February 6, 2025 • 46 mins
In this episode of Stuff to Blow Your Mind, Robert and Joe return once more to the Jovian moon of Io, to discuss more recent findings about its volcanism and geology, as well as a look at the mythology behind its name.
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Speaker 1 (00:03):
Welcome to Stuff to Blow Your Mind production of iHeartRadio.
Speaker 2 (00:12):
Hey you welcome to Stuff to Blow Your Mind. My
name is Robert.
Speaker 3 (00:15):
Lamb and I am Joe McCormick. And today on Stuff
to Blow Your Mind, we're going to begin a series
on Jupiter's moon Io. Now, years ago, we did a
whole series of episodes on the moons of Jupiter as
a whole, focusing mainly on the four Galilean moons. We'll
talk more about that in a bit. But recently I
(00:36):
decided I wanted to come back and do a deeper
revisit on Io. In particular, iobing Jupiter's innermost moon. And
this was in part because I learned some new interesting
things about it. But what really triggered this, this new
rabbit trail of research, was that one night, I don't know,
sometime in the past week, I got obsessed with new
(00:58):
imagery generated by the NASA Juno mission in late twenty
twenty three and twenty twenty four. And so, Rob, if
it's all right with you, I'd like to start off
with us looking at one of these images in particular,
and folks at home, we will describe it for you.
Speaker 2 (01:13):
All right, let's do it so.
Speaker 3 (01:14):
This is a very crisp color image of Io's northern
polar region taken by the Juno spacecraft on December thirtieth,
twenty twenty three, during Juno's fifty seventh close flyby of
the Moon. The image was released by NASA JPL based
on data taken by the Juno spacecraft, with some additional
(01:36):
image processing by somebody named Gerald Eichstadt. And I found
this picture so weird and thrilling to the imagination. For
those who can't look it up, if you can look
it up, i'd recommend checking it out again. Keywords are
probably Io northern Polar Region, December twenty twenty three. I'm
sure that I'll pull it up. But for those who
(01:58):
can't look it up, what we're seeing here is half
of the Moon as an illuminated hemisphere, fading into darkness
at the meridian. Now, there's a lot we could say
about the color of Io, and we'll come back to
that actually in a few minutes. But in this photo
we see wide empty planes of a faded rose color,
(02:20):
a kind of pale, rusty pink, dotted by gaping sunken
craters and mountains that rise up into space. With alarming sharpness.
In some cases, they're rising up like thorns, casting these
long shadows on their night side slopes, And the craters
are often darker than the plains around them, as if
(02:42):
containing silent, cold seas of water. That's what I saw
when I first looked at this. But of course we
know it's not going to be water in those craters.
What is in those craters? We'll get to that. Then
in some spots we see surface features that look almost
like a biological growth or infection, and a kind of
mass of yellow orange slime mold shaped just like pure chaos,
(03:06):
just reaching its fingers out across the moon looking for something.
And then surrounding these colonies of mold, and around the
sharp mountains there are pale gray flats that look like
borders marked in ash. I just love this photo. It
makes me want to personally explore space. It's bizarre, lovely,
(03:28):
frightening and seething with drama.
Speaker 2 (03:32):
Yeah, absolutely, this image. It looks like perhaps the pinkish
disease scalp of a zombie.
Speaker 3 (03:39):
It.
Speaker 2 (03:39):
I also thought, well that this looks exactly like the
sort of world that would be your destination in a
Doom video game. Oh, you know, it just looks like
a hellish planet where you're probably going to have to
blast demonoids.
Speaker 3 (03:52):
I very much see the zombie comparison, especially like a
close up on zombie skin, because when you zoom in,
especially on these mountains, I see something that looks like
the texture of those liquid latex makeup effects, where there's
like a scab or a scar on a zombie. That's gonna,
you know, if it's a full chew movie, it's gonna
peel off. And sorry to get gross, but that is
(04:13):
what it looks like.
Speaker 2 (04:15):
It looks infected. It looks infected.
Speaker 3 (04:17):
In more ways than one. But so anyway, this photo
and some others got my brain racing about IO. I
started reading some things about it, and I realized that
there's a lot of interesting stuff about this moon that
we did not get into in our larger series on
the Galilean Moons years ago. So I wanted to come
back and go deep on this moon. That's why we're
(04:37):
here today.
Speaker 2 (04:39):
Yeah, I was looking back at our notes on the
Jovian Moons series and I found that, yeah, we didn't
even really get into the mythology of Io at all,
Like where this name comes from? And all of that
is quite fascinating as well, So that's going to be
fun to explore as we proceed here.
Speaker 3 (04:55):
Yeah, knowing the mythology definitely does enliven and kind of
throw into shadows over the geology and all of the
physical facts. So I figure a good place to start
is to just do a brief kind of refresher course
on the Moon. So Io is the innermost of the
what are known as Jupiter's Galilean moons. These are the
(05:18):
four large moons that were discovered by the Italian astronomer
and scientific pioneer Galileo Galilei in January sixteen ten using
a refracting telescope with twenty times magnification power. These four
moons are from innermost to outermost. So you're starting at
the planet, going out, you get Io, then you get Europa,
(05:40):
then Ganymede, than Callisto. Now these are not Jupiter's only moons.
Jupiter actually has ninety five total moons according to the
International Astronomical Union, and that's not even everything orbiting the planet.
That's just the recognized moons. It's not including a bunch
of small orbiters reaching down to the scale of human furniture.
(06:01):
We've talked on the show before about how the observation
of the Galilean moons was not just an important thing
in the history of astronomy, not just like, oh, we
learned about some new things out in the sky in
the Solar System, but it was an important moment in
the history of science because it was one of many
(06:23):
pieces of evidence that Galileo marshaled against the geocentric model
of the cosmos. Because, to simplify the argument, if it
can be shown that objects orbit another planet like Jupiter,
why then should we assume that everything in the universe
orbits the Earth. Maybe instead, the Earth and the planets
(06:44):
all orbit the Sun, and moons orbit the planets, and
orbital pathways are a result of some deeper general principle
other than everything goes around the Earth. Now, technically, when
Galileo first spied the moons of Jupiter through his telescope,
at the very beginning, he thought that they were fixed stars.
Speaker 2 (07:03):
He thought he was.
Speaker 3 (07:04):
Looking at stars beyond Jupiter and marked their place. But
then he looked at Jupiter again later and the stars
were in a different arrangement, so he realized, like, oh,
those are not stars, those are something else in the foreground.
They're going around the planet. And when he first saw them,
he thought he saw three, not four, because he was
not able to distinguish Io and Europa. Europa being the
(07:26):
second innermost of the large moons, he was not able
to distinguish them as separate points of light. It was
only in later observations he realized that there were four
of them. Now, in terms of mass and volume, Io
is the third largest of Jupiter's moons, after Ganymede and Callisto,
and it is just slightly larger in diameter than Earth's Moon.
(07:48):
As the nearest of the Galilean moons to Jupiter, its
average orbital distance from the planet is four hundred and
twenty two thousand kilometers or two hundred and sixty two
thousand miles. Now, the fact that you might know which
really sets Io apart and is probably going to be
one of our main focuses in this series, is that
(08:09):
Io is the most volcanically active object in our solar system,
with hundreds of active volcanoes at any given time. I
think there are more than one hundred and fifty active
volcanoes that have been directly observed, and scientists have estimated
based on what we have observed, that there are probably
(08:29):
like four hundred or so in total on the surface. Now,
just earlier today, I was actually reading the story of
how the existence of those volcanoes on Io was first confirmed.
(08:50):
And this actually brings us back to the question of
the color, the color of the surface of the Moon,
which I brought up earlier, and where I was reading
about this was in Carl Sagan's book Cosmos, first published
in nineteen eighty, sort of as a companion to the
documentary series he did. Sagan was writing about Io in
(09:10):
that saying that the following was his favorite of what
he called the traveler's tales that were returned by the
voyager probe.
Speaker 2 (09:20):
Are you going to do the voice?
Speaker 3 (09:22):
I appreciate you putting me on the spot, but no,
I can't do the voice.
Speaker 1 (09:25):
No.
Speaker 2 (09:25):
Anytime I read Sagan, though, I hear it in his voice.
Speaker 3 (09:28):
Oh good, I know exactly what.
Speaker 2 (09:29):
Yeah.
Speaker 3 (09:30):
I hear it in the voice too. Yeah, but I can't. Okay,
So here it is in my voice, his words, my voice,
Sagan writes, quote, before voyager we were aware of something
strange about Io. We could resolve few features on its surface,
but we knew it was red, extremely read redder than Mars,
(09:50):
perhaps the reddest object in the Solar System. Over a
period of years, something seemed to be changing on it
in infrared light and perhaps in its radar reflection properties.
We also know that partially surrounding Jupiter in the orbital
position of Io was a great doughnut shaped tube of
atoms sulfur and sodium and potassium material somehow lost from Io.
(10:17):
Oh wow, what a mystery. Okay, so you know, we've
never gotten close enough to see what's happening on the surface,
but for some reason, it looks super red, redder than
anything else we can see around, and it's leaving this
trail of atoms in space, like it's just spitting out
atoms into orbit around Jupiter. And then the mystery only
gets weirder once the voyager probe actually approaches the Moon
(10:40):
and sends back images in nineteen seventy nine. What they
see is very strange. First of all, the surface is
multi colored, as we brought up earlier. If you see
what they call true color photos of Io, they are
often overwhelmingly yellow, like a I don't know, a canary
or a ban and I kind of yellow except I
(11:01):
don't know, maybe a little paler and more sickly, some
kind of vomitous duckling yellow with these blotches of red, pink, gray,
and green. I feel like this has too normative of
a connotation, but it really does always kind of remind
me of sickness in some way, not trying to say
io is a bad place. So one of the happier
(11:23):
comparisons that astronomers sometimes make about the different coloration patterns
is they call it a pizza planet. They're like, it's
got like cheese and pepperonis and olives and all that.
