November 5, 2019 • 40 mins
Listen for up to date news about suprising developments in our solar system.
Contest for naming Saturn's newly discovered moon.
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Episode Transcript
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Speaker 1 (00:08):
Hey, Crystal, I have a question for you. Do you
believe in planet number nine? Do you mean the planet
that rob Pluto of its real planetary designation? That's right, exactly,
Pluto is outseas, But I'm talking about another planet, a
planet that might be hiding behind Neptune and Uranus. So
(00:29):
just like the hottest new planet on the block. That's right.
Every ten years there's something new, something sexy that astronomers
want to talk about, something hidden out there. So you
can always be replaced by a better idea or a
better planet. That's right. No planet is safe. That's cold, man,
that's right. But you know there's no room for sentiment
out there in the far reaches of the Solar System.
(00:49):
It is a cold, cold place out there. Hi. I'm Daniel.
(01:10):
I'm a particle physicist and the co author of the
book We Have No Idea, A Guide to the Unknown Universe,
with my friend and frequent collaborator, Jorge cham And you're
listening to the podcast Daniel and Jorge Explain the Universe,
brought to you by I Heart Radio. Jorge is still
away for a little while, but don't worry, folks, he'll
(01:30):
be back soon. And until then, we have our wonderful
guest host, Crystal here with us today. I'm Crystal Dilworth.
I'm a neuroscientist by training and a triple A s
IF then STEM ambassador, and I'm super excited to do
my best to do what Jorge does and help explain
the universe. Are you going to be a Jorge simulator?
(01:51):
I could try, but I don't have any bananas with me.
Maybe offline. I want to hear your best Jorge impression.
I could probably do most of his talk. That's hilarious,
but a dangerous road, so let's not go down there.
But thanks for tuning in, folks. Our podcast is all
(02:11):
about the amazing things about the universe, the crazy bonker
stuff that we discover when we are trying to understand
this universe that we find ourselves in. And often we
talk about things super far away, but sometimes we like
to talk about things that are happening right in our backyard,
things that are happening recently, things that are happening right
here at home. Because it turns out there are lots
(02:32):
of discoveries to be made and stuff is happening all
the time. So if you haven't been keeping up with
the latest greatest scientific news stuff that's happening in our
Solar system. We're here to break it down for you,
breaking science, Well, I don't know. We want to break
science or just break the news or maybe break people's minds.
I'm on board with that. Sounds good. So today on
(02:54):
the episode, folks, we're going to be talking about scientific
news of the Solar system? What is out there? Do
we really understand what the Solar system is made out of?
How can it be possible that we still haven't figured
out what's in our own backyard? What's in your backyard? Crystal?
(03:15):
There are lots of mysteries hiding out there. There's like
a lot of potted plants and bugs, but nothing like
new astrological or astronomical phenomenon. Are you sure there are
no aliens in your backyard? Can we ever be sure
that there are not aliens in our backyard? Crystal admits
(03:36):
there might be aliens in her backyard by some definition
of alien, by some definition of might. All right, But
specifically today we want to dig into some news you
might have heard about about a potential extra planet out
there at a visitor from another solar system, and new
discoveries about one of the familiar planets, Saturn. So before
(03:59):
we dig into that, is wondering if people around town
had heard about the news of the Solar system, if
they were keeping up with the latest breaking information. So
I walked around you see, Irvine, and I asked folks
if they had heard of some of the latest discoveries.
Here's what people that you see Irvine had to say.
I haven't heard of planet nine, but I've heard of
planet X, which might be the same thing, which is
(04:21):
a theoretical planet which nobody has seen, but they've seen
potential effects from it, sort of the gravitational disruption on
other bodies. I think they believe it has a very
large orbit beyond the other eight planets, and probably very
elliptical and even possibly on a completely different plane. No,
(04:44):
I haven't heard of that. I just know that, like
we discovered it, and that there could be potential to
be life. So I don't know. That's why we're interested
in it. And what about the comment from another Solar
system we heard about that guy? I don't think so. No,
I haven't heard of that. No, is that Pluto? No
that I haven't I don't think I have. No. I
think I just read a headline and then that was it. No,
(05:07):
I haven't heard of Yes, I'm not aware of what
it is, all right, So what do you think of
those responses, Crystal, Well, it's kind of shocking that people
are still associating with Pluto, although I do get it.
Pluto was charismatic, was it? Though? I mean, it's just
a cold spec out there. I never really understood why
Pluto struck so many heartstrings with people because it was
(05:29):
tiny and cute and adorable and lonely. Or is it
like the baby planet or is it like the underdog planet,
the scrappy little rascal. I think both right, like, depending
on which you more identified with. But now we know
that Pluto is like not even by itself. But I'm
sure we'll get into that. Yes, So you think Pluto
has lost some sort of special place in our hearts
(05:50):
now that we discovered there's a whole lot of cosmic
junk out there in Pluto's orbit. I think that scientists
would want us to open our hearts to all of
the cosmics junk. That's right. It's all part of our family, right,
and we really need to put labels on it. Every
rock is just you know, it self identifies as a rock.
We don't really care if it's a rock or a
(06:10):
dwarf planet or a real planet or an asteroid or whatever.
It all deserves love and investigation. That's right. Every object
in the Solar System is worthy of our curiosity, perfect right.
And on that note, let's dig into some of this news.
I was surprised that people hadn't heard more about this
interstellar comment, because that blows my mind. That kind of
(06:32):
thing really gets me interested in potential news from other
parts of the universe and sort of messages from other
places that we can't normally access. It's like a special
opportunity to learn something. A comma is a messenger from
the great beyond. Yeah, sort of, it's coming from a
place that we can't normally get to, and so it
carries with it some information maybe about where it came from.
(06:54):
And so, because we're trapped on this little tiny rock
and we can't see most of the univer is very easily,
we have to develop every kind of eyeball we can,
and mostly we're just looking. So when something actually comes
from somewhere else, carrying with it like samples and bits,
then wow, that's an incredible opportunity to really see something
that otherwise would be totally invisible to us. Okay, I'm
(07:15):
way more excited about comments now alright, where you're gonna
have to hold your horses because we'll be talking about
that at the end of the episode. First, let's dig
into planet nine and is most of you know, we
have eight planets in our Solar system since Pluto was demoted.
One of the things that I've always found amazing is
that modern science is only responsible before discovering two of those,
(07:37):
Neptune and Uranus. All the planets before that we're basically
discovered by ancient civilizations. So from that I must infer
it is easy to find a planet. While you're really
throwing some shade on those ancient civilizations, you know, no,
it is not that hard to find nearby planets. And
remember the way that we spot planets is only in
their reflected light, because planets don't actually glow. If you're
(07:58):
seeing Jupiter or more Us in the sky, you're seeing
the reflected sunlight off of those planets. They don't actually
emit any light. And so for us to see a
planet has to be close enough that that reflected light
get to Earth and if it's far enough away from
the Sun it doesn't even get much light, not to
mention reflected all the way back to Earth. So as
the planets get further and further from the Sun, they
(08:19):
are harder and harder to spot. So yeah, the ancient
civilization sort of found all the easy ones. So which
ones did we find? We discovered Neptune and Uranus. And
there's a really interesting story there which is sort of
going to lead into Planet nine, which is that people
found Uranus and you know, they saw it by actually
seeing it in the sky, by finding this little dot
(08:40):
and tracking its orbit and discovering where it was. But
urine is is what gave us a clue that Neptune
even existed, because when they found Uranus, when they saw
its orbit, it didn't quite make sense. They're like, huh,
this doesn't move like a gravitational object. This doesn't move
the way you would expect just a rock out there
to move. So those ancient scientists that I threw shade
(09:02):
on a little bit earlier, we're actually amazing because they
were able to predict how those objects should be moving,
so we know when we see something abnormal, is that right? Well,
the ancient scientists. They could see things moving in the sky,
and they deduced that Mars, for example, in Venus were
not stars. There were other planets, but it wasn't kntild
about the eighteen hundreds that we found Uranus and that
(09:24):
we deduced from Uranus is orbit. At that point we
had like a solid theory of gravitation, and we could
calculate the predictions for how these planets should move. And
when we did that, we found that our predictions for
Uranus weren't right, Like they just didn't add up. Urinus
wasn't moving the way we expected to, and things made
a lot more sense if you sort of added one
(09:45):
more element, like there's some chaos and Uranus is orbited.
It wasn't as simple as they expected, and that's what
suggested that there might be something else out there, something
tugging on it, something tweaking it, something making it. So
it wasn't just moving smoothly and simply so we knew
the math was right. So something about the way that
we described what we were seeing had to be wrong. Yeah, well,
(10:06):
that's a great point. You know, whenever we have a
theory and then the data disagrees with the theory, you
have two questions. You're like, well, is the theory wrong?
And we were pretty sure about the theory of gravitation,
so that's not the first thing we're going to go to.
