May 9, 2023 • 40 mins
In this episode of Stuff to Blow Your Mind, Robert and Joe continue their multi-year mission to discuss the various moons of our solar system – this time with the literary-themed moons of the ice giant Uranus. (Part 1 of 2)
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Speaker 1 (00:06):
What's the color of ice? I think about the wedge
of ice broken from the lid of the lake in winter.
It goes from dusky white to clear as it leaks
itself into your hands. But when the glacier shears off
and unveils its inner face, forged over one hundred thousand years,
(00:29):
now you see a questioning blue. Now the glacier melts
into the sea and it's gone, becomes green with algae,
gray with mud, and a color that was once called
wine dark. But what is the color of ice? That's
not the ice we know that lies hidden behind a
(00:51):
haze and swims in a darkness, crushed by diamond rain.
We approach our destination along the orbital plain, great wide
table of the sun.
Speaker 2 (01:03):
But as the.
Speaker 1 (01:04):
Planet comes into view, we're looking at the north pole.
This is summer. The frozen eye reclines on its flank.
There's the pole now bathing in the season of light.
The hidden face the opposite pole now holds cord in
the bitter cold of the stars. There's something about that blue,
(01:28):
almost as cold as a thing can be, but joyful
in the way it devours the sunshine. It reminds us
of something something on Earth. That brings life, or invites
the living, or is alive itself.
Speaker 3 (01:52):
Welcome to Stuff to Blow Your Mind, a production of iHeartRadio.
Speaker 2 (02:02):
Hey you, welcome to Stuff to Blow your Mind. My
name is Robert Lamb.
Speaker 1 (02:05):
And I'm Joe McCormick, and today we're going to be
fulfilling a very common request. Years ago, we did a
series of episodes where we looked at the moons of
various planets in the Solar System, the moons of Jupiter,
the moons of Saturn, the moons of Mars, and I
think we even did one even though Venus doesn't have
(02:26):
a moon.
Speaker 2 (02:26):
We did an.
Speaker 1 (02:26):
Episode sort of about the alternative universe where there would
be a moon of Venus something like that. But today
we're going to be talking about the moons of the
seventh planet in our Solar System. In this first episode
in the series, I think we're going to be focusing
mainly on the planet itself, and then we will get
more into the moons in the subsequent part or parts.
(02:49):
And since this is an audio medium, the question of
how to pronounce that planet's name is unavoidable. I thought
we should tackle it right here at the beginning, because
I know we have said it moultiple ways on the
podcast before. I think I have said it multiple ways before,
and the only thing to do is give ourselves preemptive,
full absolution to pronounce it any which way we want.
(03:09):
But basically, so I was trying to figure out, like
what is actually the right way, and I think it
goes like this. If you listen to astronomers and planetary
scientists talk about this planet, most often you will hear
them pronounce it urinus, basically the word urine and then
the word us. On the other hand, there's sort of
(03:30):
a dos Boot situation going on with this planet name,
like for the most part, like the scientists might say urinus,
but for the most part, just people say uranus, you know,
at least they do in America. I don't know if
it's different in other English speaking cultures or other languages
where the name would be you know, a direct homophone.
But anyway, Uranus is. It's sort of part of the culture,
(03:52):
it's part of the world we grew up in, and
there's really no fixing that. So I think that will
probably come out of our mouths as well.
Speaker 2 (03:59):
Well. The tragedy of it is that I feel like
most of the time. When you hear uranus as the
pronunciation for the planet Uranus, it is coming out of
the mouth of, say a of a talk show host
or you know, late night news situation, a little bit
of t he. Yeah, I mean not just a little
bit of t he, but like a front loaded, like
(04:21):
dump truck quality of t he to the to the
to the detriment of whatever the actual news is. Like,
it could be announced tomorrow that life was discovered on Uranus,
but the the the late night talk show hosts would
say you're anus, everyone would laugh and completely forget that
the most breathtaking news in the history of our species
(04:44):
was just revealed. Because Uranus if pronounced slightly incorrectly, I'm sorry.
From my point of view, it sounds like you're saying
somebody's anus.
Speaker 1 (04:54):
Right, a benevolent jellyfish inhabit the clouds. It's it's very interesting,
But the main thing is we did successfully probe uranus.
Speaker 2 (05:03):
Haha. Yeah, yeah, So it's it's I mean, especially for
a professional space science communicators, people working for NASA and
so forth. I don't know, I guess it probably comes
to the point where you've got to just embrace it, yeah,
and enroll with it, but it also there has to
still be some at least low level of just fixed
(05:23):
frustration over the situation.
Speaker 1 (05:26):
I think it's one of those things that becomes annoying
and then it comes full circle and becomes funny again. Yeah,
but for another wrinkle, we have the apparently correct uranus
and then we have the common uranus. But according to
an interview I saw with the American physicist Kevin Grazier,
who writes a lot about space and about science fiction
(05:46):
from a science perspective, he was the editor and a
contributing author on the science of Doune, which we have
talked about on the show before. He says in one
interview that it technically it is uranus. So you know,
maybe he's right, But apparently nobody says it that way.
Speaker 2 (06:02):
I mean, it starts with everyone who wants to start
pronouncing it differently. You know, say uranus sounds good to.
Speaker 1 (06:09):
Me, so you say uranus. I say uranus. Most experts
say urinus. But in any case, it's gonna be fine.
We all know which planet we're talking about. It's number seven.
It's big, it's blue, it's cold, it's beautiful, and it
has a heck of a lot of moons.
Speaker 2 (06:26):
Yeah, and and the fair amount of mystery surrounding it.
You know, in this episode we're venturing farther out into
the void here, so we're gonna encounter some more space
to wonder. We'll also, I think eventually be getting to
a fourth pronunciation for your old boy, So so strap in,
but Urinus. Here are some of the basics for anyone
(06:47):
who needs a refresher, and I think we can all
deal with a refresher. Uranus is the seventh planet from
the Sun, and in size it has the third largest
diameter in the Solar System. It's about four times larger
than Earth in diama. Yes, While Uranus and its neighbor
Neptune were previously classified as gas giants like Jupiter and Saturn,
(07:07):
it became clear in the nineteen nineties so they are
actually a subset of gas giants ice giants. So most
of the planet's mass is believed to be a hot
and dense fluid of icy materials around a small rocky core.
Its atmosphere is mostly molecular hydrogen and atomic helium, and
there also seems to be a small amount of methane.
(07:28):
It experiences the equivalent of a seventeen hour day like
a seventeen hour seventeen hours of Earth day, and an
eighty four year solar orbit.
Speaker 1 (07:38):
Now, you mentioned that most of the planet's mass is
this relatively hot and dense fluid of icy materials. But
that should not give you the wrong impression about the
planet overall, because an interesting fact about Uranus is that
it is the coldest planet in the Solar System, even
though it is not the farthest from the Sun. Neptune
(07:59):
is much farther away from the Sun. I think something
like ten times the distance from the Earth to the
Sun farther away than Urinus is, and yet it is
actually a little bit warmer. On average, the temperature in
the upper atmosphere of Urinus reaches negative two hundred and
twenty four degrees celsius, colder than equivalent measures on Neptune,
(08:20):
which are about ten degrees celsius higher. I want to
come back in a little bit to why that might be.
But yeah, not the farthest away, but the coldest.
Speaker 2 (08:29):
It's cold out there. It's lonely out there.
Speaker 1 (08:31):
Now, you mentioned that it takes eighty four years for
Uranus to orbit the Sun once. That means since its
discovery in seventeen eighty one, which we will narrate in
a few minutes. Here, less than three full years have
elapsed on Uranus. It's seventeen eighty one plus eighty four
Earth years is eighteen sixty five plus another eighty four
(08:52):
is nineteen forty nine, and then it will be another
full year on that planet. When it's twenty thirty three
on Earth. Calendar pages tear away quite a bit slower there.
This longer year also gives you an idea of how
far away from the Sun this planet is. You know.
This comes up on the show a good bit. When
(09:13):
we make visual representations of the Solar System. One thing
that's pretty much always impossible to capture is the real
relative size and distance between objects. There really, I think
is no convincing way to represent the real distance between
planets in the Solar System within the same image and
(09:35):
have it make intuitive sense. So let's talk about the
scaling up of distances as one moves further out from
the Sun. The average distance from Earth to the Sun
is a commonly used measurement. It's called an astronomical unit,
or AU for short, and it's equivalent to about one
hundred and forty nine point six million kilometers, pulling up
(09:57):
numbers cited by NASA JPL for these other planets. Both
Mercury and Venus, of course, are within one AU, so
Mercury is about zero point four and Venus is about
zero point seven AU from the Sun. They're both closer
than Us. Mars is about one point five AU, so
about one point one and a half times the distance
(10:17):
from Us to the Sun. Suddenly Jupiter is more than
five times the distance. Saturn is nine point five AU,
and then Urinus is suddenly nineteen point two AU, So
the distances multiply greatly the further you go out, and
then Neptune is about thirty so another another ten basically
(10:41):
sort of ten AU between Saturn and Uranus, and then
another ten between Uranus and Neptune.
