Latest / Daniel and Kelly’s Extraordinary Universe / What's up with Iapetus?

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What's up with Iapetus? · Daniel and Kelly’s Extraordinary Universe

0:08
Speaker 1: Orne, Hey, do you ever feel like being a parent
0:11
Speaker 1: is a little bit like being a detective? Yikes? What
0:15
Speaker 1: kind of crimes are your kids doing these days? Well,
0:17
Speaker 1: sometimes I walk into my kitchen and it looks like
0:19
Speaker 1: a disaster scene and I had to try to figure out,
0:22
Speaker 1: like what happened here? Oh, man, they had some big
0:25
Speaker 1: spaghetti parties or something. Yes, spaghetti sauce on the ceiling. Well,
0:29
Speaker 1: it sounds like you have to use your noodle to
0:31
Speaker 1: solve that saucy mystery. Hi, am or hand. My cartoonists
0:49
Speaker 1: and the co author frequently asked questions about the universe. Hi,
0:52
Speaker 1: I'm Daniel. I'm a particle physicist and a professor at
0:56
Speaker 1: UC Irvine, and my kitchen is often used as a
0:59
Speaker 1: chemistry laugh. Oh yeah, it makes dangerous chemicals or delicious chemicals,
1:04
Speaker 1: dangerous and experimental recipes, mostly by my daughter. Last week,
1:08
Speaker 1: I went to the kitchen and she was making boba
1:11
Speaker 1: from scratch. Oh, we've done that. It's pretty fun. Yeah,
1:13
Speaker 1: it's pretty fun. Not that dangerous, though. You make it
1:15
Speaker 1: sounds like you're making a you know, a breaking bad
1:18
Speaker 1: situation in your kitchen. Well, I didn't eat any of
1:21
Speaker 1: this boba because, you know, who knows what really went
1:22
Speaker 1: into it, but I did get to clean up after it,
1:25
Speaker 1: so that was fun. Yeah, it's the privilege of being
1:27
Speaker 1: a part I guess we're just the clean up crew
1:31
Speaker 1: and the finance ears at the same time. Somehow that
1:34
Speaker 1: doesn't make sense. Welcome to our podcast Daniel and Jorge
1:36
Speaker 1: Explained the Universe, a production of I Heart Radio, in
1:39
Speaker 1: which we act like the clean up crew for the universe.
1:43
Speaker 1: It's out there creating incredible mysteries and cosmic connections, slashing
1:48
Speaker 1: around and buzzing particles and throwing things in the black holes,
1:52
Speaker 1: but it's not always doing a great job of explaining itself.
1:55
Speaker 1: So we step in. We asked the big questions, We
1:57
Speaker 1: try to give as many answers as we in, and
2:00
Speaker 1: we embrace the eternal mysteries that is, the remaining vast
2:04
Speaker 1: unknown about the universe. Yes, because it is a pretty
2:07
Speaker 1: messy universe, full of amazing and sometimes can explicable phenomenon
2:11
Speaker 1: that no one is going to clean up apparently, if
2:14
Speaker 1: not for physicists and scientists. Yeah, that's exactly our job.
2:17
Speaker 1: We can't always organize the universe, but at least we
2:19
Speaker 1: can try to figure out why it ended up in
2:22
Speaker 1: this messy state that it's in. And when we see
2:25
Speaker 1: something we don't understand, you might think we get frustrated
2:28
Speaker 1: and confused, But actually those are the most glorious moments
2:32
Speaker 1: when you find a clue that tells you that the
2:34
Speaker 1: story you've been telling about the universe is not complete
2:37
Speaker 1: and you have an in road to figure out the
2:40
Speaker 1: true story. Well, I've seen your desktop, Daniel. I'm not
2:42
Speaker 1: sure I would trust you to clean anything up. It's
2:45
Speaker 1: pretty messy. It's part of the process. Man. The spaghetti
2:49
Speaker 1: stains and you're ceiling too. There's no boba making allowed
2:53
Speaker 1: in my office, at least for kids, because then they
2:55
Speaker 1: would know how messy you are now. Actually, all the
2:58
Speaker 1: chalkboards that I have in my office are cover in
3:00
Speaker 1: my kids scribbles, which is wonderful, but I hate erasing them,
3:03
Speaker 1: which means most of my chalkboards are no longer useful
3:06
Speaker 1: to me. Are there any good physics ideas in there?
3:09
Speaker 1: Have they done your job for you yet? I'm not
3:13
Speaker 1: done training them up yet to be grad students. Oh boy,
3:17
Speaker 1: I'm sure that they're looking forward to being their dad's
3:21
Speaker 1: grad students. That should be fun. No, neither of them
3:24
Speaker 1: look like they're heading into the science direction, but I
3:26
Speaker 1: wish them the best. Well, there are incredible mysteries out
3:29
Speaker 1: there are some of them pretty messy, some of them
3:31
Speaker 1: pretty neat. I think the universe it's a broad range
3:34
Speaker 1: of cleanliness and its phenomena, and we're here to explain
3:39
Speaker 1: all of them too. And you might think that most
3:41
Speaker 1: of the mysteries are deep out in space, at the
3:44
Speaker 1: heart of black holes, or only visible to particle physicists
3:48
Speaker 1: able to smash open the tiniest bits of matter. But
3:51
Speaker 1: there are a lot of mysteries that are sort of
3:53
Speaker 1: at our size, things the size of the Moon or
3:57
Speaker 1: the Earth. Things in our backyard that we still do
4:00
Speaker 1: not understand, things that are covered in clues left by
4:03
Speaker 1: a really interesting sequence of events that we get to unravel.
4:07
Speaker 1: It's right, there are big mysteries right here in our
4:10
Speaker 1: solar system. So to be on the podcast, we'll be
4:12
Speaker 1: asking the question what happened to yepid is? First of all,
4:22
Speaker 1: what is yepid is? And is that the correct way
4:25
Speaker 1: to pronounce it? According to my Internet googling, that is
4:30
Speaker 1: the correct pronunciation of this solar system body, which originally
4:34
Speaker 1: comes from the Greek I see and if it's on
4:37
Speaker 1: the Internet, it must be true exactly. I also found
4:39
Speaker 1: people from New Jersey who pronounced the epidis, but I
4:42
Speaker 1: think we should go with the Greek version. Are you
4:46
Speaker 1: sure they're talking about a celestial body and not not you?
4:49
Speaker 1: I was googling on campus and I thought this is
4:51
Speaker 1: probably danger zone, so I just stopped right there. And
4:54
Speaker 1: the whole Internet is a danger zone. But yeah, this
4:58
Speaker 1: is an interesting body in our olar system, one that
5:01
Speaker 1: we don't quite understand how it got to be the
5:03
Speaker 1: way it is exactly. And everything that's out there in
5:05
Speaker 1: our solar system tells a story. It tells us a
5:07
Speaker 1: story because of what it's made out of. It tells
5:09
Speaker 1: us a story because of what it looks like, and
5:11
Speaker 1: it tells us a story because of how it moves.
5:14
Speaker 1: You know, physics is a set of laws that governs
5:17
Speaker 1: how things evolve, and so if something is doing something
5:20
Speaker 1: weird or looking weird, there's a reason. There's a clue.
5:23
Speaker 1: It's like if you meet some person and they have
5:24
Speaker 1: a scar on their arm, you know that there's probably
5:27
Speaker 1: an interesting story there, and if you know them well
5:29
Speaker 1: enough to you might ask them about it. And so
5:31
Speaker 1: everything in the solar system is also covered in scars
5:35
Speaker 1: and comes with an interesting story. Yeah, maybe they were
5:38
Speaker 1: making boba in their kitchen and had a boba accident
5:42
Speaker 1: and their dad got really mad. And something that we've
5:45
Speaker 1: learned over the last few decades is how many interesting
5:48
Speaker 1: stories there are in our solar system. You probably have
5:51
Speaker 1: a picture in your mind of the Sun with the
5:53
Speaker 1: planets moving around it in a very orderly fashion and
5:57
Speaker 1: not changing, right, that this is the way the Solar
5:59
Speaker 1: system is and probably always has been. But as we
6:02
Speaker 1: look deeper into the Solar system and study with more detail,
6:05
Speaker 1: we discover that there's a lot of really interesting and
6:08
Speaker 1: chaotic history there. It's more like the mountains on Earth
6:12
Speaker 1: that changed slowly on our time scale, but very rapidly
6:15
Speaker 1: on geological time scales. Yeah, the story of how the
6:18
Speaker 1: Solar system form is not just a big story. It's
6:21
Speaker 1: also an important story, right, because it tells us kind
6:23
Speaker 1: of where we came from and how we came to
6:25
Speaker 1: be here, and also maybe what are the chances that
6:28
Speaker 1: life could develop in other places in the universe? Exactly
6:31
Speaker 1: is our solar system weird? What kind of strange early
6:34
Speaker 1: cataclysms do solar systems have to survive in order to
6:38
Speaker 1: produce life bearing planets. We know from our own solar
6:42
Speaker 1: system that Jupiter probably was formed on the outer Solar System,
6:45
Speaker 1: then moved inwards, and then moved back outwards again, maybe
6:49
Speaker 1: even ejecting an entire planet from the Solar System along
6:52
Speaker 1: the way. Is this a typical kind of thing in
6:55
Speaker 1: our solar system? Fortunately, everything that happens in the Solar
6:58
Speaker 1: system leaves a mark. There's always some evidence of something
7:01
Speaker 1: that happened, and so we can unravel that story by
7:04
Speaker 1: working backwards, and then we can give it fun name
7:07
Speaker 1: like yep it is. Yep, we can. It's a good thing.