Speaker 2 (11:33):
Well that's a way to make it attractive, I guess.
But yeah, it does look like some sort of a
strange like nergal world.
Speaker 3 (11:39):
So yeah, yeah. Also, scientists looking at the images of
iosurface realized it was missing something impact craters due to
its position near the asteroid belt. Sagan writes that this
object really would have to have undergone repeated impacts from space,
(12:00):
should be hammered by asteroids, by things coming down on
it and leaving pocks in its surface that we would
be able to see, you know, just like look at
the Moon. It should maybe look something like that, but
instead its surface showed little to no sign of impacts,
as if something was rapidly erasing the evidence of collisions. Now,
(12:21):
whatever was doing that erasing could not be atmospheric in nature,
because Io has almost no atmosphere. It does have an atmosphere,
but it's incredibly thin, made primarily of sulfur dioxide. If
those surface features are being erased, they couldn't be erased
by erosion of running water because the conditions on the
surface of Io would not permit liquid water. So it
(12:44):
had been theorized by some astrophysicists. Segan names an astrophysicist
named Stanton Peel that Io might have erupting volcanoes due
to tidal heating of its interior. So this is a
frictional heating of the inside of the planet caused by
gravitational forces. We'll explain more about this as we go
(13:06):
on in the series. But that could lead to volcanic eruptions,
which could do the job of repaving the surface if
these volcanoes existed. But up until this point in nineteen
seventy nine, there was no way to know if any
of that was true. It was just an idea. That's
one thing that could be going on. Here then Sagan
tells of the discovery. He writes, quote Linda Moribto, a
(13:29):
member of the Voyager navigation team responsible for keeping Voyager
precisely on its trajectory, was routinely ordering a computer to
enhance an image of the edge of Io to bring
out the stars behind it. To her astonishment, she saw
a bright plume standing off in the darkness from the
satellite's surface, and soon determined that the plume was in
(13:53):
exactly the position of one of the suspected volcanoes. Voyager
had discovered, the first active volcano being on the Earth.
We now know of nine large volcanoes spewing out gas
and debris. Remember this was in nineteen eighty when this
book was written. Nine large volcanoes spewing out gas and debris,
and hundreds, perhaps thousands of extinct volcanoes on Io. The
(14:15):
debris rolling and flowing down the sides of the volcanic mountains,
arching in great jets over the polychrome landscape is more
than enough to cover the impact craters. We are looking
at a fresh planetary landscape, a surface newly hatched. How
Galileo and Huygens would have marveled now I love that
story for multiple reasons, one of which is the idea
(14:38):
that the plume from the volcano was spotted not by
somebody who was intentionally hunting four volcanoes, but in the
process of trying to better resolve navigation navigationally relevant data.
But I also love how it paints this picture of
Io as a place of a freshness of chain.
Speaker 2 (15:01):
Rob.
Speaker 3 (15:01):
I think we've talked about this on the show before
that often when we think of anything beyond Earth, things
in space, we tend to think of a kind of inert, changeless,
frozen or dead landscape, places where nothing all that interesting
ever really happens. Like what is interesting about the places
(15:24):
beyond Earth is kind of a I don't know, features
of permanent interest, just the way things are and have
always been and will always be. Obviously, we know that's
not true, and if you like fast forward the tape
of geologic time and cosmic time, things change a lot.
But just thinking about other planets and moons seems like
not a lot is happening there, and that is absolutely
(15:45):
not the case on the surface of Io. You know
he's talking Segan here is talking about Io as a
place where the surface changes on a timescale of months.
Speaker 2 (15:57):
It is a dynamic world.
Speaker 3 (15:59):
And so this leads to another thing he gets into
about the chemistry of Io and its volcanic activity, and
how this actually relates to the strange patterns of what
he called the polychrome surface, the different coloration patterns we
see on the surface. Sagan writes that this is actually
what we would expect to see from the release of
molten sulfur and the interactions of sulfur compounds from Io's
(16:23):
volcanoes and on the surface of the moon. So you
get like these black coloration at the hottest places where
the sulfur is just coming out, and maybe near the
top of the volcano or the mouth of the volcano,
and then nearby where there would be flows of what's
coming out of the volcanoes, you get something more like
red and orange. And then beyond that you get these
(16:44):
big empty planes that are just kind of like yellow,
yellowish sulfur. Now, on the subject of what is coming
out of the mouth of the volcanoes, or what might
be forming sort of lakes or rivers of flows beyond
beyond a volcano on Io, it's worth noting that materials
ejected from volcanoes tend to be very hot. That's true,
(17:06):
whether we're talking about Earth or Io. They can form
these searing lava flows. But a crazy fact that I
came across is that apparently lava flows on Io are
even hotter than lava flows on Earth. You know, I
might have just assumed that la lava is going to
be roughly the same temperature wherever it is. You know,
(17:28):
once it sort of reaches the surface, it's you know,
it's probably cooling off. I don't know, I don't know
why I would have thought that, but that's clearly wrong.
So I was reading about this in an August first,
two thousand and one press release from NASA JPL that
included an interview with a JPL volcanologist named doctor Rosalie Lopez,
(17:48):
and she says a number of really interesting things in
this little interview. One of them comes back to that
sort of designation that people have of Io as the
most volcanic body in the Solar System. She stresses that
this is not because Io has the most volcanoes, as in, like,
(18:09):
you count up all the volcanoes and it has the most.
Because I actually checked, this Earth has more volcanoes total.
Earth has more than Io does, but Earth is also larger.
Of course, the reason that scientists call Io the most
volcanic body in the Solar System is that its volcanoes
put out the most total heat. So it's the most
(18:31):
volcanic because it's a question of total energy released. Io
is only about one third the size of Earth, but
it puts out like double the heat of Earth from
its volcanoes. And Lopez notes that one single volcano on Io,
known as Loki, is more powerful than every volcano on
(18:52):
Earth put together. Now, another interesting part in this exchange
is that the interviewer asks Lopez whether the volcanoes on
Io would be similar to volcanoes on Earth. How would
they be similar? How would they be different? And Lopez says, quote,
the types of eruptions we've observed on Io are similar
to types of eruptions on Earth. Lava flows, calderas, fire
(19:14):
fountains like in Hawaii. But there are some very different aspects.
One is that lava on Io is much hotter than
any lava that flows on Earth today. Billions of years ago,
Earth had lava that hot. Another difference is that the calderas,
the volcanic craters on Io are much larger, than on Earth.
(19:36):
Lava flows are much larger too, and then she cites
a volcano on Io named Amirani that has a lava
flow going three hundred kilometers long or about one hundred
and ninety miles. She of course notes that that's longer
than any known lava flow on Earth, but I looked
up something to try to find a comparison. Three hundred
(19:57):
kilometers is roughly the distance from New York to Providence,
Rhode Island, So just imagine an active lava flow that long.
And then finally, in this answer, she notes that io
eruptions on Io produce like one hundred times as much
molten lava per year as eruptions on Earth. And that's
counting up all of the erupting volcanoes on Earth, even
(20:18):
the ones under the sea. So that's all amazing. I'm
especially fascinated by the idea that Earth used to have
hotter lava, Like we're kind of in decline and our
planets just like we can't put out lava like we
used to. But if you take all that together, think
about like the massive number of erupting volcanoes on Io,
(20:39):
how much heat they put out, and just like what
a in some ways boiling world. This is that might
paint a picture of a hothouse, a sort of planetary
hell world like Venus, but actually that would not be
accurate if you're trying to imagine what it's like on
the surface of Io. Because the apage surface temperature of
(21:01):
Io is extremely cold. Io has a very thin atmosphere,
extremely thin sulfur dioxide atmosphere, too thin to trap heat effectively,
and that's you know, one reason Venus is so hot.
It's it's because it's got a very thick atmosphere that
traps heat within the atmosphere. Io does not have that.
(21:22):
So while it's got these super you know, extremely hot
hot spots where the volcanoes are erupting or the lava
flows are taking place. You might have a lake of
lava that's you know, going to be incredibly hot. Most
of the Moon is very cold, with an average surface
temperature of negative one hundred and thirty degrees celsius or
negative two two fahrenheit, So astronomers sometimes call it a
(21:45):
like a world of fire and ice. It's a place
where you have these these gigantic, massive erupting volcanoes and
giant long lava flows, you know, going New York to Providence,
Rhode Island. But at the same time you'll have these
almost whimsic frisky ice world conditions. For example, I mentioned
the fact that Io has this very thin atmosphere of
(22:06):
mostly sulfur dioxide. Some of that sulfur dioxide comes directly
from volcanic eruptions venting screaming hot sulfur from below, but
the other half comes from the gradual evaporation or technically
sublimation of vast fields of sulfurous ice already on the
planet's surface. So there's a pattern that goes like this.
(22:29):
The volcanoes erupt and they shoot sulfur dioxide into the atmosphere.
It floats around. Then, once every forty two hours or so,
Io passes briefly into Jupiter's shadow, so it becomes eclipsed
and all sunlight is blocked, and this causes the surface
temperature to drop even further. It causes the Moon to
(22:50):
temporarily go into a deep cold cold enough to actually
cause the lower SO two atmosphere level to freeze and
fall to the surface. Then, when I emerges from its
eclipse and comes back into the sunlight, the frozen planes
of sulfur snow start to warm up and sublimate into
gas once again, which becomes part of the tenuous atmosphere.
(23:14):
So there's a lot more we'll have to get into
about the Moon, but just starting with this portrait, this
sketch here, I really would make the case for Io
as one of the most interesting places in the Solar System,
you know, beyond Earth, of one of the most challenging
and strange and dramatic and fascinating places in all of space.
