February 13, 2025 • 49 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, welcome to Stuff to Blow Your Mind. My name
is Robert Lamb.
Speaker 3 (00:16):
And I am Joe McCormick, and we're back with the
third and final part in our series on Jupiter's moon Io,
the innermost and third largest of Jupiter's four Galilean moons
and the most volcanic body in our Solar system. Years ago,
we did a multi part series on the moons of
Jupiter at large, but this time we wanted to come
(00:37):
back and do a deeper focus on Io, in particular
to explore its own peculiar Hadian prodigies, because it really is,
as I've said in the previous two parts, I think,
probably one of the most dramatic places in our Solar system,
certainly beyond Earth. Now, if you haven't heard the previous
two parts yet, I would recommend you go back and
(00:59):
listen listen to those in order. But to briefly recap,
we started off by talking in detail about some really
eerie and thrilling images of the surface of Io, mostly
based on data collected in twenty twenty three and twenty
twenty four by NASA's Juno mission. These images highlighted a
lot of the really enigmatic features of the Moon's topography,
(01:21):
including these gargantuan thorn like mountains and volcanic highlands, huge
fields blanketed and yellow sulfurous frost, Vast lakes of molten
lava constantly overturning with waves, giant lava flows spreading in
some cases hundreds of kilometers, forever resurfacing the Moon and
erasing all the scars of its history. We also talked
(01:44):
about the physical ironies of the conditions on Io, including
the fact that it is at once deep cold due
to its extremely thin sulfur dioxide atmospheres inability to trap heat,
doesn't really have much of an atmosphere, can't trap heat
there of course, in places it is unimaginably hot, due
of course, two volcanic eruptions, according to a volcanologist we
(02:07):
discussed in Part one, a single one of the Moon's volcanoes,
the lava lake known as Loki Ptera, which we did
do a little focus on. That was the one that
has a big island in the middle of it actually
has a number of islands, but one big old island
in the middle which shall not be named. That one
volcano emits more heat than all of Earth's volcanoes combined,
(02:32):
which is a pretty startling fact. We also talked in
previous parts a bit very briefly about the historical exploration
of Io, including Carl Sagan's account of the discoveries made
by the Voyager one probe in nineteen seventy nine. We
talked about the character from Greek myth that provides Io
its name, about how the story of Io was told
(02:52):
by Avid and other ancient authors, and how in ancient
times the character of Io was said to overlap or
interact with other religious figures, such as the Egyptian goddess Isis.
In Part two, we discussed when and how Io tends
to pop up in science fiction storytelling. There's sometimes what
(03:13):
at least feels like a dearth of Io stories, and
then we talked about a mystery regarding images of so
called ridges on the Moon's surface, which paradoxically look extremely
similar to wind driven sand dunes on Earth and Mars.
This is paradoxical because of the tenuous, barely there atmosphere
(03:33):
of Io, which wouldn't seem to be thick enough to
support the winds needed to make dunes. And then we
got into a paper that offered a likely solution to
this mystery. Finally, in the last episode, we talked about
the possibility of life on Io being a blasted, cursed, irradiated, waterless, sulfurous,
freezing cold, searing hot kind of nightmare ball, a place
(03:55):
from the video game Doom I would not seem to
be a good place to look for science of extraterrestrial life,
but if it were to exist there, we talked about
some astrobiology speculation on where and how that life might persist.
And now we are back today to round out the discussion,
talk about a few more things.
Speaker 2 (04:14):
That's right, all new things quite true.
Speaker 3 (04:16):
In fact. To kick things off today, I want to
talk about a pretty new research paper I think it
was just published a couple of months ago in the
journal Nature, I believe in December twenty twenty four, which
addresses a longstanding mystery about the interior of We've talked
about the mysteries of its surface, but now we're going
to talk about mysteries of what lies inside. So this
(04:38):
paper was by park at All and it's called Io's
title response precludes a shallow magma ocean. Again published in
Nature twenty twenty four, So a bit of context about this.
For the past four decades or so, there has been
a question about what powered the vulcan canic corruptions on Io,
(05:02):
and it was long suspected for a number of reasons,
but not confirmed, that underneath the surface of the Moon
there lay a vast planetary magma ocean, sometimes thought to
be maybe roughly fifty kilometers deep below the surface, a
vast ocean of liquid magma stretching around the planet, which
(05:23):
found release points at each of Io's roughly four hundred
active volcanoes. So this was long suspected by some researchers
to be the case. But this new paper published in
Nature in twenty twenty four has a group of researchers
who took information gathered by the NASA Juno mission and
(05:44):
used it to argue that the magma ocean hypothesis cannot
be correct and instead each volcano is probably powered by
its own distinct magma chamber. And I'm going to try
to explain how we get there. So a reminder, going
back to part one of this series, volcanic activity on
Io was not directly detected until the discovery of a
(06:07):
volcanic plume by NASA JPL scientists Linda Morabito in nineteen
seventy nine. The image was found in actually navigational images
created by the Voyager one spacecraft. Volcanism had been hypothesized
by the astrophysicist Stanton Peel beforehand, but this was the
first time direct evidence was identified. But ever since the
(06:30):
erupting volcanoes were first discovered, there has been this mystery
about what's inside the Moon to feed the eruptions. And
I wanted to read a quote here by Juno principal
investigator Scott Bolton, who is quoted in a NASA press
release about this new paper. Bolton summarizes it saying, quote,
since Morabido's discovery, planetary scientists have wondered how the volcanoes
(06:54):
were fed from the lava underneath the surface. Was there
a shallow ocean of white hot magma fueling the volcanoes
or was their source more localized. We knew data from
Juno's two very close flybys could give us some insights
on how this tortured moon actually worked. So how did
they investigate this? Well? I thought this was pretty cool.
(07:17):
So the Juno spacecraft did flybys of Io in December
twenty twenty three and February twenty twenty four, and during
those close passes, Juno interfaced with an Earth based tool
called NASA's Deep Space Network, which is a network of
three equidistant ground based radio antennas on Earth. There's one
(07:37):
in California, there's one in Australia, and one in Spain.