7:11
Speaker 1: They didn't call it nupidus. Yeah, that would be more
7:14
Speaker 1: negative name. But as usually, we were wondering how many
7:17
Speaker 1: people had heard of something in our solar system called
7:19
Speaker 1: the yep it is and what is the story with
7:22
Speaker 1: that body? So thanks to everybody who's willing to participate.
7:25
Speaker 1: As usual, if you would like to answer these questions
7:28
Speaker 1: for future versions in the podcast, please don't be shy
7:31
Speaker 1: right to me two questions at Daniel and Jorge dot com.
7:34
Speaker 1: So think about it for a second. If someone went
7:36
Speaker 1: up to you and ask you what is the story
7:38
Speaker 1: with yep it is? What would you say? I think
7:41
Speaker 1: I Petis or a Petis is a moon around Saturn.
7:45
Speaker 1: If I recall correctly, UM, it has a very light
7:49
Speaker 1: and a very dark side, UM, so the surface is different.
7:54
Speaker 1: I have no idea where this is. Maybe um, somebody
7:57
Speaker 1: who's half the moon as an ashtray UM. I don't know.
8:03
Speaker 1: I don't know what a Petus is. So I'm going
8:07
Speaker 1: to take a random guests and assume it's one of
8:09
Speaker 1: Jupiter's moons, and based on that assumption, I'm also going
8:13
Speaker 1: to guess that something unusual is happening, like maybe there
8:17
Speaker 1: is some sort of cloud formation around it that may
8:23
Speaker 1: indicate a volcanic eruption. I don't know it's it's a moon,
8:26
Speaker 1: it's it's on Saturn. I think it's one of the
8:29
Speaker 1: ones that has a really rough time because the tides
8:31
Speaker 1: ripping it around. If it's one of Saturn's moons, that
8:33
Speaker 1: it's got more problems with being smacked upside the head
8:36
Speaker 1: by the bits of the rings. So I'm going to
8:40
Speaker 1: go out on a limb and guess volcanic action. I
8:43
Speaker 1: have no idea. I Appenenus is a moon of Jupiter,
8:47
Speaker 1: I think, but I have not seen any recent news
8:52
Speaker 1: on it, And I don't remember what in particular is
8:55
Speaker 1: significant about that moon Iapetus. I think that's one of
9:01
Speaker 1: Saturn's moons. What's going on there? Um? Some icy stuff,
9:08
Speaker 1: some cracking and plumes and hopefully lots of organisms. Um.
9:17
Speaker 1: Judging by the name, I guess Yeapetus is a moon,
9:21
Speaker 1: but I don't really know of which planet and it
9:24
Speaker 1: does anything special about it? What is going on on
9:27
Speaker 1: Lapidus or Yapetus? Well, I'm not even sure what it is.
9:30
Speaker 1: Maybe a star fall way and that does funny things,
9:34
Speaker 1: but I totally sure what it does, and I didn't
9:37
Speaker 1: get invitation to whatever it does. All right, Well, a
9:40
Speaker 1: lot of people seem to guess that it was some
9:42
Speaker 1: kind of moon, yeah, though they're not sure exactly what's
9:45
Speaker 1: the moon of Yeah, a lot of people said it's
9:48
Speaker 1: a moon of Jupiter. But first of all, how do
9:50
Speaker 1: people know it was a moon? I don't know. I
9:52
Speaker 1: guess it sort of sounds like a moon. It sounds moony, yeah,
9:56
Speaker 1: but it is. But yeah, a lot of people seem
9:58
Speaker 1: to know it's a moon or guess it was a moon,
10:00
Speaker 1: but some people have thought it was maybe a star
10:02
Speaker 1: mm hmmm. Yeah, there's a lot of good guesses out there.
10:05
Speaker 1: I didn't give people really a lot of clues. I
10:07
Speaker 1: was really curious if people had heard about this strange object,
10:11
Speaker 1: already knew about the mysteries that it was hiding, or
10:14
Speaker 1: whether it was something that nobody had heard of. You
10:16
Speaker 1: make it sounds super mysterious, So let's get into it, Daniel,
10:20
Speaker 1: what is yeap it is? Assuming that's the correct pronunciation.
10:24
Speaker 1: Assuming that's a correct pronunciation, Yeapidus is a moon, and
10:27
Speaker 1: it's a moon of Saturn. It's a good guess moon
10:30
Speaker 1: of Jupiter because Jupiter is big and it's got lots
10:32
Speaker 1: of moons, so if you're not sure, Jupiter is always
10:34
Speaker 1: a good guess. But in this case it's one of
10:37
Speaker 1: the moons of Saturn. Saturn has a ton of moons too,
10:40
Speaker 1: Right does have more moons and Jupiter Saturn does have
10:43
Speaker 1: a lot of moons. Right, And Saturn is really interesting
10:45
Speaker 1: because it has obviously the big ring system and also
10:48
Speaker 1: the moons. Right with with complex interplace sometimes interesting. It
10:52
Speaker 1: has a lot of blings it does. It's a very
10:54
Speaker 1: bad rings and rocks. It says Yeapidus to ordering new
11:00
Speaker 1: stuff online anything, it's up for anything. Um. Yes, So
11:05
Speaker 1: Saturn has a bunch of moons. This moon is really
11:08
Speaker 1: interesting though, because it's much further out from the other moons,
11:11
Speaker 1: like the other seven major moons of Saturn. The furthest
11:14
Speaker 1: one out is Hyperion, and yeapa Is is twice as
11:17
Speaker 1: far out as Hyperion. So it's this huge ball of
11:22
Speaker 1: mostly ice a little bit rock that's orbiting Saturn. It's
11:25
Speaker 1: interesting how you know a planet can be kind of
11:28
Speaker 1: its own solar system, right, It's like a solar system
11:31
Speaker 1: within a solar system. Yeah, it really is. It's fascinating
11:33
Speaker 1: and it shows you just sort of like the general
11:35
Speaker 1: gravitational structure of the Solar system, everything is really determined
11:40
Speaker 1: by its gravitational attraction. You know, we talk a lot
11:42
Speaker 1: about how gravity is the weakest force in the universe.
11:45
Speaker 1: It's so much weaker than even the weak force, and
11:48
Speaker 1: yet you see here very physically, very viscerally, how it
11:52
Speaker 1: determines the structure of the universe. Right. The reason that
11:56
Speaker 1: these things orbit Saturn and Saturn orbits the Sun and
11:58
Speaker 1: the Sun orbits the center of the key way is
12:01
Speaker 1: all just gravity. It's pretty interesting. I guess it has
12:03
Speaker 1: to do with the fact that gravity is kind of
12:05
Speaker 1: a very local force, right, Like it's very powerful when
12:08
Speaker 1: you're up closed, but a little bit less powerful when
12:10
Speaker 1: you're far away. Yeah, gravity definitely falls like one over
12:13
Speaker 1: distance squared. I think it mostly has to do with
12:16
Speaker 1: the fact that gravity is different from the other forces
12:19
Speaker 1: because it's almost always just attractive, so it can't really
12:23
Speaker 1: be canceled out. Like the electromagnetic force is much more
12:26
Speaker 1: powerful than gravity, but it has two charges, positive and negative,
12:30
Speaker 1: and so you can neutralize it. Like the Earth and
12:32
Speaker 1: Sun don't have a very large overall electromagnetic charge because
12:36
Speaker 1: that would lead to a large force and a lot
12:38
Speaker 1: of transfer of mass between the two. They're mostly neutral.
12:41
Speaker 1: It can be neutralized, but gravity you can't neutralize. It's
12:45
Speaker 1: only has positive masses as we've discovered in the universe,
12:48
Speaker 1: and no negative masses as far as we're aware, which
12:51
Speaker 1: means that everything always attracts and you can't balance that out. Yeah,
12:55
Speaker 1: it's pretty interesting, I guess. Like to a moon, gravitationally
12:58
Speaker 1: mostly just sees the plan that it's orbiting, right, Like
13:01
Speaker 1: it's probably getting a little bit tugged by the Sun
13:03
Speaker 1: and the other planets, but mostly it just kind of
13:05
Speaker 1: sees what's in front of it, right, just like we're
13:07
Speaker 1: going around the Sun, but we're also kind of a
13:09
Speaker 1: little bit being pulled by other stars and other things
13:12
Speaker 1: in our galaxy. Yeah, I see what you're saying. Absolutely,
13:15
Speaker 1: it's true that gravity dominates the structure of the universe.