But the other option is, well, maybe we're missing some data,
Maybe there's some missing element in our theory, maybe there's
something asked out that it's not in our model. And
(10:28):
when they added the concept of another planet, like, well,
what if there's another planet out there, then it made
a lot more sense. If they put another planet, Neptune
into the model, then the orbit of uriness makes perfect sense.
And then they went and looked for Neptune and actually
found it. So the cool thing about Neptune is that
we suspected it was there from the gravitational hints before
(10:49):
we found it. How long between the time when scientists
are able to predict that there should be a gravitational
mass in an area and the actual concrete servation of
that planet or mass, Like, what should we expect that
timeline to be? That's a great question. I wish I knew.
It depends on a lot of things. That it depends
(11:10):
on the size of the planet, the distance from the Sun,
and its shining nous. Because the only way to really
see it is to see it reflecting life from the Sun,
and the further they are from the Sun, the less
light they reflect. And it also depends, you know, on
the color of the planet and its shining nous. Some
planets absorb more light than they reflecting, so they are
just harder to spot. I think scientists call this the albedo,
(11:31):
which always makes me think of the libido. You know,
it's not that exciting, but scientists get excited about different
things for different reasons. That's right. You gotta get interested
in something about science. And the cool thing is that
now we're in the same situation with Urinus and Neptune
and also all these little objects he's called sort of
(11:52):
trans Neptune objects, a bunch of dwarf planets and weird
rocks floating out there in the Solar System, deep deep
in the Solar System. Those orbits don't make sense, sort
of in the same way that Urin is used to
not make sense, and then we found Neptune. Now we're
looking at Uranus and Neptune and all these trans Neptune
objects and we're thinking, these don't make sense. These are
(12:12):
weird orbits for them to have so a piecing the
puzzle together. As we go further and further away from
the Sun, it gets harder and harder for us to
see what we're looking for. Yeah, but the story is
the same. We ask, can we explain everything we're seeing
in terms of the objects we have? We say, well,
would it makes sense if we added another object? And
this is really fun because that's a clue. If you
(12:36):
build a model and then you're like, Okay, this makes
much more sense, and we add this new planet, then
you can go look for It gives you something sort
of specific to look for, rather than just scanning the
sky and wondering if you're going to see something. If
you know where to look, you have a much better
chance of actually finding it. So what do we know
about Planet nine. We don't even know if it exists, right.
We know that these trans Neptune objects have weird orbits,
(12:59):
like they've clustered around a common plane that's tilted with
respect to the Solar System. You know, there's a bunch
of these guys with really long orbits and they're all tilted,
and that's not the kind of thing you expect, like
it can happen. But in order to get a tilt
relative to sort the sort of Solar System plane you
have to have a collision or be tugged by something else.
(13:19):
And they did all these calculations and they found this,
like a one in five of our Solar System ending
up in this sort of situation without a planet nine.
So I wouldn't say they're pretty sure that there's a
planet nine, but it seems unlikely that there isn't a
planet nine. How do you like that sort of scientific
word word jumble there? That was a good hedge. I
(13:40):
like that. But before before these calculations for planet nine
were made, and before the erratic behavior of these other
bodies became so obvious that we couldn't ignore them, the
existence of a ninth planet was kind of like relegated
to the crazies that wear tin hats and jump around
(14:01):
in lightning storms, wasn't it. I'm not a member of
that community, so I'm not sure. But you know, people
have been wondering about a planet none for a long time,
and when Pluto is discovered, some people thought, ah, there
it is. This answers the question about Uranus and Neptune's
weird orbits and this other stuff. But of course Pluto
can't actually explain that because it's too tiny. Pluto is
(14:23):
really small. That's why it got downgraded from planet to
dwarf planet, so it doesn't actually answer this question. So yeah,
I think that this idea of a of another planet
out there was a bit of a bit of a
crazy theory. But now that we get more information, we
have better telescopes to see more of these trans neptune objects,
and people have done more careful calculations that I think
(14:43):
they're better received. But you tell me, you know some
of these researchers, don't you. I do. Yeah. Mike Brown,
who was one of the researchers that actually worked to
demote Pluto because he found other objects that were just
as big or bigger, so Pluto wasn't as exciting anymore.
And Constantine Patigue in who the theorists who helped do
those calculations, are both from my institution, Caltech, So I
(15:06):
had the opportunity to talk to them when they had
first made this prediction, and they kind of knew people
were going to think they were crazy, but they are crazy,
just not in a scientific way. So they were very
happy to be making this outrageous statement knowing that they
could back it up with math Um, and they are
very excited about the idea of observing what they've predicted.
(15:30):
But in Constantine's predictions, the mass is like five thousand
times the size of Pluto, So they're looking for something
that's really significantly large. That's right, Pluto cannot explain this
weird stuff they're seeing out there. And let me just
say that I'm so jealous of those guys because it's
sort of a scientific fantasy to find evidence for something
(15:52):
that seems bonkers. Because you know, we know the universe
is bonkers, we know it has surprises waiting for us.
But you can't just make stuff up. You have to
discover it. And so to be in that situation where
you the data are telling you something fascinating and new
that you know most of the community is gonna have
a hard time accepting that, honestly seems like a lot
of fun to me. Yeah, these two guys, they really
(16:13):
enjoy shaking things up. Yeah, but you asked earlier, like,
what do we know about planet nine? Well, again, we
don't know that it exists. But the hypothesis, like sort
of the theory that would explain these orbits more simply
is that it's orbiting really far out there. It's like
four hundred to eight hundred times the radius of Earth's orbit,
(16:34):
so really deep in space, and that far out in space,
it would take like ten thousand or twenty thousand years
just to go around the Sun one time. That is
a really really long time to wait to get data
for your PhD. I'm just saying, it's also a really
long time to have a birthday. I mean, you're born
on planet nine and like your ten Earth years have
passed before your first birthday. Wow. And then also it's
(16:56):
going to make it really hard for us to see right,
and like coming from like the people's perspective, the neuroscience perspective,
like the visual system is our primary system. That's how
we feel that we really know what's going on. So
until scientists can really put eyes on this planet, is
it going to be something that's accepted by the community.
Do you think No? I think you're totally right. It's
(17:18):
like a murder, you need a body, you know it's Uh,
until you've seen it directly, you're not sure that it exists.
I totally agree. Otherwise it's sort of circumstantial or indirect
evidence it's the same deal. In particle physics, we suspected
the Higgs Boson was there. We had a lot of
clues about where it might be and how it might work.
All the other information pointed to it, but until we
(17:39):
actually saw it, until we created it and and saw
it in the lab, we didn't even believe it existed.
And I think in the same way, this is a
great idea. But until they actually spotted, they see light
reflected off of it, they see its motion and complaud
its orbit, I don't think it would be accepted as
a real thing. So I understand the thrill of discovery.
I understand how addictive and amazing it can be when
(18:03):
you make a prediction based on the things that you
think you know about the universe, and that prediction is true.
But once we and I'm going to be optimistic, care
once we see evidence of planet nine, what is that
going to tell us other than it's there. Well, your
friends are gonna throw a big party and say we
(18:23):
told you so, we told you so, which is probably
gonna be really satisfying. But it also it's every piece
of information we get about the nature of the Solar
System gives us a clue about how it formed because
it rules out a bunch of stories. You know, scientists
work in the framework of stories. I think a lot
of people think of science is like super objective, But
in the end, we're telling a story. We're trying to
explain the universe. We're trying to say, this is what
(18:45):
happened this and then that and the other thing. And
right now we have lots of different ideas about how
the Solar system might have formed, and the more data
we get, the more we can rule some of those
out because they're inconsistent with that data. So the more
we know about the Solar System, especially out in the
far reaches, the more we can get a sense for
how things came together. And that's of course important and interesting,
(19:06):
not just because we want to know, like what is
the context of our existence? How is our solar system formed?
But we want to know if our solar solar system
is unusual, if other solar systems might have formed this way,
if there are other planets like this out there. And
so I think this touches on a lot of really
deep and broad scientific questions. So does planet nine have
(19:27):
to be a planet or could it be something else?
With like a huge mass. You put your finger right
on the question there, because what we know about Planet nine,
if it exists, comes just from its gravitational interactions. We
can speculate about how much mass it has and how
it's moving and how that is tugging on those other objects,
but you're right, that doesn't tell us what its nature is.
(19:47):
Is it a ball of rock. A ball of rock
or a ball of ice, for example, that have the
same mass would have the same exact gravitational effects, and
even something crazy like a black hole. We talked down
on the podcast once about what would happen if the
Sun became a black hole. I think a lot of
people were surprised to learn that a black hole has
the same gravitational force as a star of the same mass,
(20:11):
And so if you've fixed the mass of the object,
it really could be anything um and have the same
gravitational effects. So we won't know until we see it.
