January 31, 2026 • 47 mins
In this classic 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. (part 1 of 3) (originally published 2/6/2025)
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Speaker 1 (00:06):
Hey, you welcome to Stuff to Blow your Mind. My
name is Robert Lamb. Today is Saturday, so we have
a rerun for you. This is going to be The
Burning Mountains of Io Part one. This was a three
part series that we did getting into another one of
the fabulous Jovian moons. This originally published two six, twenty
(00:26):
twenty five. Let's jump right.
Speaker 2 (00:28):
In Welcome to Stuff to Blow Your Mind production of iHeartRadio.
Speaker 1 (00:42):
Hey are you welcome to Stuff to Blow your Mind?
My name is Robert.
Speaker 3 (00:44):
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
(01:05):
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
(01:27):
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 1 (01:42):
All right, let's do it.
Speaker 3 (01:44):
So 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 NASA JPL based on
data taken by the Juno spacecraft, with some additional image
(02:06):
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 can't look
(02:27):
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, a kind of pale,
(02:51):
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 containing silent, cold
(03:13):
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, a kind of mass of yellow orange slime, mold,
shaped just like pure chaos, just reaching its fingers out
(03:37):
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, frightening and see with drama.
Speaker 1 (04:02):
Yeah, absolutely this image. It looks like perhaps the pinkish
disease scalp of a zombie.
Speaker 3 (04:09):
It.
Speaker 1 (04:09):
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 (04:21):
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 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
(04:43):
that is what it looks like. It looks infected. It
looks infected 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
(05:04):
come back and go deep on this moon. That's why
we're here today.
Speaker 1 (05:08):
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 (05:24):
Yeah, knowing the mythology definitely does enliven and kind of
throw interesting 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 Galileian moons. These are the
(05:47):
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,
(06:09):
than 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.
(06:31):
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, out
in the Solar System, but it was an important moment
in the history of science because it was one of
(06:52):
many 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
(07:13):
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.
He thought he was looking at stars beyond Jupiter and
(07:35):
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 second innermost of the large moons,
(07:57):
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. As the nearest of the
(08:19):
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 Io is the most volcanically
(08:41):
active object in our Solar system, with hundreds of active
volcanoes at any given time. I think there are more
than 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 like four
hundred or so in total on the surface. Now. Just
(09:12):
earlier today, I was actually reading the story of how
the existence of those volcanoes on Io was first confirmed,
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
(09:32):
in nineteen eighty, sort of as a companion to the
documentary series he did. Sagan was writing about Io in
that saying that the following was his favorite of what
he called the traveler's tales that were returned by the
voyager probe.
Speaker 1 (09:49):
Are you going to do the voice?
Speaker 3 (09:51):
I appreciate you putting me on the spot, but no,
I can't do the voice.
Speaker 1 (09:54):
No, anytime I read Segan, though, I hear it in
his voice.
Speaker 3 (09:57):
Oh god, I know exactly what. Yeah, I hear it
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 red, redder than Mars,
(10:19):
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.
(10:47):
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
(11:09):
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 banana kind of yellow, except I don't know,
(11:31):
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 play. So one of the happier
(11:53):
comparisons that astronomers sometimes make about the different coloration patterns
is they call it a pizza planet. They're like, like
cheese and pepperonis and olives and all that.
Speaker 1 (12:03):
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 (12:09):
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.
(12:29):
It should be hammered by asteroids by you know, 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, whatever was doing that erasing could
(12:52):
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 had been theorized by some astrophysicists.
(13:17):
Sagan 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 on in the series. But that
(13:38):
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 Morabito, a member of the Voyage navigation team
(14:01):
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
(14:21):
the plume was in exactly the position of one of
the suspected volcanoes. Voyager had discovered the first active volcano
beyond 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
(14:43):
volcanoes on Io. The 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.