Speaker 2 (10:47):
Yeah, So venturing into into the outer Solar system, you know,
it's like it's like leaving an urban center and traveling
out into the boonies. The gas stations that you you
would venture into or are are farther and farther apart,
and you begin to wonder where your next tank is
going to come from.
Speaker 1 (11:07):
Yeah, so it's always impossible to reckon the real scale
of space. And the funny thing is, this is just
our Solar system. You know, this is like the things
that are actually relatively very close together from a space perspective.
Speaker 2 (11:19):
Yeah, absolutely, all right, So let's see some more facts
about Urinus itself. It has thirteen rings, and like Venus,
it rotates east to west. It also rotates at a
near ninety degree angle from the plane of its orbit,
so this gives it the appearance of spinning on its side.
Speaker 1 (11:37):
That is a very interesting and unique fact about Uranus.
So if you can picture it, all of the other
planets in the Solar system, you know, they all have
some degree of axial tilt, but they more or less
spin like a top, with the north and south poles
facing more or less perpendicular to the solar plane. So
you can imagine the Sun in the middle of the
Solar system, and then there is a disc of flat
(11:59):
discs spreading out from the Sun that all of the
planets orbit on. Those planets have some tilt, but they
more or less rotate so that their equator is in
line with that plane, and their north and south poles
are at right angles to it. Urinus is the exception.
It lies on its side Its axial tilt is something
(12:19):
like ninety seven or ninety eight degrees, so almost perfectly
sideways from the perspective of the solar plane. Its equator
rotates up and down, and its poles point to the sides,
which has the strange effect that its seasons as it
orbits the Sun throughout its year, mean that the poles
(12:41):
get like many Earth years of light and darkness as
the year progresses. So for forty two years, its north
pole will be in relative sunshine and its south pole
will be in relative darkness, and then it flips around
for the other season. It's a weird planet, very strange.
This actually comes back to the question of why Uranus
(13:04):
is the coldest planet, even though it's not the farthest
from the Sun. How could a planet closer to the
Sun be colder than one farther away. The answer is
that planets give off their own heat, and compared to most,
Urinus gives off very little. So one major idea proposed
to explain why Urinus gives off so little intrinsic heat,
(13:27):
is the same as the reason it, unlike other planets
in the Solar System, rotates on its side. Scientists think
that billions of years ago during the formation of the
Solar System, Urinus very likely suffered a colossal impact from
a roughly Earth sized or Mars sized object, which was
(13:48):
able to both knock it out of its original orientation
and give it its its backwards rotation pattern opposite the
rest of the Solar System and its a sideways orientation
sways axial tilt, but also to blast away much of
its mass and energy, leaving it with less intrinsic heat
than even other ice giants like Neptune, and so if
(14:12):
this impact hypothesis is correct, it would explain much of
what we know about Uranus, why it's so cold, why
it's tilted, and why its rotation is the way it is.
One of the most striking things about Uranus is its appearance,
which can vary based on seasonal conditions. But in the
famous true color images assembled from what was captured by
(14:34):
the narrow angle camera of Voyager two in nineteen eighty six,
the planet looks like an almost perfectly uniform field of
pale blue green color, like a featureless Cyan ocean of fog.
And this is especially strange when you think about it
in contrast to the sort of banded surface of Jupiter,
(14:56):
it's just ripping with visible storms, or or like the
sandy stripes you see on Saturn with that big, nasty
polar hexagon. The truth is Urinus is not always as
calm looking as it is in these famous photos. For
one example, I found a February seventh, twenty nineteen NASA
news article by Ray Villard and Claire Seravia noting photos
(15:20):
that had been taken by the Hubble Space Telescope of
visible storms on both Uranus and Neptune. And in these pictures,
the storm on Urinus appears as a gigantic white dome
of clouds swarming over the planet's north pole, and the
authors note that this gigantic weather pattern might have been
formed by seasonal changes of flow in the atmosphere, because remember,
(15:44):
the planet is tilted on its side, so as the
seasons change, the part of the planet facing the direction
of the sun goes from a polar region that basically
remains in direct sunlight for many, many Earth years at
a time to an equatorial reaon that rotates through standard
day night cycles like Earth does, except it's rotating on
(16:05):
its side, and these drastic changes in seasons may give
rise to major changes in the flow of the atmosphere,
resulting in weather like this. I was reading an article
by the astrophysics blogger Ethan Seagull which made the point
that the Voyager two images are probably especially featureless because
(16:27):
they were taken during the solstice on Uranus, when the
continuous rays of sunlight had been falling on one of
the planet's polar regions for many earth years, and so
this regime of NonStop polar daytime created a haze of
methane in the upper atmosphere. So up at the top
of the atmosphere, there's all this methane up there, which
(16:50):
both masks the clouds and the visible weather patterns below,
so you can't really see what's going on beneath all
that methane, and it absorbs red light, leading to the
pale blue green color that we can't stop staring at.
By contrast, when you see photos of Uranus taken by
telescopes during its equinox, you will see more defined atmospheric
(17:13):
bands and storms and clouds, not as dramatic at all
as what you'd see on Jupiter, but the stuff is there,
so Uranus is not actually always featureless. This seems to
be a function of when and how it was photographed
by Voyager two. But in those voyager images it is
deeply striking, almost haunting, how frozen and unperturbed and uniform
(17:39):
the planet appears.
Speaker 2 (17:40):
Very interesting. Yeah, yeah, it's a it's there's a there's
a calmness. So it's a call like you look at
images of of of Urinus and it's it's calming compared
to like the the the the the evident kind of
complexity and chaos of Jupiter.
Speaker 1 (17:54):
Absolutely colder, stiller, more uniform, it'll even lying on its side,
and not to get to anthropomorphic, but as if dead.
Speaker 2 (18:05):
Yeah, and there's also a sense of the sky to it,
which is fitting. We'll come back to that in a second.
But yeah, mostly though this episode, we're getting into the
moons of Uranus and it has a healthy number of
moons twenty seven known moons. This is a good n
this is a number that we can handle, we can
(18:25):
actually name, I think, all the moons of Urinus, where as,
of course there are some really robust moon counts for
Jupiter and Saturn. So things are leveling out a little
bit for us as we continue our journey out through
the Solar system.
Speaker 1 (18:40):
Yeah, I think this is more of a fair fight.
I don't think we said the names of all the
moons of Jupiter or Saturn.
Speaker 2 (18:45):
Right.
Speaker 1 (18:46):
Well, we can't promise in this series that we're going
to like discuss all of Urinus's moons deeply, because some
of them are just kind of rocks that I don't
know how much there is to say about them. I
don't mean to be offensive if you're a devotee of
any particular Bianca or something, but yeah, we will have
more to say about some than others.
Speaker 2 (19:04):
Yeah, and there's just not a lot to say about
some of them, just because we just haven't explored Uranus
or its moons as much. We've only had the one
voyager two fly by, really, and that's it, basically.
Speaker 3 (19:17):
Know.
Speaker 2 (19:18):
In addition to things like Hubble analysis and so.
Speaker 1 (19:20):
Forth, Before we explore more about the planet and its moons,
I think we should take a little bit of time
to discuss the origins of this name, the mythological moniker
that has caused so much pleasure and pain among astronomers worldwide.
Speaker 2 (19:44):
Yeah, that's right, and you know, it could have been
it could have been weirder in some respects because it
took about seventy years for this to be firmly decided
upon that, yes, this planet is Uranus. William Herschel wanted
to name it after King George the Third, so he
wanted to call it essentially the George Star Georgian Sidas,
(20:07):
but luckily we didn't. Can you imagine if if that
was the we had all these you know, these Roman
deity names, and then George Starr amazing presumably not.
Speaker 1 (20:18):
I've got a story to tell about William Herschel in
a little bit here, but yeah, wanting to name it
after King George the third, He's just forever in the
heavens that that would be hilarious. Yeah, I don't know
what the modern equivalent like this is the this is
the gerald Ford planet.