And the ideas with this equidistant spacing of these antennas,
they always at least one of them can maintain contact
with something in space. You never have it going dark. Together,
these instruments were able to acquire high precision Doppler readings
(07:57):
to detect minute changes in Juno's acceleration, which was in
turn able to tell us things about the gravity of
iob the gravitational influence of IO, because it was primarily
Io's gravity that would have been affecting Juno's acceleration at
these moments. So essentially, researchers were looking for how the
(08:19):
gravitational field of IO changes during its tidal stretching cycle,
more on that than just a minute, because that would
help us know how rigid the Moon is. A more
rigid IO would be consistent with a more solid interior,
but a more flexible IO would indicate a liquid magma
ocean underneath. Now on that sort of flexing and stretching cycle,
(08:44):
IO is in a very close orbit around Jupiter. The
average distance between the planet and the Moon is four
hundred and twenty two thousand kilometers over the course of
its roughly forty two point five hour orbits. Now that is,
this is not much further than the distance between the
Earth and the Moon, which is about three hundred and
(09:05):
eighty four thousand kilometers, except think of how big Jupiter is.
In the words of Scott Bolton, the Juno principal investigator,
IO is orbiting a monster, and this has many different effects.
We've talked about some of them already, but a big
one is a gravitational effect. Gravity follows the inverse square law,
(09:27):
meaning that the attractive force between two objects in space
is inversely proportional to the square of the distance between them.
And another way of thinking about that is, as you
get closer to a planet, the force of gravity asserted
on you rapidly becomes greater. So get a little bit
closer to Jupiter and you get pulled harder toward it.
(09:49):
A strange thing about IO is that in addition to
being very close in orbit around a very massive planet,
the orbit of this moon is also not circular. It
is slightly elliptical, meaning that if you look down from
above the orbital plane, you're going to see the orbit
being slightly longer in one direction than another. It's a
(10:11):
little bit more oval shaped than a circle. This elliptical
orbit is actually because of regular gravitational influence by two
more of the Galilean moons, Europa and Ganymede. These moons
are in what's called an orbital resonance with Io, which
means that their orbits are sort of like small integer
(10:32):
multiples of the orbits of iOS. They frequently line up
in the same place as Io as they're going around
the planet, and the fact that they continually line up
in the same direction over and over means that they
sort of stretch Io's orbit in that one direction. So
the elliptical orbit of Io means that the distance between
(10:53):
Io and Jupiter keeps changing, and so as the distance
keeps changing, the string of Jupiter's gravitational pull on Io
keeps changing. Two. And this really affects the Moon because
it's always the case that the side of the Moon
facing Jupiter experiences a stronger pull than the side that's
(11:15):
farther away. The nearer side is pulled harder than the
far side, But because of the constantly changing distance between
Io and Jupiter, the difference between the pull on the
far side and the near side of the planet keeps
changing too, And this manifests as what planetary geologists might
call tidal flexing. It's a squeezing, stretching of the solid
(11:38):
material that the Moon is made of in the fluctuating
gravitational field. You can kind of just imagine this by
like holding a rubber ball in your hand and just
like squeezing it over and over again. It's a flexing
of the material that the moon is made of. Now, Rob,
did you ever do the thing in like the school
cafeteria when you were younger, where you you get one
(12:00):
of those, you know, cheap metal forks, cafeteria forks, and
you bend it back and forth a bunch of times,
real fast until it gets hot.
Speaker 2 (12:08):
No, I never did this. I didn't even know this
was a thing. I mean, I mean, physically, I understand
why it's possible, but I didn't know it was a
thing that kids do.
Speaker 3 (12:18):
I guess it was the thing I did. I don't
know sure is that are most forks supposed to bend
like that? You're using your hands right, not your mind? Yes,
just hands, just hands. This this has got to be
possible only with like real bottom shelf cutlery. But yeah,
so you know, you flex a piece of piece of
metal back and forth a bunch of times. Usually what
(12:39):
you will find is that the metal heats up. The
flexing causes a frictional force within the material that excites
the atoms, and it makes the metal hot or at
least warm. Similar principle here, The flexing of the Moon
by the by the changing gravitational field as it gets
closer and farther away from Jupiter causes frictional heat of
(13:00):
the inside of the Moon, and that heat is immense.
It is so immense that it melts parts of the
Moon's interior and this massive build up of internal heat
energy is released to the surface through volcanic eruptions. But
this brings us back to the question we started with,
what is the nature of the subsurface magma source to
(13:22):
read from the paper in Nature quote For decades it
has been speculated that this extreme tidal heating may be
sufficient to melt a substantial fraction of Io's interior, plausibly
forming a global subsurface magma ocean. Many worlds are believed
to have had magma oceans early in their evolution, notably
(13:44):
the early Moon referring to Earth's moon there, notably the
early Moon, which is thought to have had a shallow
magma ocean in the first one hundred million years, caused
by the giant impact that birthed the body, which that
is not new information in this paper, but that on
its own is just a fascinating fact to consider it,
(14:05):
you know. So there is the main theory of the
origin of the current Earth and Moon is the giant
impact hypothesis. So the idea is that roughly four and
a half billion years ago, during the formation of the
Solar System, when the you know, the planets were just accreting,
there was a collision between the early proto Earth and
(14:26):
some kind of roughly Mars sized object, and this collision
caused a fracturing that eventually ended up causing the separation
of the material that became the Earth and became the Moon.