We won't know until we see it. And there's been
some press recently about the possibility that planet nine might
be a black hole, which is exciting because it seems
cool and wow, it would be kind of awesome now
have a black hole so nearby that we could study Um,
(20:33):
there's not a whole lot of specific evidence pointing in
that direction. Um. But the cool thing is that if
it is a black hole, there are some things we
can look for if a black hole. If it was there,
would probably have a big blob of dark matter surrounding it,
and we could look for dark matter smashing into itself
and giving us gamma rays, and a black hole if
(20:54):
it's there again, because it's denser than a planet or
something else, might give us some gravitational lensing. And actually,
in some data there are a few signs of sort
of unexpected micro lensing, like weird distortions of the background
galaxies that would be consistent with the passing of black hole.
But they're not really conclusive, so it's more than like
(21:15):
fun speculation at this point. But yeah, it's totally possible
that planet nine is not a ball of rock with
water on it, but a tiny black hole left over
from the creation of the universe. I feel a little
uneasy about like a casual black hole in the backyard
of our Solar system. For all you know, you have
a black hole in your backyard. It doesn't sound like
(21:36):
you have a really good inventory what's out there. Yeah,
I'm not a big gardener. No, you're right, a black
hole does us. It sounds awesome. It also sounds a
little scary. But this black hole, if it exists, is
orbiting really far out there and probably very stable, and
so it's unlikely to come anywhere near the Earth. But yeah,
it's if it's there, it would certainly be the closest
(21:57):
black hole to the Earth. And then you have to
one or like, what if he got tweaked out of
its orbit and plunged in towards the Sun. Actually, just
read an amazing science fiction novel just that topic. Yeah,
I was gonna say that sounds like a movie that
I'm not sure if I want to see. No, it's
a great science fiction novel by one of my favorite authors,
Greg Egan, and he talks about what would happen if
(22:18):
a black hole passed near the Earth but didn't gobble it,
and it has crazy effects on the tides and all
sorts of other cool stuff. Anyway, we don't know if
Planet Night is there. If it's there, we don't know
if it's the black hole or another planet. We don't
even know what we would call it. Right if we
actually discover it, we can't call it planet nine. What
do you think we should call it Crystal? I don't.
(22:40):
All I know is that scientists are historically, I'm gonna say,
bad at naming things. I mean, there's like a ligand
pro to mic receptor pair in my field, which is
like sonic and hedgehog. Clearly, these people were Saga fans
and they couldn't think of anything on their own. So
I'm saying, let's not let them name this planet. If
(23:01):
it's Discovery, we should get all of our listeners to
come together and come up with a good name. I
do a little survey, and I think people are calling
it planet nine. Some scientists call it planet X, some
scientists are calling it George, and other ones are even
calling it Fatty. So I think you're right. The scientists
need a lot of help in its regard George George.
It's like I know, I think that shows some people
(23:24):
sort of generic bias for objects. They need Jrees help on,
like something that's really catchy and informative. We have a
long list of things to talk to Core about when
he returns, but I'll put that on the top of
the list. So do we have to look that far
out for things that we don't know about our Solar system,
or are we still learning about stuff that's closer to us.
There's a huge amount to learn about stuff that's even
(23:45):
closer than the far far depths of the Solar System.
Let's talk about that, but first let's take a short break.
All right, we're back and we're talking about news of
(24:08):
the Solar system, crazy discoveries, things that we're learning just
recently in the last weeks and months about our own
cosmic backyard, and Krystal, you were saying, are there things
we're learning that are closer to home than the far
reaches a space past Pluto, And in fact there are
people have probably learned recently in the Science news that
Saturn has been upgraded. It is now the moon king
(24:30):
of the Solar system because it now has eighty two moons,
so it's beating Jupiter Stuper that are the second place
moon owner. That's right, as far as we know. You know,
we can't say we know all the moons that are
out there, because we keep finding more as we look
more carefully and build new instruments. But so far Saturn
has the most moons of the Solar System, and I
(24:50):
don't know if that's a point of pride among planets,
or they just don't care how many moons the Saturn have.
Saturn now has eighty two moons. That's a lot. It's
a lot of things. It is the name. Also, I
don't even know the names of all these objects. But
you know scientists are gonna be arguing about things the
way scientists usually argue about things. Then this is gonna
be a long conversation about how to name all these moons.
Are just gonna have a lot of moons named after
(25:12):
scientists or scientists dogs or family members or stuff like that.
Mm hmm. Sounds reasonable. But actually you can contribute. You
listener can participate because there's a contest out there to
name these moons. So if you have an idea for
how to name the new moons of Saturn, you should
throw your ideas into the hat. Save the scientists from
(25:34):
themselves come up with a good name. That's right. We
are crowdsourcing the hardest part of solar system science, which
is naming all the new stuff they find. So usually
when scientists are finding something new, that means there's been
some type of technological advance that's allowing them to see
things that they couldn't see before, or detect things that
they previously couldn't detect. Is that true here? Yeah, And
(25:55):
it's also sometimes just a question of scientific resources. Sometimes
we have the divice is it's just been sort of
pointed somewhere else, and so here people were interested in
questions about the formation of the Solar System, so they
wrote these proposals to dedicate telescope time to look specifically
for these for moons around Saturn. Moons are sort of
further out than the other moons. These moons are really
(26:17):
far away from Saturn. They're like in very distant orbits.
So the scientific machine finally got around to thinking this
was important. That's right exactly, or the scientists who think
this is important finally got the attention they deserve. And
you know, all these moons they're not like really big objects.
If you're looking up in the night sky and you
(26:37):
see our moon and you think that that's typical, remember
that our moon is huge compared to most of the
moons in the Solar System. These moons are like rocks
three miles wide, and some of them take like three
years to go around Saturn. So it really is just
more like a careful catalog of all the stuff around Saturn,
whether you call it a moon, whether you call it
a rock. Like we were saying before, we love it all.
(27:00):
So where do these smaller moons come from? Like how
do they end up orbiting these these larger planets. Yeah,
that's a great question you might wonder, like why are
their moons at all? Why don't objects just coalesce into planets?
And one reason is that these planets have very strong
gravitational fields, and those gravitational fields provide tidal forces. If
(27:21):
you're big enough, then there's a difference between the gravitational
tug on the side of you that's close to the planet,
then the gravitational tug that's on the side of you
that's far from the planet. If you're large enough for
that to have a big effect, that means because there's
a difference in the gravitational force from one side to
the other side, that essentially the planet is pulling you
apart because it's tugging on one part more than the
(27:42):
other part. And so if you're around a big enough
planet and you're in sort of the right gravitational zone,
the planet will tear you up. It will shred you
and so that's why you don't have all the stuff
around Saturn just coalesced into one big moon. That's why,
for example, Saturn has rings, we think because is the
tidal forces are too great for those rings to coalesce
(28:04):
into moons. So Saturn's so big that it's gravitational force
is doing crazy things to what's around it. Basically, this
is my technical interpretation. I heard shredding, I heard a
lot of other things like so crazy things. No, you're
totally right. And it also gives us a bit of
a window into the timeline of Saturn because some of
(28:24):
this stuff, if he had been around since the beginning
of the Solar system, probably would have found a way
to get into a stable place that it might have
been able to coalesce into a moon. Like for example,
we don't know how long Saturn's rings have been around,
and we don't know how long they will be around.
It might be that another hundred million years or billion
years they will eventually coalesced into an object um that
(28:46):
Saturn's tidal forces won't pull apart. And so if we
look at where these moons are, we don't think these
moons could have been around for very long because if so,
they would have been slowed by all sorts of gas
and dust that surrounds Saturn, and they would have slowed
them down and they would have been sort of dragged
down into lower orbits. So by understanding sort of where
(29:07):
the moons are, the close by ones and the far
away ones, it gives us a window into the time frame,
like how long this happening and what's the sort of
dynamics Saturn looked the same way since the beginning of
the Solar system, or the new features that aliens from
a billion years ago wouldn't recognize if they came and
visited today. Yeah, So I learned a long time ago
that when different types of scientists used time to always
(29:30):
ask what scale we're talking about. So when an astrophysicist
says these moons haven't been around for very long weeks,
they don't mean months, they mean hundreds of millions of years.
They mean the time scale of the Solar System, which is,
you know, four and a half billion years. So they're
way old, but yet young for the universe. Yeah, exactly.
(29:53):
They are probably hundreds of millions of years old, which
is pretty young compared to Saturday itself and other things.
In the Solar system, So why does it matter to
us how many moons Saturn has? No? I think, um,
some people out there might be excited every time we
discover a moon because it's sort of a new element
in the Solar system. People like like discovery, like finding
(30:15):
things in their backyard. Um, that never really gets it
for me, because I feel like, you know, we know
there's rocks out there. Doesn't really matter how many rocks
there are, but it does help us scientifically, it doesn't
really give us a clue as to how things happened.