Speaker 2 (20:36):
I mean it is. There's always gonna be something weird
about naming these astral bodies after things and a given culture,
and we'll run into some of that again when we
get into some of the literary names that are invoked
in the moons. But but yeah, I just can't imagine
this being the George Star. So the namesake here is
the Greek primordial deity of the sky urin Us or
(20:59):
I think I think more correctly, or it would be Urunas. Right.
We've talked about this before on the show.
Speaker 1 (21:05):
I don't know if i'd stand by that. I've heard
it said that way too, So we've got Urinus is
what most astronomers and planetary scientists say. The lay public,
at least in the US, says Uranus. We got one
interview with the guy who says, technically it's Uranus, and yes,
I've also heard uranus.
Speaker 2 (21:24):
Yeah, though, I love Uruanas. But I'm gonna feel like
a weirdo if i start calling it that just among
friends and family or even on the podcast. So I'm
just gonna have to stick with you. Okay, let's do
it all right, So who is we can say Urunas?
Though when we're referring to the god, I think maybe
that's a good way of differentiating it. Here Greek primordial
(21:48):
deity of the sky and both a child and a
consort of Gaya, the parent and a parent of Titans
of the Cyclopses, as well as the Hecataneries, the one
hundred handed warriors who don't get enough I think attention
in the various wars of the gods, perhaps just because
they're hard to illustrate. It's hard to maybe imagine what
(22:09):
one hundred handed monster looks like.
Speaker 1 (22:12):
I don't know, you can imagine two hands is just
kind of multiply from there.
Speaker 2 (22:15):
Yeah, just like an absurdity of goro coming at you. There.
Speaker 1 (22:19):
What's the Latin prefix for fifty? Like the quinta deca goro?
Speaker 2 (22:26):
I don't know that sounds good. Okay, that's a lot
of button inputs though, for the punches. Anyway, Uranas is
the one who stands on high. He is the rain maker.
Among his many children was the titan Cronus, who, at
Gaya's urging, rebelled against his father, And of course Cronus
famously castrated his father in the myths and cast the
(22:48):
bloody pieces over his shoulder and ushered in a new
age of gods. Cronus would of course, eventually be overthrown
by his own son Zeus.
Speaker 1 (22:58):
Okay, well, here I thought, this is a good opportune, ever,
reading from Hesiod's Theogony to explain what happened to old Urinus. Here, Oh,
let's happy, Okay. This is the version hosted on Harvard
Center for Hellenic Studies website. This is a translation by
Naggie and banks. Oh, and it's gonna mention Earth and Sky.
I think Earth would be the goddess Gaia, and Sky
would be Urinus. Here yeah, Hesiod writes, Now monstrous strength
(23:22):
is powerful joined with vast size. Four of as many
sons as were born of Earth and Sky. They were
the fiercest and were hated by their father from the
very first. As soon as any of these was born,
he would hide them all and not send them up
to the light. In a cave of the Earth and
Sky exulted over the work of mischief, while huge Earth
(23:45):
groaned from within. Straightened as she was, and she devised
a subtle and evil scheme. For quickly, having produced a
stock of white iron, she forged a large sickle blade,
and gave the word to her children, and said, encouragingly,
though troubled in her heart, children, of me and of
a father madly violent, if you would obey me, we
(24:06):
shall avenge the baneful injury of your father, for he
was the first that devised acts of indignity, so spoke she,
But soon seized on them all, nor did any of
them speak till, having gathered courage, great and wily Cronos
addressed his dear mother. Thus in reply, Mother, this deed
at any rate I will undertake and accomplished. Since our
(24:27):
father of detested name, I care not, for he was
the first that devised acts of indignity. They're really hitting
the talking points here. Thus spoke he and huge Earth
rejoiced much at heart, and hid and planted him in ambush.
In his hand she placed a sickle with jagged teeth,
(24:48):
and suggested to him all the stratagem. Then came vast Sky,
bringing night with him, and eager for love, brooded around Earth,
and lay stretched on all sides but his from out
his ambush grasped at him with his left hand, while
in his right he took the huge sickle, long and
jagged toothed, and hastily mowed off the genitals of his father,
(25:11):
and threw them backwards to be carried away behind him.
Speaker 2 (25:15):
Pretty rough stuff. I don't know why the sickle had
to have jagged teeth.
Speaker 1 (25:19):
I don't know either.
Speaker 2 (25:20):
Thed was just laying it in there a little bit.
Speaker 1 (25:22):
It's a serrated sickle. I've never even heard of such
a thing. It's like a steak knife.
Speaker 2 (25:27):
Yeah.
Speaker 1 (25:29):
But as I mentioned Urinus there, his name is synonymous
with Sky, so in this translation they just call him Sky.
So I think it's very interesting that we end up
with a planet that, in a way, based on the
original mythological context, could just be called sky. It is
the sky planet.
Speaker 2 (25:45):
Yeah, yeah, And of course it's interesting that we're switching
from Roman to Greek in coming out here to Uranus.
And of course this may raise the question of why
why are we talking about modern discussions of what this
planet will be named? And of course you know that
has to do with with how late it was discovered,
(26:06):
properly discovered, because when discussing basically this comes down to
a discussion of the classical planets versus the the more
outer and I guess you could say modern planets. The
classical planets are those visible to the naked eye and
bright enough to be considered important in ancient astronomy and astrology.
(26:26):
And we'll discuss a little bit more about what that
means in just a second there. There there are many
names for the classical planets because they pop up in
various astronomical systems.
Speaker 1 (26:37):
Right, they were known to many different ancient cultures, so
they have many different names exactly.
Speaker 2 (26:43):
Yeah, So you know, for instance, mercury through Saturn have
names that indicate elemental alignment in Chinese tradition, So Mars
is the fire star, Jupiter is the wood star, that
sort of thing. But the Chinese for the outer planets,
interestingly enough, is not based in an actual like Chinese
(27:03):
at astrological history, but in translation of at least the
spirit of the Western names. So Uranus in Mandarin is
Tan wang Shing or sky king star. So I think
that's that's center, just basically alluding to this is a
sky god. That's the name that we've used in naming
(27:25):
the planet. So it's sky sky king star. Neptune is
ocean king star, Pluto is nether World king star. In translation.
Speaker 1 (27:34):
I love that, Yes, translating the sense of the names.
So the name in Mandarin is like a summary of
where the name comes from, like the Latin or Greek name.
Speaker 2 (27:44):
Yeah. So again talking about the classical planets here, these
were the planets that were known to antiquity Mercury, Venus, Mars, Jupiter,
and Saturn. Uranus was the first planet discovered via the
aid of a telescope, and it happened in seventeen eighty
one by astronomer William Herschel In addition, he also discovered
(28:04):
infrared radiation. He's also credited with the discovery of Titania
and Oberon, which are some moons we'll get into in
a bit, as well as two of the moons of Saturn,
Enceladus and Mimas. His son John Herschel got to carry
on their tradition and named seven moons of Saturn and
four moons of Uranus.
Speaker 1 (28:25):
Now, a really interesting thing about the discovery of Uranus
by William Herschel is that at first he did not
realize he had discovered a new planet in the Solar System.
And the reason for this will sort of tie into
things we've been talking about. I was reading about this
in a paper called Uranus in the Establishment of Herschel's
Astronomy by Simon Schaeffer, published in the Journal of the
(28:49):
History of Astronomy in nineteen eighty one, and so the
story of the discovery of Urinus goes like this. William
Herschel had undertaken a project, beginning in seventeen seventy nine,
to survey all of the stars in the sky to
the limit of the eighth magnitude using a seven foot
reflecting telescope, mainly for the purpose of identifying double stars
(29:12):
so that Herschel could try to make measurements of stellar parallax.
In March seventeen eighty one, Herschel had his telescope moved
to his house on New King Street in Bath in Somerset, England,
and he was picking up with his observations from this location.
And on the week of the discovery of Uranus, he
(29:33):
had been occupied cataloging the visible stars within the constellation Gemini,
and also with some observations of the planet's Mars and Saturn.
And on Tuesday, March thirteenth, at ten thirty pm, Herschel
made a note of an object in the area of
the star Pollux, also known as Beta Geminorum. The object
(29:53):
was quote a curious either nebulous star or perhaps a comet,
and later translated this discovery to his volume in progress,
which was called Observations on the Fixed Stars.
Speaker 2 (30:06):
Quote.
Speaker 1 (30:07):
Looking at a star in the quartile between oreguess right
foot and the left foot of Castor, I discovered a comet.