(15:04):
I love that story for multiple reasons, one of which
is the idea that the plume from the volcano was
spotted not by somebody who was intentionally hunting for 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
(15:28):
of change. Rob. 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
(15:52):
is interesting about the places beyond Earth is kind of
a I don't know, features of permanent interest, just the
way things are and have all been and will always
be Obviously, we know that's not true. And if you
like fast forward the tape of geologic time cosmic time,
things change a lot. But just thinking about other planets
and moons seems like not a lot is happening there,
(16:13):
and that is absolutely not the case on the surface
of Io. You know he's talking. Sagan here is talking
about Io as a place where the surface changes on
a timescale of months.
Speaker 1 (16:26):
It is a dynamic world.
Speaker 3 (16:28):
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's sulfur and the interactions of sulfur compounds from Io's
(16:52):
volcanoes and on the surface of the moon. So you
get like these, you know, 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
(17:13):
get these 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.
(17:35):
That's true, 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 lava lava is going
(17:55):
to be roughly the same temperature wherever it is. You know,
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,
(18:18):
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,
(18:38):
like 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
(19:00):
it's the most 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
(19:20):
than every volcano on 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
(19:41):
on Earth lava flows, calderas, fire 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 different is that the calderas the
(20:01):
volcanic craters on Io are much larger than on Earth.
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
(20:24):
something to try to find a comparison. Three hundred 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
(20:45):
up all of the erupting volcanoes on Earth, even 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. Our planet's just like
we can't put out like we used to. But if
you take all that together, think about like the massive
(21:06):
number of erupting volcanoes on Io, 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 hot house, 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,
(21:28):
because the average surface temperature of 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.
(21:50):
Io does not have that. 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 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
(22:14):
call it a like a world of fire and ice.
It's a place where you have 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 whimsically frisky ice world conditions. For example,
I mentioned the fact that Io has this very thin
(22:35):
atmosphere of 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
(22:55):
the planet's surface. So there's a pattern that goes like this.
The volcano 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
(23:17):
temperature to drop even further. It causes the Moon to
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 Io emerges from its
eclipse and comes back into the sunlight, the frozen planes
of sulfur snow start to warm up and sublimate into
(23:39):
gas once again, which becomes part of the tenuous atmosphere.
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, one of the most challenging and
(24:00):
range and dramatic and fascinating places in all of space.
Speaker 1 (24:05):
Absolutely yeah, the closer you look at it than the
more amazing details there are.
Speaker 3 (24:11):
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,
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's concept based on data
(24:31):
from Juno's Juno CAAM instrument, So it's not just 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
(24:54):
top of it. And so if you look this up,
there are sort of animation 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
(25:17):
just one giant blade of mountain raising up out of
an otherwise relatively flat plane.
Speaker 1 (25:23):
Yeah, with these two spires, one has the appearance of
being broken. Reminds me of the horns of Golgataath, two
horns coming up out of the ruined earth. So yeah,
it's pretty evocative.
Speaker 3 (25:38):
But Io is actually full of these strange and gorgeous
surface features both the ones that rise and the ones
that sink.
Speaker 1 (25:45):
That's right. Another interesting feature is Boa sally monts. This
apparently stands as the tallest known peak on Io, standing
between seventeen point five kilometers that's ten point nine mile
and eighteen point two kilometers are eleven point three miles
in height. It is named for the cave where the
(26:09):
we'll 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 this mythology. But it is the third tallest
known mountain ridge in our solar system, behind only Olympus
(26:33):
Monds on Mars, which is the tallest, and the equatorial
ridge on the Saturn nine moon Iapetus.
Speaker 3 (26:40):
Oh yeah, the big spine in the middle of the Appetus.
That was good.
Speaker 1 (26:45):
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
(27:10):
Io's father. There's Epaphus Mensa named for Io's son, there's
Hermes Mensa. You'll find out how Hermei's factors into everything.
And then there's an Anachius Tholus, name for Io's father.
Now you mentioned Loki earlier. This is, of course the
(27:30):
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 ptera.
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
(27:52):
with islands, but with one 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
(28:13):
unholy castle there. You know, the island in the lake
of magma that cannot be named.
Speaker 3 (28:19):
Do not ask after its name, for it has none.