Speaker 2 (23:35):
Absolutely. Yeah, the closer you look at it than the
more amazing details there are.
Speaker 3 (23:41):
Now, speaking of dramatic landscapes, I did want to mention
one more of the images that really got me interested
in doing the series of episodes. This one actually is
less a I think, less directly a photograph and more
kind of an image generated based on It was like
a three D image that's like an artist concept based
on data from Juno's Junokam instrument. So it's not just
(24:05):
made up like it is based on data they took
from the surface. But it's like a generated three D
image and it's of iOS steeple mountain that's worth looking
up at home, folks. It's this mountain that comes up
out of the surface like a blade. It's just like
so sharp, and then has the spires reaching up from
the top of it. And so if you look this up,
(24:28):
there are sort of animations you can find online where
the perspective goes around the mountain to sea from its
day side into its night side and shadow. And it's Oh,
it's very haunting, especially because it has a strong, lonely
mountain energy. It's not part of a mountain range. It's
just one giant blade of mountain raising up out of
(24:51):
an otherwise relatively flat plane.
Speaker 2 (24:54):
Yeah, with these two spires, one has the appearance of
being broken. Reminds me of the the horns of Golgadaath,
two horns coming up out of the ruined earth. So yeah,
it's pretty evocative.
Speaker 3 (25:08):
But Io is actually full of these strange and gorgeous
surface features, both the ones that rise and the ones
that sink.
Speaker 2 (25:16):
That's right. Another interesting feature is Boa Sali Monts. This
apparently stands as the tallest known peak on Io, standing
between seventeen point five kilometers that's ten point nine miles
and eighteen point two kilometers are eleven point three miles
in height. It is named for the cave where we'll
(25:39):
get into this. The Greek mythological figure Io is said
to have given birth to her son. We'll get into
all that in a bit. And Boa salle means cowpin
will also get into what that means how cows feature
into this mythology. But it is the third tallest known
mountain ridge in our soul system, behind only Olympus monds
(26:04):
on Mars, which is the tallest, and the equatorial ridge
on the Saturn nine moon Iapetus.
Speaker 3 (26:11):
Oh yeah, the big spine in the middle of the Appetus.
That was good.
Speaker 2 (26:16):
Let's see there are a number There are a number
of other mountains mountains. The mountains on Io have all
sorts of names, some related, some related to Dante's Inferno,
some related to other mythological traditions. But there are at
least four other ones that have names that are related
to the myth of Io that will get into in
a bit. There's Argos Planum, named for the land of
(26:40):
Io's father. There's Epaphus Mensa, named for Io's son, There's
Hermes Mensa. You'll find out how Hermes factors into everything,
and then there's Innachius Tholus, name for Io's father. Now,
you mentioned Loki earlier. This is an of course, the
(27:01):
namesake is the Norse god Loki, and rather than a mountain,
it is, of course a great volcanic depression with a
lake of magma in it. This is a Loki patera.
As described by the JPL website, this is one hundred
and twenty four mile long or two hundred kilometer long
lake filled with magna, rimmed with hot lava, and dotted
(27:23):
with islands, but with one like huge island in the
middle of it. And they stress on the JPL website
that this large island in the lake does not have
a name, which I think only intensifies the feeling that
either a it does have some sort of name and
you just can't say it, or that there is some
sort of unholy castle there. You know, the island in
(27:47):
the lake of magma that cannot be named.
Speaker 3 (27:49):
Do not ask after its name, for it has none.
Speaker 2 (27:52):
Yeah, but if they're looking for a name, I'm thinking, well, okay,
if the area is named for Loki and it's within Loki,
will name it after one of the monsters that Loki
gives birth to. I mean, you have, like I think,
four good ones to choose from there's Hell, there's yormagand
there's fin Rear, and there's slept Near. But hey, I'm
no astronomer. Those names may be taken already now. They
(28:12):
also add that there were reflective aspects to the Loki
Petera during the Juno flyover, suggesting that its surface was
as smooth as glass. Now, perhaps smooth as glass in
these passes, but also food for thought. There's a previous
twenty seventeen analysis that turned up infrared data that suggested
(28:35):
that the temperature of the lava lake steadily increased from
one end to the other, suggesting overturning waves. Overturning lava
is a popular explanation for fluctuations in the Moon's apparent brightness,
with brightenings occurring every four hundred to six hundred days.
Another explanation is that it's due to just regular volcanic
eruptions that spike the brightness of the Moon.
Speaker 3 (28:58):
I wonder if that's related to different from what Sagan
brought up about the changes in like the radar reflectivity
of the of the moon over time.
Speaker 2 (29:06):
I think it's related. That's my understanding, and I am
for you, Joe. Others can look this up as of publication.
It's certainly on the JPL website. You can see a
computer generated image of what this lake would look like,
and it's this is from like a short computer animated
video that kind of like zooms in on it, and
(29:28):
it's it's I like this image because it's it's maybe
not one hundred percent blockbuster CGI. It feels a little
you know, mind's eye to me. And also the magma
in the lake has the coloration of like deep crimson blood,
which of course only intensifies the the unholy qualities of
(29:48):
this place. This is just fitting.
Speaker 3 (29:50):
Something seems very beyond the mind's eye about Io. It's
a place where if I went there, I would expect
to be seeing like you know, those nude early nineties
CGI figure is kind embracing and then melting into each
other and then turning into bats.
Speaker 2 (30:03):
Yeah. All to a nice Jon Hammer soundtrack for sure,
too far? Take it easy, all right? Well, shall we
get into the mythology of Io a bit? Oh?
Speaker 3 (30:23):
Absolutely?
Speaker 2 (30:24):
Now, we mentioned already about the discovery of Jupiter's moon Io,
and we mentioned the discovery sixteen to ten by Italian
astronomer or Galileo. However, there is also a case to
be made, and it was made by him, specifically that
German astronomer Simon Marius discovered it independently or instead of depending.
(30:48):
He's making the argument.
Speaker 3 (30:49):
I think I've read that it was said like they
probably discovered it around the same time.
Speaker 2 (30:54):
Yeah, yeah, but Marius is often credited with naming the
moon after the Greek mythological your Io, who is fittingly
associated with Zeus aka Jupiter in Roman traditions. Now, if
you're not familiar with Simon Marius, do look. Do go
to the Wikipedia page about him, if nothing else, just
(31:15):
to see this wonderful illustration of the man. This is
an engraving of Marius in his own book Mundus Lovialis
the World of Jupiter from sixteen fourteen. He looks like
a dashing necromancer in this shot.
Speaker 3 (31:31):
Yes, yes, warlock, infernal packed warlock. Actually, though he looks
a bit this is gonna sound funny. He looks a
bit like Galileo. Yeah, he's got a similar kind of face,
a similar kind of eyes and scowl, and a similar beard.
He's like warlock Galileo.
Speaker 2 (31:50):
Look at that collar though, such an amazing collar packed
of the lens. All right, So what is the myth
of Io. Well, the basic story, as it is usually told,
is as follows. Io was the mortal daughter of Anachus,
the river god of Argos, and the oceanid Melia, herself
the daughter of the Titans Oceanus and Tethys. The exact
(32:13):
number varies, but Io had many sisters, and Anachus also
is also referenced in mythology as the first king of Argos,
which is an ancient city in Greece. So the story
goes that Io served as the high priestess of Hera,
who is of course the wife of the high king
of the god Zeus. But the king of the gods
(32:37):
was of course ever lustful, to put it mildly, and
soon came to desire Io. Now the story the tellings
of this tale vary, but at the very least he
became enamored with her, and some accounts describe his feelings
for her as love. Avid in the Metamorphosis describes the
encounter in more threatening and ultimately violent terms. I'm going
(32:58):
to read from the Henry t Riley translation. Jupiter had
seen Io as she was returning from her father's stream,
and had said, O maid worthy of Jove and destined
to make I know not whom happy in thy marriage,
repair to the shades of this lofty grove. And he
pointed at the shade of the grove, while it is warm,
and while the sun is at his height, in the
(33:20):
midst of his course. But if thou art afraid to
enter the lonely abodes of the wild beasts alone, thou
shalt enter the recesses of the groves, safe under the
protection of a god, and that a god of no
common sort. But with me, who hold the scepter of
heaven in my powerful hand, me who hurl the wandering lightnings,
(33:42):
do not fly from me. For now she was flying,
and now she had left behind the pastures of Lerna
and the Lsayan plains planted with trees, when the God
covered the earth far and wide with darkness overspreading, and
arrested her flight and forced her modesty. So to be clear,
what Avid is describing here is supernatural pursuit and sexual assault.
Speaker 3 (34:04):
Yeah, from what I've read, I think some versions of
the story describe it as a kind of seduction. Other
versions describe it as a rape. In this version, I mean,
either way, we're seeing something that we see a lot
of Zeus doing in Greek mythology.
Speaker 2 (34:19):
Yeah, yeah, and again it does vary with the tellings.
I believe there's at least one version where he ultimately
impregnates her by just touching her with his hand. So,
as is generally the case, there's no real canon with mythology.
There are just the more popularized versions of the tale,
and sometimes those are very much connected to Avid's work
in the Metamorphosis. So after this has occurred, Zeus transforms
(34:44):
Io into a cow, a white heifer, in order to
hide her and his own transgressions from his wife Harah,
because of course, of course, Harah is too wise for
any of this, and she knows her husband too well,
so she almost immediately shows up and begins asking qu
questions about this beautiful white cow that Zeus is suddenly
hanging out with, and Ovid writes quote, Jupiter falsely asserts
(35:08):
that it was produced out of the earth and that
the owner may cease to be inquired after which, despite
the horror of the situation setting this up, this line
has a certain dry comedy to it, and I wonder
if that was at present in the original writing, or
if this is like an artifact of translation.