It was at the distance of almost two thirds of
my field of view from a small telescopic star which
followed it, and seemed to have the same declination. Now
Herschel didn't seem to be immediately overwhelmed with ideas of
(30:27):
the importance of this finding. He after this just went
back to looking for double stars, and it wasn't until
Saturday March seventeenth, which was four days later, that he
went back and looked for the curious nebulous star or
perhaps comet again, and this time he concluded that it
must be a comet rather than a star, because it
had changed its place. So he invited some friends over,
(30:50):
including a guy named doctor William Watson, to come take
a look at the comet he had found, and he
noted in his journal that unfortunately the measurements he took
that night were written down wrong because Watson and another
gentleman wouldn't stop talking at him while he was trying
to write them. But he eventually sent off his findings
in a letter to the Royal Society in London, and
(31:11):
Herschel reported that the object was a newly discovered comet,
but there were some strange things about it. Based on
initial observations, it would seem that the comet was quote
much larger in diameter but less luminous than any comet
known at the time, and that quote its body seemed
very well defined, having neither beard nor tail. Now that
(31:34):
struck me because I was like, what is a beard?
Comets are often said to have tails, but the idea
of a beard I was less familiar with. As best
I could figure out, this, I think seems to just
be another way of describing the tale of a comet, which,
of course the tale is an elongated cloud trailing off
of the comet away from the Sun, caused when the
(31:55):
comet approaches closer in its orbit to the Sun and
then solar radiation and heats the volatile materials on the
surface of the comet and they vaporize and stream away
into space. I don't know if the following is the
difference emphasized by beard versus tail, but comets often do
have two distinct tails. A dust tail made of the
(32:16):
dust to find particles coming off of the comet from
this outgassing when it's heated, and then also a gas
tail made of glowing ionized gases. However, I could find
archaic references to comets in general simply calling them quote
bearded stars. So I don't know. Maybe a beard means
either one. I guess the other ideas that it could
(32:38):
possibly refer to the idea of a coma, which is
the sort of tenuous atmosphere of a comet, seen usually
as a fuzzy spherical cloud around the solid nucleus.
Speaker 2 (32:49):
I wonder too if this might come down to sort
of the distinction between sort of more modern telescope generated
imagery and your telescope observation. You know, we've talked about
that a little bit, like the role of the observer
in real time and sort of you know, classical telescope
(33:11):
astronomy versus the more modern use of imagery.
Speaker 1 (33:15):
I don't know for sure about that, but so he's like, ah, okay,
it's a comet, but it just it doesn't have a
lot of the characteristics we would expect of a comment.
In fact, the paper cites a letter from the French
astronomer Charles Messier, who was known as quote the ferret
of comets. I'd never heard that before, but I think
he found a lot of them. Messier, the Ferret of comments,
(33:37):
wrote to Herschel in April of seventeen eighty one. It
was quoted in the paper in French, so I had
to translate. Apologies if this is a little bit approximate
but Messier says, I'm amazed at this comment, which does
not carry with it any distinctive character of comets, and
that it does not resemble any of those which I
have observed, which are eighteen in number. So I just
(33:59):
thought this was interesting. It seemed at first all of
the learned astronomers were calling it a comet, even though
they recognize that it's really not like a comet at all,
Like it doesn't have any of the characteristics we would expect,
doesn't behave like a comet. It seems that the first
person on record to have mentioned that this new comet
might actually be a planet was the British astronomer Royal
(34:21):
Neville Masculine, who argued that it might be a comet,
but it might also be a new planet, and if
it were a comet, it would be unlike any other
Herschel apparently did not refer to Uranus as a planet
until the summer of seventeen eighty two, when he called
it quote my planet and again he wanted to originally
(34:41):
call it GEORGI mciitas the George Star again lol. But
so I was just wondering, like, why is everybody so
quick to assume it's a comet? Why did it take
them a little while to come around to the conclusion
(35:03):
that it was actually a planet? And Schaeffer in this
paper argues that even though Maskerline was the first to
suggest it might be a planet, quote, Maskerline's own practice
was fundamentally conditioned by the eighteenth century triumphs in cometary astronomy.
Comets dominated the contemporary perception of the heavens. It seemed
inconceivable that a new planet could be discovered. And I
(35:26):
think this must just come back to the state of
astronomy as it was at the time, because as you
were talking about rob Mercury, Venus, Mars, Jupiter, Saturn, all
the other planets up to this point had been known
about since antiquity. They were written about by Babylonian astronomers
thousands of years ago. They were charted with the naked eye,
and Copernicus had correctly figured out that they orbited the
(35:49):
Sun and not the Earth.
Speaker 2 (35:51):
Now, I just want to drive home here that again, Yeah,
the classical planets are those that could be seen with
the naked eye, but also were distinct enough to be
of value. But if you're really looking with the naked eye,
and the conditions are just right, you apparently can see Urinus.
But again, the whole deal here is that what you
(36:11):
see is not significant enough to have, you know, had
any impact on these ancient astrological and astronomical systems. According
to Pete Lawrence, writing for BBC Sky at Night magazine
in twenty twenty, yeah, it is possible to see Uranus
with the naked eye conditions and preparations or just right.
He stresses, however, that the planet quote shines at the
(36:33):
edge of naked eye visibility, and any direct views of
Urinus aren't always conclusive.
Speaker 1 (36:41):
Yeah, that was my understanding from reading all this stuff
as well, that it's sort of right on the edge
of naked eye visibility, to the point where some people
argue that, oh, maybe this thing that somebody said, you know,
a naked eye astronomer in the ancient world observed was
actually an observation of Urinus. But it's hard to know.
Speaker 2 (36:58):
To put it in terms of are weird how cinema
listeners might appreciate. It's like watching The Devil's Rain and
then asking is John Travolta in this is John Travolta
a star?
Speaker 1 (37:09):
Evidence is inconclusive, right, but so coming back to this,
so like all the planets through Saturn had been known
since antiquity to multiple different cultures, there had been other
heavenly bodies identified since the invention of telescopes, but none
of them were planets in the Solar System. Galileo had
identified moons of Jupiter, Cassini and Heuygen's identified moons of Saturn,
(37:32):
but Herschel's identification of Uranus was actually the first time
since ancient times that the existence of a new planet
in the Solar System had been confirmed. That's just not
something these astronomers were really expecting to find. Comets, on
the other hand, were constantly being discovered. Discovering new comets
was one of the major endeavors of astronomers of the day.
(37:55):
You had the ferret of comets out there doing ferreting
them out, so you could think of this as a
kind of astronomical confirmation bias. Comets were just that's what
you discover, that's the thing you're expecting to see.
Speaker 2 (38:09):
Yeah, yeah, it's planets, and then just it's filthy with
comets and you got to send the comet truffle hog
out there to root them out.
Speaker 1 (38:16):
So of course there were many subsequent discoveries of the
moons of Urinus, but a lot of what we now
know about Urinus really comes in the later twentieth century
with the fly by a Voyager two.
Speaker 2 (38:29):
Yeah, and as we'll really be driven home as we
discuss these moons one by one. It's like Voyager two
is the defining mission. Like a lot of what we
know comes either in it from that fly by or
it's the combination of that flyby information combined with say
Hubble telescope information as well. So it's a lot of
(38:53):
the mysteries of Uranus and its moons remains all right,
So when we come back in the next stepisodeisode, we
will blow through the twenty seven known moons of Urinus.
Speaker 1 (39:05):
All twenty seven in one episode.
Speaker 2 (39:06):
I don't know if we can do that all twenty
seven one episode. That's a guarantee. That's a guarantee, so
be sure to join us for that. And then I
don't know, And then at some point in the future
we'll move on to Neptune. But next episode will be
Moon by Moon the moons of Uranus. In the meantime,
if you would like to check out other episodes of
(39:27):
stuff to blow your mind. Well, check out the Stuff
to Blow Your Mind podcast feed. If you go back
far enough, you'll find those episodes we did about the
other moons in our solar system and Jupiter, Saturn, Mars,
et cetera. But yeah, core episodes published on Tuesdays and Thursdays.
On Mondays we do listener mail. Wednesdays we do a
short form monster fact or artifact, and tomorrow's will also
(39:49):
tie into Urinus, so tune in for that. And then
on Fridays we set aside most serious concerns and just
talk about a weird movie on Weird House Cinema.
Speaker 1 (39:58):
Huge thanks to our audio producer JJ Pausway. If you
would like to get in touch with us with feedback
on this episode or any other, to suggest a topic
for the future, or just to say hello, you can
email us at contact at stuff to Blow your Mind
dot com.