Like we were saying before, there's a story by the
formation of Saturn, and now some of those stories don't
make sense anymore because they're inconsistent with finding these moons
(30:37):
out there this far away. And so the more data
we get, the more we can narrow it down and
find the one true story of our solar system. And hey,
who doesn't want to know the story of the origin
of our solar system? Right? I think all of us
are interested in where we came from and how we
came to be, and the beginning of the Solar system
is like going as far back as we could possibly
(31:00):
we could possibly think. But you said that like everybody
knows there's rocks out there, Like, yeah, planets are just rocks,
are not They're not that interesting. But I heard some
deep passionate excitement about comments. So tell me why comments,
and about this one in particular. Yeah, let's do that.
Let's talk about comments and comments from other solar systems.
But first let's take another break. So we're back, and
(31:34):
we're talking about exciting stuff that's been discovered in our
solar system pretty recently. So we are updating you on
news of our solar system. And one of the most
interesting things to happen in our solar system in the
last few years was that we got a visitor. Our
solar system is a little island in the middle of
an enormous empty ocean of space. The next solar system
(31:54):
over is light years and light years away. What that
means is that we don't expect a lot of messages
is from all our solar system to the other, or
from other solar systems to us. We expect to basically
be isolated. It should it should be very very rarely
that something gets tossed out of our solar system and
actually happens to land in another one. It's like if
there are two basketball hoops on the Earth, one here
(32:17):
and one on the other side of the Earth, and
you lost your basketball and ended up somehow drifting all
the way around the Earth and making a slam dunk
in the other basketball highly improbable. But those of you
who have listened to our podcasts know that in we
did get a visitor from another solar system. It's called Omuamua,
(32:38):
and it was really weird. It was long, it was thin,
it was shiny. It seemed to accelerate as it left
the Solar system. Those you interested in that, go check
out our whole podcast on it. But these days most
people think it probably was a comet, a comet from
another solar system, so that when we say interstellar, that's
what we mean. Yeah, into selling means from another star.
(33:02):
Because stars are big and they're exciting and they're bright,
but they are not very dense. You can fly through
a whole galaxy and not encounter any stars because they
are light years and light years apart. And that's why
we thought it was very unusual for things from one
solar system to end up in another one. And we
talked about the Solar system in terms of the planets,
and these objects that are sort of in the far
(33:23):
reaches of the solar system. But there's stuff in our
solar system that's even further away. This is thing we
call the art cloud, which is basically a huge collection
of balls of ice, and that's where comments in our
solar system come from. They get nudged and they fall
in towards the star, and they accelerate on their journey
towards the center of the solar system, whizz around and
(33:44):
go all the way back those where our comments come from.
The ideas maybe sometimes one of those objects in the
war cloud gets nudged. Instead of falling in, it sort
of falls out. And so that would be like us
sending a message. That would be us sending a message.
And it's a message in the sense that it tells
you some thing about our solar system. That Commet has
in it a particular mix of ice and rocks and
(34:06):
and other trace elements to tell you about the blob
that formed our solar system, that huge you know, nebula
of gas and dust and stuff that made our solar system.
But because we're trapped on this one island, we never
know is what we're looking at. Typical or unusual. That's
the frustration with having an equals one, with only having
a single example and trying to generalize to the whole universe,
(34:29):
because of course, what we want to do is understand
the whole universe. So if we can get comments from
other solar systems and study them, then we can figure out, like, hey,
does that commet look like ours or is it totally
weird in comparison? So how often do we have the
privilege of encountering an interstellar object. It's super duper rare. Oh,
(34:51):
Mua Mua was the first one ever found, and they
found it, as you said, because they turned on a
new kind of telescope, a telescope that could see this
kind that thing. Now, the amazing thing about that was
when they turned it on, they really had no idea
how often they would expect to see things, but they
expected it would be really rare. And then just days
or weeks after they turned it on, they saw Omama.
(35:13):
In fact, they saw it as it was leaving the
solar system, so we only got this sort of trailing
glimpse as it accelerated out of our field of view,
and we got less and less information. Now they've been
watching the skies and they found a second one, So
not as rare as we thought, then, yes, and that's exciting.
It's also sort of surprising. If we're getting comments from
other solar systems fairly regularly, like every couple of years,
(35:37):
that means that it can't be very unusual for these
rocks to get knocked out of solar systems and end
up in other solar systems. Because you know they're so
far apart, it seems really unlikely. So for a couple
to end up here means it must be happening all
the time. So this interstellar object, this comment that we
saw coming in, do we know where it came from?
(35:58):
So this one we don't yet know where it came from,
but this is very recent. We've only got a few
snapshots of it, and to figure out where it came
from we need to sort of track it and understand
the direction it's moving in. But this one is a
very clearly an icy blob, and it has a tail.
It's got this sort of halo as as stuff melts
off of it, and that makes it harder to know
(36:19):
its exact location, and that makes it hard to pinpoint
its exact trajectory. Um So We don't know exactly where
it came from, but we can see very clearly that
its trajectory is not consistent with anything that's orbiting the Sun. Right.
That's how we know that something is an interstellar object,
that it just doesn't look like it's moving in an
orbit around the Sun. And this one, in particular, if
(36:39):
you if you take the plane of the Solar system
sort of the palm of your hand, this one is
shooting like straight down into the palm of your hand.
It's very clearly coming from somewhere else. We don't know
exactly where yet. We love to like point back to
the Solar System it came from, but there's a lot
of uncertainty still. Yeah, you know, it's like sort of
conjures up these images of being able to chip and
(37:00):
ask it all the scientific questions do you want to ask,
like what's in your ice? And what are your rocks
made out of? Yes, and we're already doing that. The
lucky thing about this one is that we're catching it
on the way in which means it's getting closer and closer,
and we can prepare and we can prepare for that
moment when it comes closest to Earth. Just gives us
our best chance to understand it. And we can't like
(37:22):
launch a spaceship and go visit it. We don't have
the time or the expertise to do that. But we
can study it just by looking at the light that
reflects off of it. That tells us about you know,
what is the atomic makeup? Does it have this kind
of gas and that kind of gas. We talked on
this podcast a few weeks ago about how different kinds
of gas shine different kinds of lights. Just like if
you put weird stuff in a Bunsen burner will turn
(37:43):
green or purple. We can look at the colors of
lights coming from this thing and get a sense for
what's in it, and as he gets closer and closer,
we get better and better measurements. So yeah, it's gonna
be visiting and we're gonna be asking it a lot
of questions. So we're not just figuring out things that
are happening in our own solar system, but like the
our reaches of what we have known about before, but
we're also learning new things that are coming to us
(38:05):
from other stars, other solar systems. Yeah, of course, and
my fantasy is that one day one of these things
will not just be a comment. It will be some
alienship and the physicists from that solar system will have
arrived to solve all these problems and answer all of
our deep questions about the nature of the universe. I've
seen that movie. It doesn't end well, I know, but
(38:27):
there's always a moment of satisfaction when they have learned
some deep secrets about the universe before the aliens eat everybody.
And that's the moment. I'm living for, the moment of
discovery before complete and utter destruction. That's right. I will
sacrifice the future of humanity just for a fleeting glimpse
at the secrets of the universe. Do you think that
when the aliens that are going to come and share
(38:49):
their physics with us before eventually just showing us all,
do you think they'll have that moment of looking down
on us the way that we look up at comments
and thinking, wow, the versus pretty amazing and pretty beautiful.
I hope so. I hope that being a super intelligent
alien that travels the universe comes with moments of grandiose
wonder at the at all, at this beautiful universe that
(39:12):
we find ourselves in. I certainly hope so. Well. I
will continue to read the news looking for well evidence
of planet nine and also contact with an alien species. Well,
I think that's a good idea, and keep your ears
tuned from more Solar System news because that interstellar comment
is coming and it will be here. The closest approach
to the Earth will be on December seven, So we
(39:35):
hope to learn something. Maybe it's a comment, maybe it's
hiding an alien spaceship. We don't know. You know, listeners know,
of course, the solution we're hoping for. So until we
learn more secrets about the nature of our Solar system
or get clues from other Solar systems, we're here to
break down today's news for you. Thanks everybody for tuning in,
and thank you Crystal for joining us again on the podcast.
(39:57):
Thanks for having me tune in next time for more
crazy the amazing, mind blowing facts about our universe. Thanks
for listening. Before you still have a question after listening
to all these explanations, please to drop us the line.
We'd love to hear from you. You can find us
(40:19):
on Facebook, Twitter, and Instagram at Daniel and Jorge That's
one word, or email us at Feedback at Daniel and
Jorge dot com. Thanks for listening and remember that Daniel
and Jorge Explaining the Universe is a production of I
Heart Radio. More podcast from my heart Radio, visit the
I heart Radio Apple Podcasts, or wherever you listen to
(40:40):
your favorite shows. Yea.