Speaker 1 (28:21):
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 finn Rear, and there's slept Near. But hey, I'm
no astronomer. Those names may be taken already now. They
(28:42):
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 was a
previous twenty seventeen analysis that turned up infrared data that
(29:04):
suggested 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 you know, spike the brightness of
(29:26):
the moon.
Speaker 3 (29:28):
I wonder if that's related to or different from what
Sagan brought up about the changes in like the radar
reflectivity of the of the moon over time.
Speaker 1 (29:36):
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 this is from like a short computer animated video
that kind of like zooms in on it. And it's
(29:59):
I like this image because it's it's maybe not one
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 this place.
Speaker 3 (30:19):
This is just fitting 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 figures kind of embracing and then
melting into each other and then turning into bats.
Speaker 1 (30:33):
Yeah, all to a nice Yon Hammer soundtrack for sure,
too far, take it easy, all right, Well, shall we
get into the mythology.
Speaker 3 (30:51):
Of Io a bit? Oh? Absolutely.
Speaker 1 (30:54):
Now, we mentioned already about the discovery of Jupiter's moon Io,
and we we mentioned the discovery sixteen 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
(31:17):
depending on he's making the argument.
Speaker 3 (31:19):
I think I've read that it was said like they
probably discovered it around the same time.
Speaker 1 (31:23):
Yeah, yeah, But Marius is often credited with naming the
moon after the Greek mythological figure 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
(31:45):
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 Necroman there in this shot.
Speaker 3 (32:01):
Yes, yes, Warlock infernal pack to 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 1 (32:20):
Look at that collar though, such an amazing.
Speaker 3 (32:21):
Collar packed of the lens.
Speaker 1 (32:23):
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 number varies, but
(32:44):
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 was of
(33:06):
course ever lustful, to put it mildly, and soon came
to desire Io. Now thet 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 to read from the
(33:28):
Henry t Riley translation. Jupiter had seen Io as she
was returning from her father's stream, and had said, Oh, 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
(33:48):
is at his height, in the 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 grove's 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,
(34:08):
me who hurl the wandering lightnings, do not fly from me.
For now she was flying, and now she had left
behind the pastures of Lerna and the Lursaan, planes 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
(34:30):
here is supernatural pursuit and sexual assault.
Speaker 3 (34:34):
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. Yeah.
Speaker 1 (34:49):
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 c cannon 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
(35:13):
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, Hara is too wise for any
of this, and she knows her husband too well, so
she almost immediately shows up and begins asking questions about
this beautiful white cow that Zeus is suddenly hanging out with.
(35:34):
And Ovid writes, quote Jupiter falsely asserts 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 (35:52):
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.
Speaker 1 (36:01):
So he's trying to get out of it. 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
(36:21):
cow up to Hara, and Harah entrusts the White effort
to the protection of the one hundred eyed giant Argos
Panopties 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 with no special features, or as
(36:44):
a humanoid with a bunch of eyes on or in
his head. 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 all the time. Sitting
(37:06):
on the top 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 heifer, then
the gig is up and he is almost has to
admit defeat.
Speaker 3 (37:25):
Yeah, Harrow will find out exactly now.
Speaker 1 (37:29):
In the midst of all this, it is said that
that Io is suffering the metamorphosis here is quite miserable.
The way av 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
(37:50):
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 it's heartbreaking. And there are
numerous paintings that explore this scene with like an old
(38:11):
man having this this heart breaking encounter with a white cow.
Speaker 2 (38:16):
Oh.
Speaker 3 (38:16):
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 was 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
(38:37):
not get much of a hundred eyed giant in this. Instead,
Argust just looks like he's like a shepherd.
Speaker 1 (38:43):
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 (38:51):
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 1 (38:59):
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?
Speaker 3 (39:12):
Joe sounds vaguely familiar, But we don't like read this
one in the house.
Speaker 1 (39:18):
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 Caldocott Metal back
in nineteen seventy.
Speaker 3 (39:36):
I'll look it up. But okay, so we're in a
really sad place in the middle of this myth.
Speaker 1 (39:40):
Right right, I was in a terrible place Zeus Sometimes
it's described as if he finds this heartbreaking 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 murder.