13:18
Speaker 1: But I think you're saying that we get this sort
13:19
Speaker 1: of hierarchical system where you have things orbiting things orbiting
13:23
Speaker 1: other things because you can mostly ignore things that are
13:26
Speaker 1: further away, like the Moon mostly just orbits the Earth
13:29
Speaker 1: and doesn't have to worry about the Sun and Jupiter
13:32
Speaker 1: and that kind of stuff. Yeah, that's true, although as
13:34
Speaker 1: we'll hear today, Jupiter does play a role in the
13:37
Speaker 1: orbits of all the other planets. Also, it does really
13:40
Speaker 1: have a little bit of an effect that tugs on
13:42
Speaker 1: all of these things and creates chaos that can mess
13:45
Speaker 1: up the whole system and also protect us. You know,
13:47
Speaker 1: Jupiter's enormous gravity breaks up things that come into the
13:51
Speaker 1: Solar System, like it's shredded comet Shoemaker Levy when it
13:54
Speaker 1: came into the Solar System a few decades ago, and
13:57
Speaker 1: that helps protect the Earth sometimes. Yeah, it AC's kind
13:59
Speaker 1: of like magnet, right, like pulls dangerous things away from
14:03
Speaker 1: us and also sucks the mint. Yeah, exactly. So the
14:05
Speaker 1: whole system is sort of very delicately balanced, and understanding
14:09
Speaker 1: exactly how things orbit and where they're going requires understanding
14:13
Speaker 1: everything in great detail. Like when we send a probe
14:16
Speaker 1: out into the far reaches of the Solar System, we
14:19
Speaker 1: have to account for the gravity of all of those planets,
14:21
Speaker 1: which give it little tugs, because even a little tug
14:24
Speaker 1: early on is going to change the direction of that probe,
14:27
Speaker 1: which you can really add up when you're going zillions
14:29
Speaker 1: and zillions of miles. So I think, like to first order,
14:32
Speaker 1: you know, to a simple approximation, you can mostly just
14:35
Speaker 1: think about the Earth orberating the Sun. But you want
14:37
Speaker 1: to get all the details right, then you need to
14:39
Speaker 1: factor in Jubiter's orbit and Jubiter's gravity. But back to yeah,
14:43
Speaker 1: it is, so it's a moon of Saturn, And is
14:45
Speaker 1: this something we can see with the naked eye? Because
14:47
Speaker 1: I know, like if you look at it through a
14:48
Speaker 1: telescope at Saturn and you can see the reins, can
14:50
Speaker 1: you also maybe see this moon? You can't see the
14:52
Speaker 1: moon of Saturn with the naked eye. In fact, it
14:55
Speaker 1: was Galle who saw moons are on Jupiter for the
14:57
Speaker 1: first time because of his telescope. You really need a
15:00
Speaker 1: telescope to see these things. This moon was discovered by Cassini,
15:05
Speaker 1: not by Galileo, and he also used a telescope, and
15:08
Speaker 1: it was in sixteen seventy one that he discovered it.
15:10
Speaker 1: So we've known about this moon for a long long time,
15:13
Speaker 1: basically since the advent of the telescope. So if you
15:16
Speaker 1: have a telescope at home, you can maybe see this moon. Right. Yeah,
15:19
Speaker 1: you don't need a very powerful telescope to see Yapous,
15:21
Speaker 1: but as we'll learn later, you can only really see
15:24
Speaker 1: one side of Yapodus with a telescope. Right. Well, we've
15:27
Speaker 1: been yapping a lot about Yeapidus. Uh, let's stay into
15:30
Speaker 1: why it's so interesting and what is there is some
15:32
Speaker 1: kind of strange story about it. So there's like three
15:35
Speaker 1: really weird things about Yeapoitis, how it moves, its shape,
15:39
Speaker 1: and its color. To me, the motion is really interesting
15:42
Speaker 1: because not only is Yapatis much further out than all
15:46
Speaker 1: the other moons, like the other moons are much closer
15:48
Speaker 1: in they all sort of clustered together, and then you
15:51
Speaker 1: got Yeapais like way way out there. Not only that,
15:55
Speaker 1: but also it's not in the plane as the other moons.
15:59
Speaker 1: So you have like Saturn is rotating and around it
16:02
Speaker 1: are the rings, and then also the moons which rotate
16:04
Speaker 1: around Saturn, and those all move around the same axis.
16:07
Speaker 1: Like if you drew a line through the north and
16:09
Speaker 1: south pole of Saturn, Saturn itself rotates around that axis,
16:13
Speaker 1: and then all the moons and the rings rotate around
16:16
Speaker 1: that same axis, but not yeapitus, yapatus orbits on like
16:20
Speaker 1: a tilted axis. Interesting, it's not in the same plane.
16:22
Speaker 1: And that is um weird, right, because usually, like in
16:26
Speaker 1: our solar system, almost everything is going around the same plane, right,
16:30
Speaker 1: the same kind of um level. So when you have
16:33
Speaker 1: a lot of stuff going around you, it's usually in
16:35
Speaker 1: the same level, right. Yeah, And there's a good physics
16:38
Speaker 1: reason for that. It comes from conservation of angular momentum.
16:42
Speaker 1: Like the whole solar system is mostly spinning in the
16:45
Speaker 1: same direction because the big cloud of gas and dust
16:48
Speaker 1: that created the solar system was originally spinning, and that
16:52
Speaker 1: spin can't just go away. In our universe, angulamentum sticks around.
16:56
Speaker 1: If you have a top spinning without friction, it will
16:59
Speaker 1: continue spinning forever. The only way to slow it down
17:03
Speaker 1: is to come in with some sort of outside force,
17:05
Speaker 1: to bump it from something external, right, And so as
17:09
Speaker 1: solar systems started to coalesce, that very gentle spin became
17:12
Speaker 1: faster and faster. So the Sun is spinning in one direction,
17:15
Speaker 1: the planets are mostly moving around the Sun in the
17:18
Speaker 1: same direction as it's spinning in that same plane. And
17:22
Speaker 1: then all the planets are spinning in that same direction,
17:24
Speaker 1: and their moons are mostly moving around them in that
17:27
Speaker 1: same direction. So everything is super well aligned. Right. So
17:31
Speaker 1: if you see something that is spinning around another object
17:34
Speaker 1: in kind of a skewed or inclined level, that means
17:37
Speaker 1: there's maybe an interesting story going on there, right exactly.
17:40
Speaker 1: It means that you have some sort of external force
17:43
Speaker 1: that has tweaked it. And so the cool thing there
17:45
Speaker 1: is that it tells you something about the history, right.
17:47
Speaker 1: It tells you something happened here that's interesting. It wasn't
17:50
Speaker 1: just the normal formation of a moon that you would expect.
17:54
Speaker 1: You know, there's a few different ways that you can
17:55
Speaker 1: make a moon for a planet, Yeah, including in your kitchen.
17:58
Speaker 1: I guess we're along with Bobo. But let's get into
18:03
Speaker 1: the different ways you can make a moon. I guess
18:05
Speaker 1: a lot of people might want to know that if
18:06
Speaker 1: they want to make their own moon. And let's get
18:09
Speaker 1: into why it's so weird that yep it Is has
18:11
Speaker 1: a skewed orbit. But first let's take a quick break.
18:26
Speaker 1: All right, we're talking about yep it is, which, Um,
18:29
Speaker 1: it's a great name. I think I'm going to name
18:31
Speaker 1: my next child yep yep it is a great name. Well,
18:36
Speaker 1: it's a moon of Saturn, and it's a weird moon.
18:38
Speaker 1: And it's a little interesting and a bit of a
18:40
Speaker 1: mystery because, first of all, because it has kind of
18:42
Speaker 1: a skewed orbit, it's not orbiting along with the rings
18:46
Speaker 1: of Saturn. It's not orbiting at the same level as
18:48
Speaker 1: the other moons of Saturn. It's ordering kind of a
18:50
Speaker 1: in a tilted orbit. Yeah, and when you look at
18:53
Speaker 1: the moon of a planet, you gotta wonder, like, where
18:54
Speaker 1: did this moon come from? And as far as we know,
18:57
Speaker 1: there's a few different ways that a plane and it
19:00
Speaker 1: can get a moon. There's the idea that it's made
19:02
Speaker 1: from the same stuff, Like you have a big cloud
19:04
Speaker 1: of stuff and some of it comes together into a planet.
19:07
Speaker 1: But if you have a big enough blob of it
19:09
Speaker 1: that's like far enough away, then it's going to coalesce
19:12
Speaker 1: into its own little blob rather than falling into the
19:15
Speaker 1: planet and becoming part of the planet. And so it
19:18
Speaker 1: can coalesce into its own little blob of stuff, right
19:21
Speaker 1: because initially, like every planet in the Solar System was
19:24
Speaker 1: like a cloud of stuff. Right, Yeah, all you had
19:26
Speaker 1: is a big cloud and the sunsuted form and it's
19:29
Speaker 1: swallowed up most of the gas. But then you also
19:32
Speaker 1: have other heavy seeds of like places where you had
19:34
Speaker 1: a little bit more stuff than everywhere else. And you know,
19:37
Speaker 1: gravity is this runaway effect. When you have something with
19:40
Speaker 1: a little bit more density, it has more gravity, so
19:42
Speaker 1: it's able to pull other stuff in, which gives it
19:44
Speaker 1: more density, which gives it more gravity. So any place
19:47
Speaker 1: that is like a little bit more dense by chance
19:50
Speaker 1: than another place is a seed for something to form.