Hey, Crystal, I have a question for you. Do you
believe in planet number nine? Do you mean the planet
that rob Pluto of its real planetary designation? That's right, exactly,
Pluto is outseas, But I'm talking about another planet, a
planet that might be hiding behind Neptune and Uranus. So
(00:29):
just like the hottest new planet on the block. That's right.
Every ten years there's something new, something sexy that astronomers
want to talk about, something hidden out there. So you
can always be replaced by a better idea or a
better planet. That's right. No planet is safe. That's cold, man,
that's right. But you know there's no room for sentiment
out there in the far reaches of the Solar System.
(00:49):
It is a cold, cold place out there. Hi. I'm Daniel.
(01:10):
I'm a particle physicist and the co author of the
book We Have No Idea, A Guide to the Unknown Universe,
with my friend and frequent collaborator, Jorge cham And you're
listening to the podcast Daniel and Jorge Explain the Universe,
brought to you by I Heart Radio. Jorge is still
away for a little while, but don't worry, folks, he'll
(01:30):
be back soon. And until then, we have our wonderful
guest host, Crystal here with us today. I'm Crystal Dilworth.
I'm a neuroscientist by training and a triple A s
IF then STEM ambassador, and I'm super excited to do
my best to do what Jorge does and help explain
the universe. Are you going to be a Jorge simulator?
(01:51):
I could try, but I don't have any bananas with me.
Maybe offline. I want to hear your best Jorge impression.
I could probably do most of his talk. That's hilarious,
but a dangerous road, so let's not go down there.
But thanks for tuning in, folks. Our podcast is all
(02:11):
about the amazing things about the universe, the crazy bonker
stuff that we discover when we are trying to understand
this universe that we find ourselves in. And often we
talk about things super far away, but sometimes we like
to talk about things that are happening right in our backyard,
things that are happening recently, things that are happening right
here at home. Because it turns out there are lots
(02:32):
of discoveries to be made and stuff is happening all
the time. So if you haven't been keeping up with
the latest greatest scientific news stuff that's happening in our
Solar system. We're here to break it down for you,
breaking science, Well, I don't know. We want to break
science or just break the news or maybe break people's minds.
I'm on board with that. Sounds good. So today on
(02:54):
the episode, folks, we're going to be talking about scientific
news of the Solar system? What is out there? Do
we really understand what the Solar system is made out of?
How can it be possible that we still haven't figured
out what's in our own backyard? What's in your backyard? Crystal?
(03:15):
There are lots of mysteries hiding out there. There's like
a lot of potted plants and bugs, but nothing like
new astrological or astronomical phenomenon. Are you sure there are
no aliens in your backyard? Can we ever be sure
that there are not aliens in our backyard? Crystal admits
(03:36):
there might be aliens in her backyard by some definition
of alien, by some definition of might. All right, But
specifically today we want to dig into some news you
might have heard about about a potential extra planet out
there at a visitor from another solar system, and new
discoveries about one of the familiar planets, Saturn. So before
(03:59):
we dig into that, is wondering if people around town
had heard about the news of the Solar system, if
they were keeping up with the latest breaking information. So
I walked around you see, Irvine, and I asked folks
if they had heard of some of the latest discoveries.
Here's what people that you see Irvine had to say.
I haven't heard of planet nine, but I've heard of
planet X, which might be the same thing, which is
(04:21):
a theoretical planet which nobody has seen, but they've seen
potential effects from it, sort of the gravitational disruption on
other bodies. I think they believe it has a very
large orbit beyond the other eight planets, and probably very
elliptical and even possibly on a completely different plane. No,
(04:44):
I haven't heard of that. I just know that, like
we discovered it, and that there could be potential to
be life. So I don't know. That's why we're interested
in it. And what about the comment from another Solar
system we heard about that guy? I don't think so. No,
I haven't heard of that. No, is that Pluto? No
that I haven't I don't think I have. No. I
think I just read a headline and then that was it. No,
(05:07):
I haven't heard of Yes, I'm not aware of what
it is, all right, So what do you think of
those responses, Crystal, Well, it's kind of shocking that people
are still associating with Pluto, although I do get it.
Pluto was charismatic, was it? Though? I mean, it's just
a cold spec out there. I never really understood why
Pluto struck so many heartstrings with people because it was
(05:29):
tiny and cute and adorable and lonely. Or is it
like the baby planet or is it like the underdog planet,
the scrappy little rascal. I think both right, like, depending
on which you more identified with. But now we know
that Pluto is like not even by itself. But I'm
sure we'll get into that. Yes, So you think Pluto
has lost some sort of special place in our hearts
(05:50):
now that we discovered there's a whole lot of cosmic
junk out there in Pluto's orbit. I think that scientists
would want us to open our hearts to all of
the cosmics junk. That's right. It's all part of our family, right,
and we really need to put labels on it. Every
rock is just you know, it self identifies as a rock.
We don't really care if it's a rock or a
(06:10):
dwarf planet or a real planet or an asteroid or whatever.
It all deserves love and investigation. That's right. Every object
in the Solar System is worthy of our curiosity, perfect right.
And on that note, let's dig into some of this news.
I was surprised that people hadn't heard more about this
interstellar comment, because that blows my mind. That kind of
(06:32):
thing really gets me interested in potential news from other
parts of the universe and sort of messages from other
places that we can't normally access. It's like a special
opportunity to learn something. A comma is a messenger from
the great beyond. Yeah, sort of, it's coming from a
place that we can't normally get to, and so it
carries with it some information maybe about where it came from.
(06:54):
And so, because we're trapped on this little tiny rock
and we can't see most of the univer is very easily,
we have to develop every kind of eyeball we can,
and mostly we're just looking. So when something actually comes
from somewhere else, carrying with it like samples and bits,
then wow, that's an incredible opportunity to really see something
that otherwise would be totally invisible to us. Okay, I'm
(07:15):
way more excited about comments now alright, where you're gonna
have to hold your horses because we'll be talking about
that at the end of the episode. First, let's dig
into planet nine and is most of you know, we
have eight planets in our Solar system since Pluto was demoted.
One of the things that I've always found amazing is
that modern science is only responsible before discovering two of those,
(07:37):
Neptune and Uranus. All the planets before that we're basically
discovered by ancient civilizations. So from that I must infer
it is easy to find a planet. While you're really
throwing some shade on those ancient civilizations, you know, no,
it is not that hard to find nearby planets. And
remember the way that we spot planets is only in
their reflected light, because planets don't actually glow. If you're
(07:58):
seeing Jupiter or more Us in the sky, you're seeing
the reflected sunlight off of those planets. They don't actually
emit any light. And so for us to see a
planet has to be close enough that that reflected light
get to Earth and if it's far enough away from
the Sun it doesn't even get much light, not to
mention reflected all the way back to Earth. So as
the planets get further and further from the Sun, they
(08:19):
are harder and harder to spot. So yeah, the ancient
civilization sort of found all the easy ones. So which
ones did we find? We discovered Neptune and Uranus. And
there's a really interesting story there which is sort of
going to lead into Planet nine, which is that people
found Uranus and you know, they saw it by actually
seeing it in the sky, by finding this little dot
(08:40):
and tracking its orbit and discovering where it was. But
urine is is what gave us a clue that Neptune
even existed, because when they found Uranus, when they saw
its orbit, it didn't quite make sense. They're like, huh,
this doesn't move like a gravitational object. This doesn't move
the way you would expect just a rock out there
to move. So those ancient scientists that I threw shade
(09:02):
on a little bit earlier, we're actually amazing because they
were able to predict how those objects should be moving,
so we know when we see something abnormal, is that right? Well,
the ancient scientists. They could see things moving in the sky,
and they deduced that Mars, for example, in Venus were
not stars. There were other planets, but it wasn't kntild
about the eighteen hundreds that we found Uranus and that
(09:24):
we deduced from Uranus is orbit. At that point we
had like a solid theory of gravitation, and we could
calculate the predictions for how these planets should move. And
when we did that, we found that our predictions for
Uranus weren't right, Like they just didn't add up. Urinus
wasn't moving the way we expected to, and things made
a lot more sense if you sort of added one
(09:45):
more element, like there's some chaos and Uranus is orbited.
It wasn't as simple as they expected, and that's what
suggested that there might be something else out there, something
tugging on it, something tweaking it, something making it. So
it wasn't just moving smoothly and simply so we knew
the math was right. So something about the way that
we described what we were seeing had to be wrong. Yeah, well,
(10:06):
that's a great point. You know, whenever we have a
theory and then the data disagrees with the theory, you
have two questions. You're like, well, is the theory wrong?
And we were pretty sure about the theory of gravitation,
so that's not the first thing we're going to go to.