Speaker 3 (39:59):
Argus Mercury the hit man here.
Speaker 1 (40:02):
Yes, yes, the harbinger of the gods ere 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 (40:19):
Interesting.
Speaker 1 (40:20):
Now, at this point, the white effer can wander free,
and Harra sends a gadfly to torment her. Gadflies are
livestock biting flies, probably horse flies 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 Balerafin was riding Pegasus,
(40:44):
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
(41:05):
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 (41:28):
Interesting, Yeah, for those not aware, we did serious of
episodes on the Egyptian deity Osiris. When was this like
last year or the year.
Speaker 1 (41:38):
Before, Yes, sometime in the last couple of years. Yeah,
And we talked about Siapis 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 maddened with dreadful visions, runs
(41:59):
over me any 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.
Speaker 3 (42:09):
Wow. 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 1 (42:20):
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. Well again, maybe they employ some of this,
but yeah, at this point in our telling of the
myth of ioh we can appreciate that we're talking about
something that is probably a Greek and Roman take on
(42:41):
the Egyptian throne 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 other artistic depictions of Io, and there's one
(43:04):
that from the 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 (43:24):
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 1 (43:36):
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
(43:57):
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 (44:11):
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 moon,
how do we get from there?
Speaker 1 (44:25):
To hear well, 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
(44:46):
made between mythic 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
(45:08):
heavens symbolized by Argus's one hundred shining eyes, and then
her transformation into a horned heifer represents nothing other than
the crescent moon. Oh interesting, Yeah, so yeah, the more
you look at it, like, the myth of Io is
is ultimately fairly complicated because you have all these different,
(45:28):
you know, cross cultural 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 thousands of years of history.
All Right, on that note, we're gonna go ahead and
(45:49):
close up this episode of stuff to blow your mind,
but we're gonna be back in a part two on
the Moon of Io. We'll get into some more cure
curious details about the moon in that episode. In the meantime,
we'd like to remind you all this Stuff to Blow
Your Mind is primarily a science and culture podcast, with
(46:10):
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 (46:19):
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 2 (46:41):
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.
Speaker 1 (47:00):
West West d d RAT
Hey, you welcome to Stuff to Blow your Mind. My
name is Robert Lamb. Today is Saturday, so we have
a rerun for you. This is going to be The
Burning Mountains of Io Part one. This was a three
part series that we did getting into another one of
the fabulous Jovian moons. This originally published two six, twenty
(00:26):
twenty five. Let's jump right.
Speaker 2 (00:28):
In Welcome to Stuff to Blow Your Mind production of iHeartRadio.
Speaker 1 (00:42):
Hey are you welcome to Stuff to Blow your Mind?
My name is Robert.
Speaker 3 (00:44):
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
(01:05):
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
(01:27):
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 1 (01:42):
All right, let's do it.
Speaker 3 (01:44):
So 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 NASA JPL based on
data taken by the Juno spacecraft, with some additional image
(02:06):
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 can't look
(02:27):
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, a kind of pale,
(02:51):
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 containing silent, cold
(03:13):
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, a kind of mass of yellow orange slime, mold,
shaped just like pure chaos, just reaching its fingers out
(03:37):
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, frightening and see with drama.
Speaker 1 (04:02):
Yeah, absolutely this image. It looks like perhaps the pinkish
disease scalp of a zombie.
Speaker 3 (04:09):
It.
Speaker 1 (04:09):
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 (04:21):
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 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
(04:43):
that is what it looks like. It looks infected. It
looks infected 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
(05:04):
come back and go deep on this moon. That's why
we're here today.
Speaker 1 (05:08):
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 (05:24):
Yeah, knowing the mythology definitely does enliven and kind of
throw interesting 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 Galileian moons. These are the
(05:47):
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,
(06:09):
than 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.
(06:31):
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, out
in the Solar System, but it was an important moment
in the history of science because it was one of
(06:52):
many 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
(07:13):
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.