So that's the common origin of the Earth we have now,
and where the Moon came from. And so the idea
here is that for the first one hundred million years
or so after that, the Moon probably had a global
(14:51):
shallow magma ocean surrounded by liquid by molten rock. Wow
would have been cool to see. Perhaps not physically cool,
but anyway. So the authors cite that as an example
of a global shallow magma ocean surrounding a planetary body
or a moon, and then the quote goes on to
(15:13):
say Io's extreme volcanism strongly suggests the existence of at
least a partially molten interior. Whether the interior contains a
shallow global magma ocean has been an outstanding question since
the discovery of Io's volcanism. Now, beyond these theoretical models,
were there any recent experiments that would have provided support
(15:36):
for the idea of a global magma ocean. I was
looking into this and it appears yes, there were some
good reasons from findings that pointed in this direction. Apparently,
the Galileo mission took some magnetic measurements that were thought
to be consistent with a shallow, shallow reserve of global magma,
(15:56):
and I also wanted to flag another argument for the
magma ocean, and I came across in a space dot
Com article by Keith Cooper, which pointed out that previous
data collected by the JUNO mission had actually enabled researchers
to create the first global map of Io's volcanic activity.
(16:17):
Rob actually pasted a picture of this global map in
the outline for you to look at here. And so
it's got little color coded polka dots of different energy
levels of volcanic corruptions all over Io's surface. The authors
here assembled this map based on near infrared signatures of
iOS polar regions. In particular, data collected by previous missions
(16:38):
had already done some of this mapping, I think, but
had left us with an incomplete picture of volcanic activity
near the poles. And I was reading a space dot
com article that quoted study author Ashley Davies, a volcanologist
at NASA, JPL and Calteche, Pasadena, and Davies explained their
findings by saying, quote before this anal it was thought
(17:00):
that Iowe's polar volcanoes were fewer and more powerful than
at lower latitudes. We show that polar volcanoes are about
as prevalent as at lower latitudes, and actually with lower
emitted power. Suggesting smaller eruptions. And another thing the researchers
found is that these findings were interpreted by computer modeling
(17:22):
to lend support to the hypothesis of a global subsurface
magma ocean. So it seemed like this looked good for
the for the magma ocean.
Speaker 2 (17:31):
Did they consider connecting these dots and seeing if it
made a pentagram or not, because that's that's generally what
you do in detective movies.
Speaker 3 (17:39):
It really does look like people should be putting tax
in and putting string between them, doesn't it.
Speaker 2 (17:44):
Yeah, yeah, see it all lines up with that unnamed island.
Speaker 3 (17:47):
Yeah, well, that unnamed island is I'm sure going to
be right around one of the yellow dots here. In fact,
I think I see where Loki Ptera is, and yes,
it is, in fact one of the It is one
of the hottest types of dots. Any pentangle, I'm not
really seeing it.
Speaker 2 (18:02):
If you want them bad enough, they will manifest.
Speaker 3 (18:05):
But anyway, coming back to the new Jono experiment park
it all from twenty twenty four, so the authors use
the Doppler data from the JUNO flybys and the Deep
Space Network radio telescopes, as well as data previously collected
by the Galileo mission to try to look at the
tidal deformation of Io. And again, remember they're looking for
(18:26):
if it's more if it's stretching more, if it seems
more easily deformed, that probably means liquid magma ocean underneath.
And if it's more rigid, that probably means that it
is more solid underneath. And they concluded, based on their
findings that Io could not have a global magma ocean
underneath its surface. Instead, the Moon must be mostly solid,
(18:47):
with individual magma chambers driving the hundreds of volcanoes. The
authors of the paper right quote our results indicate that
tidal forces do not universally create global magma oceans, which
may be prevented from forming owing to rapid melt ascent
intrusion and eruption. So even strong tidal heating, such as
(19:08):
that expected on several known exoplanets and super earths, may
not guarantee the formation of magma oceans on moons or
planetary bodies. And Rob, I've got a little artist's rendition
for you to look at here. This is an artist's
impression of the interior of Io informed by these new findings,
does not show a global magma ocean instead shows these
(19:30):
the pockets, these magma chambers that are leading up to
the volcanoes on the surface, some of these volcanoes being
connected to plumes that we see erupting far over the
surface of the planet. This has more the look of
you know, it's like when you see superheroes and movies
that like have the fire inside and you see their
(19:51):
skin kind of cracking and then the fire is ready
to come out. It looks like it's about to go
supermode exactly.
Speaker 2 (19:56):
Yeah, yeah, these kind of yeah, these deep the I
want to describe them as veins because they don't really
have that kind of rooting pattern. But deep fissures, I
guess would be more glowing fissures would be the way
to describe them.
Speaker 3 (20:11):
And so perhaps one reason Io doesn't have a magma
ocean would be all of its volcanoes. They may in
fact be dissipating the heat that would otherwise melt the mantle,
the author's write in their conclusion quote. On Earth, deep
melts can be denser than the surrounding mantle and thus
remain sequestered. In a basal magma ocean. On Io, pressures
(20:34):
are much lower, so mantle melts are expected to be
always less dense than the surrounding solid mantle. The melts
will tend to ascend, making maintenance of a deep magma
ocean dynamically problematic. Conversely, if the melts are dense, for example,
if sufficiently iron rich, although a deep magma ocean could
then form, it would be hard to explain how any
(20:57):
such melt would ascend and erupt. Thus, we conclude that
the volcanism scene on iosurface is not sourced from a
global magma ocean. So it seems like that interesting idea
is likely put to rest unless something causes us to
really reinterpret these results. But despite the magma reserves not
being part of a sort of global shared ocean in nature,
(21:21):
I still think that leaves the volcanoes and the plumes
and the eruptions and the lava lakes no less fascinating
and charismatic.
Speaker 2 (21:29):
Yeah. Yeah, Plus, you know that if you miss that,
if you miss that vision of what iowe is, it's
probably out there somewhere else in the universe. So you
can just imagine that it's out there somewhere waiting for you.
Speaker 3 (21:42):
Used to be present on our moon.
Speaker 2 (21:45):
Yeah, yeah, it's somewhere else in time and space, and
in time maybe a lot closer than you thought. Now.