Speaker 3 (35:23):
I read that same line that it was produced out
of the earth. Yeah, this cow just kind of grew
out of the ground. That happens sometimes, so he's trying
to get out of it.
Speaker 2 (35:33):
But Hara, she knows what's up, and so she requests
this beautiful cow as a gift, and Zeus has no
choice but to comply, because if he says no, well
then he's admitting that this is no mere cow. And
if he just gives it up, well then you know,
they both know what's going on here. And so he
gives the cow up to Hara, and Harah entrusts the
(35:54):
white effort to the protection of the one hundred eyed
giant Argos panoptis, the all seeing and there are different
depictions of what Argus looks like. Sometimes he's depicted as
a giant with eyes all over his body. Other times
he's depicted as a humanoid or you know, with no
special features, or as a humanoid with a bunch of
(36:16):
eyes on or in his head, and in either event,
not to be confused with Argos. The place that we
mentioned earlier, this is Argus. So the basic idea is
Zeus cannot come and get his cow back at this
point because there is an all seeing giant that is
watching it at all the time. Sitting on the top
(36:37):
of a mountain, he can see in all directions at once.
Nothing is getting past him. And yes, Zeus is king
of the gods. But I think the idea is that, yes,
Zeus is all powerful, but if he actually shows up
to claim the white heffer, then the gig is up
and he is almost has to admit defeat.
Speaker 3 (36:56):
Yeah, Haro will find out exactly now.
Speaker 2 (37:00):
Now, in the midst of all this, it is said
that Io is suffering the metamorphosis here is quite miserable
the way Ava describes it. She has to live as
an animal, not mistreated by the all seeing giant, but
also not well loved either, making matters all the more traumatic.
When she wanders close to the water, which is described
(37:21):
as the water off her father, her own father and
her various sisters do not recognize her, at least not
at first. They see only the white heifer, and eventually
her father recognizes her and its heartbreaking. And there are
numerous paintings that explore this scene with like an old
(37:41):
man having this heart breaking encounter with a white cow. Oh.
Speaker 3 (37:46):
Yeah, so I was trying to tell if that was
one of the things depicted in there's a painting of
the second half of this myth that I put in
our outline by Bartolomeo di Giovanni, who is an Italian
painter like the end of the fifteenth century. This painting
is called the Myth of Io, and it's showing a
bunch of different scenes from it, though we really do
(38:08):
not get much of a hundred eyed giant in this. Instead,
Argust just looks like he's like a shepherd.
Speaker 2 (38:14):
Yeah. Sometimes he's just a dude. Other times he's this
like weird psychedelic giant with eyes all over his body.
So it just varies.
Speaker 3 (38:21):
But we do see the heifer at various places, at
one point near the water's edge, so I can't tell
if that's the part of the myth that's being depicted here.
Speaker 2 (38:29):
This story of like transformation and loved ones not recognized
you recognizing you in your transformed state reminds me of
a children's book that came out in nineteen sixty nine
called Sylvester and the Magic Pebble. Are you familiar with
this one? Joe?
Speaker 3 (38:45):
Sounds vaguely familiar, but we don't like read this one
in the house.
Speaker 2 (38:48):
So okay, well, you might have picked up at some
point because it's heartbreaking as well. It has a magical
transformation and parents not recognizing their own child in a
transformed state. But it's a great book. Well, you know,
won a number of awards, won the Calvacott Metal back
in nineteen seventy.
Speaker 3 (39:06):
I'll look it up. But okay, so we're in a
really sad place in the middle of this myth, right right, I.
Speaker 2 (39:12):
Was in a terrible place Zeus. Sometimes it's described as
if he finds this heart breaking as well, but at
the very least he tires of being controlled. And what
does he do? Well, he can't show himself, apparently, so
he sends Hermes to simply.
Speaker 3 (39:29):
Murder Argus Mercury the hit man here.
Speaker 2 (39:33):
Yes, yes, the harbinger of the gods here, the messenger
of the gods this time shows up with his Caduceius
to put the giant to sleep and then slays him
with the sword and the eyes of Argus then go
to the tail of the peacock, a symbol of Hara. Oh.
Speaker 3 (39:49):
Interesting.
Speaker 2 (39:50):
Now at this point the white effer can wander free,
and Harrah sends a gadfly to torment her gadflies are
li stock biting flies, probably horseflies or bot flies, but
in Greek mythology they're sometimes employed by the gods elsewhere.
Zeus was once said to send one to sting Pegasus.
At one point. This was while Balerifan was riding Pegasus,
(40:15):
so caused him to fall out of the sky. But
don't worry. Athena then softened his fall. So anyway, Io,
in the form of the white cow, basically wanders driven
by flies sent by the gods, and eventually she is
driven to Egypt, where she resumes her human form and
(40:36):
gives birth to a son of Zeus in a cave.
We mentioned that earlier, and this is Epaphus, who becomes
king of Egypt, and it said founds the city of Memphis.
Avid also mentions that Io went on to marry none
other than APIs or Osiris, who after his death was
numbered among the deities of Egypt by the name Serapis. Oh.
Speaker 3 (40:59):
Interesting, Yeah, for those not aware, we did serious episodes
on the Egyptian deity Osiris. When was this like last
year or the.
Speaker 2 (41:08):
Year before, Yes, sometime in the last couple of years. Yeah,
And we talked about Si Rapist as a Greco Egyptian
Syncretic deity based on both of Cyrus and APIs, as
well as aspects of various other Greek deities. Under Potomaic rule,
Avid writes Io terrified and madden with dreadful visions, runs
(41:30):
over many regions and stops in Egypt when Juno, at
length being pacified, restores her to her former shape and
permits her to be worshiped there under the name of Isis. Wow.
Speaker 3 (41:40):
Well, that is a fascinating cross cultural backstory, though not
to imply that the same backstory would actually be understood
by the people who worshiped Isis in Egypt.
Speaker 2 (41:51):
Right, right, though, of course, the worship of Isis like
spreads out of Egypt, and then you know how they're
worshiping Isis in other areas, such as in Greek and
Roman times. Yeah, maybe they employ some of this, but yeah,
at this point in our telling of the myth of Io,
we can appreciate that we're talking about something that is
probably a Greek and Roman take on the Egyptian throne
(42:13):
goddess Isis, mother of every Egyptian king. It's worth noting
that elsewhere in Greek tradition, Isis is also associated with Demeter.
In either case, the popularity of Isis in Egypt spreads
over into Greek mythology here. Yeah, Now it can be
a little confusing though, because I was looking at other
artistic depictions of Io, and there's one that from the
(42:36):
first century BCE. It's a fresco from the Temple of
Isis in POMPEII that depicts Io being received by Isis
upon her arrival in Egypt. And if you can see
an image of it here Joe in our notes in
this Io actually has the horns of a cow as well.
Speaker 3 (42:54):
Yeah, I mean that may not square in some ways
with what we just talked about it, but that seems
to me perfectly consistent with the sort of shuffling mix
and match quality of ancient mythology.
Speaker 2 (43:06):
Yeah. In Egyptomania a History of Fascination, Obsession, and Fantasy
by Ronald H. Fritz. This is the book I've cited
on the show before. The author points to the myth
of Io is one of several examples of contact and
cultural exchange between Greece and Egypt during the era of
the New Kingdom. This was between the sixteenth century BC
(43:28):
in the eleventh century BCE. You know, they're fairly difficult
travel between the two regions at the time, but there
was still cultural exchange and other sorts of exchange as
well well.
Speaker 3 (43:41):
So it's an emotionally powerful myth with interesting cross cultural relevance.
But this does bring me back to the question of like,
how does it fit into the planet Jupiter and its moons?
How do we get from there to hear well?
Speaker 2 (43:56):
Most likely most of it does come down to just
the Jupiter Zeus association. Marius's choice in naming it Io
was apparently based on a sixteen thirteen suggestion by Johannes
Kepler that the Jovian moons all be named for the
lovers of Zeus, but it's also worth stressing that there
was apparently there's a connection to be made between mythic
(44:18):
Io and Earth's own moon, so she has seemingly has
lunar qualities all her own anyway. According to classicist Peter T.
Struck in his online Pin State Classics Dictionary, Io is
the wanderer and is generally explained as a moon goddess
wandering in the starry heavens. These heavens symbolized by Argus's
(44:41):
one hundred shining eyes and then her transformation into a
horned heifer represents nothing other than the crescent moon.
Speaker 3 (44:50):
Oh interesting.
Speaker 2 (44:51):
Yeah, so yeah, the more you look at it, like,
the myth of Io is ultimately fairly complicated because you
have all these different, you know, cross culture exchanges bound
up in it. There's the lunar aspect of it, as
well as you know, some of these aspects of the
story that can be troubling and confounding, especially to modern
readers that are learning about it, you know, across the
(45:16):
thousands of years of history. All right, on that note,
we're gonna go ahead and close up this episode of
Stuff to Blow Your Mind, but we're going to be
back in a part two on the Moon of Io.
We'll get into some more curious details about the moon
in that episode. In the meantime, we'd like to remind
(45:37):
you all this Stuff to Blow Your Mind is primarily
a science and culture podcast, with core episodes on Tuesdays
and Thursdays, short form episodes on Wednesdays and on Fridays.
We set aside most serious concerns to just talk about
a weird film on Weird House Cinema.
Speaker 3 (45:50):
Huge thanks as always to our excellent audio producer JJ Posway.
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 stuff to Blow your
Mind dot com.
Speaker 1 (46:12):
Stuff to Blow Your Mind is production of iHeartRadio. For
more podcasts from iHeartRadio, visit the iHeartRadio app, Apple Podcasts,
or wherever you're listening to your favorite shows.