19:53
Speaker 1: These seeds form, and then sometimes they pull themselves together
19:55
Speaker 1: and form something larger, right, But sometimes they don't. Sometimes
19:59
Speaker 1: they're spinning fast enough to get into orbit around each other,
20:02
Speaker 1: which is why the Earth is orbiting the Sun instead
20:04
Speaker 1: of just falling into its massive gravity, because it had
20:07
Speaker 1: enough motions going fast enough to avoid falling in And
20:11
Speaker 1: so when you have a planet forming, the same thing happens. Right.
20:14
Speaker 1: Not all of the stuff in the neighborhood of the
20:16
Speaker 1: planet necessarily forms the planet. Some of it can form
20:20
Speaker 1: a moon, and that moon can get into orbit around
20:22
Speaker 1: the planet. But when that happens, you expect it to
20:25
Speaker 1: be aligned with the motion of the planet, expected to
20:28
Speaker 1: be orbiting around the same axis that the planet is spinning.
20:31
Speaker 1: That's not happening here. Yeap it Is is is orbiting a
20:33
Speaker 1: different axis, this tilted orbit. Right. I think you're saying
20:36
Speaker 1: that if yeap it Is was formed along with Saturn,
20:39
Speaker 1: it should be spinning in the same level, at the
20:41
Speaker 1: same level as its rings and all the other moons
20:43
Speaker 1: if it had been made that way. So something must
20:46
Speaker 1: have happened to it, or maybe it wasn't made the
20:48
Speaker 1: same along with Saturn. Yeah, one really fun idea is capture.
20:52
Speaker 1: You know, maybe some rock came from somewhere else, maybe
20:54
Speaker 1: it was lost from another planet, or even like interstellar
20:57
Speaker 1: object came and was captured by Saturn. Because Saturn is
21:00
Speaker 1: a big, heavy dude, right, It's got a lot of
21:03
Speaker 1: gravity on its own. It's can't compare to Jupiter. Jupiter
21:06
Speaker 1: is much more massive than Saturn, but Saturn is no lightweight,
21:10
Speaker 1: and so it's possible for it to capture our Capture
21:13
Speaker 1: is sort of like exotic and seems really cool, And
21:16
Speaker 1: it's also likely to lead to weird orbits because the
21:19
Speaker 1: orbit of that object would just depend on the angle
21:21
Speaker 1: that came in on, and it's not likely necessarily for
21:24
Speaker 1: it to be aligned with a Solar system. It could
21:26
Speaker 1: come like from the top or from the bottom, or
21:28
Speaker 1: any random angle and then get captured, and then it
21:31
Speaker 1: would have a weird orbit and it's kind of a
21:33
Speaker 1: big coincidence if if that happens, right, it's rare, Right,
21:36
Speaker 1: It's like it's rare for something to come in with
21:38
Speaker 1: just the right velocity, angle and position to actually fall
21:41
Speaker 1: into a stable orbit. Right. Yeah. Orbits are not easy.
21:45
Speaker 1: If you shoot rocks and Saturn, most of them will
21:47
Speaker 1: just fall into Saturn or be deflected away from Saturn.
21:50
Speaker 1: To get into a stable orbit, you have to like
21:52
Speaker 1: really hit the window. And there's something about yeapetus Is
21:55
Speaker 1: orbit that makes it unlikely that it came from capture,
21:59
Speaker 1: which is that it's though it's tilted, is really really circular,
22:03
Speaker 1: like it's not some weird eccentric elliptical orbit or something crazy,
22:08
Speaker 1: and a captured orbit is very very unlikely to be
22:10
Speaker 1: like perfectly circular. For that to happen, you not only
22:14
Speaker 1: have to hit just the right window, you have to
22:15
Speaker 1: hit like a perfect dot in inside that window to
22:18
Speaker 1: get into a perfectly circular orbit. So scientists think that Yeapodus,
22:22
Speaker 1: though it's tilted, probably didn't come from capture, right, not
22:26
Speaker 1: just because it's rare to have a circular orbit in
22:28
Speaker 1: a capture, but also because of what this moon is
22:31
Speaker 1: made out of. Right, that's right. And as far as
22:33
Speaker 1: we can tell, this moon seems to be made out
22:36
Speaker 1: of basically the same stuff as the other moons. It's
22:39
Speaker 1: like ice and rock. We haven't visited this moon, but
22:43
Speaker 1: we can tell by how the light reflects off of
22:45
Speaker 1: it something about what it's made out of. And so
22:48
Speaker 1: it looks like it's made out of basically the same
22:51
Speaker 1: stuff that Saturn and its moons were made out of.
22:53
Speaker 1: So it doesn't look like it's captured, doesn't look like
22:56
Speaker 1: capture can explain. It looks too much like it's a
23:00
Speaker 1: parent exactly, which is I guess ice? Is it really ice?
23:04
Speaker 1: But is it's not water? Ice? Is it. It is ice.
23:06
Speaker 1: But astronomers have a different meaning for the word ice
23:09
Speaker 1: than you and I do, of course, right, because they've
23:12
Speaker 1: taken this word that we are familiar with and adopted
23:15
Speaker 1: it for something else. Remember, astronomers also think that everything
23:18
Speaker 1: heavier than helium is a metal, right, I think oxygen
23:21
Speaker 1: is a metal. We are a metal breathing species, according
23:24
Speaker 1: to astronomers. But ice in this case can also refer
23:27
Speaker 1: to like methane ice, or ammonia ice, or all sorts
23:30
Speaker 1: of other hydrocarbons. But there is also a lot of
23:33
Speaker 1: like water ice there. There's no shortage of water in
23:36
Speaker 1: the outer Solar system, right, So I guess that's one
23:39
Speaker 1: of the mysteries is that, yeah, it is. It looks
23:41
Speaker 1: a lot like Saturn. Looks like it was made from
23:43
Speaker 1: the same stuff Saturn was, but it's in an orbit
23:46
Speaker 1: that's tilted, unlike the other stuff that's orbiting Saturn. Mm
23:50
Speaker 1: hmm exactly. So that's very weird. It tells you something
23:53
Speaker 1: happened here, m all right. What are some of the
23:56
Speaker 1: other mysteries of Yevidis. The other mystery is that its
24:00
Speaker 1: is kind of like a walnut. Most of the things
24:03
Speaker 1: out there in the Solar system that are this big
24:05
Speaker 1: are pretty round, Like the Earth is round and the
24:08
Speaker 1: Moon is round, and Jupiter is round. And that's just
24:11
Speaker 1: because of gravity. Right. If you have a big, heavy object,
24:14
Speaker 1: it's gonna pull on stuff and eventually it's gonna pull
24:16
Speaker 1: stuff down, and any bit that's sticking up is going
24:19
Speaker 1: to get yanked down by gravity. It's like the simplest shape.
24:22
Speaker 1: It's the lowest energy shape for a huge blob of stuff.
24:26
Speaker 1: That's not true for a really small blob. Like if
24:28
Speaker 1: you have rock in your hand, it's strong enough to
24:31
Speaker 1: resist the pull of gravity. Gravity is not going to
24:33
Speaker 1: form every rock into a sphere, but a big enough
24:36
Speaker 1: piece of stuff has it powerful enough gravity to overcome that.
24:40
Speaker 1: But YEAPS is not a sphere, right, But the things
24:43
Speaker 1: in the source system aren't perfectly spherical, right, Like the
24:45
Speaker 1: Earth is not a perfect sphere. It's kind of you know,
24:48
Speaker 1: a little little wide around the waist. Earth has been
24:52
Speaker 1: having too much boba at home. I think, Yeah, things
24:54
Speaker 1: are not perfect spheres because they're spinning, right, So things
24:57
Speaker 1: would be a perfect sphere if they weren't spinning, or
25:00
Speaker 1: when you're spinning, you can think of it like creating
25:02
Speaker 1: this fictitious force that works against gravity. So, like the
25:05
Speaker 1: force of gravity on you is a little weaker at
25:08
Speaker 1: the equator than it is at the north pole, so
25:11
Speaker 1: you're like way less at the equator than at the
25:14
Speaker 1: north pole. Right, It's it's kind of like hanging on
25:16
Speaker 1: at the edge of a merry go round, right, You're
25:18
Speaker 1: being kind of pulled outwards exactly, and that force counteracts
25:22
Speaker 1: the force of gravity, so it makes a lesser effective force.
25:25
Speaker 1: It's not really a force, it's just a product of
25:28
Speaker 1: you being in an accelerated frame of reference because you're spinning.
25:31
Speaker 1: You're moving in a circle. But that's what happens. And
25:34
Speaker 1: so if you spin the Earth, it makes it fatter,
25:36
Speaker 1: and exactly how fat it gets depends on how strong
25:39
Speaker 1: it is. If you had like a planet made of
25:42
Speaker 1: graphene or diamond or something and you spun it, it
25:45
Speaker 1: wouldn't get much fatter, whereas if you had a planet
25:47
Speaker 1: made of like maple syrup and you spun it, it
25:49
Speaker 1: would mostly make it into a disk. Which is why
25:52
Speaker 1: I like the galaxy is a disk rather than a spear,
25:55
Speaker 1: whereas the Earth is a sphere rather than a disc
25:57
Speaker 1: or more like a sphere. Interesting, what about the Sun.