But the other option is, well, maybe we're missing some data,
Maybe there's some missing element in our theory, maybe there's
something asked out that it's not in our model. And
(10:28):
when they added the concept of another planet, like, well,
what if there's another planet out there, then it made
a lot more sense. If they put another planet, Neptune
into the model, then the orbit of uriness makes perfect sense.
And then they went and looked for Neptune and actually
found it. So the cool thing about Neptune is that
we suspected it was there from the gravitational hints before
(10:49):
we found it. How long between the time when scientists
are able to predict that there should be a gravitational
mass in an area and the actual concrete servation of
that planet or mass, Like, what should we expect that
timeline to be? That's a great question. I wish I knew.
It depends on a lot of things. That it depends
(11:10):
on the size of the planet, the distance from the Sun,
and its shining nous. Because the only way to really
see it is to see it reflecting life from the Sun,
and the further they are from the Sun, the less
light they reflect. And it also depends, you know, on
the color of the planet and its shining nous. Some
planets absorb more light than they reflecting, so they are
just harder to spot. I think scientists call this the albedo,
(11:31):
which always makes me think of the libido. You know,
it's not that exciting, but scientists get excited about different
things for different reasons. That's right. You gotta get interested
in something about science. And the cool thing is that
now we're in the same situation with Urinus and Neptune
and also all these little objects he's called sort of
(11:52):
trans Neptune objects, a bunch of dwarf planets and weird
rocks floating out there in the Solar System, deep deep
in the Solar System. Those orbits don't make sense, sort
of in the same way that Urin is used to
not make sense, and then we found Neptune. Now we're
looking at Uranus and Neptune and all these trans Neptune
objects and we're thinking, these don't make sense. These are
(12:12):
weird orbits for them to have so a piecing the
puzzle together. As we go further and further away from
the Sun, it gets harder and harder for us to
see what we're looking for. Yeah, but the story is
the same. We ask, can we explain everything we're seeing
in terms of the objects we have? We say, well,
would it makes sense if we added another object? And
this is really fun because that's a clue. If you
(12:36):
build a model and then you're like, Okay, this makes
much more sense, and we add this new planet, then
you can go look for It gives you something sort
of specific to look for, rather than just scanning the
sky and wondering if you're going to see something. If
you know where to look, you have a much better
chance of actually finding it. So what do we know
about Planet nine. We don't even know if it exists, right.
We know that these trans Neptune objects have weird orbits,
(12:59):
like they've clustered around a common plane that's tilted with
respect to the Solar System. You know, there's a bunch
of these guys with really long orbits and they're all tilted,
and that's not the kind of thing you expect, like
it can happen. But in order to get a tilt
relative to sort the sort of Solar System plane you
have to have a collision or be tugged by something else.
(13:19):
And they did all these calculations and they found this,
like a one in five of our Solar System ending
up in this sort of situation without a planet nine.
So I wouldn't say they're pretty sure that there's a
planet nine, but it seems unlikely that there isn't a
planet nine. How do you like that sort of scientific
word word jumble there? That was a good hedge. I
(13:40):
like that. But before before these calculations for planet nine
were made, and before the erratic behavior of these other
bodies became so obvious that we couldn't ignore them, the
existence of a ninth planet was kind of like relegated
to the crazies that wear tin hats and jump around
(14:01):
in lightning storms, wasn't it. I'm not a member of
that community, so I'm not sure. But you know, people
have been wondering about a planet none for a long time,
and when Pluto is discovered, some people thought, ah, there
it is. This answers the question about Uranus and Neptune's
weird orbits and this other stuff. But of course Pluto
can't actually explain that because it's too tiny. Pluto is
(14:23):
really small. That's why it got downgraded from planet to
dwarf planet, so it doesn't actually answer this question. So yeah,
I think that this idea of a of another planet
out there was a bit of a bit of a
crazy theory. But now that we get more information, we
have better telescopes to see more of these trans neptune objects,
and people have done more careful calculations that I think
(14:43):
they're better received. But you tell me, you know some
of these researchers, don't you. I do. Yeah. Mike Brown,
who was one of the researchers that actually worked to
demote Pluto because he found other objects that were just
as big or bigger, so Pluto wasn't as exciting anymore.
And Constantine Patigue in who the theorists who helped do
those calculations, are both from my institution, Caltech, So I
(15:06):
had the opportunity to talk to them when they had
first made this prediction, and they kind of knew people
were going to think they were crazy, but they are crazy,
just not in a scientific way. So they were very
happy to be making this outrageous statement knowing that they
could back it up with math Um, and they are
very excited about the idea of observing what they've predicted.
(15:30):
But in Constantine's predictions, the mass is like five thousand
times the size of Pluto, So they're looking for something
that's really significantly large. That's right, Pluto cannot explain this
weird stuff they're seeing out there. And let me just
say that I'm so jealous of those guys because it's
sort of a scientific fantasy to find evidence for something
(15:52):
that seems bonkers. Because you know, we know the universe
is bonkers, we know it has surprises waiting for us.
But you can't just make stuff up. You have to
discover it. And so to be in that situation where
you the data are telling you something fascinating and new
that you know most of the community is gonna have
a hard time accepting that, honestly seems like a lot
of fun to me. Yeah, these two guys, they really
(16:13):
enjoy shaking things up. Yeah, but you asked earlier, like,
what do we know about planet nine? Well, again, we
don't know that it exists. But the hypothesis, like sort
of the theory that would explain these orbits more simply
is that it's orbiting really far out there. It's like
four hundred to eight hundred times the radius of Earth's orbit,
(16:34):
so really deep in space, and that far out in space,
it would take like ten thousand or twenty thousand years
just to go around the Sun one time. That is
a really really long time to wait to get data
for your PhD. I'm just saying, it's also a really
long time to have a birthday. I mean, you're born
on planet nine and like your ten Earth years have
passed before your first birthday. Wow. And then also it's
(16:56):
going to make it really hard for us to see right,
and like coming from like the people's perspective, the neuroscience perspective,
like the visual system is our primary system. That's how
we feel that we really know what's going on. So
until scientists can really put eyes on this planet, is
it going to be something that's accepted by the community.
Do you think No? I think you're totally right. It's
(17:18):
like a murder, you need a body, you know it's Uh,
until you've seen it directly, you're not sure that it exists.
I totally agree. Otherwise it's sort of circumstantial or indirect
evidence it's the same deal. In particle physics, we suspected
the Higgs Boson was there. We had a lot of
clues about where it might be and how it might work.
All the other information pointed to it, but until we
(17:39):
actually saw it, until we created it and and saw
it in the lab, we didn't even believe it existed.
And I think in the same way, this is a
great idea. But until they actually spotted, they see light
reflected off of it, they see its motion and complaud
its orbit, I don't think it would be accepted as
a real thing. So I understand the thrill of discovery.
I understand how addictive and amazing it can be when
(18:03):
you make a prediction based on the things that you
think you know about the universe, and that prediction is true.
But once we and I'm going to be optimistic, care
once we see evidence of planet nine, what is that
going to tell us other than it's there. Well, your
friends are gonna throw a big party and say we
(18:23):
told you so, we told you so, which is probably
gonna be really satisfying. But it also it's every piece
of information we get about the nature of the Solar
System gives us a clue about how it formed because
it rules out a bunch of stories. You know, scientists
work in the framework of stories. I think a lot
of people think of science is like super objective, But
in the end, we're telling a story. We're trying to
explain the universe. We're trying to say, this is what
(18:45):
happened this and then that and the other thing. And
right now we have lots of different ideas about how
the Solar system might have formed, and the more data
we get, the more we can rule some of those
out because they're inconsistent with that data. So the more
we know about the Solar System, especially out in the
far reaches, the more we can get a sense for
how things came together. And that's of course important and interesting,
(19:06):
not just because we want to know, like what is
the context of our existence? How is our solar system formed?
But we want to know if our solar solar system
is unusual, if other solar systems might have formed this way,
if there are other planets like this out there. And
so I think this touches on a lot of really
deep and broad scientific questions. So does planet nine have
(19:27):
to be a planet or could it be something else?
With like a huge mass. You put your finger right
on the question there, because what we know about Planet nine,
if it exists, comes just from its gravitational interactions. We
can speculate about how much mass it has and how
it's moving and how that is tugging on those other objects,
but you're right, that doesn't tell us what its nature is.
(19:47):
Is it a ball of rock. A ball of rock
or a ball of ice, for example, that have the
same mass would have the same exact gravitational effects, and
even something crazy like a black hole. We talked down
on the podcast once about what would happen if the
Sun became a black hole. I think a lot of
people were surprised to learn that a black hole has
the same gravitational force as a star of the same mass,
(20:11):
And so if you've fixed the mass of the object,
it really could be anything um and have the same
gravitational effects. So we won't know until we see it.