Speaker 3 (40:19):
Stuff to Blow Your Mind is production of iHeartRadio. For
more podcasts from my Heart Radio, visit the iHeartRadio app,
Apple Podcasts, or wherever you're listening to your favorite shows.
What's the color of ice? I think about the wedge
of ice broken from the lid of the lake in winter.
It goes from dusky white to clear as it leaks
itself into your hands. But when the glacier shears off
and unveils its inner face, forged over one hundred thousand years,
(00:29):
now you see a questioning blue. Now the glacier melts
into the sea and it's gone, becomes green with algae,
gray with mud, and a color that was once called
wine dark. But what is the color of ice? That's
not the ice we know that lies hidden behind a
(00:51):
haze and swims in a darkness, crushed by diamond rain.
We approach our destination along the orbital plain, great wide
table of the sun.
Speaker 2 (01:03):
But as the.
Speaker 1 (01:04):
Planet comes into view, we're looking at the north pole.
This is summer. The frozen eye reclines on its flank.
There's the pole now bathing in the season of light.
The hidden face the opposite pole now holds cord in
the bitter cold of the stars. There's something about that blue,
(01:28):
almost as cold as a thing can be, but joyful
in the way it devours the sunshine. It reminds us
of something something on Earth. That brings life, or invites
the living, or is alive itself.
Speaker 3 (01:52):
Welcome to Stuff to Blow Your Mind, a production of iHeartRadio.
Speaker 2 (02:02):
Hey you, welcome to Stuff to Blow your Mind. My
name is Robert Lamb.
Speaker 1 (02:05):
And I'm Joe McCormick, and today we're going to be
fulfilling a very common request. Years ago, we did a
series of episodes where we looked at the moons of
various planets in the Solar System, the moons of Jupiter,
the moons of Saturn, the moons of Mars, and I
think we even did one even though Venus doesn't have
(02:26):
a moon.
Speaker 2 (02:26):
We did an.
Speaker 1 (02:26):
Episode sort of about the alternative universe where there would
be a moon of Venus something like that. But today
we're going to be talking about the moons of the
seventh planet in our Solar System. In this first episode
in the series, I think we're going to be focusing
mainly on the planet itself, and then we will get
more into the moons in the subsequent part or parts.
(02:49):
And since this is an audio medium, the question of
how to pronounce that planet's name is unavoidable. I thought
we should tackle it right here at the beginning, because
I know we have said it moultiple ways on the
podcast before. I think I have said it multiple ways before,
and the only thing to do is give ourselves preemptive,
full absolution to pronounce it any which way we want.
(03:09):
But basically, so I was trying to figure out, like
what is actually the right way, and I think it
goes like this. If you listen to astronomers and planetary
scientists talk about this planet, most often you will hear
them pronounce it urinus, basically the word urine and then
the word us. On the other hand, there's sort of
(03:30):
a dos Boot situation going on with this planet name,
like for the most part, like the scientists might say urinus,
but for the most part, just people say uranus, you know,
at least they do in America. I don't know if
it's different in other English speaking cultures or other languages
where the name would be you know, a direct homophone.
But anyway, Uranus is. It's sort of part of the culture,
(03:52):
it's part of the world we grew up in, and
there's really no fixing that. So I think that will
probably come out of our mouths as well.
Speaker 2 (03:59):
Well. The tragedy of it is that I feel like
most of the time. When you hear uranus as the
pronunciation for the planet Uranus, it is coming out of
the mouth of, say a of a talk show host
or you know, late night news situation, a little bit
of t he. Yeah, I mean not just a little
bit of t he, but like a front loaded, like
(04:21):
dump truck quality of t he to the to the
to the detriment of whatever the actual news is. Like,
it could be announced tomorrow that life was discovered on Uranus,
but the the the late night talk show hosts would
say you're anus, everyone would laugh and completely forget that
the most breathtaking news in the history of our species
(04:44):
was just revealed. Because Uranus if pronounced slightly incorrectly, I'm sorry.
From my point of view, it sounds like you're saying
somebody's anus.
Speaker 1 (04:54):
Right, a benevolent jellyfish inhabit the clouds. It's it's very interesting,
But the main thing is we did successfully probe uranus.
Speaker 2 (05:03):
Haha. Yeah, yeah, So it's it's I mean, especially for
a professional space science communicators, people working for NASA and
so forth. I don't know, I guess it probably comes
to the point where you've got to just embrace it, yeah,
and enroll with it, but it also there has to
still be some at least low level of just fixed
(05:23):
frustration over the situation.
Speaker 1 (05:26):
I think it's one of those things that becomes annoying
and then it comes full circle and becomes funny again. Yeah,
but for another wrinkle, we have the apparently correct uranus
and then we have the common uranus. But according to
an interview I saw with the American physicist Kevin Grazier,
who writes a lot about space and about science fiction
(05:46):
from a science perspective, he was the editor and a
contributing author on the science of Doune, which we have
talked about on the show before. He says in one
interview that it technically it is uranus. So you know,
maybe he's right, But apparently nobody says it that way.
Speaker 2 (06:02):
I mean, it starts with everyone who wants to start
pronouncing it differently. You know, say uranus sounds good to.
Speaker 1 (06:09):
Me, so you say uranus. I say uranus. Most experts
say urinus. But in any case, it's gonna be fine.
We all know which planet we're talking about. It's number seven.
It's big, it's blue, it's cold, it's beautiful, and it
has a heck of a lot of moons.
Speaker 2 (06:26):
Yeah, and and the fair amount of mystery surrounding it.
You know, in this episode we're venturing farther out into
the void here, so we're gonna encounter some more space
to wonder. We'll also, I think eventually be getting to
a fourth pronunciation for your old boy, So so strap in,
but Urinus. Here are some of the basics for anyone
(06:47):
who needs a refresher, and I think we can all
deal with a refresher. Uranus is the seventh planet from
the Sun, and in size it has the third largest
diameter in the Solar System. It's about four times larger
than Earth in diama. Yes, While Uranus and its neighbor
Neptune were previously classified as gas giants like Jupiter and Saturn,
(07:07):
it became clear in the nineteen nineties so they are
actually a subset of gas giants ice giants. So most
of the planet's mass is believed to be a hot
and dense fluid of icy materials around a small rocky core.
Its atmosphere is mostly molecular hydrogen and atomic helium, and
there also seems to be a small amount of methane.
(07:28):
It experiences the equivalent of a seventeen hour day like
a seventeen hour seventeen hours of Earth day, and an
eighty four year solar orbit.
Speaker 1 (07:38):
Now, you mentioned that most of the planet's mass is
this relatively hot and dense fluid of icy materials. But
that should not give you the wrong impression about the
planet overall, because an interesting fact about Uranus is that
it is the coldest planet in the Solar System, even
though it is not the farthest from the Sun. Neptune
(07:59):
is much farther away from the Sun. I think something
like ten times the distance from the Earth to the
Sun farther away than Urinus is, and yet it is
actually a little bit warmer. On average, the temperature in
the upper atmosphere of Urinus reaches negative two hundred and
twenty four degrees celsius, colder than equivalent measures on Neptune,
(08:20):
which are about ten degrees celsius higher. I want to
come back in a little bit to why that might be.
But yeah, not the farthest away, but the coldest.
Speaker 2 (08:29):
It's cold out there. It's lonely out there.
Speaker 1 (08:31):
Now, you mentioned that it takes eighty four years for
Uranus to orbit the Sun once. That means since its
discovery in seventeen eighty one, which we will narrate in
a few minutes. Here, less than three full years have
elapsed on Uranus. It's seventeen eighty one plus eighty four
Earth years is eighteen sixty five plus another eighty four
(08:52):
is nineteen forty nine, and then it will be another
full year on that planet. When it's twenty thirty three
on Earth. Calendar pages tear away quite a bit slower there.
This longer year also gives you an idea of how
far away from the Sun this planet is. You know.
This comes up on the show a good bit. When
(09:13):
we make visual representations of the Solar System. One thing
that's pretty much always impossible to capture is the real
relative size and distance between objects. There really, I think
is no convincing way to represent the real distance between
planets in the Solar System within the same image and
(09:35):
have it make intuitive sense. So let's talk about the
scaling up of distances as one moves further out from
the Sun. The average distance from Earth to the Sun
is a commonly used measurement. It's called an astronomical unit,
or AU for short, and it's equivalent to about one
hundred and forty nine point six million kilometers, pulling up
(09:57):
numbers cited by NASA JPL for these other planets. Both
Mercury and Venus, of course, are within one AU, so
Mercury is about zero point four and Venus is about
zero point seven AU from the Sun. They're both closer
than Us. Mars is about one point five AU, so
about one point one and a half times the distance
(10:17):
from Us to the Sun. Suddenly Jupiter is more than
five times the distance. Saturn is nine point five AU,
and then Urinus is suddenly nineteen point two AU, So
the distances multiply greatly the further you go out, and
then Neptune is about thirty so another another ten basically
(10:41):
sort of ten AU between Saturn and Uranus, and then
another ten between Uranus and Neptune.