One of the features of the illustration that you showed me,
(22:06):
and certainly listeners can find various images that either depict
this or are actual captures of this. One of the
distinguishing features that you often see with IO is that
of these plumes coming up from its surface volcanic eruption
that is ejecting material into space, and it is always
(22:28):
kind of weird to look at because it feels completely
out of scale, like we're not used to seeing. You know,
we've all seen images of volcanic eruptions, and yes they
can actually they can look quite alarming from orbit, but
this just looks These just look amazing because the Moon
in profile has this plume coming off of it, just
this ridiculously far reaching plume of volcanic eruption. And so
(22:55):
that's what I want to explore here in this next section,
getting into like what exactly this is, what is it
mean for not only IO, but for the the basically
the entire orbital realm of Jupiter itself.
Speaker 3 (23:09):
I totally agree with what you say about looking at
these plumes, that the plumes even in real. Direct images
taken from reality look fake. They look like they look
like art. The word photo can be misleading because the
instruments used to capture these images can be different in nature,
and it's not always just visual light. But but yeah,
like direct images of reality that we're looking at, but
(23:32):
they're that they look like a cartoon.
Speaker 2 (23:34):
Yeah, yeah, like this is grotesque and ridiculous, But I'm
reminded of of pimples. You know, usually in profile, you
are not going to notice a pimple, And if a
pimple were to burst on a person, you wouldn't see
that in profile. You wouldn't see like the silhouette of
the eruption. And if you were to see that, well,
(23:55):
you would be watching like an Itchy and scratchy cartoon
or a SpongeBob cartoon or something. It be a cartoon
exaggeration of reality. And that's what the scale of these
things really looks like.
Speaker 3 (24:06):
Yeah, that's right. We see plumes on io that are
like somebody with a three inch high pimple that when
you pop it, it squirts like six feet off their body.
Speaker 2 (24:15):
Yes, so what's going on here? Well, you know, here
on Earth, we certainly have powerful volcanic eruptions as well.
We have in the past, and they occur periodically, and
they will continue to occur. But we also have some
other things going for us that you don't find on
IO and you don't find everywhere else in our solar system.
(24:37):
We have a robust atmosphere, We have resulting wind resistance
and sufficient gravity to place the necessary escape velocity beyond
what even a very powerful terrestrial eruption is capable of reaching.
Speaker 3 (24:51):
Right, So that escape velocity number is going to mean
that our volcanoes they might erupt quite powerfully, but they're
not blasting stuff out into space so that it never
comes back, or not much stuff certainly.
Speaker 2 (25:02):
Yeah. I've read that while terrestrial volcanoes can't really blast
things into orbit, they can reach really high into the atmosphere,
in arguably touching space. For instance, the twenty twenty two
Hanga Tonga volcanic eruption supposedly shot water vapor up that
high to where it was essentially touching space. But it's
(25:24):
not quite what we're seeing with IO at all.
Speaker 3 (25:27):
Right, And even if it were to go into space
and go into orbit, that still wouldn't be escape velocity.
Speaker 2 (25:32):
Right, right, Yeah, you've got to get all the way
out of there. You got to it's got to be
a complete breakup with the planet, not one of these things.
We'll continue to see each other socially. No, no, no,
you've got to be out of there.
Speaker 3 (25:42):
Volcanoes are not doing that.
Speaker 2 (25:46):
So this thinking about this led me to, you know,
get into escape velocity here on Earth and elsewhere, and
ways to escape it. You know, the most obvious way
to do it is, of course, in a rocket. That's
what we're used to seeing with our Earth space technology.
The escape velocity on Earth is eleven point one eighty
(26:09):
six kilometers per second. That is, that's going to be
a higher velocity than is necessary for any of the
other inner planets. On Earth's own moon it's two point
thirty eight kilometers per second, and on Io the number
I've seen is two point five five eight. So just
(26:29):
to give you a little frame of reference for what
we're talking about here again coming back to what does
Earth have that a lot of these other suspects don't
you know? It has. It has the gravity, it has
the robust atmosphere and so forth. So this all adds
up to a greater necessary escape velocity for anything that
is leaving the surface of the planet or any point
(26:51):
within the atmosphere of the planet, and hoping to free
itself of our orbital dominion. Now one thing I want
to go ahead, get out of the at the top here there.
I think a lot of people have probably heard the
legendary manhole shot into space story via Operation plumb Bob.
(27:12):
These were atomic tests in nineteen fifty seven. The idea
here was that you had these test wells for atomic
detonations with a metal cap on the top, essentially a
manhole cover, and at least one of these blasted the
cap off, and it was said that it achieved such velocity.
(27:33):
In fact, I think the number that is often cited
is six times the necessary escape velocity and therefore flew
off into space and is potentially still out there well.
According to a twenty twenty two Snop's article by Bethania Palma,
there's nothing actual actually out there to back this up.
This all seems to stem from a comment by Robert Brownly,
(27:57):
who worked on the project, who remarked that the manhole
cover in question would have been blasted off at six
times the necessary escape velocity. It apparently went flying, but
that's all that's really known. We don't know if it
was launched into space, and if it was, we have
no records or recording of it. I think it's also
been mentioned that it's possible that it would have burnt
(28:20):
burnt up on the way up as well. So you know,
we have to consider all these options. But there's no
like clear evidence that this thing actually made it into
orbit or beyond orbit and so forth.
Speaker 3 (28:32):
Yeah, all we actually know is that this was a piece,
a solid piece of metal that was hit from below
with tremendous energy. But we don't know exactly what happened
to that matter and energy afterwards, what its journey was
question mark right now.
Speaker 2 (28:49):
Of course we already mentioned rockets. Rockets are you know,
we can compare rockets to volcanoes in that, you know,
the rocket is taking advantage of a very explosive chemical
reaction in order to propel this you know, tower of
steel and so forth upwards through the atmosphere. And you know,
it's and rocket science has come a long way. It's
(29:11):
ultimately a lot more dependable than trying to blast into
space on a volcano, which again probably wouldn't give you
the exactly the push you needed anyway.