26:01
Speaker 1: Is the Sun also a little wide around its waist,
26:03
Speaker 1: and the Sun is a little wide around its waist.
26:05
Speaker 1: And even though it's sort of like more like maple
26:08
Speaker 1: syrup than a diamond, because it's just a big ball
26:10
Speaker 1: of plasma, it's gravity is so powerful. So it's this
26:14
Speaker 1: interplay between the mass and the spinning rate and the
26:17
Speaker 1: sort of interior tension of the object that determines the
26:20
Speaker 1: final shape, right, okay, And so then yeah, it is
26:22
Speaker 1: this moon of Saturn is also not privently spherical. It
26:26
Speaker 1: has kind of a weird feature around its waist. Yeah,
26:30
Speaker 1: it's got two weird features. Actually. First of all, it's bulging.
26:33
Speaker 1: It's bulging as if it was spinning a lot, right,
26:36
Speaker 1: Like we said, things that spin faster should bulge more, right,
26:39
Speaker 1: But Yeapais doesn't spin very fast, and yet it has
26:42
Speaker 1: a really big bulge. It's like sort of fatter around
26:46
Speaker 1: the middle than it should be for its spin. So
26:49
Speaker 1: that's kind of weird. It's like inconsistent, right. I feel
26:52
Speaker 1: like you're attacking yeap It is this body positivity here, Daniel,
26:56
Speaker 1: I mean, there's no normal right in the Solar system
27:00
Speaker 1: regards to our bulges. I'm not criticizing. I'm saying it's fascinating, right,
27:04
Speaker 1: It's individual, it's different, and I love that, right. I
27:07
Speaker 1: don't want it to just like fall into the same
27:10
Speaker 1: rules as everybody else, you know yourself, yaps. Yeah, but
27:14
Speaker 1: it's but you're saying it a little bit too wide
27:18
Speaker 1: around its ways than it should be. We can't explain
27:20
Speaker 1: how wide it is around its waist just from its spinning.
27:23
Speaker 1: Could it be that maybe the inside of it is
27:25
Speaker 1: more liquid than we think it is or something like that.
27:27
Speaker 1: That's a really cool idea. Typically the insides are liquid
27:30
Speaker 1: due to tidal forces, but Yeapaus is really far from Saturn,
27:35
Speaker 1: too far for Saturn to like be heating it from
27:37
Speaker 1: the interior. There are other like big moons of Saturn
27:40
Speaker 1: and Jupiter that we think might have like underground oceans
27:43
Speaker 1: because of tidal forces, but yeap it is is too
27:45
Speaker 1: small and too far for those kind of effects. Could
27:49
Speaker 1: it be spinning faster than we think it is. No,
27:51
Speaker 1: we can measure it's been pretty well. That's not something
27:54
Speaker 1: we're confused about. But it also has a weird thing
27:56
Speaker 1: on top of this bulg Right, not only is it bulging,
27:59
Speaker 1: but a long it's waist. It has this huge ridge
28:03
Speaker 1: that makes it look like a walnut. And this is
28:05
Speaker 1: not something like a little bump we're exaggerating here. This
28:07
Speaker 1: thing is like fifteen kilometers high and twenty kilometers wide.
28:12
Speaker 1: Is one of the biggest features in the Solar system.
28:16
Speaker 1: Like when we did our Tallest Mountains in the Solar
28:18
Speaker 1: System episode, this featured on it. It's this crazy ring
28:21
Speaker 1: around its waist. It's like a one long mountain ridge
28:25
Speaker 1: kind of right that goes along the equator. The first
28:28
Speaker 1: approximation is like a big ridge around the equator, kind
28:31
Speaker 1: of like a walnut. If you zoom in, it's actually
28:33
Speaker 1: like a complicated system that has a few isolated peaks
28:37
Speaker 1: and then like a two kilometer section with like three
28:40
Speaker 1: parallel ridges. It's really strange, but mostly it seems like
28:44
Speaker 1: a sort of a ring around the middle. And there's
28:47
Speaker 1: nothing else in the Solar system that looks anything like this. Typically,
28:51
Speaker 1: when you see something in the Solar system, you can
28:52
Speaker 1: see other examples of it because it's a common process.
28:56
Speaker 1: But this, whatever caused this must have been rare because
28:59
Speaker 1: it's the only exam ample we've ever seen of like
29:01
Speaker 1: a walnut object in the Solar system. Yeah, that's pretty nuts.
29:06
Speaker 1: We're hoping to crack the mystery one, all right. Yeah,
29:09
Speaker 1: and then you said there's a third mystery about the
29:12
Speaker 1: third and the most amazing mystery in my view, is
29:14
Speaker 1: that it has two colors. So when Cassini first saw
29:18
Speaker 1: Yeapois in sixteen seventy one, it looked pretty bright. He
29:22
Speaker 1: saw on one side of Saturn, and then he thought, well,
29:24
Speaker 1: if this thing is orbiting Saturn, I should be able
29:26
Speaker 1: to see it on the other side also, So he
29:29
Speaker 1: trained his telescope to the other side of Saturn and
29:32
Speaker 1: didn't see anything, and it was very confused. And then
29:35
Speaker 1: he saw it again on the original side, and then
29:38
Speaker 1: he didn't see it on the other side. So you
29:40
Speaker 1: can only see it on one side of the planet,
29:43
Speaker 1: like as it goes around you can see it and
29:45
Speaker 1: when it's on the right side, but you can't see
29:47
Speaker 1: it when it comes around on the left side exactly.
29:49
Speaker 1: And he actually guessed the reason. He guessed that it's
29:52
Speaker 1: because it's a two toned planet. One side of it
29:55
Speaker 1: is white, the other side of it is black. It's
29:58
Speaker 1: like one of those black and white cookie or like
30:00
Speaker 1: a scoop of vanilla ice cream that's been half dipped
30:03
Speaker 1: into chocolate. Wait what and so is the idea that
30:06
Speaker 1: it's when it's one one side of the planet, it's
30:08
Speaker 1: always facing us on the chocolate side, But when it's
30:12
Speaker 1: on the other side of the planet, it's always facing
30:14
Speaker 1: us on the vanilla side, exactly because it's tidally locked.
30:17
Speaker 1: So the same part of it is always facing Saturn.
30:20
Speaker 1: So when it goes around, we always see the trailing
30:22
Speaker 1: edge on one side and the leading edge on the
30:24
Speaker 1: other side, so we see black and then white, and
30:26
Speaker 1: then black and then white. I see it. So it
30:28
Speaker 1: is spinning in place, but it's spinning in place at
30:31
Speaker 1: the same rate as it's going around Saturn, sort of
30:34
Speaker 1: like our moon. How we when you look at the
30:35
Speaker 1: moon here on Earth, you always see the same side
30:37
Speaker 1: of it, even though it's spinning around us, exactly because
30:40
Speaker 1: Saturn has pulled it to be a little bit oblong,
30:43
Speaker 1: and so it's sort of relaxed into this gravitational minimum
30:46
Speaker 1: where the closer bits get pulled on a little bit
30:48
Speaker 1: more strongly by Saturn. It's called tidal locking, and so
30:51
Speaker 1: the same side of it is always facing Saturn. So
30:54
Speaker 1: we always see the trailing side of Yappitus when it's
30:58
Speaker 1: on one side of Saturn and the lead inside of
31:00
Speaker 1: Yopotus when it's on the other and those are different colors.
31:03
Speaker 1: One is very dark and one is very bright. It's
31:06
Speaker 1: super weird because you said it looks like a walnut, right,
31:09
Speaker 1: it has a ridge in the middle, But it's not
31:13
Speaker 1: like one side of the walnut is one color, the
31:15
Speaker 1: other one is another color. It's like it has the
31:18
Speaker 1: two sides of the walnut. But then it was somebody
31:20
Speaker 1: dipped it sideways. Yeah, somebody dipped it sideways. Yeah, it's
31:23
Speaker 1: super weird. So now it has like four quadrants kind
31:26
Speaker 1: of right, like four there are four different Yepidus is Yepti. Yeah,
31:31
Speaker 1: and somebody probably made a big mess in the universe
31:33
Speaker 1: kitchen when they were cooking up this project. Maybe they're
31:35
Speaker 1: trying to make a moon size boba ball, and that
31:38
Speaker 1: would also explain why it's a little bit bulging. Maybe
31:41
Speaker 1: all the moons are just boba. There you go, you
31:44
Speaker 1: need to get into tap yoga physics. My daughter asked
31:48
Speaker 1: me once if it was true that horse hoofs were
31:51
Speaker 1: made of gummy bears. Technically, um, it depends on what
31:56
Speaker 1: the horse has been eating. I guess, Yeah, I mean,
31:59
Speaker 1: I think it's true that gummy bears are made of
32:01
Speaker 1: horses hooves, which is a little discomforting for a girl
32:04
Speaker 1: who loves horses so much and gummy bears. She had
32:07
Speaker 1: to pick one, horses or gummy bears. Yeah, well, I
32:09
Speaker 1: don't know how a horse could run with gummy bear hooves,
32:11
Speaker 1: but you know, some cartoonis could probably figure that out. Yeah, well,
32:14
Speaker 1: they have vegan gummies. Did you tell her about those?