Speaker 2 (10:47):
Yeah, So venturing into into the outer Solar system, you know,
it's like it's like leaving an urban center and traveling
out into the boonies. The gas stations that you you
would venture into or are are farther and farther apart,
and you begin to wonder where your next tank is
going to come from.
Speaker 1 (11:07):
Yeah, so it's always impossible to reckon the real scale
of space. And the funny thing is, this is just
our Solar system. You know, this is like the things
that are actually relatively very close together from a space perspective.
Speaker 2 (11:19):
Yeah, absolutely, all right, So let's see some more facts
about Urinus itself. It has thirteen rings, and like Venus,
it rotates east to west. It also rotates at a
near ninety degree angle from the plane of its orbit,
so this gives it the appearance of spinning on its side.
Speaker 1 (11:37):
That is a very interesting and unique fact about Uranus.
So if you can picture it, all of the other
planets in the Solar system, you know, they all have
some degree of axial tilt, but they more or less
spin like a top, with the north and south poles
facing more or less perpendicular to the solar plane. So
you can imagine the Sun in the middle of the
Solar system, and then there is a disc of flat
(11:59):
discs spreading out from the Sun that all of the
planets orbit on. Those planets have some tilt, but they
more or less rotate so that their equator is in
line with that plane, and their north and south poles
are at right angles to it. Urinus is the exception.
It lies on its side Its axial tilt is something
(12:19):
like ninety seven or ninety eight degrees, so almost perfectly
sideways from the perspective of the solar plane. Its equator
rotates up and down, and its poles point to the sides,
which has the strange effect that its seasons as it
orbits the Sun throughout its year, mean that the poles
(12:41):
get like many Earth years of light and darkness as
the year progresses. So for forty two years, its north
pole will be in relative sunshine and its south pole
will be in relative darkness, and then it flips around
for the other season. It's a weird planet, very strange.
This actually comes back to the question of why Uranus
(13:04):
is the coldest planet, even though it's not the farthest
from the Sun. How could a planet closer to the
Sun be colder than one farther away. The answer is
that planets give off their own heat, and compared to most,
Urinus gives off very little. So one major idea proposed
to explain why Urinus gives off so little intrinsic heat,
(13:27):
is the same as the reason it, unlike other planets
in the Solar System, rotates on its side. Scientists think
that billions of years ago during the formation of the
Solar System, Urinus very likely suffered a colossal impact from
a roughly Earth sized or Mars sized object, which was
(13:48):
able to both knock it out of its original orientation
and give it its its backwards rotation pattern opposite the
rest of the Solar System and its a sideways orientation
sways axial tilt, but also to blast away much of
its mass and energy, leaving it with less intrinsic heat
than even other ice giants like Neptune, and so if
(14:12):
this impact hypothesis is correct, it would explain much of
what we know about Uranus, why it's so cold, why
it's tilted, and why its rotation is the way it is.
One of the most striking things about Uranus is its appearance,
which can vary based on seasonal conditions. But in the
famous true color images assembled from what was captured by
(14:34):
the narrow angle camera of Voyager two in nineteen eighty six,
the planet looks like an almost perfectly uniform field of
pale blue green color, like a featureless Cyan ocean of fog.
And this is especially strange when you think about it
in contrast to the sort of banded surface of Jupiter,
(14:56):
it's just ripping with visible storms, or or like the
sandy stripes you see on Saturn with that big, nasty
polar hexagon. The truth is Urinus is not always as
calm looking as it is in these famous photos. For
one example, I found a February seventh, twenty nineteen NASA
news article by Ray Villard and Claire Seravia noting photos
(15:20):
that had been taken by the Hubble Space Telescope of
visible storms on both Uranus and Neptune. And in these pictures,
the storm on Urinus appears as a gigantic white dome
of clouds swarming over the planet's north pole, and the
authors note that this gigantic weather pattern might have been
formed by seasonal changes of flow in the atmosphere, because remember,
(15:44):
the planet is tilted on its side, so as the
seasons change, the part of the planet facing the direction
of the sun goes from a polar region that basically
remains in direct sunlight for many, many Earth years at
a time to an equatorial reaon that rotates through standard
day night cycles like Earth does, except it's rotating on
(16:05):
its side, and these drastic changes in seasons may give
rise to major changes in the flow of the atmosphere,
resulting in weather like this. I was reading an article
by the astrophysics blogger Ethan Seagull which made the point
that the Voyager two images are probably especially featureless because
(16:27):
they were taken during the solstice on Uranus, when the
continuous rays of sunlight had been falling on one of
the planet's polar regions for many earth years, and so
this regime of NonStop polar daytime created a haze of
methane in the upper atmosphere. So up at the top
of the atmosphere, there's all this methane up there, which
(16:50):
both masks the clouds and the visible weather patterns below,
so you can't really see what's going on beneath all
that methane, and it absorbs red light, leading to the
pale blue green color that we can't stop staring at.
By contrast, when you see photos of Uranus taken by
telescopes during its equinox, you will see more defined atmospheric
(17:13):
bands and storms and clouds, not as dramatic at all
as what you'd see on Jupiter, but the stuff is there,
so Uranus is not actually always featureless. This seems to
be a function of when and how it was photographed
by Voyager two. But in those voyager images it is
deeply striking, almost haunting, how frozen and unperturbed and uniform
(17:39):
the planet appears.
Speaker 2 (17:40):
Very interesting. Yeah, yeah, it's a it's there's a there's
a calmness. So it's a call like you look at
images of of of Urinus and it's it's calming compared
to like the the the the the evident kind of
complexity and chaos of Jupiter.
Speaker 1 (17:54):
Absolutely colder, stiller, more uniform, it'll even lying on its side,
and not to get to anthropomorphic, but as if dead.
Speaker 2 (18:05):
Yeah, and there's also a sense of the sky to it,
which is fitting. We'll come back to that in a second.
But yeah, mostly though this episode, we're getting into the
moons of Uranus and it has a healthy number of
moons twenty seven known moons. This is a good n
this is a number that we can handle, we can
(18:25):
actually name, I think, all the moons of Urinus, where as,
of course there are some really robust moon counts for
Jupiter and Saturn. So things are leveling out a little
bit for us as we continue our journey out through
the Solar system.
Speaker 1 (18:40):
Yeah, I think this is more of a fair fight.
I don't think we said the names of all the
moons of Jupiter or Saturn.
Speaker 2 (18:45):
Right.
Speaker 1 (18:46):
Well, we can't promise in this series that we're going
to like discuss all of Urinus's moons deeply, because some
of them are just kind of rocks that I don't
know how much there is to say about them. I
don't mean to be offensive if you're a devotee of
any particular Bianca or something, but yeah, we will have
more to say about some than others.
Speaker 2 (19:04):
Yeah, and there's just not a lot to say about
some of them, just because we just haven't explored Uranus
or its moons as much. We've only had the one
voyager two fly by, really, and that's it, basically.
Speaker 3 (19:17):
Know.
Speaker 2 (19:18):
In addition to things like Hubble analysis and so.
Speaker 1 (19:20):
Forth, Before we explore more about the planet and its moons,
I think we should take a little bit of time
to discuss the origins of this name, the mythological moniker
that has caused so much pleasure and pain among astronomers worldwide.
Speaker 2 (19:44):
Yeah, that's right, and you know, it could have been
it could have been weirder in some respects because it
took about seventy years for this to be firmly decided
upon that, yes, this planet is Uranus. William Herschel wanted
to name it after King George the Third, so he
wanted to call it essentially the George Star Georgian Sidas,
(20:07):
but luckily we didn't. Can you imagine if if that
was the we had all these you know, these Roman
deity names, and then George Starr amazing presumably not.
Speaker 1 (20:18):
I've got a story to tell about William Herschel in
a little bit here, but yeah, wanting to name it
after King George the third, He's just forever in the
heavens that that would be hilarious. Yeah, I don't know
what the modern equivalent like this is the this is
the gerald Ford planet.
Speaker 2 (20:36):
I mean it is. There's always gonna be something weird
about naming these astral bodies after things and a given culture,
and we'll run into some of that again when we
get into some of the literary names that are invoked
in the moons. But but yeah, I just can't imagine
this being the George Star. So the namesake here is
the Greek primordial deity of the sky urin Us or
(20:59):
I think I think more correctly, or it would be Urunas. Right.