He thought he was looking at stars beyond Jupiter and
(07:35):
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 second innermost of the large moons,
(07:57):
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. As the nearest of the
(08:19):
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 Io is the most volcanically
(08:41):
active object in our Solar system, with hundreds of active
volcanoes at any given time. I think there are more
than 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 like four
hundred or so in total on the surface. Now. Just
(09:12):
earlier today, I was actually reading the story of how
the existence of those volcanoes on Io was first confirmed,
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
(09:32):
in nineteen eighty, sort of as a companion to the
documentary series he did. Sagan was writing about Io in
that saying that the following was his favorite of what
he called the traveler's tales that were returned by the
voyager probe.
Speaker 1 (09:49):
Are you going to do the voice?
Speaker 3 (09:51):
I appreciate you putting me on the spot, but no,
I can't do the voice.
Speaker 1 (09:54):
No, anytime I read Segan, though, I hear it in
his voice.
Speaker 3 (09:57):
Oh god, I know exactly what. Yeah, I hear it
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 red, redder than Mars,
(10:19):
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.
(10:47):
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
(11:09):
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 banana kind of yellow, except I don't know,
(11:31):
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 play. So one of the happier
(11:53):
comparisons that astronomers sometimes make about the different coloration patterns
is they call it a pizza planet. They're like, like
cheese and pepperonis and olives and all that.
Speaker 1 (12:03):
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 (12:09):
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.
(12:29):
It should be hammered by asteroids by you know, 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, whatever was doing that erasing could
(12:52):
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 had been theorized by some astrophysicists.
(13:17):
Sagan 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 on in the series. But that
(13:38):
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 Morabito, a member of the Voyage navigation team
(14:01):
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
(14:21):
the plume was in exactly the position of one of
the suspected volcanoes. Voyager had discovered the first active volcano
beyond 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
(14:43):
volcanoes on Io. The 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.
(15:04):
I love that story for multiple reasons, one of which
is the idea that the plume from the volcano was
spotted not by somebody who was intentionally hunting for 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
(15:28):
of change. Rob. 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
(15:52):
is interesting about the places beyond Earth is kind of
a I don't know, features of permanent interest, just the
way things are and have all been and will always
be Obviously, we know that's not true. And if you
like fast forward the tape of geologic time cosmic time,
things change a lot. But just thinking about other planets
and moons seems like not a lot is happening there,
(16:13):
and that is absolutely not the case on the surface
of Io. You know he's talking. Sagan here is talking
about Io as a place where the surface changes on
a timescale of months.
Speaker 1 (16:26):
It is a dynamic world.
Speaker 3 (16:28):
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's sulfur and the interactions of sulfur compounds from Io's
(16:52):
volcanoes and on the surface of the moon. So you
get like these, you know, 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
(17:13):
get these 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.
(17:35):
That's true, 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 lava lava is going
(17:55):
to be roughly the same temperature wherever it is. You know,
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,
(18:18):
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,
(18:38):
like 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
(19:00):
it's the most 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
(19:20):
than every volcano on 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
(19:41):
on Earth lava flows, calderas, fire 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 different is that the calderas the
(20:01):
volcanic craters on Io are much larger than on Earth.
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
(20:24):
something to try to find a comparison. Three hundred 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
(20:45):
up all of the erupting volcanoes on Earth, even 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. Our planet's just like
we can't put out like we used to. But if
you take all that together, think about like the massive
(21:06):
number of erupting volcanoes on Io, 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 hot house, 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,
(21:28):
because the average surface temperature of 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.
(21:50):
Io does not have that. 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 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
(22:14):
call it a like a world of fire and ice.
It's a place where you have 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 whimsically frisky ice world conditions. For example,
I mentioned the fact that Io has this very thin
(22:35):
atmosphere of 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
(22:55):
the planet's surface. So there's a pattern that goes like this.
The volcano 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
(23:17):
temperature to drop even further. It causes the Moon to
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 Io emerges from its
eclipse and comes back into the sunlight, the frozen planes
of sulfur snow start to warm up and sublimate into
(23:39):
gas once again, which becomes part of the tenuous atmosphere.
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, one of the most challenging and
(24:00):
range and dramatic and fascinating places in all of space.