Welcome to Stuff to Blow Your Mind production of iHeartRadio.
Speaker 2 (00:12):
Hey you welcome to Stuff to Blow Your Mind. My
name is Robert.
Speaker 3 (00:15):
Lamb and I am Joe McCormick. And today on Stuff
to Blow Your Mind, we're going to begin a series
on Jupiter's moon Io. Now, years ago, we did a
whole series of episodes on the moons of Jupiter as
a whole, focusing mainly on the four Galilean moons. We'll
talk more about that in a bit. But recently I
(00:36):
decided I wanted to come back and do a deeper
revisit on Io. In particular, iobing Jupiter's innermost moon. And
this was in part because I learned some new interesting
things about it. But what really triggered this, this new
rabbit trail of research, was that one night, I don't know,
sometime in the past week, I got obsessed with new
(00:58):
imagery generated by the NASA Juno mission in late twenty
twenty three and twenty twenty four. And so, Rob, if
it's all right with you, I'd like to start off
with us looking at one of these images in particular,
and folks at home, we will describe it for you.
Speaker 2 (01:13):
All right, let's do it so.
Speaker 3 (01:14):
This is a very crisp color image of Io's northern
polar region taken by the Juno spacecraft on December thirtieth,
twenty twenty three, during Juno's fifty seventh close flyby of
the Moon. The image was released by NASA JPL based
on data taken by the Juno spacecraft, with some additional
(01:36):
image processing by somebody named Gerald Eichstadt. And I found
this picture so weird and thrilling to the imagination. For
those who can't look it up, if you can look
it up, i'd recommend checking it out again. Keywords are
probably Io northern Polar Region, December twenty twenty three. I'm
sure that I'll pull it up. But for those who
(01:58):
can't look it up, what we're seeing here is half
of the Moon as an illuminated hemisphere, fading into darkness
at the meridian. Now, there's a lot we could say
about the color of Io, and we'll come back to
that actually in a few minutes. But in this photo
we see wide empty planes of a faded rose color,
(02:20):
a kind of pale, rusty pink, dotted by gaping sunken
craters and mountains that rise up into space. With alarming sharpness.
In some cases, they're rising up like thorns, casting these
long shadows on their night side slopes, And the craters
are often darker than the plains around them, as if
(02:42):
containing silent, cold seas of water. That's what I saw
when I first looked at this. But of course we
know it's not going to be water in those craters.
What is in those craters? We'll get to that. Then
in some spots we see surface features that look almost
like a biological growth or infection, and a kind of
mass of yellow orange slime mold shaped just like pure chaos,
(03:06):
just reaching its fingers out across the moon looking for something.
And then surrounding these colonies of mold, and around the
sharp mountains there are pale gray flats that look like
borders marked in ash. I just love this photo. It
makes me want to personally explore space. It's bizarre, lovely,
(03:28):
frightening and seething with drama.
Speaker 2 (03:32):
Yeah, absolutely, this image. It looks like perhaps the pinkish
disease scalp of a zombie.
Speaker 3 (03:39):
It.
Speaker 2 (03:39):
I also thought, well that this looks exactly like the
sort of world that would be your destination in a
Doom video game. Oh, you know, it just looks like
a hellish planet where you're probably going to have to
blast demonoids.
Speaker 3 (03:52):
I very much see the zombie comparison, especially like a
close up on zombie skin, because when you zoom in,
especially on these mountains, I see something that looks like
the texture of those liquid latex makeup effects, where there's
like a scab or a scar on a zombie. That's gonna,
you know, if it's a full chew movie, it's gonna
peel off. And sorry to get gross, but that is
(04:13):
what it looks like.
Speaker 2 (04:15):
It looks infected. It looks infected.
Speaker 3 (04:17):
In more ways than one. But so anyway, this photo
and some others got my brain racing about IO. I
started reading some things about it, and I realized that
there's a lot of interesting stuff about this moon that
we did not get into in our larger series on
the Galilean Moons years ago. So I wanted to come
back and go deep on this moon. That's why we're
(04:37):
here today.
Speaker 2 (04:39):
Yeah, I was looking back at our notes on the
Jovian Moons series and I found that, yeah, we didn't
even really get into the mythology of Io at all,
Like where this name comes from? And all of that
is quite fascinating as well, So that's going to be
fun to explore as we proceed here.
Speaker 3 (04:55):
Yeah, knowing the mythology definitely does enliven and kind of
throw into shadows over the geology and all of the
physical facts. So I figure a good place to start
is to just do a brief kind of refresher course
on the Moon. So Io is the innermost of the
what are known as Jupiter's Galilean moons. These are the
(05:18):
four large moons that were discovered by the Italian astronomer
and scientific pioneer Galileo Galilei in January sixteen ten using
a refracting telescope with twenty times magnification power. These four
moons are from innermost to outermost. So you're starting at
the planet, going out, you get Io, then you get Europa,
(05:40):
then Ganymede, than Callisto. Now these are not Jupiter's only moons.
Jupiter actually has ninety five total moons according to the
International Astronomical Union, and that's not even everything orbiting the planet.
That's just the recognized moons. It's not including a bunch
of small orbiters reaching down to the scale of human furniture.
(06:01):
We've talked on the show before about how the observation
of the Galilean moons was not just an important thing
in the history of astronomy, not just like, oh, we
learned about some new things out in the sky in
the Solar System, but it was an important moment in
the history of science because it was one of many
(06:23):
pieces of evidence that Galileo marshaled against the geocentric model
of the cosmos. Because, to simplify the argument, if it
can be shown that objects orbit another planet like Jupiter,
why then should we assume that everything in the universe
orbits the Earth. Maybe instead, the Earth and the planets
(06:44):
all orbit the Sun, and moons orbit the planets, and
orbital pathways are a result of some deeper general principle
other than everything goes around the Earth. Now, technically, when
Galileo first spied the moons of Jupiter through his telescope,
at the very beginning, he thought that they were fixed stars.
Speaker 2 (07:03):
He thought he was.
Speaker 3 (07:04):
Looking at stars beyond Jupiter and marked their place. But
then he looked at Jupiter again later and the stars
were in a different arrangement, so he realized, like, oh,
those are not stars, those are something else in the foreground.
They're going around the planet. And when he first saw them,
he thought he saw three, not four, because he was
not able to distinguish Io and Europa. Europa being the
(07:26):
second innermost of the large moons, he was not able
to distinguish them as separate points of light. It was
only in later observations he realized that there were four
of them. Now, in terms of mass and volume, Io
is the third largest of Jupiter's moons, after Ganymede and Callisto,
and it is just slightly larger in diameter than Earth's Moon.
(07:48):
As the nearest of the Galilean moons to Jupiter, its
average orbital distance from the planet is four hundred and
twenty two thousand kilometers or two hundred and sixty two
thousand miles. Now, the fact that you might know which
really sets Io apart and is probably going to be
one of our main focuses in this series, is that
(08:09):
Io is the most volcanically active object in our solar system,
with hundreds of active volcanoes at any given time. I
think there are more than one hundred and fifty active
volcanoes that have been directly observed, and scientists have estimated
based on what we have observed, that there are probably
(08:29):
like four hundred or so in total on the surface. Now,
just earlier today, I was actually reading the story of
how the existence of those volcanoes on Io was first confirmed.
(08:50):
And this actually brings us back to the question of
the color, the color of the surface of the Moon,
which I brought up earlier, and where I was reading
about this was in Carl Sagan's book Cosmos, first published
in nineteen eighty, sort of as a companion to the
documentary series he did. Sagan was writing about Io in
(09:10):
that saying that the following was his favorite of what
he called the traveler's tales that were returned by the
voyager probe.
Speaker 2 (09:20):
Are you going to do the voice?
Speaker 3 (09:22):
I appreciate you putting me on the spot, but no,
I can't do the voice.
Speaker 1 (09:25):
No.
Speaker 2 (09:25):
Anytime I read Sagan, though, I hear it in his voice.
Speaker 3 (09:28):
Oh good, I know exactly what.
Speaker 2 (09:29):
Yeah.
Speaker 3 (09:30):
I hear it in the voice too. Yeah, but I can't. Okay,
So here it is in my voice, his words, my voice,
Sagan writes, quote, before voyager we were aware of something
strange about Io. We could resolve few features on its surface,
but we knew it was red, extremely read redder than Mars,
(09:50):
perhaps the reddest object in the Solar System. Over a
period of years, something seemed to be changing on it
in infrared light and perhaps in its radar reflection properties.
We also know that partially surrounding Jupiter in the orbital
position of Io was a great doughnut shaped tube of
atoms sulfur and sodium and potassium material somehow lost from Io.
(10:17):
Oh wow, what a mystery. Okay, so you know, we've
never gotten close enough to see what's happening on the surface,
but for some reason, it looks super red, redder than
anything else we can see around, and it's leaving this
trail of atoms in space, like it's just spitting out
atoms into orbit around Jupiter. And then the mystery only
gets weirder once the voyager probe actually approaches the Moon
(10:40):
and sends back images in nineteen seventy nine. What they
see is very strange. First of all, the surface is
multi colored, as we brought up earlier. If you see
what they call true color photos of Io, they are
often overwhelmingly yellow, like a I don't know, a canary
or a ban and I kind of yellow except I
(11:01):
don't know, maybe a little paler and more sickly, some
kind of vomitous duckling yellow with these blotches of red, pink, gray,
and green. I feel like this has too normative of
a connotation, but it really does always kind of remind
me of sickness in some way, not trying to say
io is a bad place. So one of the happier
(11:23):
comparisons that astronomers sometimes make about the different coloration patterns
is they call it a pizza planet. They're like, it's
got like cheese and pepperonis and olives and all that.