Speaker 3 (29:20):
I wonder if it's been tried.
Speaker 2 (29:23):
You'd have to be you'd have to be so patient.
I don't think. I don't think it's just maybe there's
some sort of sci fi scenario, or it would make
sense if you know of a science fiction tale in
which someone uses a volcano to escape a planet's orbit,
do write in and tell us about it. Now. In
terms of just using explosions though, and explosive events to
(29:46):
potentially transfer into orbit or beyond orbit, we do have
to mention Project Ryan here. This has come up on
the show in the past because it is, you know,
it's an early concept of how we might achieve interplanetary travel.
It was a nuclear pulse spaceship concept from the nineteen
(30:10):
fifties and sixties. I think a lot of you may
be familiar with this. Essentially built around the idea was
built around the concept you could propel a craft through
space via a series of nuclear detonations behind the craft.
Not to be confused with nuclear thermal rockets such as
(30:30):
the Nerva project, in that you'd have a nuclear reaction
that was heating fuel rather than depending on a chemical
reaction to do so.
Speaker 3 (30:42):
So the Nerv rocket would still be a reaction drive,
but it would just be the heating is from nuclear sources.
Speaker 2 (30:48):
Correct, Yeah, And that one was never tested in space,
nor was Orion. But the Orion program is like, let's
keep throwing atomic bombs behind the ship, allowing them to explode,
thus propelling our ship onward and onward through space with
each blast like pushing up against a blast plate on
the rear of the vessel, an idea that I've just
(31:11):
always found. I mean, it's it's it's preposterous and yet reasonable,
amazing in its own right, and you know, in Inner
Yourself to the Stars, Yeah, yeah, and uh yeah, it's it's.
It's one that I've come back to a few different times.
But it's one of Sagan wrote about as well. Actually
(31:34):
looked up an old like press briefing where someone asked
Sagan about it, and you know, he pointed out he'd
written about it in Cosmos or I don't remember if
you'd written about it in Cosmos or if you just
discussed it on the television series, but you know, pointed
out that like, Okay, well, this is actually not a
bad way to go ahead and get rid of some
of our atomic weapons. Let's use them to propel a spaceship.
(31:56):
But of course there are all these various hazards to
such a technique as well. Some of these we'll get
into here in the discussion. So I was, you know,
I was mostly familiar with the concepts involved here, the
potential benefits and the downsides. But one thing that I
didn't quite realize is that early models of the project
(32:17):
Orion nuclear pulse spaceship during the fifties and sixties actually
considered it not only for propelling a vehicle through space,
but for using it in liftoff in order to achieve
escape velocity from Earth.
Speaker 3 (32:32):
WHOA, I don't think I'd ever thought of it that way.
Speaker 2 (32:35):
Yeah, I was reading about this in a couple of sources.
One was in a nuclear pulse Propulsion Oriyan and Beyond
by Schmidt at All for NASA, and they pointed out
that early drafts of the proposal called for a bullet
light capsule to be launched from the ground. From the
ground via an atomic detonation, likely from a Nevada nuclear
(32:56):
test site. The mass of the vehicle on takeoff would
have been on the order of ten thousand tons, most
of which would have gone into orbit at takeoff, the
zero point one kiloton yield pulse units would be ejected
at a frequency of one per second. As the vehicle accelerated,
the rate would slow down and the yield would increase
(33:16):
until twenty kiloton pulses would have been detonated every ten seconds.
The vehicle would fly straight up until it cleared the
atmosphere so as to minimize radioactive contamination. This is one
of the big hazards and downsides to this whole concept
is that you would it would entail detonating multiple multiple
(33:37):
atomic weapons in this model within the atmosphere. But even
if you weren't using that within its atmosphere to achieve liftoff,
if you were going to the program where okay, once
you get your spaceship away from Earth, then you can
start dropping bombs in order to accelerate. Even then you're
still causing all of these detonations. And then what happens
(33:59):
when you reach sure destination. There are some models that
were outlined that would call for detonating bombs as you landed,
thus like nuking the landing site ahead of your arrival.
And if there are people on board, well they're gonna
have to deal with the literal fallout of all of that.
The original concept was created by Ted Taylor and Freeman Dyson,
(34:22):
and Freeman Dyson's son, George Dyson, claims, historian of science,
wrote about all this in the book project Orion, The
True Story of the Atomic Spaceship, and he points out
quote these early four thousand ton ground launched versions of
Orion specified the ejection of about eight hundred bombs raging
(34:45):
and yield from zero point fifteen kilotons at sea level
to five kilotons in space to reach a three hundred
mile orbit around Earth. Points out that each bomb would
have weighed around half a ton. Less yield would be
necessary at lower out tod since the thicker air itself
would absorb energy and add to the kick against that plate.
(35:06):
But then you would need more yield. You'd have to
steadily increase the yield of the detonations as the vessel
was propelled upwards. And this would have all required like
tight precision and exactly how you're detonating these bombs and
even how you're getting them back there underneath the ship,
like is it a trapdoor or is there some sort
(35:26):
of a you know, some sort of a targeted rocket
system that launches them alongside the vessel and then back
underneath it. You know, you would have to work out
all of those problems. So that's about eight hundred bombs.
The original design called for about two thousand bombs or
two thousand pulse units, far more than needed to reach
orbit according to their calculations, but that was because they'd
(35:47):
set their sites pretty high. Their slogan was Mars by
nineteen sixty five, Saturn by nineteen seventy, and they were
talking about like crews of one hundred and fifty people.
So this was a really ambitious concept. Obviously, this is
not the way it all worked out.
Speaker 3 (36:05):
I mean I said this in a totally different context earlier.
But there's a cartoonishness to this. It kind of reads
like a joke.