32:17
Speaker 1: They're not as good. You love that hoof aftertaste, that's
32:22
Speaker 1: what makes so so good. All right, Well, let's get
32:26
Speaker 1: into what these mysteries really mean about the history of
32:30
Speaker 1: our solar system and one are some possible explanations for
32:33
Speaker 1: these strange phenomenon. But first, let's take another quick break light.
32:50
Speaker 1: We're talking about gummy bears and horse foods. Apparently, somehow
32:54
Speaker 1: that's related to the moon of Saturn called yep Is.
32:57
Speaker 1: You take a bunch of gummy bears, you launch amount
33:00
Speaker 1: into space, and you get them spinning, and eventually you
33:02
Speaker 1: get a Boba moon. I mean, isn't boba basically just
33:05
Speaker 1: gummy bears in your drink? But it's pretty spacey and celestial. Alright,
33:10
Speaker 1: we we're talking about the moon of Saturn called yeap
33:12
Speaker 1: it Is, and it's many mysteries. It's mysterious because it
33:15
Speaker 1: has a weird orbit, it has a weird ridge around
33:18
Speaker 1: its equator, and it's also got two sides of it,
33:21
Speaker 1: literally a dark side and a light side. Yeah, and
33:24
Speaker 1: forever will it dominate its destiny? Yeah, it's like an
33:27
Speaker 1: actual ying yang ball out there in space. Yeah, it
33:31
Speaker 1: really is that. It It looks like a huge art project.
33:35
Speaker 1: All right, Well, let's tackle each of these mysteries one
33:37
Speaker 1: at a time, Daniel. What could be causing its or
33:39
Speaker 1: what could have caused it's weird orbit. So we're pretty
33:42
Speaker 1: sure that Yeapitus was formed around Saturn. As we said,
33:46
Speaker 1: it was made at the same stuff as Saturn. So
33:48
Speaker 1: that precludes the idea that it's like some weird rock
33:51
Speaker 1: from somewhere else that came in at a strange angle.
33:54
Speaker 1: But if it formed around Saturn, then we think probably
33:57
Speaker 1: should be in the same plane as all the other moons.
33:59
Speaker 1: So another possibility is that it was struck by something. Right,
34:03
Speaker 1: another way to get external angular momentum is to be
34:06
Speaker 1: hit by something that comes from somewhere else, maybe like
34:09
Speaker 1: an asteroid that lost its way or something from another
34:12
Speaker 1: Solar system that banged into it could give it a
34:14
Speaker 1: tilted orbit. I see, like, if there's something scwed it,
34:18
Speaker 1: it came in and crashed into it and scwed it.
34:20
Speaker 1: But wouldn't that also kind of make the orbit more
34:23
Speaker 1: elliptical or some weird shape, isn't it? It's still weird
34:26
Speaker 1: that it's so perfectly circular and tilted. Yeah, I think
34:29
Speaker 1: it's likely that a collision would also perturb the shape
34:32
Speaker 1: of the orbit. So a better explanation is a series
34:35
Speaker 1: of gentle tugs from Jupiter. Remember Jupiter, we said it's
34:39
Speaker 1: sort of like the bad boy of the Solar System.
34:41
Speaker 1: It's not staying and it's laying. It's tugging on everybody
34:44
Speaker 1: because it's so massive. Remember, Jupiter is like ten times
34:47
Speaker 1: as massive as Saturn, and Yeapodus is a really far
34:50
Speaker 1: out moon. It's like really distant from Saturn. So if
34:53
Speaker 1: all of Saturn's moons, this is the one that's most
34:55
Speaker 1: susceptible to Jupiter's gravity. So it might be that sometime
34:59
Speaker 1: in the earlier history of the Solar System, when things
35:02
Speaker 1: were funky and Jupiter and Saturn were migrating their places
35:05
Speaker 1: in the Solar System, some gravitational interaction between Jupiter and
35:09
Speaker 1: Saturn could have tugged on Yapotus in such a way
35:12
Speaker 1: as to give it this weird tilt. But isn't that
35:15
Speaker 1: kind of weird because Jupiter is in the same claim
35:18
Speaker 1: and the same level as all the rings of Saturn,
35:21
Speaker 1: right and all its spoons, So if it pulled in,
35:23
Speaker 1: it wouldn't just kind of pulled it outwards on the orbit.
35:26
Speaker 1: You do have to conserve angular momentum, right, and so
35:29
Speaker 1: to create something that's off tilt, you would have to
35:32
Speaker 1: shoot something else off in the other direction. So maybe
35:35
Speaker 1: like there were two moons of Saturn and one of
35:37
Speaker 1: them got this tilt and another one got ejected out
35:40
Speaker 1: of the Solar system to sort of balance things out.
35:43
Speaker 1: We think probably it was a pretty chaotic event, But
35:45
Speaker 1: it's still sort of like a big question mark. People
35:48
Speaker 1: are running simulations, and in those simulations you can sometimes
35:51
Speaker 1: generate these kinds of tilts. So it's still a big mystery.
35:54
Speaker 1: Then it's still a big mystery we do not understand,
35:57
Speaker 1: but we know that something happened here. It's not just
36:00
Speaker 1: the ordinary formation of rings and moons around a planet.
36:04
Speaker 1: The tidal forces of Saturn are not enough to explain
36:07
Speaker 1: this weird moon. So it's like a huge clue that
36:10
Speaker 1: something big happened in the Solar System. It's so it's
36:12
Speaker 1: so far away from all the other moons of Saturn.
36:14
Speaker 1: I wonder is that if it's possibly it could have
36:16
Speaker 1: just formed that way, right, Like, maybe it's some of
36:19
Speaker 1: the some of the outer stuff that we're that was
36:22
Speaker 1: far away from Saturn just had this kind of extra
36:25
Speaker 1: angular momentum in another direction, and because it's so far
36:28
Speaker 1: away from all the other stuff, it just you know,
36:30
Speaker 1: form its own orbit plane. It's a good point that
36:33
Speaker 1: the whole Solar system has an overall average angular momentum,
36:37
Speaker 1: but like a random pocket of the Solar system can
36:39
Speaker 1: have its own angular momentum, and then you expect all
36:42
Speaker 1: those pockets to add up to the overall angular momentum
36:45
Speaker 1: of the Solar System. So it is possible to get
36:47
Speaker 1: a fluctuation there. We have like one blob that has
36:50
Speaker 1: a different direction, but it's pretty rare. Otherwise we would
36:53
Speaker 1: see this more often around other planets, and so it's
36:56
Speaker 1: a possibility, but we don't see that happening very often
36:59
Speaker 1: in simulations, all right, So maybe it could be Jupiter
37:02
Speaker 1: or maybe it had a collision, but it like, none
37:05
Speaker 1: of it is a slam dunk case. None of it
37:07
Speaker 1: is a slam dunk case. It's still an open question,
37:09
Speaker 1: and it might not be something that's very easy to
37:11
Speaker 1: figure out unless we go and explore Yapodus itself and
37:14
Speaker 1: like look at this geology and try to understand if
37:16
Speaker 1: there's something they're consistent with a big collision or not.
37:19
Speaker 1: It's so weird. Well, I guess you know, you're we
37:22
Speaker 1: were just saying that it's not likely that it was
37:25
Speaker 1: a collision because it would be hard to sort of
37:28
Speaker 1: get that orbit right. But it could still could happen, right,
37:31
Speaker 1: it still could happened possible, I mean, if it's if
37:33
Speaker 1: it's there today, and maybe that's what did happen. And
37:36
Speaker 1: actually collisions are part of the hypothesis for some of
37:39
Speaker 1: the other mysteries of the Yapodus, so it might come
37:42
Speaker 1: together interesting. All right, Well, let's getting too the other mysteries. Um,
37:45
Speaker 1: what might explain it's bulge around its middle. So the
37:48
Speaker 1: weird thing about the bulge is that Yapodus is not
37:51
Speaker 1: spinning fast enough to have that bulge. But it might
37:54
Speaker 1: be that the bulge got sort of like frozen in
37:57
Speaker 1: back when Yappotus was softer and was spinning fast. Like
38:00
Speaker 1: imagine as Yeapitus forms, it's not as cold and as
38:04
Speaker 1: frozen and as firm as it is today. It was
38:06
Speaker 1: more like a huge ball of boba. And maybe it
38:09
Speaker 1: was spinning faster before it got like tidally locked by Saturn.