We've talked about this before on the show.
Speaker 1 (21:05):
I don't know if i'd stand by that. I've heard
it said that way too, So we've got Urinus is
what most astronomers and planetary scientists say. The lay public,
at least in the US, says Uranus. We got one
interview with the guy who says, technically it's Uranus, and yes,
I've also heard uranus.
Speaker 2 (21:24):
Yeah, though, I love Uruanas. But I'm gonna feel like
a weirdo if i start calling it that just among
friends and family or even on the podcast. So I'm
just gonna have to stick with you. Okay, let's do
it all right, So who is we can say Urunas?
Though when we're referring to the god, I think maybe
that's a good way of differentiating it. Here Greek primordial
(21:48):
deity of the sky and both a child and a
consort of Gaya, the parent and a parent of Titans
of the Cyclopses, as well as the Hecataneries, the one
hundred handed warriors who don't get enough I think attention
in the various wars of the gods, perhaps just because
they're hard to illustrate. It's hard to maybe imagine what
(22:09):
one hundred handed monster looks like.
Speaker 1 (22:12):
I don't know, you can imagine two hands is just
kind of multiply from there.
Speaker 2 (22:15):
Yeah, just like an absurdity of goro coming at you. There.
Speaker 1 (22:19):
What's the Latin prefix for fifty? Like the quinta deca goro?
Speaker 2 (22:26):
I don't know that sounds good. Okay, that's a lot
of button inputs though, for the punches. Anyway, Uranas is
the one who stands on high. He is the rain maker.
Among his many children was the titan Cronus, who, at
Gaya's urging, rebelled against his father, And of course Cronus
famously castrated his father in the myths and cast the
(22:48):
bloody pieces over his shoulder and ushered in a new
age of gods. Cronus would of course, eventually be overthrown
by his own son Zeus.
Speaker 1 (22:58):
Okay, well, here I thought, this is a good opportune, ever,
reading from Hesiod's Theogony to explain what happened to old Urinus. Here, Oh,
let's happy, Okay. This is the version hosted on Harvard
Center for Hellenic Studies website. This is a translation by
Naggie and banks. Oh, and it's gonna mention Earth and Sky.
I think Earth would be the goddess Gaia, and Sky
would be Urinus. Here yeah, Hesiod writes, Now monstrous strength
(23:22):
is powerful joined with vast size. Four of as many
sons as were born of Earth and Sky. They were
the fiercest and were hated by their father from the
very first. As soon as any of these was born,
he would hide them all and not send them up
to the light. In a cave of the Earth and
Sky exulted over the work of mischief, while huge Earth
(23:45):
groaned from within. Straightened as she was, and she devised
a subtle and evil scheme. For quickly, having produced a
stock of white iron, she forged a large sickle blade,
and gave the word to her children, and said, encouragingly,
though troubled in her heart, children, of me and of
a father madly violent, if you would obey me, we
(24:06):
shall avenge the baneful injury of your father, for he
was the first that devised acts of indignity, so spoke she,
But soon seized on them all, nor did any of
them speak till, having gathered courage, great and wily Cronos
addressed his dear mother. Thus in reply, Mother, this deed
at any rate I will undertake and accomplished. Since our
(24:27):
father of detested name, I care not, for he was
the first that devised acts of indignity. They're really hitting
the talking points here. Thus spoke he and huge Earth
rejoiced much at heart, and hid and planted him in ambush.
In his hand she placed a sickle with jagged teeth,
(24:48):
and suggested to him all the stratagem. Then came vast Sky,
bringing night with him, and eager for love, brooded around Earth,
and lay stretched on all sides but his from out
his ambush grasped at him with his left hand, while
in his right he took the huge sickle, long and
jagged toothed, and hastily mowed off the genitals of his father,
(25:11):
and threw them backwards to be carried away behind him.
Speaker 2 (25:15):
Pretty rough stuff. I don't know why the sickle had
to have jagged teeth.
Speaker 1 (25:19):
I don't know either.
Speaker 2 (25:20):
Thed was just laying it in there a little bit.
Speaker 1 (25:22):
It's a serrated sickle. I've never even heard of such
a thing. It's like a steak knife.
Speaker 2 (25:27):
Yeah.
Speaker 1 (25:29):
But as I mentioned Urinus there, his name is synonymous
with Sky, so in this translation they just call him Sky.
So I think it's very interesting that we end up
with a planet that, in a way, based on the
original mythological context, could just be called sky. It is
the sky planet.
Speaker 2 (25:45):
Yeah, yeah, And of course it's interesting that we're switching
from Roman to Greek in coming out here to Uranus.
And of course this may raise the question of why
why are we talking about modern discussions of what this
planet will be named? And of course you know that
has to do with with how late it was discovered,
(26:06):
properly discovered, because when discussing basically this comes down to
a discussion of the classical planets versus the the more
outer and I guess you could say modern planets. The
classical planets are those visible to the naked eye and
bright enough to be considered important in ancient astronomy and astrology.
(26:26):
And we'll discuss a little bit more about what that
means in just a second there. There there are many
names for the classical planets because they pop up in
various astronomical systems.
Speaker 1 (26:37):
Right, they were known to many different ancient cultures, so
they have many different names exactly.
Speaker 2 (26:43):
Yeah, So you know, for instance, mercury through Saturn have
names that indicate elemental alignment in Chinese tradition, So Mars
is the fire star, Jupiter is the wood star, that
sort of thing. But the Chinese for the outer planets,
interestingly enough, is not based in an actual like Chinese
(27:03):
at astrological history, but in translation of at least the
spirit of the Western names. So Uranus in Mandarin is
Tan wang Shing or sky king star. So I think
that's that's center, just basically alluding to this is a
sky god. That's the name that we've used in naming
(27:25):
the planet. So it's sky sky king star. Neptune is
ocean king star, Pluto is nether World king star. In translation.
Speaker 1 (27:34):
I love that, Yes, translating the sense of the names.
So the name in Mandarin is like a summary of
where the name comes from, like the Latin or Greek name.
Speaker 2 (27:44):
Yeah. So again talking about the classical planets here, these
were the planets that were known to antiquity Mercury, Venus, Mars, Jupiter,
and Saturn. Uranus was the first planet discovered via the
aid of a telescope, and it happened in seventeen eighty
one by astronomer William Herschel In addition, he also discovered
(28:04):
infrared radiation. He's also credited with the discovery of Titania
and Oberon, which are some moons we'll get into in
a bit, as well as two of the moons of Saturn,
Enceladus and Mimas. His son John Herschel got to carry
on their tradition and named seven moons of Saturn and
four moons of Uranus.
Speaker 1 (28:25):
Now, a really interesting thing about the discovery of Uranus
by William Herschel is that at first he did not
realize he had discovered a new planet in the Solar System.
And the reason for this will sort of tie into
things we've been talking about. I was reading about this
in a paper called Uranus in the Establishment of Herschel's
Astronomy by Simon Schaeffer, published in the Journal of the
(28:49):
History of Astronomy in nineteen eighty one, and so the
story of the discovery of Urinus goes like this. William
Herschel had undertaken a project, beginning in seventeen seventy nine,
to survey all of the stars in the sky to
the limit of the eighth magnitude using a seven foot
reflecting telescope, mainly for the purpose of identifying double stars
(29:12):
so that Herschel could try to make measurements of stellar parallax.
In March seventeen eighty one, Herschel had his telescope moved
to his house on New King Street in Bath in Somerset, England,
and he was picking up with his observations from this location.
And on the week of the discovery of Uranus, he
(29:33):
had been occupied cataloging the visible stars within the constellation Gemini,
and also with some observations of the planet's Mars and Saturn.
And on Tuesday, March thirteenth, at ten thirty pm, Herschel
made a note of an object in the area of
the star Pollux, also known as Beta Geminorum. The object
(29:53):
was quote a curious either nebulous star or perhaps a comet,
and later translated this discovery to his volume in progress,
which was called Observations on the Fixed Stars.
Speaker 2 (30:06):
Quote.
Speaker 1 (30:07):
Looking at a star in the quartile between oreguess right
foot and the left foot of Castor, I discovered a comet.