Speaker 2 (36:12):
Yeah, it does, and I think that's one of the
reasons it resonates so well. It's like this interesting perversion
of the accumulation of atomic weapons, though not necessarily a
negative pervert, like the accumulation of atomic weapons is already
a perversion in many respects, but the idea of then
taking them all and using them to propel a spaceship
(36:34):
to another planet, you know, with such ambition it, you know,
it's ultimately more attractive. Like Sagan said, it's like, well,
that's one way to get rid of the weapons, or
at least that's the way he put it at one point.
(36:58):
Now the concept here continued to again they ended up
moving away from the idea of it potentially blasting off
of the surface of the Earth like this via atomic
weapon detonations. It had many powerful supporters, but it never
came to fruition for a variety of reasons, including cost,
including risk, and of course including international treaties about nuclear testing.
(37:21):
George Dyson points out that, yeah, you had these various
drawbacks to such a program, including the idea that if
you were going to use detonations while potentially a landing
a ship in another world, again, you would be pre
contaminating the landing site. So even if you even if
that wasn't going to make it too you know, radioactive
for then humans to venture out on the surface of
(37:43):
this destination world, you're still messing with what you were
going to explore to begin with. You know, so so
many different reasons to not go in this direction. Now
you might be wondering was there another way to get
something into orbit from Earth's surface without some sort of
an explosion. Well, there has been research into the use
of centrifugal force, and such research actually continues at least
(38:07):
as a rocket aid to decrease the dependence on traditional rockets.
You know, you can think essentially like slingshots in terms
of like the basic fundamentals here, this is the sort
of thing we could potentially come back and do a
more dedicated episode on this idea, because again there as
(38:27):
at least one company out there that continues doing a
lot of well funded work in this area. Now elsewhere
in speculation and in science fiction, there are some ideas
related to directed panspermia to consider, so directed PAMs spermias.
Of course, this would entail the intentional seeding of other
worlds with life, and in some creative takes on what
(38:51):
this might look like, it might entail some manner of
biological propulsion, maybe some sort of biocanon that enables a
seed of some sort to escape from one world's gravity,
drift through space and find another world. And we actually
saw a vision of what this might look like in
a recent film that we discussed on Weird House Cinema,
(39:11):
Beyond the Mind's Eye.
Speaker 3 (39:13):
Oh that's right with the Yon Homer soundtrack, It's like
the second or third track on there is the one
that the seed's blasting into space and then we see
them form, and what was the deal with that?
Speaker 1 (39:24):
It?
Speaker 3 (39:25):
Like, why do I associate that with a cover of
Black Sabbath's Planet Caravan.
Speaker 2 (39:34):
Because it was used as a music video for that
cover the Planet Caravan. Yeah, which kind of shakes out
kind of makes sense. Now is this at all feasible?
I don't know. Again, I think it comes down to
what sort of world are you attempting to escape with
this seed? You know, what's the gravity like, what's the
atmosphere like? And so forth. Now I haven't seen this
(39:57):
movie in ages, but I believe the bugs in the
eteen ninety seven Starship Troopers movie also have something like this.
I think they're called plasma bugs in that, and these
are some sort of organic cannon system.
Speaker 3 (40:09):
Right, biological artillery. Yeah, there's some big bugs that kind
of bend over and they like eject something out of
their backside that goes up into orbit and it takes
out the capital ships.
Speaker 2 (40:21):
All right, So some maybe some sort of weaponized version
of something that might otherwise be used for pan spermic.
Speaker 3 (40:29):
Purposes, possibly, who knows.
Speaker 2 (40:32):
Now there's another major player in the world of science
fiction biothreats, and that's the Tyranids in the Warhammer forty
thousand universe. These are if you're not familiar with these,
they're kind of there's a little bit of xenomorph to them,
except they are a spacefaring species. They have big, big
leviathan bioships and they arrive on worlds and they invade
them and eventually like turn all the bio they convert
(40:55):
all the biomass on the planet, But then they have
to get it off the planet. And interestingly enough, unless
I'm mistaken, they don't have any kind of way of
like launching it directly back up with their you know,
entirely biological civilization. Instead, they depend on something called capillary towers,
(41:16):
which are like organic space elevators. So they just have
the big ships in orbit suck it all up back
off the surface of the planet, which I guess is
one way to potentially do this.
Speaker 3 (41:27):
Sounds kind of Necromonger style, Yeah, yeah, yeah, there's a
certain necromongernous to them, or there's a certain Tyranid nature
to the Necromongers.
Speaker 2 (41:36):
One way or the other, including an image an illustration
here of what this might look like, you know, the
big coiling ambilical cord going from the planet's surface up
to some sort of you know, horrifying living alien vessel.
Speaker 3 (41:52):
Yikes, give me out.
Speaker 2 (41:53):
But anyway, back to the real world, back to volcanoes. Yeah, so,
while Earth volcanoes can't blast things in orbit space, volcanoes,
including ice volcanoes, which I think we've talked about on
the show before, absolutely can and the volcanoes of Io,
dealing with much less gravity and atmosphere, can easily jet
their contents into orbit, and not only into their orbit,
(42:17):
but into the orbit of Jupiter. Ah.
Speaker 3 (42:19):
Well, this actually brings us back to the one of
the first things we talked about in the series, when
we were discussing Carl Sagan's comments about what scientists knew
as the voyager probe was approaching Jupiter before they actually
had direct evidence of the volcanoes. One of the indications
that there might be something strange going on with Io
(42:40):
was he said that they had already detected a huge
doughnut shaped tube of atoms in orbit around Jupiter basically
within the sort of the same position as the orbit
of the moon Io made up of just like just
isolated atoms of things like sulfur and potassium and sodium,
and for some reason that's just going around the planet.
Speaker 2 (43:02):
Why that's right. Yeah, These eruptions create a terroidal or
doughnut shaped cloud of charged particles that follow Io's orbit
and wraps part of the way around Jupiter. It's also
referred to as a plasma taurus, and it produces ultra
violet light, intense radiation, and as Io orbits Jupiter, it
(43:24):
travels through the torrent, generating an enormous electrical current, thus
amplifying Jupiter's magnetosphere. So the ioplasma Taurus plays a major
role in strengthening the most powerful magnetosphere in the Solar System.