Speaker 2 (11:33):
Well that's a way to make it attractive, I guess.
But yeah, it does look like some sort of a
strange like nergal world.
Speaker 3 (11:39):
So yeah, yeah. Also, scientists looking at the images of
iosurface realized it was missing something impact craters due to
its position near the asteroid belt. Sagan writes that this
object really would have to have undergone repeated impacts from space,
(12:00):
should be hammered by asteroids, by things coming down on
it and leaving pocks in its surface that we would
be able to see, you know, just like look at
the Moon. It should maybe look something like that, but
instead its surface showed little to no sign of impacts,
as if something was rapidly erasing the evidence of collisions. Now,
(12:21):
whatever was doing that erasing could not be atmospheric in nature,
because Io has almost no atmosphere. It does have an atmosphere,
but it's incredibly thin, made primarily of sulfur dioxide. If
those surface features are being erased, they couldn't be erased
by erosion of running water because the conditions on the
surface of Io would not permit liquid water. So it
(12:44):
had been theorized by some astrophysicists. Segan names an astrophysicist
named Stanton Peel that Io might have erupting volcanoes due
to tidal heating of its interior. So this is a
frictional heating of the inside of the planet caused by
gravitational forces. We'll explain more about this as we go
(13:06):
on in the series. But that could lead to volcanic eruptions,
which could do the job of repaving the surface if
these volcanoes existed. But up until this point in nineteen
seventy nine, there was no way to know if any
of that was true. It was just an idea. That's
one thing that could be going on. Here then Sagan
tells of the discovery. He writes, quote Linda Moribto, a
(13:29):
member of the Voyager navigation team responsible for keeping Voyager
precisely on its trajectory, was routinely ordering a computer to
enhance an image of the edge of Io to bring
out the stars behind it. To her astonishment, she saw
a bright plume standing off in the darkness from the
satellite's surface, and soon determined that the plume was in
(13:53):
exactly the position of one of the suspected volcanoes. Voyager
had discovered, the first active volcano being on the Earth.
We now know of nine large volcanoes spewing out gas
and debris. Remember this was in nineteen eighty when this
book was written. Nine large volcanoes spewing out gas and debris,
and hundreds, perhaps thousands of extinct volcanoes on Io. The
(14:15):
debris rolling and flowing down the sides of the volcanic mountains,
arching in great jets over the polychrome landscape is more
than enough to cover the impact craters. We are looking
at a fresh planetary landscape, a surface newly hatched. How
Galileo and Huygens would have marveled now I love that
story for multiple reasons, one of which is the idea
(14:38):
that the plume from the volcano was spotted not by
somebody who was intentionally hunting four volcanoes, but in the
process of trying to better resolve navigation navigationally relevant data.
But I also love how it paints this picture of
Io as a place of a freshness of chain.
Speaker 2 (15:01):
Rob.
Speaker 3 (15:01):
I think we've talked about this on the show before
that often when we think of anything beyond Earth, things
in space, we tend to think of a kind of inert, changeless,
frozen or dead landscape, places where nothing all that interesting
ever really happens. Like what is interesting about the places
(15:24):
beyond Earth is kind of a I don't know, features
of permanent interest, just the way things are and have
always been and will always be. Obviously, we know that's
not true, and if you like fast forward the tape
of geologic time and cosmic time, things change a lot.
But just thinking about other planets and moons seems like
not a lot is happening there, and that is absolutely
(15:45):
not the case on the surface of Io. You know
he's talking Segan here is talking about Io as a
place where the surface changes on a timescale of months.
Speaker 2 (15:57):
It is a dynamic world.
Speaker 3 (15:59):
And so this leads to another thing he gets into
about the chemistry of Io and its volcanic activity, and
how this actually relates to the strange patterns of what
he called the polychrome surface, the different coloration patterns we
see on the surface. Sagan writes that this is actually
what we would expect to see from the release of
molten sulfur and the interactions of sulfur compounds from Io's
(16:23):
volcanoes and on the surface of the moon. So you
get like these black coloration at the hottest places where
the sulfur is just coming out, and maybe near the
top of the volcano or the mouth of the volcano,
and then nearby where there would be flows of what's
coming out of the volcanoes, you get something more like
red and orange. And then beyond that you get these
(16:44):
big empty planes that are just kind of like yellow,
yellowish sulfur. Now, on the subject of what is coming
out of the mouth of the volcanoes, or what might
be forming sort of lakes or rivers of flows beyond
beyond a volcano on Io, it's worth noting that materials
ejected from volcanoes tend to be very hot. That's true,
(17:06):
whether we're talking about Earth or Io. They can form
these searing lava flows. But a crazy fact that I
came across is that apparently lava flows on Io are
even hotter than lava flows on Earth. You know, I
might have just assumed that la lava is going to
be roughly the same temperature wherever it is. You know,
(17:28):
once it sort of reaches the surface, it's you know,
it's probably cooling off. I don't know, I don't know
why I would have thought that, but that's clearly wrong.
So I was reading about this in an August first,
two thousand and one press release from NASA JPL that
included an interview with a JPL volcanologist named doctor Rosalie Lopez,
(17:48):
and she says a number of really interesting things in
this little interview. One of them comes back to that
sort of designation that people have of Io as the
most volcanic body in the Solar System. She stresses that
this is not because Io has the most volcanoes, as in, like,
(18:09):
you count up all the volcanoes and it has the most.
Because I actually checked, this Earth has more volcanoes total.
Earth has more than Io does, but Earth is also larger.
Of course, the reason that scientists call Io the most
volcanic body in the Solar System is that its volcanoes
put out the most total heat. So it's the most
(18:31):
volcanic because it's a question of total energy released. Io
is only about one third the size of Earth, but
it puts out like double the heat of Earth from
its volcanoes. And Lopez notes that one single volcano on Io,
known as Loki, is more powerful than every volcano on
(18:52):
Earth put together. Now, another interesting part in this exchange
is that the interviewer asks Lopez whether the volcanoes on
Io would be similar to volcanoes on Earth. How would
they be similar? How would they be different? And Lopez says, quote,
the types of eruptions we've observed on Io are similar
to types of eruptions on Earth. Lava flows, calderas, fire
(19:14):
fountains like in Hawaii. But there are some very different aspects.
One is that lava on Io is much hotter than
any lava that flows on Earth today. Billions of years ago,
Earth had lava that hot. Another difference is that the calderas,
the volcanic craters on Io are much larger, than on Earth.
(19:36):
Lava flows are much larger too, and then she cites
a volcano on Io named Amirani that has a lava
flow going three hundred kilometers long or about one hundred
and ninety miles. She of course notes that that's longer
than any known lava flow on Earth, but I looked
up something to try to find a comparison. Three hundred
(19:57):
kilometers is roughly the distance from New York to Providence,
Rhode Island, So just imagine an active lava flow that long.
And then finally, in this answer, she notes that io
eruptions on Io produce like one hundred times as much
molten lava per year as eruptions on Earth. And that's
counting up all of the erupting volcanoes on Earth, even
(20:18):
the ones under the sea. So that's all amazing. I'm
especially fascinated by the idea that Earth used to have
hotter lava, Like we're kind of in decline and our
planets just like we can't put out lava like we
used to. But if you take all that together, think
about like the massive number of erupting volcanoes on Io,
(20:39):
how much heat they put out, and just like what
a in some ways boiling world. This is that might
paint a picture of a hothouse, a sort of planetary
hell world like Venus, but actually that would not be
accurate if you're trying to imagine what it's like on
the surface of Io. Because the apage surface temperature of
(21:01):
Io is extremely cold. Io has a very thin atmosphere,
extremely thin sulfur dioxide atmosphere, too thin to trap heat effectively,
and that's you know, one reason Venus is so hot.
It's it's because it's got a very thick atmosphere that
traps heat within the atmosphere. Io does not have that.
(21:22):
So while it's got these super you know, extremely hot
hot spots where the volcanoes are erupting or the lava
flows are taking place. You might have a lake of
lava that's you know, going to be incredibly hot. Most
of the Moon is very cold, with an average surface
temperature of negative one hundred and thirty degrees celsius or
negative two two fahrenheit, So astronomers sometimes call it a
(21:45):
like a world of fire and ice. It's a place
where you have these these gigantic, massive erupting volcanoes and
giant long lava flows, you know, going New York to Providence,
Rhode Island. But at the same time you'll have these
almost whimsic frisky ice world conditions. For example, I mentioned
the fact that Io has this very thin atmosphere of
(22:06):
mostly sulfur dioxide. Some of that sulfur dioxide comes directly
from volcanic eruptions venting screaming hot sulfur from below, but
the other half comes from the gradual evaporation or technically
sublimation of vast fields of sulfurous ice already on the
planet's surface. So there's a pattern that goes like this.
(22:29):
The volcanoes erupt and they shoot sulfur dioxide into the atmosphere.
It floats around. Then, once every forty two hours or so,
Io passes briefly into Jupiter's shadow, so it becomes eclipsed
and all sunlight is blocked, and this causes the surface
temperature to drop even further. It causes the Moon to
(22:50):
temporarily go into a deep cold cold enough to actually
cause the lower SO two atmosphere level to freeze and
fall to the surface. Then, when I emerges from its
eclipse and comes back into the sunlight, the frozen planes
of sulfur snow start to warm up and sublimate into
gas once again, which becomes part of the tenuous atmosphere.
(23:14):
So there's a lot more we'll have to get into
about the Moon, but just starting with this portrait, this
sketch here, I really would make the case for Io
as one of the most interesting places in the Solar System,
you know, beyond Earth, of one of the most challenging
and strange and dramatic and fascinating places in all of space.