It was at the distance of almost two thirds of
my field of view from a small telescopic star which
followed it, and seemed to have the same declination. Now
Herschel didn't seem to be immediately overwhelmed with ideas of
(30:27):
the importance of this finding. He after this just went
back to looking for double stars, and it wasn't until
Saturday March seventeenth, which was four days later, that he
went back and looked for the curious nebulous star or
perhaps comet again, and this time he concluded that it
must be a comet rather than a star, because it
had changed its place. So he invited some friends over,
(30:50):
including a guy named doctor William Watson, to come take
a look at the comet he had found, and he
noted in his journal that unfortunately the measurements he took
that night were written down wrong because Watson and another
gentleman wouldn't stop talking at him while he was trying
to write them. But he eventually sent off his findings
in a letter to the Royal Society in London, and
(31:11):
Herschel reported that the object was a newly discovered comet,
but there were some strange things about it. Based on
initial observations, it would seem that the comet was quote
much larger in diameter but less luminous than any comet
known at the time, and that quote its body seemed
very well defined, having neither beard nor tail. Now that
(31:34):
struck me because I was like, what is a beard?
Comets are often said to have tails, but the idea
of a beard I was less familiar with. As best
I could figure out, this, I think seems to just
be another way of describing the tale of a comet, which,
of course the tale is an elongated cloud trailing off
of the comet away from the Sun, caused when the
(31:55):
comet approaches closer in its orbit to the Sun and
then solar radiation and heats the volatile materials on the
surface of the comet and they vaporize and stream away
into space. I don't know if the following is the
difference emphasized by beard versus tail, but comets often do
have two distinct tails. A dust tail made of the
(32:16):
dust to find particles coming off of the comet from
this outgassing when it's heated, and then also a gas
tail made of glowing ionized gases. However, I could find
archaic references to comets in general simply calling them quote
bearded stars. So I don't know. Maybe a beard means
either one. I guess the other ideas that it could
(32:38):
possibly refer to the idea of a coma, which is
the sort of tenuous atmosphere of a comet, seen usually
as a fuzzy spherical cloud around the solid nucleus.
Speaker 2 (32:49):
I wonder too if this might come down to sort
of the distinction between sort of more modern telescope generated
imagery and your telescope observation. You know, we've talked about
that a little bit, like the role of the observer
in real time and sort of you know, classical telescope
(33:11):
astronomy versus the more modern use of imagery.
Speaker 1 (33:15):
I don't know for sure about that, but so he's like, ah, okay,
it's a comet, but it just it doesn't have a
lot of the characteristics we would expect of a comment.
In fact, the paper cites a letter from the French
astronomer Charles Messier, who was known as quote the ferret
of comets. I'd never heard that before, but I think
he found a lot of them. Messier, the Ferret of comments,
(33:37):
wrote to Herschel in April of seventeen eighty one. It
was quoted in the paper in French, so I had
to translate. Apologies if this is a little bit approximate
but Messier says, I'm amazed at this comment, which does
not carry with it any distinctive character of comets, and
that it does not resemble any of those which I
have observed, which are eighteen in number. So I just
(33:59):
thought this was interesting. It seemed at first all of
the learned astronomers were calling it a comet, even though
they recognize that it's really not like a comet at all,
Like it doesn't have any of the characteristics we would expect,
doesn't behave like a comet. It seems that the first
person on record to have mentioned that this new comet
might actually be a planet was the British astronomer Royal
(34:21):
Neville Masculine, who argued that it might be a comet,
but it might also be a new planet, and if
it were a comet, it would be unlike any other
Herschel apparently did not refer to Uranus as a planet
until the summer of seventeen eighty two, when he called
it quote my planet and again he wanted to originally
(34:41):
call it GEORGI mciitas the George Star again lol. But
so I was just wondering, like, why is everybody so
quick to assume it's a comet? Why did it take
them a little while to come around to the conclusion
(35:03):
that it was actually a planet? And Schaeffer in this
paper argues that even though Maskerline was the first to
suggest it might be a planet, quote, Maskerline's own practice
was fundamentally conditioned by the eighteenth century triumphs in cometary astronomy.
Comets dominated the contemporary perception of the heavens. It seemed
inconceivable that a new planet could be discovered. And I
(35:26):
think this must just come back to the state of
astronomy as it was at the time, because as you
were talking about rob Mercury, Venus, Mars, Jupiter, Saturn, all
the other planets up to this point had been known
about since antiquity. They were written about by Babylonian astronomers
thousands of years ago. They were charted with the naked eye,
and Copernicus had correctly figured out that they orbited the
(35:49):
Sun and not the Earth.
Speaker 2 (35:51):
Now, I just want to drive home here that again, Yeah,
the classical planets are those that could be seen with
the naked eye, but also were distinct enough to be
of value. But if you're really looking with the naked eye,
and the conditions are just right, you apparently can see Urinus.
But again, the whole deal here is that what you
(36:11):
see is not significant enough to have, you know, had
any impact on these ancient astrological and astronomical systems. According
to Pete Lawrence, writing for BBC Sky at Night magazine
in twenty twenty, yeah, it is possible to see Uranus
with the naked eye conditions and preparations or just right.
He stresses, however, that the planet quote shines at the
(36:33):
edge of naked eye visibility, and any direct views of
Urinus aren't always conclusive.
Speaker 1 (36:41):
Yeah, that was my understanding from reading all this stuff
as well, that it's sort of right on the edge
of naked eye visibility, to the point where some people
argue that, oh, maybe this thing that somebody said, you know,
a naked eye astronomer in the ancient world observed was
actually an observation of Urinus. But it's hard to know.
Speaker 2 (36:58):
To put it in terms of are weird how cinema
listeners might appreciate. It's like watching The Devil's Rain and
then asking is John Travolta in this is John Travolta
a star?
Speaker 1 (37:09):
Evidence is inconclusive, right, but so coming back to this,
so like all the planets through Saturn had been known
since antiquity to multiple different cultures, there had been other
heavenly bodies identified since the invention of telescopes, but none
of them were planets in the Solar System. Galileo had
identified moons of Jupiter, Cassini and Heuygen's identified moons of Saturn,
(37:32):
but Herschel's identification of Uranus was actually the first time
since ancient times that the existence of a new planet
in the Solar System had been confirmed. That's just not
something these astronomers were really expecting to find. Comets, on
the other hand, were constantly being discovered. Discovering new comets
was one of the major endeavors of astronomers of the day.
(37:55):
You had the ferret of comets out there doing ferreting
them out, so you could think of this as a
kind of astronomical confirmation bias. Comets were just that's what
you discover, that's the thing you're expecting to see.
Speaker 2 (38:09):
Yeah, yeah, it's planets, and then just it's filthy with
comets and you got to send the comet truffle hog
out there to root them out.
Speaker 1 (38:16):
So of course there were many subsequent discoveries of the
moons of Urinus, but a lot of what we now
know about Urinus really comes in the later twentieth century
with the fly by a Voyager two.
Speaker 2 (38:29):
Yeah, and as we'll really be driven home as we
discuss these moons one by one. It's like Voyager two
is the defining mission. Like a lot of what we
know comes either in it from that fly by or
it's the combination of that flyby information combined with say
Hubble telescope information as well. So it's a lot of
(38:53):
the mysteries of Uranus and its moons remains all right,
So when we come back in the next stepisodeisode, we
will blow through the twenty seven known moons of Urinus.
Speaker 1 (39:05):
All twenty seven in one episode.
Speaker 2 (39:06):
I don't know if we can do that all twenty
seven one episode. That's a guarantee. That's a guarantee, so
be sure to join us for that. And then I
don't know, And then at some point in the future
we'll move on to Neptune. But next episode will be
Moon by Moon the moons of Uranus. In the meantime,
if you would like to check out other episodes of
(39:27):
stuff to blow your mind. Well, check out the Stuff
to Blow Your Mind podcast feed. If you go back
far enough, you'll find those episodes we did about the
other moons in our solar system and Jupiter, Saturn, Mars,
et cetera. But yeah, core episodes published on Tuesdays and Thursdays.
On Mondays we do listener mail. Wednesdays we do a
short form monster fact or artifact, and tomorrow's will also
(39:49):
tie into Urinus, so tune in for that. And then
on Fridays we set aside most serious concerns and just
talk about a weird movie on Weird House Cinema.
Speaker 1 (39:58):
Huge thanks to our audio producer JJ Pausway. If you
would like to get in touch with us with feedback
on this episode or any other, to suggest a topic
for the future, or just to say hello, you can
email us at contact at stuff to Blow your Mind
dot com.
Speaker 3 (40:19):
Stuff to Blow Your Mind is production of iHeartRadio. For
more podcasts from my Heart Radio, visit the iHeartRadio app,
Apple Podcasts, or wherever you're listening to your favorite shows.
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