you say maybe the answer is that some
Speaker 4: of the things in the asteroid belt are comments or
Speaker 4: could be classified as sort of comments.
Speaker 1: Yeah, by our definition, where commets are things that have
Speaker 1: ice in them, they're icy and dusty, then yeah, there
Speaker 1: are definitely some icy, dusty things in the asteroid belt.
Speaker 1: The asteroid belt is not just asteroids anymore.
Speaker 4: Or I guess if you go by your definition of
Speaker 4: a comet, then everything is a comet.
Speaker 1: That's right, You're a comet. Right, we tossed you into
Speaker 1: the sun, you would melt and vaporize as well.
Speaker 4: So yeah, yeah, yeah, of course i'd be you know,
Speaker 4: trying to communicate with charades all the way down hoping
Speaker 4: someone picks me up.
Speaker 1: Good luck with that, all right.
Speaker 4: Well, another interesting exploration into our solar system. It's history
Speaker 4: and the mysteries that are still out there waiting to
Speaker 4: be discovered.
Speaker 1: There's so many missing chapters to the history of our
Speaker 1: solar system, so many things about our own backyard we
Speaker 1: still don't understand. And every time we look more carefully
Speaker 1: the things we thought we understood, we find weird things
Speaker 1: that defy our explanation, that tell us that it's a
Speaker 1: lot more to this story to be revealed.
Speaker 4: Yeah, to be revealed by astronomers or physicists or both,
Speaker 4: or perhaps chemists.
Speaker 1: We're all just people.
Speaker 4: No, we're all just comments.
Speaker 1: That's right, everybody's a comment.
Speaker 4: Yeah, we all have tales in komas. All right. Well,
Speaker 4: we hope you enjoyed that. Thanks for joining us, See
Speaker 4: you next time.
Speaker 1: For more science and curiosity, come find us on social
Speaker 1: media where we answer questions and post videos. We're on Twitter, Discord, Insta,
Speaker 1: and now TikTok. Thanks for listening, and remember that Daniel
Speaker 1: and Jorge Explain the Universe is a production of iHeartRadio.
Speaker 1: For more podcasts from iHeart Radio, visit the iHeartRadio app,
Speaker 1: Apple Podcasts, or wherever you listen to your favorite shows.
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