We won't know until we see it. And there's been
some press recently about the possibility that planet nine might
be a black hole, which is exciting because it seems
cool and wow, it would be kind of awesome now
have a black hole so nearby that we could study Um,
(20:33):
there's not a whole lot of specific evidence pointing in
that direction. Um. But the cool thing is that if
it is a black hole, there are some things we
can look for if a black hole. If it was there,
would probably have a big blob of dark matter surrounding it,
and we could look for dark matter smashing into itself
and giving us gamma rays, and a black hole if
(20:54):
it's there again, because it's denser than a planet or
something else, might give us some gravitational lensing. And actually,
in some data there are a few signs of sort
of unexpected micro lensing, like weird distortions of the background
galaxies that would be consistent with the passing of black hole.
But they're not really conclusive, so it's more than like
(21:15):
fun speculation at this point. But yeah, it's totally possible
that planet nine is not a ball of rock with
water on it, but a tiny black hole left over
from the creation of the universe. I feel a little
uneasy about like a casual black hole in the backyard
of our Solar system. For all you know, you have
a black hole in your backyard. It doesn't sound like
(21:36):
you have a really good inventory what's out there. Yeah,
I'm not a big gardener. No, you're right, a black
hole does us. It sounds awesome. It also sounds a
little scary. But this black hole, if it exists, is
orbiting really far out there and probably very stable, and
so it's unlikely to come anywhere near the Earth. But yeah,
it's if it's there, it would certainly be the closest
(21:57):
black hole to the Earth. And then you have to
one or like, what if he got tweaked out of
its orbit and plunged in towards the Sun. Actually, just
read an amazing science fiction novel just that topic. Yeah,
I was gonna say that sounds like a movie that
I'm not sure if I want to see. No, it's
a great science fiction novel by one of my favorite authors,
Greg Egan, and he talks about what would happen if
(22:18):
a black hole passed near the Earth but didn't gobble it,
and it has crazy effects on the tides and all
sorts of other cool stuff. Anyway, we don't know if
Planet Night is there. If it's there, we don't know
if it's the black hole or another planet. We don't
even know what we would call it. Right if we
actually discover it, we can't call it planet nine. What
do you think we should call it Crystal? I don't.
(22:40):
All I know is that scientists are historically, I'm gonna say,
bad at naming things. I mean, there's like a ligand
pro to mic receptor pair in my field, which is
like sonic and hedgehog. Clearly, these people were Saga fans
and they couldn't think of anything on their own. So
I'm saying, let's not let them name this planet. If
(23:01):
it's Discovery, we should get all of our listeners to
come together and come up with a good name. I
do a little survey, and I think people are calling
it planet nine. Some scientists call it planet X, some
scientists are calling it George, and other ones are even
calling it Fatty. So I think you're right. The scientists
need a lot of help in its regard George George.
It's like I know, I think that shows some people
(23:24):
sort of generic bias for objects. They need Jrees help on,
like something that's really catchy and informative. We have a
long list of things to talk to Core about when
he returns, but I'll put that on the top of
the list. So do we have to look that far
out for things that we don't know about our Solar system,
or are we still learning about stuff that's closer to us.
There's a huge amount to learn about stuff that's even
(23:45):
closer than the far far depths of the Solar System.
Let's talk about that, but first let's take a short break.
All right, we're back and we're talking about news of
(24:08):
the Solar system, crazy discoveries, things that we're learning just
recently in the last weeks and months about our own
cosmic backyard, and Krystal, you were saying, are there things
we're learning that are closer to home than the far
reaches a space past Pluto, And in fact there are
people have probably learned recently in the Science news that
Saturn has been upgraded. It is now the moon king
(24:30):
of the Solar system because it now has eighty two moons,
so it's beating Jupiter Stuper that are the second place
moon owner. That's right, as far as we know. You know,
we can't say we know all the moons that are
out there, because we keep finding more as we look
more carefully and build new instruments. But so far Saturn
has the most moons of the Solar System, and I
(24:50):
don't know if that's a point of pride among planets,
or they just don't care how many moons the Saturn have.
Saturn now has eighty two moons. That's a lot. It's
a lot of things. It is the name. Also, I
don't even know the names of all these objects. But
you know scientists are gonna be arguing about things the
way scientists usually argue about things. Then this is gonna
be a long conversation about how to name all these moons.
Are just gonna have a lot of moons named after
(25:12):
scientists or scientists dogs or family members or stuff like that.
Mm hmm. Sounds reasonable. But actually you can contribute. You
listener can participate because there's a contest out there to
name these moons. So if you have an idea for
how to name the new moons of Saturn, you should
throw your ideas into the hat. Save the scientists from
(25:34):
themselves come up with a good name. That's right. We
are crowdsourcing the hardest part of solar system science, which
is naming all the new stuff they find. So usually
when scientists are finding something new, that means there's been
some type of technological advance that's allowing them to see
things that they couldn't see before, or detect things that
they previously couldn't detect. Is that true here? Yeah, And
(25:55):
it's also sometimes just a question of scientific resources. Sometimes
we have the divice is it's just been sort of
pointed somewhere else, and so here people were interested in
questions about the formation of the Solar System, so they
wrote these proposals to dedicate telescope time to look specifically
for these for moons around Saturn. Moons are sort of
further out than the other moons. These moons are really
(26:17):
far away from Saturn. They're like in very distant orbits.
So the scientific machine finally got around to thinking this
was important. That's right exactly, or the scientists who think
this is important finally got the attention they deserve. And
you know, all these moons they're not like really big objects.
If you're looking up in the night sky and you
(26:37):
see our moon and you think that that's typical, remember
that our moon is huge compared to most of the
moons in the Solar System. These moons are like rocks
three miles wide, and some of them take like three
years to go around Saturn. So it really is just
more like a careful catalog of all the stuff around Saturn,
whether you call it a moon, whether you call it
a rock. Like we were saying before, we love it all.
(27:00):
So where do these smaller moons come from? Like how
do they end up orbiting these these larger planets. Yeah,
that's a great question you might wonder, like why are
their moons at all? Why don't objects just coalesce into planets?
And one reason is that these planets have very strong
gravitational fields, and those gravitational fields provide tidal forces. If
(27:21):
you're big enough, then there's a difference between the gravitational
tug on the side of you that's close to the planet,
then the gravitational tug that's on the side of you
that's far from the planet. If you're large enough for
that to have a big effect, that means because there's
a difference in the gravitational force from one side to
the other side, that essentially the planet is pulling you
apart because it's tugging on one part more than the
(27:42):
other part. And so if you're around a big enough
planet and you're in sort of the right gravitational zone,
the planet will tear you up. It will shred you
and so that's why you don't have all the stuff
around Saturn just coalesced into one big moon. That's why,
for example, Saturn has rings, we think because is the
tidal forces are too great for those rings to coalesce
(28:04):
into moons. So Saturn's so big that it's gravitational force
is doing crazy things to what's around it. Basically, this
is my technical interpretation. I heard shredding, I heard a
lot of other things like so crazy things. No, you're
totally right. And it also gives us a bit of
a window into the timeline of Saturn because some of
(28:24):
this stuff, if he had been around since the beginning
of the Solar system, probably would have found a way
to get into a stable place that it might have
been able to coalesce into a moon. Like for example,
we don't know how long Saturn's rings have been around,
and we don't know how long they will be around.
It might be that another hundred million years or billion
years they will eventually coalesced into an object um that
(28:46):
Saturn's tidal forces won't pull apart. And so if we
look at where these moons are, we don't think these
moons could have been around for very long because if so,
they would have been slowed by all sorts of gas
and dust that surrounds Saturn, and they would have slowed
them down and they would have been sort of dragged
down into lower orbits. So by understanding sort of where
(29:07):
the moons are, the close by ones and the far
away ones, it gives us a window into the time frame,
like how long this happening and what's the sort of
dynamics Saturn looked the same way since the beginning of
the Solar system, or the new features that aliens from
a billion years ago wouldn't recognize if they came and
visited today. Yeah, So I learned a long time ago
that when different types of scientists used time to always
(29:30):
ask what scale we're talking about. So when an astrophysicist
says these moons haven't been around for very long weeks,
they don't mean months, they mean hundreds of millions of years.
They mean the time scale of the Solar System, which is,
you know, four and a half billion years. So they're
way old, but yet young for the universe. Yeah, exactly.
(29:53):
They are probably hundreds of millions of years old, which
is pretty young compared to Saturday itself and other things.
In the Solar system, So why does it matter to
us how many moons Saturn has? No? I think, um,
some people out there might be excited every time we
discover a moon because it's sort of a new element
in the Solar system. People like like discovery, like finding
(30:15):
things in their backyard. Um, that never really gets it
for me, because I feel like, you know, we know
there's rocks out there. Doesn't really matter how many rocks
there are, but it does help us scientifically, it doesn't
really give us a clue as to how things happened.