Speaker 2 (23:35):
Absolutely. Yeah, the closer you look at it than the
more amazing details there are.
Speaker 3 (23:41):
Now, speaking of dramatic landscapes, I did want to mention
one more of the images that really got me interested
in doing the series of episodes. This one actually is
less a I think, less directly a photograph and more
kind of an image generated based on It was like
a three D image that's like an artist concept based
on data from Juno's Junokam instrument. So it's not just
(24:05):
made up like it is based on data they took
from the surface. But it's like a generated three D
image and it's of iOS steeple mountain that's worth looking
up at home, folks. It's this mountain that comes up
out of the surface like a blade. It's just like
so sharp, and then has the spires reaching up from
the top of it. And so if you look this up,
(24:28):
there are sort of animations you can find online where
the perspective goes around the mountain to sea from its
day side into its night side and shadow. And it's Oh,
it's very haunting, especially because it has a strong, lonely
mountain energy. It's not part of a mountain range. It's
just one giant blade of mountain raising up out of
(24:51):
an otherwise relatively flat plane.
Speaker 2 (24:54):
Yeah, with these two spires, one has the appearance of
being broken. Reminds me of the the horns of Golgadaath,
two horns coming up out of the ruined earth. So yeah,
it's pretty evocative.
Speaker 3 (25:08):
But Io is actually full of these strange and gorgeous
surface features, both the ones that rise and the ones
that sink.
Speaker 2 (25:16):
That's right. Another interesting feature is Boa Sali Monts. This
apparently stands as the tallest known peak on Io, standing
between seventeen point five kilometers that's ten point nine miles
and eighteen point two kilometers are eleven point three miles
in height. It is named for the cave where we'll
(25:39):
get into this. The Greek mythological figure Io is said
to have given birth to her son. We'll get into
all that in a bit. And Boa salle means cowpin
will also get into what that means how cows feature
into this mythology. But it is the third tallest known
mountain ridge in our soul system, behind only Olympus monds
(26:04):
on Mars, which is the tallest, and the equatorial ridge
on the Saturn nine moon Iapetus.
Speaker 3 (26:11):
Oh yeah, the big spine in the middle of the Appetus.
That was good.
Speaker 2 (26:16):
Let's see there are a number There are a number
of other mountains mountains. The mountains on Io have all
sorts of names, some related, some related to Dante's Inferno,
some related to other mythological traditions. But there are at
least four other ones that have names that are related
to the myth of Io that will get into in
a bit. There's Argos Planum, named for the land of
(26:40):
Io's father. There's Epaphus Mensa, named for Io's son, There's
Hermes Mensa. You'll find out how Hermes factors into everything,
and then there's Innachius Tholus, name for Io's father. Now,
you mentioned Loki earlier. This is an of course, the
(27:01):
namesake is the Norse god Loki, and rather than a mountain,
it is, of course a great volcanic depression with a
lake of magma in it. This is a Loki patera.
As described by the JPL website, this is one hundred
and twenty four mile long or two hundred kilometer long
lake filled with magna, rimmed with hot lava, and dotted
(27:23):
with islands, but with one like huge island in the
middle of it. And they stress on the JPL website
that this large island in the lake does not have
a name, which I think only intensifies the feeling that
either a it does have some sort of name and
you just can't say it, or that there is some
sort of unholy castle there. You know, the island in
(27:47):
the lake of magma that cannot be named.
Speaker 3 (27:49):
Do not ask after its name, for it has none.
Speaker 2 (27:52):
Yeah, but if they're looking for a name, I'm thinking, well, okay,
if the area is named for Loki and it's within Loki,
will name it after one of the monsters that Loki
gives birth to. I mean, you have, like I think,
four good ones to choose from there's Hell, there's yormagand
there's fin Rear, and there's slept Near. But hey, I'm
no astronomer. Those names may be taken already now. They
(28:12):
also add that there were reflective aspects to the Loki
Petera during the Juno flyover, suggesting that its surface was
as smooth as glass. Now, perhaps smooth as glass in
these passes, but also food for thought. There's a previous
twenty seventeen analysis that turned up infrared data that suggested
(28:35):
that the temperature of the lava lake steadily increased from
one end to the other, suggesting overturning waves. Overturning lava
is a popular explanation for fluctuations in the Moon's apparent brightness,
with brightenings occurring every four hundred to six hundred days.
Another explanation is that it's due to just regular volcanic
eruptions that spike the brightness of the Moon.
Speaker 3 (28:58):
I wonder if that's related to different from what Sagan
brought up about the changes in like the radar reflectivity
of the of the moon over time.
Speaker 2 (29:06):
I think it's related. That's my understanding, and I am
for you, Joe. Others can look this up as of publication.
It's certainly on the JPL website. You can see a
computer generated image of what this lake would look like,
and it's this is from like a short computer animated
video that kind of like zooms in on it, and
(29:28):
it's it's I like this image because it's it's maybe
not one hundred percent blockbuster CGI. It feels a little
you know, mind's eye to me. And also the magma
in the lake has the coloration of like deep crimson blood,
which of course only intensifies the the unholy qualities of
(29:48):
this place. This is just fitting.
Speaker 3 (29:50):
Something seems very beyond the mind's eye about Io. It's
a place where if I went there, I would expect
to be seeing like you know, those nude early nineties
CGI figure is kind embracing and then melting into each
other and then turning into bats.
Speaker 2 (30:03):
Yeah. All to a nice Jon Hammer soundtrack for sure,
too far? Take it easy, all right? Well, shall we
get into the mythology of Io a bit? Oh?
Speaker 3 (30:23):
Absolutely?
Speaker 2 (30:24):
Now, we mentioned already about the discovery of Jupiter's moon Io,
and we mentioned the discovery sixteen to ten by Italian
astronomer or Galileo. However, there is also a case to
be made, and it was made by him, specifically that
German astronomer Simon Marius discovered it independently or instead of depending.
(30:48):
He's making the argument.
Speaker 3 (30:49):
I think I've read that it was said like they
probably discovered it around the same time.
Speaker 2 (30:54):
Yeah, yeah, but Marius is often credited with naming the
moon after the Greek mythological your Io, who is fittingly
associated with Zeus aka Jupiter in Roman traditions. Now, if
you're not familiar with Simon Marius, do look. Do go
to the Wikipedia page about him, if nothing else, just
(31:15):
to see this wonderful illustration of the man. This is
an engraving of Marius in his own book Mundus Lovialis
the World of Jupiter from sixteen fourteen. He looks like
a dashing necromancer in this shot.
Speaker 3 (31:31):
Yes, yes, warlock, infernal packed warlock. Actually, though he looks
a bit this is gonna sound funny. He looks a
bit like Galileo. Yeah, he's got a similar kind of face,
a similar kind of eyes and scowl, and a similar beard.
He's like warlock Galileo.
Speaker 2 (31:50):
Look at that collar though, such an amazing collar packed
of the lens. All right, So what is the myth
of Io. Well, the basic story, as it is usually told,
is as follows. Io was the mortal daughter of Anachus,
the river god of Argos, and the oceanid Melia, herself
the daughter of the Titans Oceanus and Tethys. The exact
(32:13):
number varies, but Io had many sisters, and Anachus also
is also referenced in mythology as the first king of Argos,
which is an ancient city in Greece. So the story
goes that Io served as the high priestess of Hera,
who is of course the wife of the high king
of the god Zeus. But the king of the gods
(32:37):
was of course ever lustful, to put it mildly, and
soon came to desire Io. Now the story the tellings
of this tale vary, but at the very least he
became enamored with her, and some accounts describe his feelings
for her as love. Avid in the Metamorphosis describes the
encounter in more threatening and ultimately violent terms. I'm going
(32:58):
to read from the Henry t Riley translation. Jupiter had
seen Io as she was returning from her father's stream,
and had said, O maid worthy of Jove and destined
to make I know not whom happy in thy marriage,
repair to the shades of this lofty grove. And he
pointed at the shade of the grove, while it is warm,
and while the sun is at his height, in the
(33:20):
midst of his course. But if thou art afraid to
enter the lonely abodes of the wild beasts alone, thou
shalt enter the recesses of the groves, safe under the
protection of a god, and that a god of no
common sort. But with me, who hold the scepter of
heaven in my powerful hand, me who hurl the wandering lightnings,
(33:42):
do not fly from me. For now she was flying,
and now she had left behind the pastures of Lerna
and the Lsayan plains planted with trees, when the God
covered the earth far and wide with darkness overspreading, and
arrested her flight and forced her modesty. So to be clear,
what Avid is describing here is supernatural pursuit and sexual assault.
Speaker 3 (34:04):
Yeah, from what I've read, I think some versions of
the story describe it as a kind of seduction. Other
versions describe it as a rape. In this version, I mean,
either way, we're seeing something that we see a lot
of Zeus doing in Greek mythology.
Speaker 2 (34:19):
Yeah, yeah, and again it does vary with the tellings.
I believe there's at least one version where he ultimately
impregnates her by just touching her with his hand. So,
as is generally the case, there's no real canon with mythology.
There are just the more popularized versions of the tale,
and sometimes those are very much connected to Avid's work
in the Metamorphosis. So after this has occurred, Zeus transforms
(34:44):
Io into a cow, a white heifer, in order to
hide her and his own transgressions from his wife Harah,
because of course, of course, Harah is too wise for
any of this, and she knows her husband too well,
so she almost immediately shows up and begins asking qu
questions about this beautiful white cow that Zeus is suddenly
hanging out with, and Ovid writes quote, Jupiter falsely asserts
(35:08):
that it was produced out of the earth and that
the owner may cease to be inquired after which, despite
the horror of the situation setting this up, this line
has a certain dry comedy to it, and I wonder
if that was at present in the original writing, or
if this is like an artifact of translation.