Speaker 1 (24:05):
Absolutely yeah, the closer you look at it than the
more amazing details there are.
Speaker 3 (24:11):
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,
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's concept based on data
(24:31):
from Juno's Juno CAAM instrument, So it's not just 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
(24:54):
top of it. And so if you look this up,
there are sort of animation 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
(25:17):
just one giant blade of mountain raising up out of
an otherwise relatively flat plane.
Speaker 1 (25:23):
Yeah, with these two spires, one has the appearance of
being broken. Reminds me of the horns of Golgataath, two
horns coming up out of the ruined earth. So yeah,
it's pretty evocative.
Speaker 3 (25:38):
But Io is actually full of these strange and gorgeous
surface features both the ones that rise and the ones
that sink.
Speaker 1 (25:45):
That's right. Another interesting feature is Boa sally monts. This
apparently stands as the tallest known peak on Io, standing
between seventeen point five kilometers that's ten point nine mile
and eighteen point two kilometers are eleven point three miles
in height. It is named for the cave where the
(26:09):
we'll 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 this mythology. But it is the third tallest
known mountain ridge in our solar system, behind only Olympus
(26:33):
Monds on Mars, which is the tallest, and the equatorial
ridge on the Saturn nine moon Iapetus.
Speaker 3 (26:40):
Oh yeah, the big spine in the middle of the Appetus.
That was good.
Speaker 1 (26:45):
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
(27:10):
Io's father. There's Epaphus Mensa named for Io's son, there's
Hermes Mensa. You'll find out how Hermei's factors into everything.
And then there's an Anachius Tholus, name for Io's father.
Now you mentioned Loki earlier. This is, of course the
(27:30):
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 ptera.
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
(27:52):
with islands, but with one 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
(28:13):
unholy castle there. You know, the island in the lake
of magma that cannot be named.
Speaker 3 (28:19):
Do not ask after its name, for it has none.
Speaker 1 (28:21):
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 finn Rear, and there's slept Near. But hey, I'm
no astronomer. Those names may be taken already now. They
(28:42):
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 was a
previous twenty seventeen analysis that turned up infrared data that
(29:04):
suggested 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 you know, spike the brightness of
(29:26):
the moon.
Speaker 3 (29:28):
I wonder if that's related to or different from what
Sagan brought up about the changes in like the radar
reflectivity of the of the moon over time.
Speaker 1 (29:36):
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 this is from like a short computer animated video
that kind of like zooms in on it. And it's
(29:59):
I like this image because it's it's maybe not one
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 this place.
Speaker 3 (30:19):
This is just fitting 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 figures kind of embracing and then
melting into each other and then turning into bats.
Speaker 1 (30:33):
Yeah, all to a nice Yon Hammer soundtrack for sure,
too far, take it easy, all right, Well, shall we
get into the mythology.
Speaker 3 (30:51):
Of Io a bit? Oh? Absolutely.
Speaker 1 (30:54):
Now, we mentioned already about the discovery of Jupiter's moon Io,
and we we mentioned the discovery sixteen 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
(31:17):
depending on he's making the argument.
Speaker 3 (31:19):
I think I've read that it was said like they
probably discovered it around the same time.
Speaker 1 (31:23):
Yeah, yeah, But Marius is often credited with naming the
moon after the Greek mythological figure 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
(31:45):
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 Necroman there in this shot.
Speaker 3 (32:01):
Yes, yes, Warlock infernal pack to 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 1 (32:20):
Look at that collar though, such an amazing.
Speaker 3 (32:21):
Collar packed of the lens.
Speaker 1 (32:23):
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 number varies, but
(32:44):
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 was of
(33:06):
course ever lustful, to put it mildly, and soon came
to desire Io. Now thet 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 to read from the
(33:28):
Henry t Riley translation. Jupiter had seen Io as she
was returning from her father's stream, and had said, Oh, 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
(33:48):
is at his height, in the 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 grove's 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,
(34:08):
me who hurl the wandering lightnings, do not fly from me.
For now she was flying, and now she had left
behind the pastures of Lerna and the Lursaan, planes 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
(34:30):
here is supernatural pursuit and sexual assault.