38:14
Speaker 1: So originally as it formed, maybe it was spinning faster
38:17
Speaker 1: and then that shape got frozen in as it cooled,
38:20
Speaker 1: And so now it's sort of like has the bulge
38:22
Speaker 1: left over from its original spin, and then it got
38:25
Speaker 1: tidally locked by Saturn, but it still has that same shape,
38:29
Speaker 1: but it has enough time pass for um the spin
38:33
Speaker 1: to slow down that much. Yes, Saturn's gravity is pretty strong,
38:36
Speaker 1: so it's had plenty of time to tidally lock an object. Right. Yeah,
38:40
Speaker 1: that's an interesting phenomenon, right, because it requires the planet
38:43
Speaker 1: to kind of change shape to right, Yeah, a little
38:46
Speaker 1: bit like like the part of the planet that's closer
38:49
Speaker 1: to the sorry, the part of the moon that's closer
38:51
Speaker 1: to the planet actually gets heavier, yeah, because remember tidal
38:55
Speaker 1: forces come from a difference in the gravitational force on
38:59
Speaker 1: the near side and the far side. As we're talking
39:01
Speaker 1: about before gravity gets weaker with distance, which means that
39:04
Speaker 1: the Earth is pulling on the near side of the
39:06
Speaker 1: Moon harder than it's pulling on the forest side of
39:09
Speaker 1: the Moon. And as you say, eventually that makes the
39:11
Speaker 1: near side of the Moon a little bit closer, like
39:13
Speaker 1: turns into an ellipsoid instead of a sphere. And then
39:16
Speaker 1: it's sort of hard to get it out of that
39:18
Speaker 1: configuration because now you have like a little bit of
39:20
Speaker 1: a heavier bit that's even closer. So it ends up
39:23
Speaker 1: in sort of a stable state where like the long
39:25
Speaker 1: axis of the Moon is not pointing towards the planet.
39:28
Speaker 1: So like maybe before you're saying it was more liquid
39:31
Speaker 1: this this moon. Yeah, So the idea is that as
39:33
Speaker 1: it was forming before it got tightly locked, maybe it
39:36
Speaker 1: was spinning faster and it was sort of softer. It
39:39
Speaker 1: wasn't like maybe fully liquid, but it wasn't as firm
39:42
Speaker 1: and as frozen as it is today, and so it's
39:44
Speaker 1: bulge got frozen in maybe early on, and then it
39:48
Speaker 1: got tidally locked by Saturn. That's sort of like one
39:51
Speaker 1: hypothesis to potentially explain the bulge you got like flash
39:56
Speaker 1: freeze or flash frozen exactly exactly. And then remember that
40:02
Speaker 1: the bulge has on top of it this weird ridge, right,
40:05
Speaker 1: these crazy tall mountains that go all the way around
40:09
Speaker 1: the bulge, And so people are trying to also explain
40:12
Speaker 1: that at the same time, right, that it's weird to
40:14
Speaker 1: have this mountain rich around your waist of any celestial body.
40:18
Speaker 1: So what are some theories about that? Well, this is
40:20
Speaker 1: really bizarre, as we said, because it doesn't appear anywhere
40:23
Speaker 1: else in the Solar system. So there's a bunch of
40:25
Speaker 1: very different stories here. One is a huge collision, Like
40:29
Speaker 1: maybe there was a really big collision and that's the
40:31
Speaker 1: explanation for why Yeppotus is tilted. And this collision might
40:35
Speaker 1: have like tossed up an enormous amount of stuff which
40:38
Speaker 1: formed a ring around the Moon, but wasn't stable and
40:40
Speaker 1: eventually like fell down and formed this ridge around the edges. Right,
40:45
Speaker 1: But if it was just made from stuff falling on
40:47
Speaker 1: the ground, Um, why would only fall in the equator?
40:51
Speaker 1: And also how can you explain, like the peaks of it,
40:53
Speaker 1: it would only fall in the equator if it had
40:55
Speaker 1: time to gather into a ring. Remember, rings conform because
40:58
Speaker 1: gravity can compress things a long the axis of spin
41:01
Speaker 1: without any resistance. It's harder for gravity to push things
41:05
Speaker 1: towards the axis of spin, but along the axis of
41:07
Speaker 1: spin isn't a big deal. That's why, like Saturn's rings
41:10
Speaker 1: are flat. So you have some big collision which creates
41:13
Speaker 1: a huge cloud of debris which orbits and forms a
41:16
Speaker 1: ring for a little while, but then the ring falls
41:18
Speaker 1: back down onto the Moon. So that would explain why
41:20
Speaker 1: it only goes around the equator. You're right that it
41:23
Speaker 1: doesn't really explain very well why it's like such a
41:26
Speaker 1: crazy tall mountain. You'd expect more of a blob or
41:29
Speaker 1: something there. Yeah, right, Yeah, especially it's just like raining rocks.
41:34
Speaker 1: So people have other ideas, like one idea that it
41:37
Speaker 1: comes from underneath, that there's some very strange geology that
41:40
Speaker 1: was happening as it was forming and freezing, that this
41:44
Speaker 1: weird icy material like upweld from the interior of Yapitus.
41:48
Speaker 1: This is very speculative. People don't really have like a
41:51
Speaker 1: great model to explain how that might have happened. Interesting,
41:54
Speaker 1: it came from the ground, sort of like maybe how
41:56
Speaker 1: mountains form here on Earth, right, like mountains here, A
41:59
Speaker 1: lot of our mountains and ridges form from the tectonic
42:02
Speaker 1: plates crashing into each other and then kind of like
42:05
Speaker 1: well like swelling up right, pushing up, And so this
42:08
Speaker 1: could be some like cracking in the exterior and friction
42:10
Speaker 1: between those pieces or things pushing up from underneath. But
42:13
Speaker 1: you have to explain why you basically only see it
42:16
Speaker 1: along the ridge. Is very strange and it's very dramatic,
42:20
Speaker 1: Like I can't accentuate enough, like how tall these mountains
42:23
Speaker 1: are there? Really are insanely high for a tiny little moon. Yeah,
42:27
Speaker 1: thirteen kilometers high. Um. I wonder if maybe the two
42:31
Speaker 1: things are kind of related to each other, like the
42:33
Speaker 1: bulge and the mountains, like maybe before yet but it
42:36
Speaker 1: was spinning a lot faster, which kind of maybe made
42:39
Speaker 1: everything on the equator kind of push out, and then
42:41
Speaker 1: which made all the technic plates also maybe push out
42:44
Speaker 1: towards the middle of the equator, and then that created
42:46
Speaker 1: the mountains. Could have been something like that, Yeah, it
42:48
Speaker 1: certainly it could be that, like the spinning makes the
42:50
Speaker 1: equator sort of like more fragile and more likely to
42:53
Speaker 1: be the place where things are going to well up
42:54
Speaker 1: from underneath. It's certainly possible, but it's definitely an area
42:58
Speaker 1: of active investigation, all right, and then the last mystery
43:01
Speaker 1: is it's weird colors that the one side of the planet,
43:05
Speaker 1: on one side of the moon, it's bright and the
43:07
Speaker 1: other side it's darker. Like how big is this contrast?
43:10
Speaker 1: Like is it really like black and white? Or is
43:12
Speaker 1: it like one shade of brown and another shade of brown?
43:14
Speaker 1: It's really like black and white. You should definitely google this.
43:17
Speaker 1: One side of it is like twenty times brighter than
43:20
Speaker 1: the other. I mean, Cassini, it took him thirty years
43:23
Speaker 1: to build a telescope powerful enough to even see the
43:26
Speaker 1: dark side of the Appitus. It's very dramatic. Well, it's
43:30
Speaker 1: interesting that it's also interesting that it's pointing towards us
43:35
Speaker 1: kind of right, Like, what are the chances that we
43:37
Speaker 1: would see both sides, the dark and light side, and
43:40
Speaker 1: not just one side? Or is it that some parts
43:43
Speaker 1: of the year we see both and sometimes we see
43:45
Speaker 1: on only the dark side. Well, it's going around Saturn
43:49
Speaker 1: counterclockwise like all the other moons, so we're always definitely
43:52
Speaker 1: going to see the trailing side and the leading side.
43:55
Speaker 1: That gives you a clue, Right, it seems to be
43:57
Speaker 1: interestingly colored, So the trailing side in the leading side
44:00
Speaker 1: are different colors. It's like flying through space in some direction,
44:03
Speaker 1: and the leading side is the dark side and the
44:06
Speaker 1: trailing side is the bright side. It's not just like
44:09
Speaker 1: randomly oriented. What do you mean like leading side? What
44:11
Speaker 1: does that mean? So, if you're like riding a motorcycle
44:13
Speaker 1: through a huge cloud of bugs, for example, the leading
44:16
Speaker 1: side is the front face plate that's going to hit
44:18
Speaker 1: all the bugs, and the trailing side is the back
44:21
Speaker 1: side of the helmet that's not hitting any of the bugs, right,
44:24
Speaker 1: And so, yeah, it is moving around saturn, it's moving
44:27
Speaker 1: through space. It's moving in the direction of one of
44:30
Speaker 1: its sides, that's the leading side. Oh you mean like
44:33
Speaker 1: ground right, Yes, like going around a merrygoround. If you're
44:36
Speaker 1: facing one way, you know you're faving in the front
44:39
Speaker 1: part of your body is going to hit all the bugs,
44:42
Speaker 1: but the backside of your body is not going to
44:43
Speaker 1: hit any bugs. Exactly. So when you get off your
44:45
Speaker 1: motorcycle and you look at the helmet and you see
44:46
Speaker 1: insects covering the front and not the back, you don't think, oh,
44:49
Speaker 1: it's weird that it only covered the front. There's like
44:52
Speaker 1: a reason. It's connected to the fact that you're moving
44:54
Speaker 1: through that cloud of bugs in a certain direction. That's
44:58
Speaker 1: why you have bugs all over the front side, the
45:00
Speaker 1: leading side of it. And so the fact that the
45:02
Speaker 1: leading side of Yapodus is the dark side is a
45:04
Speaker 1: big clue as to why it's I see, as it
45:08
Speaker 1: goes around Saturn, but then Saturn is also going around
45:10
Speaker 1: the Solar system, so if it is picking up bugs
45:14
Speaker 1: or the equivalent of bugs, it's like stuff that's near
45:17
Speaker 1: Saturn as well, exactly. And that's just what they figured out.