Speaker 3 (35:23):
I read that same line that it was produced out
of the earth. Yeah, this cow just kind of grew
out of the ground. That happens sometimes, so he's trying
to get out of it.
Speaker 2 (35:33):
But Hara, she knows what's up, and so she requests
this beautiful cow as a gift, and Zeus has no
choice but to comply, because if he says no, well
then he's admitting that this is no mere cow. And
if he just gives it up, well then you know,
they both know what's going on here. And so he
gives the cow up to Hara, and Harah entrusts the
(35:54):
white effort to the protection of the one hundred eyed
giant Argos panoptis, the all seeing and there are different
depictions of what Argus looks like. Sometimes he's depicted as
a giant with eyes all over his body. Other times
he's depicted as a humanoid or you know, with no
special features, or as a humanoid with a bunch of
(36:16):
eyes on or in his head, and in either event,
not to be confused with Argos. The place that we
mentioned earlier, this is Argus. So the basic idea is
Zeus cannot come and get his cow back at this
point because there is an all seeing giant that is
watching it at all the time. Sitting on the top
(36:37):
of a mountain, he can see in all directions at once.
Nothing is getting past him. And yes, Zeus is king
of the gods. But I think the idea is that, yes,
Zeus is all powerful, but if he actually shows up
to claim the white heffer, then the gig is up
and he is almost has to admit defeat.
Speaker 3 (36:56):
Yeah, Haro will find out exactly now.
Speaker 2 (37:00):
Now, in the midst of all this, it is said
that Io is suffering the metamorphosis here is quite miserable
the way Ava describes it. She has to live as
an animal, not mistreated by the all seeing giant, but
also not well loved either, making matters all the more traumatic.
When she wanders close to the water, which is described
(37:21):
as the water off her father, her own father and
her various sisters do not recognize her, at least not
at first. They see only the white heifer, and eventually
her father recognizes her and its heartbreaking. And there are
numerous paintings that explore this scene with like an old
(37:41):
man having this heart breaking encounter with a white cow. Oh.
Speaker 3 (37:46):
Yeah, so I was trying to tell if that was
one of the things depicted in there's a painting of
the second half of this myth that I put in
our outline by Bartolomeo di Giovanni, who is an Italian
painter like the end of the fifteenth century. This painting
is called the Myth of Io, and it's showing a
bunch of different scenes from it, though we really do
(38:08):
not get much of a hundred eyed giant in this. Instead,
Argust just looks like he's like a shepherd.
Speaker 2 (38:14):
Yeah. Sometimes he's just a dude. Other times he's this
like weird psychedelic giant with eyes all over his body.
So it just varies.
Speaker 3 (38:21):
But we do see the heifer at various places, at
one point near the water's edge, so I can't tell
if that's the part of the myth that's being depicted here.
Speaker 2 (38:29):
This story of like transformation and loved ones not recognized
you recognizing you in your transformed state reminds me of
a children's book that came out in nineteen sixty nine
called Sylvester and the Magic Pebble. Are you familiar with
this one? Joe?
Speaker 3 (38:45):
Sounds vaguely familiar, but we don't like read this one
in the house.
Speaker 2 (38:48):
So okay, well, you might have picked up at some
point because it's heartbreaking as well. It has a magical
transformation and parents not recognizing their own child in a
transformed state. But it's a great book. Well, you know,
won a number of awards, won the Calvacott Metal back
in nineteen seventy.
Speaker 3 (39:06):
I'll look it up. But okay, so we're in a
really sad place in the middle of this myth, right right, I.
Speaker 2 (39:12):
Was in a terrible place Zeus. Sometimes it's described as
if he finds this heart breaking as well, but at
the very least he tires of being controlled. And what
does he do? Well, he can't show himself, apparently, so
he sends Hermes to simply.
Speaker 3 (39:29):
Murder Argus Mercury the hit man here.
Speaker 2 (39:33):
Yes, yes, the harbinger of the gods here, the messenger
of the gods this time shows up with his Caduceius
to put the giant to sleep and then slays him
with the sword and the eyes of Argus then go
to the tail of the peacock, a symbol of Hara. Oh.
Speaker 3 (39:49):
Interesting.
Speaker 2 (39:50):
Now at this point the white effer can wander free,
and Harrah sends a gadfly to torment her gadflies are
li stock biting flies, probably horseflies or bot flies, but
in Greek mythology they're sometimes employed by the gods elsewhere.
Zeus was once said to send one to sting Pegasus.
At one point. This was while Balerifan was riding Pegasus,
(40:15):
so caused him to fall out of the sky. But
don't worry. Athena then softened his fall. So anyway, Io,
in the form of the white cow, basically wanders driven
by flies sent by the gods, and eventually she is
driven to Egypt, where she resumes her human form and
(40:36):
gives birth to a son of Zeus in a cave.
We mentioned that earlier, and this is Epaphus, who becomes
king of Egypt, and it said founds the city of Memphis.
Avid also mentions that Io went on to marry none
other than APIs or Osiris, who after his death was
numbered among the deities of Egypt by the name Serapis. Oh.
Speaker 3 (40:59):
Interesting, Yeah, for those not aware, we did serious episodes
on the Egyptian deity Osiris. When was this like last
year or the.
Speaker 2 (41:08):
Year before, Yes, sometime in the last couple of years. Yeah,
And we talked about Si Rapist as a Greco Egyptian
Syncretic deity based on both of Cyrus and APIs, as
well as aspects of various other Greek deities. Under Potomaic rule,
Avid writes Io terrified and madden with dreadful visions, runs
(41:30):
over many regions and stops in Egypt when Juno, at
length being pacified, restores her to her former shape and
permits her to be worshiped there under the name of Isis. Wow.
Speaker 3 (41:40):
Well, that is a fascinating cross cultural backstory, though not
to imply that the same backstory would actually be understood
by the people who worshiped Isis in Egypt.
Speaker 2 (41:51):
Right, right, though, of course, the worship of Isis like
spreads out of Egypt, and then you know how they're
worshiping Isis in other areas, such as in Greek and
Roman times. Yeah, maybe they employ some of this, but yeah,
at this point in our telling of the myth of Io,
we can appreciate that we're talking about something that is
probably a Greek and Roman take on the Egyptian throne
(42:13):
goddess Isis, mother of every Egyptian king. It's worth noting
that elsewhere in Greek tradition, Isis is also associated with Demeter.
In either case, the popularity of Isis in Egypt spreads
over into Greek mythology here. Yeah, Now it can be
a little confusing though, because I was looking at other
artistic depictions of Io, and there's one that from the
(42:36):
first century BCE. It's a fresco from the Temple of
Isis in POMPEII that depicts Io being received by Isis
upon her arrival in Egypt. And if you can see
an image of it here Joe in our notes in
this Io actually has the horns of a cow as well.
Speaker 3 (42:54):
Yeah, I mean that may not square in some ways
with what we just talked about it, but that seems
to me perfectly consistent with the sort of shuffling mix
and match quality of ancient mythology.
Speaker 2 (43:06):
Yeah. In Egyptomania a History of Fascination, Obsession, and Fantasy
by Ronald H. Fritz. This is the book I've cited
on the show before. The author points to the myth
of Io is one of several examples of contact and
cultural exchange between Greece and Egypt during the era of
the New Kingdom. This was between the sixteenth century BC
(43:28):
in the eleventh century BCE. You know, they're fairly difficult
travel between the two regions at the time, but there
was still cultural exchange and other sorts of exchange as
well well.
Speaker 3 (43:41):
So it's an emotionally powerful myth with interesting cross cultural relevance.
But this does bring me back to the question of like,
how does it fit into the planet Jupiter and its moons?
How do we get from there to hear well?
Speaker 2 (43:56):
Most likely most of it does come down to just
the Jupiter Zeus association. Marius's choice in naming it Io
was apparently based on a sixteen thirteen suggestion by Johannes
Kepler that the Jovian moons all be named for the
lovers of Zeus, but it's also worth stressing that there
was apparently there's a connection to be made between mythic
(44:18):
Io and Earth's own moon, so she has seemingly has
lunar qualities all her own anyway. According to classicist Peter T.
Struck in his online Pin State Classics Dictionary, Io is
the wanderer and is generally explained as a moon goddess
wandering in the starry heavens. These heavens symbolized by Argus's
(44:41):
one hundred shining eyes and then her transformation into a
horned heifer represents nothing other than the crescent moon.
Speaker 3 (44:50):
Oh interesting.
Speaker 2 (44:51):
Yeah, so yeah, the more you look at it, like,
the myth of Io is ultimately fairly complicated because you
have all these different, you know, cross culture exchanges bound
up in it. There's the lunar aspect of it, as
well as you know, some of these aspects of the
story that can be troubling and confounding, especially to modern
readers that are learning about it, you know, across the
(45:16):
thousands of years of history. All right, on that note,
we're gonna go ahead and close up this episode of
Stuff to Blow Your Mind, but we're going to be
back in a part two on the Moon of Io.
We'll get into some more curious details about the moon
in that episode. In the meantime, we'd like to remind
(45:37):
you all this Stuff to Blow Your Mind is primarily
a science and culture podcast, with core episodes on Tuesdays
and Thursdays, short form episodes on Wednesdays and on Fridays.
We set aside most serious concerns to just talk about
a weird film on Weird House Cinema.
Speaker 3 (45:50):
Huge thanks as always to our excellent audio producer JJ Posway.
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 stuff to Blow your
Mind dot com.
Speaker 1 (46:12):
Stuff to Blow Your Mind is production of iHeartRadio. For
more podcasts from iHeartRadio, visit the iHeartRadio app, Apple Podcasts,
or wherever you're listening to your favorite shows.
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Robert Lamb
Joe McCormick
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