I mean, the magnetosphere of Jupiter almost reaches the orbit
of Saturn.
Speaker 3 (43:44):
Wow.
Speaker 2 (43:45):
Now, there are other sources of charge particles in Jupiter's orbit,
including other Jovian moons and the Solar wind, But according
to the ESA, Jupiter's magnetosphere captures all of these particles
and then speeds them up like it's a literal part
article accelerator, creating intense radiation belts out of these accelerated
particles and I owe as a major contributor. These radiation
(44:07):
belts pose an additional obstacle to missions to any missions
to the Jovian moons, particularly any possible future missions that
might feature live crew members, because this would expose them
to lethal doses of radiation for like hours at a
time potentially, and it poses a risk to equipment as well.
So any mission through these belts requires, on one hand,
(44:29):
additional navigation precision to avoid, as the ESA points out,
low latitude orbital paths around Jupiter. And also you just
need to have additional shielding and protection for any gear
because I've read that it essentially would be it would
be a case where whatever kind of equipment was aboard
one of these craft, it would encounter as much radiation
(44:53):
as a terrestrial satellite would endure over the course of
multiple decades.
Speaker 3 (44:57):
And Joe I.
Speaker 2 (44:57):
Included a couple images here in the notes for you.
Here the sort of highlight iOS Plasma Taurus and shows
shows us like how it sort of features into the
complex magnetosphere and orbital ecosystem of Jupiter.
Speaker 3 (45:14):
Ah yeah, okay, so branching out from the poles, we
see the magnetic field lines, but then closer in to
of course those extend out really far into space. But
then in closer to the planet we see the gold ring,
we see the ring of the the the atom or
the ion Taurus. And this is a lot of this,
as you said, is stuff that is actually being ejected
(45:37):
from the thin atmosphere and uh, an orbit of Io
bi volcanic eruptions and just goes off into space and
ends up in orbit not around Io but around Jupiter.
Speaker 2 (45:48):
Yeah. Yeah, so I I found found this. This is
not just another way in which Io stands out and
I think is rather fascinating. It's it's again, it's easy
to to consider Io and think, okay, well it's not
It's maybe not a top consideration for extraterdustrial life. It's
not a top consideration for some sort of uh, you know,
(46:09):
distant future human colony.
Speaker 3 (46:11):
Uh.
Speaker 2 (46:12):
And it's not even like the biggest moon. Maybe in
your opinion, it's not the most impressive moon in the
Jovian System. But when you look at details like this,
it's clear that it is a major player in the
Jovian System, like it contributes quite a bit. So it
would be you would be in great error if you
were to completely dismiss IO and be like, oh, it's
not interesting it it doesn't really do anything, et cetera. Like, no,
(46:35):
it's it's it's of extreme importance.
Speaker 3 (46:38):
I want to meet the person who says it's not
interesting because it's not the biggest size matters not. Come on,
look at the volcanoes. Yeah, I know, it's that island.
Speaker 2 (46:50):
There's a lot going on here, you know, maybe maybe
not life, but maybe life. As we discussed in the
last episode, we just don't know. There's a lot more
to learn from Io, that's for sure.
Speaker 3 (47:02):
Did I tell you I've been thinking about that big
island in the middle of Loki Potera as the Island
of Death.
Speaker 2 (47:07):
That would be something if it had they like the
signature booklan topography going on there. Once we get some
more detailed imagery. All right, well, we're going to go
ahead and close the book on Io here, you know,
at least until more data presents itself and provokes us
to come back and take another look. But in the meantime,
(47:29):
we'd love to hear from all of you out there
if you have feedback in anything we've discussed in these episodes. Likewise,
are there other moons that we've covered in the past,
Jovian moons, the moons of Saturn, and so forth that
you think deserve a second, more detailed examination on the show.
If so, right in, let us know and we will
(47:49):
consider giving it a go.
Speaker 3 (47:51):
I feel like the obvious candidate is tighten right. Yeah,
here we go deep on Titan.
Speaker 2 (47:57):
Yeah, or you know whatever, the biggest one is, right,
all right? Just a reminder to everybody. It' 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 (48:14):
Huge thanks as always to our regular audio producer JJ Posway,
and shout out special thanks today to our guest producer
Max Williams. Thank you so much. Max. If you would
like to get in touch with us with feedback on
this episode or any other, to suggest a topic for
the future, or just to say hello, you can email
us at contact at stuff to Blow your Mind dot com.
Speaker 1 (48:44):
Stuff to Blow Your Mind is production of iHeartRadio. For
more podcasts from My Heart radio, visit the iHeartRadio app,
Apple podcasts, or wherever you're listening to your favorite shows.
Speaker 2 (49:04):
Rattator
Welcome to Stuff to Blow Your Mind production of iHeartRadio.
Speaker 2 (00:12):
Hey, welcome to Stuff to Blow Your Mind. My name
is Robert Lamb.