45:20
Speaker 1: They pointed the Spitzer space telescope at Saturn, and remember
45:24
Speaker 1: Spitzer is an infrared telescope, so it's really good at
45:27
Speaker 1: seeing stuff that doesn't reflect a lot of light but
45:29
Speaker 1: glows in the infrared. And what it discovered is that
45:33
Speaker 1: there's a huge ring of Saturn that nobody knew about.
45:36
Speaker 1: It's basically like an enormous ring of dust. It extends
45:40
Speaker 1: really really far out even well beyond the Yapodus. So
45:43
Speaker 1: this is huge cloud of dust and Yeapodus is basically
45:46
Speaker 1: flying through that cloud, sort of like it's flying through
45:50
Speaker 1: a cloud of bugs. It's just like it's flying through
45:52
Speaker 1: a cloud of bugs, and this cloud is actually rotating
45:54
Speaker 1: the other direction from Yapais. So it's like flying through
45:58
Speaker 1: a headwind of this dust. It's actually one of the
46:02
Speaker 1: rings of Saturn, this really really dusty, sort of diffuse
46:05
Speaker 1: ring of Saturn that it's flying through. It's interesting that
46:08
Speaker 1: it's happening on this moon of Saturn, Like why isn't
46:12
Speaker 1: it happening in our moon? Like why doesn't our moon
46:14
Speaker 1: look half white and half a dark Well, because Earth
46:19
Speaker 1: doesn't have this huge dusty ring that our moon is
46:21
Speaker 1: flying through, and so Saturn has this huge dusty ring.
46:25
Speaker 1: They think it comes from another one of the moons
46:27
Speaker 1: of Saturn, Phoebe. Phoebe is this very very dark moon,
46:32
Speaker 1: and it's basically getting shredded, it's getting hit and it's
46:35
Speaker 1: falling apart, and it's leaving this big dust trail, and
46:38
Speaker 1: the Yeapodus is flying through that dust trail. Yeah, so
46:41
Speaker 1: it's it's creating this kind of trail. But then that's
46:44
Speaker 1: in the same level as all the other moons, whereas
46:47
Speaker 1: in yeap Its is literally like dipping in and out
46:50
Speaker 1: of this right sort of like like you were saying,
46:52
Speaker 1: it's like a chocolate like an ice cream ball being
46:55
Speaker 1: dipped in chocolate exactly, and Yeapodus is the furthest out,
46:58
Speaker 1: which is why it sees most of this dust from
47:01
Speaker 1: this dusty e ring created by Phoebe. And it's not
47:05
Speaker 1: actually the only place this happens. Like Callisto, one of
47:08
Speaker 1: the satellites of Jupiter, also sees a little bit of
47:11
Speaker 1: a contrast on its leading edge and its trailing edge
47:14
Speaker 1: for similar reasons. Well, which side do you think is
47:16
Speaker 1: better to live on? The dark side, the filled with
47:19
Speaker 1: a bugs splatter or the cleaner side behind. Well, the
47:23
Speaker 1: dark side is hotter, and that's one of the reasons
47:25
Speaker 1: why it's dark because this dust falls onto it and
47:28
Speaker 1: then absorbs more of the Sun's radiation which warms it up,
47:32
Speaker 1: which also then like boils off any of the ice
47:34
Speaker 1: which like floats up and then lands on the other side.
47:37
Speaker 1: Wait what Once the dust lands, it warms up that
47:41
Speaker 1: half of Yeapitus, and that contributes to the darkening of
47:45
Speaker 1: the planet because it boils off any of the ices
47:48
Speaker 1: which land on the other side. Wait to the ice
47:51
Speaker 1: is what makes it look clear? Yeah, the ice makes
47:54
Speaker 1: it look brighter. And so when the ice evaporates, what
47:56
Speaker 1: are you left with rocks? Yeah, So when the ice evaporates,
48:00
Speaker 1: it reduces the reflectivity of that side, right you left
48:03
Speaker 1: with rocks and other stuff that doesn't reflect as much.
48:06
Speaker 1: So it's just sort of like when you make snow dirty, right,
48:09
Speaker 1: it melts much faster because it's able to absorb the sun,
48:12
Speaker 1: and then it gets darker and darker, and it's a
48:14
Speaker 1: runaway effect. The same thing is happening on Yeapotus. One
48:17
Speaker 1: side of it got covered in dust from Phoebe, and
48:20
Speaker 1: that like melted all the ice on that side, warming
48:23
Speaker 1: it up, and all that ice like reformed on the
48:26
Speaker 1: other side, and now one side is super bright and
48:28
Speaker 1: the other side is super not that it's weird, And
48:30
Speaker 1: wouldn't that also change its shape, Like wouldn't it look
48:33
Speaker 1: flatter on the the side that's getting pelted, like the
48:37
Speaker 1: stuff is evaporating away and landing on the other side.
48:40
Speaker 1: Wouldn't that make the overall moon have kind of an
48:42
Speaker 1: oblong shape a little bit? But I think we're talking
48:45
Speaker 1: about like centimeters worth of covering out like meters or kilometers,
48:49
Speaker 1: So I don't think it makes a different sort of
48:50
Speaker 1: geologically interesting. So I guess you would want to live
48:54
Speaker 1: on the warmer side right of an ice planet, Yes,
48:58
Speaker 1: I think so. You want to live on the warmer side,
49:00
Speaker 1: but you're also going to be sweeping dust off of
49:02
Speaker 1: your solar panels basically every day book splatters. You'd be
49:07
Speaker 1: pretty excited to discover bugs out in space. I guess
49:10
Speaker 1: that would be the bigger news. All right, Well, it's
49:14
Speaker 1: pretty cool. I guess you can look at pictures of
49:16
Speaker 1: this moon and and see the contrast right between the
49:19
Speaker 1: two sides. It's very easy to spot exactly. It's very dramatic.
49:23
Speaker 1: Somebody definitely dipped the appetus in hot couco or bugs,
49:29
Speaker 1: or maybe the opposite. Maybe it's actually chocolate and it's
49:31
Speaker 1: been dipped in vanilla. Yeah, maybe it's chocolate bugs too.
49:35
Speaker 1: But is it pretty conclusive that people feel pretty confident
49:38
Speaker 1: that that this is the reason it's has two colors. Yeah,
49:40
Speaker 1: they discovered this ring about ten years ago, and they've
49:43
Speaker 1: done a bunch of calculations and they think it all
49:45
Speaker 1: clicks together that there's enough dust that comes from Phoebe
49:49
Speaker 1: to cover this moon to change the temperature to create
49:51
Speaker 1: this runaway effect. So it's a pretty solid explanation. They're
49:55
Speaker 1: pretty sure it's not boba. They're pretty sure it's not boba,
49:58
Speaker 1: but you never know until you do of the experiment.
50:00
Speaker 1: So we've got to send a mission out there to
50:03
Speaker 1: take a taste of Yeapodus that's right, the bo emission
50:07
Speaker 1: bo bo bo one to find out conclusively if the
50:10
Speaker 1: answer is Yeapidus or Nupidus that's right, or Yapides speaking
50:15
Speaker 1: of dirty snow. Not my PTIs your putis right? Al right? Well,
50:23
Speaker 1: another sign that there are still big mysteries here in
50:26
Speaker 1: our own backyard, in our Solar system. There are things
50:28
Speaker 1: that are the way they are, but nobody quite knows
50:31
Speaker 1: how they got to be their way, And everything around
50:34
Speaker 1: us is a clue about the incredible story of the
50:37
Speaker 1: Solar System and the wider universe. Everything is the way
50:40
Speaker 1: it is for a reason and has a fascinating backstory,
50:43
Speaker 1: and if you watch enough episodes, eventually all those backstory
50:46
Speaker 1: details get revealed, right, Or maybe it was the Solar
50:49
Speaker 1: System was just making it up as win alone, as
50:51
Speaker 1: most TV shows happen, because you never know. You didn't
50:54
Speaker 1: know if it was going to get renewed for another season.
50:56
Speaker 1: So you can't redcon physics, not without a time machine.
51:00
Speaker 1: I thought that's what physicists were, professional red connors, Like
51:05
Speaker 1: this is what happened. No, wait, this is what happened.
51:09
Speaker 1: We argue about what happens, but we can't actually change it.
51:12
Speaker 1: Mm hmm, but he can make up different stories about
51:16
Speaker 1: it kind of. Yeah, that's true. All right. Well, we
51:20
Speaker 1: hope you enjoyed that. Thanks for joining us, see you
51:23
Speaker 1: next time. Thanks for listening, and remember that Daniel and
51:34
Speaker 1: Jorge explained. The Universe is a production of I Heart Radio.
51:37
Speaker 1: For more podcast For my heart Radio, visit the i
51:40
Speaker 1: heart Radio app, Apple Podcasts, or wherever you listen to
51:44
Speaker 1: your favorite shows. Yeah,