Like we were saying before, there's a story by the
formation of Saturn, and now some of those stories don't
make sense anymore because they're inconsistent with finding these moons
(30:37):
out there this far away. And so the more data
we get, the more we can narrow it down and
find the one true story of our solar system. And hey,
who doesn't want to know the story of the origin
of our solar system? Right? I think all of us
are interested in where we came from and how we
came to be, and the beginning of the Solar system
is like going as far back as we could possibly
(31:00):
we could possibly think. But you said that like everybody
knows there's rocks out there, Like, yeah, planets are just rocks,
are not They're not that interesting. But I heard some
deep passionate excitement about comments. So tell me why comments,
and about this one in particular. Yeah, let's do that.
Let's talk about comments and comments from other solar systems.
But first let's take another break. So we're back, and
(31:34):
we're talking about exciting stuff that's been discovered in our
solar system pretty recently. So we are updating you on
news of our solar system. And one of the most
interesting things to happen in our solar system in the
last few years was that we got a visitor. Our
solar system is a little island in the middle of
an enormous empty ocean of space. The next solar system
(31:54):
over is light years and light years away. What that
means is that we don't expect a lot of messages
is from all our solar system to the other, or
from other solar systems to us. We expect to basically
be isolated. It should it should be very very rarely
that something gets tossed out of our solar system and
actually happens to land in another one. It's like if
there are two basketball hoops on the Earth, one here
(32:17):
and one on the other side of the Earth, and
you lost your basketball and ended up somehow drifting all
the way around the Earth and making a slam dunk
in the other basketball highly improbable. But those of you
who have listened to our podcasts know that in we
did get a visitor from another solar system. It's called Omuamua,
(32:38):
and it was really weird. It was long, it was thin,
it was shiny. It seemed to accelerate as it left
the Solar system. Those you interested in that, go check
out our whole podcast on it. But these days most
people think it probably was a comet, a comet from
another solar system, so that when we say interstellar, that's
what we mean. Yeah, into selling means from another star.
(33:02):
Because stars are big and they're exciting and they're bright,
but they are not very dense. You can fly through
a whole galaxy and not encounter any stars because they
are light years and light years apart. And that's why
we thought it was very unusual for things from one
solar system to end up in another one. And we
talked about the Solar system in terms of the planets,
and these objects that are sort of in the far
(33:23):
reaches of the solar system. But there's stuff in our
solar system that's even further away. This is thing we
call the art cloud, which is basically a huge collection
of balls of ice, and that's where comments in our
solar system come from. They get nudged and they fall
in towards the star, and they accelerate on their journey
towards the center of the solar system, whizz around and
(33:44):
go all the way back those where our comments come from.
The ideas maybe sometimes one of those objects in the
war cloud gets nudged. Instead of falling in, it sort
of falls out. And so that would be like us
sending a message. That would be us sending a message.
And it's a message in the sense that it tells
you some thing about our solar system. That Commet has
in it a particular mix of ice and rocks and
(34:06):
and other trace elements to tell you about the blob
that formed our solar system, that huge you know, nebula
of gas and dust and stuff that made our solar system.
But because we're trapped on this one island, we never
know is what we're looking at. Typical or unusual. That's
the frustration with having an equals one, with only having
a single example and trying to generalize to the whole universe,
(34:29):
because of course, what we want to do is understand
the whole universe. So if we can get comments from
other solar systems and study them, then we can figure out, like, hey,
does that commet look like ours or is it totally
weird in comparison? So how often do we have the
privilege of encountering an interstellar object. It's super duper rare. Oh,
(34:51):
Mua Mua was the first one ever found, and they
found it, as you said, because they turned on a
new kind of telescope, a telescope that could see this
kind that thing. Now, the amazing thing about that was
when they turned it on, they really had no idea
how often they would expect to see things, but they
expected it would be really rare. And then just days
or weeks after they turned it on, they saw Omama.
(35:13):
In fact, they saw it as it was leaving the
solar system, so we only got this sort of trailing
glimpse as it accelerated out of our field of view,
and we got less and less information. Now they've been
watching the skies and they found a second one, So
not as rare as we thought, then, yes, and that's exciting.
It's also sort of surprising. If we're getting comments from
other solar systems fairly regularly, like every couple of years,
(35:37):
that means that it can't be very unusual for these
rocks to get knocked out of solar systems and end
up in other solar systems. Because you know they're so
far apart, it seems really unlikely. So for a couple
to end up here means it must be happening all
the time. So this interstellar object, this comment that we
saw coming in, do we know where it came from?
(35:58):
So this one we don't yet know where it came from,
but this is very recent. We've only got a few
snapshots of it, and to figure out where it came
from we need to sort of track it and understand
the direction it's moving in. But this one is a
very clearly an icy blob, and it has a tail.
It's got this sort of halo as as stuff melts
off of it, and that makes it harder to know
(36:19):
its exact location, and that makes it hard to pinpoint
its exact trajectory. Um So We don't know exactly where
it came from, but we can see very clearly that
its trajectory is not consistent with anything that's orbiting the Sun. Right.
That's how we know that something is an interstellar object,
that it just doesn't look like it's moving in an
orbit around the Sun. And this one, in particular, if
(36:39):
you if you take the plane of the Solar system
sort of the palm of your hand, this one is
shooting like straight down into the palm of your hand.
It's very clearly coming from somewhere else. We don't know
exactly where yet. We love to like point back to
the Solar System it came from, but there's a lot
of uncertainty still. Yeah, you know, it's like sort of
conjures up these images of being able to chip and
(37:00):
ask it all the scientific questions do you want to ask,
like what's in your ice? And what are your rocks
made out of? Yes, and we're already doing that. The
lucky thing about this one is that we're catching it
on the way in which means it's getting closer and closer,
and we can prepare and we can prepare for that
moment when it comes closest to Earth. Just gives us
our best chance to understand it. And we can't like
(37:22):
launch a spaceship and go visit it. We don't have
the time or the expertise to do that. But we
can study it just by looking at the light that
reflects off of it. That tells us about you know,
what is the atomic makeup? Does it have this kind
of gas and that kind of gas. We talked on
this podcast a few weeks ago about how different kinds
of gas shine different kinds of lights. Just like if
you put weird stuff in a Bunsen burner will turn
(37:43):
green or purple. We can look at the colors of
lights coming from this thing and get a sense for
what's in it, and as he gets closer and closer,
we get better and better measurements. So yeah, it's gonna
be visiting and we're gonna be asking it a lot
of questions. So we're not just figuring out things that
are happening in our own solar system, but like the
our reaches of what we have known about before, but
we're also learning new things that are coming to us
(38:05):
from other stars, other solar systems. Yeah, of course, and
my fantasy is that one day one of these things
will not just be a comment. It will be some
alienship and the physicists from that solar system will have
arrived to solve all these problems and answer all of
our deep questions about the nature of the universe. I've
seen that movie. It doesn't end well, I know, but
(38:27):
there's always a moment of satisfaction when they have learned
some deep secrets about the universe before the aliens eat everybody.
And that's the moment. I'm living for, the moment of
discovery before complete and utter destruction. That's right. I will
sacrifice the future of humanity just for a fleeting glimpse
at the secrets of the universe. Do you think that
when the aliens that are going to come and share
(38:49):
their physics with us before eventually just showing us all,
do you think they'll have that moment of looking down
on us the way that we look up at comments
and thinking, wow, the versus pretty amazing and pretty beautiful.
I hope so. I hope that being a super intelligent
alien that travels the universe comes with moments of grandiose
wonder at the at all, at this beautiful universe that
(39:12):
we find ourselves in. I certainly hope so. Well. I
will continue to read the news looking for well evidence
of planet nine and also contact with an alien species. Well,
I think that's a good idea, and keep your ears
tuned from more Solar System news because that interstellar comment
is coming and it will be here. The closest approach
to the Earth will be on December seven, So we
(39:35):
hope to learn something. Maybe it's a comment, maybe it's
hiding an alien spaceship. We don't know. You know, listeners know,
of course, the solution we're hoping for. So until we
learn more secrets about the nature of our Solar system
or get clues from other Solar systems, we're here to
break down today's news for you. Thanks everybody for tuning in,
and thank you Crystal for joining us again on the podcast.
(39:57):
Thanks for having me tune in next time for more
crazy the amazing, mind blowing facts about our universe. Thanks
for listening. Before you still have a question after listening
to all these explanations, please to drop us the line.
We'd love to hear from you. You can find us
(40:19):
on Facebook, Twitter, and Instagram at Daniel and Jorge That's
one word, or email us at Feedback at Daniel and
Jorge dot com. Thanks for listening and remember that Daniel
and Jorge Explaining the Universe is a production of I
Heart Radio. More podcast from my heart Radio, visit the
I heart Radio Apple Podcasts, or wherever you listen to
(40:40):
your favorite shows. Yea.
Hosts And Creators
Daniel Whiteson
Kelly Weinersmith
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