Speaker 3 (34:34):
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. Yeah.
Speaker 1 (34:49):
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 c cannon 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
(35:13):
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, Hara is too wise for any
of this, and she knows her husband too well, so
she almost immediately shows up and begins asking questions about
this beautiful white cow that Zeus is suddenly hanging out with.
(35:34):
And Ovid writes, quote Jupiter falsely asserts 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 (35:52):
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.
Speaker 1 (36:01):
So he's trying to get out of it. 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
(36:21):
cow up to Hara, and Harah entrusts the White effort
to the protection of the one hundred eyed giant Argos
Panopties 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 with no special features, or as
(36:44):
a humanoid with a bunch of eyes on or in
his head. 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 all the time. Sitting
(37:06):
on the top 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 heifer, then
the gig is up and he is almost has to
admit defeat.
Speaker 3 (37:25):
Yeah, Harrow will find out exactly now.
Speaker 1 (37:29):
In the midst of all this, it is said that
that Io is suffering the metamorphosis here is quite miserable.
The way av 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
(37:50):
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 it's heartbreaking. And there are
numerous paintings that explore this scene with like an old
(38:11):
man having this this heart breaking encounter with a white cow.
Speaker 2 (38:16):
Oh.
Speaker 3 (38:16):
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 was 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
(38:37):
not get much of a hundred eyed giant in this. Instead,
Argust just looks like he's like a shepherd.
Speaker 1 (38:43):
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 (38:51):
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 1 (38:59):
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?
Speaker 3 (39:12):
Joe sounds vaguely familiar, But we don't like read this
one in the house.
Speaker 1 (39:18):
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 Caldocott Metal back
in nineteen seventy.
Speaker 3 (39:36):
I'll look it up. But okay, so we're in a
really sad place in the middle of this myth.
Speaker 1 (39:40):
Right right, I was in a terrible place Zeus Sometimes
it's described as if he finds this heartbreaking 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 murder.
Speaker 3 (39:59):
Argus Mercury the hit man here.
Speaker 1 (40:02):
Yes, yes, the harbinger of the gods ere 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 (40:19):
Interesting.
Speaker 1 (40:20):
Now, at this point, the white effer can wander free,
and Harra sends a gadfly to torment her. Gadflies are
livestock biting flies, probably horse flies 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 Balerafin was riding Pegasus,
(40:44):
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
(41:05):
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 (41:28):
Interesting, Yeah, for those not aware, we did serious of
episodes on the Egyptian deity Osiris. When was this like
last year or the year.
Speaker 1 (41:38):
Before, Yes, sometime in the last couple of years. Yeah,
And we talked about Siapis 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 maddened with dreadful visions, runs
(41:59):
over me any 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.
Speaker 3 (42:09):
Wow. 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 1 (42:20):
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. Well again, maybe they employ some of this,
but yeah, at this point in our telling of the
myth of ioh we can appreciate that we're talking about
something that is probably a Greek and Roman take on
(42:41):
the Egyptian throne 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 other artistic depictions of Io, and there's one
(43:04):
that from the 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 (43:24):
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 1 (43:36):
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
(43:57):
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 (44:11):
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 moon,
how do we get from there?
Speaker 1 (44:25):
To hear well, 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
(44:46):
made between mythic 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
(45:08):
heavens symbolized by Argus's one hundred shining eyes, and then
her transformation into a horned heifer represents nothing other than
the crescent moon. Oh interesting, Yeah, so yeah, the more
you look at it, like, the myth of Io is
is ultimately fairly complicated because you have all these different,
(45:28):
you know, cross cultural 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 thousands of years of history.
All Right, on that note, we're gonna go ahead and
(45:49):
close up this episode of stuff to blow your mind,
but we're gonna be back in a part two on
the Moon of Io. We'll get into some more cure
curious details about the moon in that episode. In the meantime,
we'd like to remind you all this Stuff to Blow
Your Mind is primarily a science and culture podcast, with
(46:10):
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 (46:19):
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 2 (46:41):
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.
Speaker 1 (47:00):
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