Speaker 3 (00:16):
And I am Joe McCormick, and we're back with the
third and final part in our series on Jupiter's moon Io,
the innermost and third largest of Jupiter's four Galilean moons
and the most volcanic body in our Solar system. Years ago,
we did a multi part series on the moons of
Jupiter at large, but this time we wanted to come
(00:37):
back and do a deeper focus on Io, in particular
to explore its own peculiar Hadian prodigies, because it really is,
as I've said in the previous two parts, I think,
probably one of the most dramatic places in our Solar system,
certainly beyond Earth. Now, if you haven't heard the previous
two parts yet, I would recommend you go back and
(00:59):
listen listen to those in order. But to briefly recap,
we started off by talking in detail about some really
eerie and thrilling images of the surface of Io, mostly
based on data collected in twenty twenty three and twenty
twenty four by NASA's Juno mission. These images highlighted a
lot of the really enigmatic features of the Moon's topography,
(01:21):
including these gargantuan thorn like mountains and volcanic highlands, huge
fields blanketed and yellow sulfurous frost, Vast lakes of molten
lava constantly overturning with waves, giant lava flows spreading in
some cases hundreds of kilometers, forever resurfacing the Moon and
erasing all the scars of its history. We also talked
(01:44):
about the physical ironies of the conditions on Io, including
the fact that it is at once deep cold due
to its extremely thin sulfur dioxide atmospheres inability to trap heat,
doesn't really have much of an atmosphere, can't trap heat
there of course, in places it is unimaginably hot, due
of course, two volcanic eruptions, according to a volcanologist we
(02:07):
discussed in Part one, a single one of the Moon's volcanoes,
the lava lake known as Loki Ptera, which we did
do a little focus on. That was the one that
has a big island in the middle of it actually
has a number of islands, but one big old island
in the middle which shall not be named. That one
volcano emits more heat than all of Earth's volcanoes combined,
(02:32):
which is a pretty startling fact. We also talked in
previous parts a bit very briefly about the historical exploration
of Io, including Carl Sagan's account of the discoveries made
by the Voyager one probe in nineteen seventy nine. We
talked about the character from Greek myth that provides Io
its name, about how the story of Io was told
(02:52):
by Avid and other ancient authors, and how in ancient
times the character of Io was said to overlap or
interact with other religious figures, such as the Egyptian goddess Isis.
In Part two, we discussed when and how Io tends
to pop up in science fiction storytelling. There's sometimes what
(03:13):
at least feels like a dearth of Io stories, and
then we talked about a mystery regarding images of so
called ridges on the Moon's surface, which paradoxically look extremely
similar to wind driven sand dunes on Earth and Mars.
This is paradoxical because of the tenuous, barely there atmosphere
(03:33):
of Io, which wouldn't seem to be thick enough to
support the winds needed to make dunes. And then we
got into a paper that offered a likely solution to
this mystery. Finally, in the last episode, we talked about
the possibility of life on Io being a blasted, cursed, irradiated, waterless, sulfurous,
freezing cold, searing hot kind of nightmare ball, a place
(03:55):
from the video game Doom I would not seem to
be a good place to look for science of extraterrestrial life,
but if it were to exist there, we talked about
some astrobiology speculation on where and how that life might persist.
And now we are back today to round out the discussion,
talk about a few more things.
Speaker 2 (04:14):
That's right, all new things quite true.
Speaker 3 (04:16):
In fact. To kick things off today, I want to
talk about a pretty new research paper I think it
was just published a couple of months ago in the
journal Nature, I believe in December twenty twenty four, which
addresses a longstanding mystery about the interior of We've talked
about the mysteries of its surface, but now we're going
to talk about mysteries of what lies inside. So this
(04:38):
paper was by park at All and it's called Io's
title response precludes a shallow magma ocean. Again published in
Nature twenty twenty four, So a bit of context about this.
For the past four decades or so, there has been
a question about what powered the vulcan canic corruptions on Io,
(05:02):
and it was long suspected for a number of reasons,
but not confirmed, that underneath the surface of the Moon
there lay a vast planetary magma ocean, sometimes thought to
be maybe roughly fifty kilometers deep below the surface, a
vast ocean of liquid magma stretching around the planet, which
(05:23):
found release points at each of Io's roughly four hundred
active volcanoes. So this was long suspected by some researchers
to be the case. But this new paper published in
Nature in twenty twenty four has a group of researchers
who took information gathered by the NASA Juno mission and
(05:44):
used it to argue that the magma ocean hypothesis cannot
be correct and instead each volcano is probably powered by
its own distinct magma chamber. And I'm going to try
to explain how we get there. So a reminder, going
back to part one of this series, volcanic activity on
Io was not directly detected until the discovery of a
(06:07):
volcanic plume by NASA JPL scientists Linda Morabito in nineteen
seventy nine. The image was found in actually navigational images
created by the Voyager one spacecraft. Volcanism had been hypothesized
by the astrophysicist Stanton Peel beforehand, but this was the
first time direct evidence was identified. But ever since the
(06:30):
erupting volcanoes were first discovered, there has been this mystery
about what's inside the Moon to feed the eruptions. And
I wanted to read a quote here by Juno principal
investigator Scott Bolton, who is quoted in a NASA press
release about this new paper. Bolton summarizes it saying, quote,
since Morabido's discovery, planetary scientists have wondered how the volcanoes
(06:54):
were fed from the lava underneath the surface. Was there
a shallow ocean of white hot magma fueling the volcanoes
or was their source more localized. We knew data from
Juno's two very close flybys could give us some insights
on how this tortured moon actually worked. So how did
they investigate this? Well? I thought this was pretty cool.
(07:17):
So the Juno spacecraft did flybys of Io in December
twenty twenty three and February twenty twenty four, and during
those close passes, Juno interfaced with an Earth based tool
called NASA's Deep Space Network, which is a network of
three equidistant ground based radio antennas on Earth. There's one
(07:37):
in California, there's one in Australia, and one in Spain.
And the ideas with this equidistant spacing of these antennas,
they always at least one of them can maintain contact
with something in space. You never have it going dark. Together,
these instruments were able to acquire high precision Doppler readings
(07:57):
to detect minute changes in Juno's acceleration, which was in
turn able to tell us things about the gravity of
iob the gravitational influence of IO, because it was primarily
Io's gravity that would have been affecting Juno's acceleration at
these moments. So essentially, researchers were looking for how the
(08:19):
gravitational field of IO changes during its tidal stretching cycle,
more on that than just a minute, because that would
help us know how rigid the Moon is. A more
rigid IO would be consistent with a more solid interior,
but a more flexible IO would indicate a liquid magma
ocean underneath. Now on that sort of flexing and stretching cycle,
(08:44):
IO is in a very close orbit around Jupiter. The
average distance between the planet and the Moon is four
hundred and twenty two thousand kilometers over the course of
its roughly forty two point five hour orbits. Now that is,
this is not much further than the distance between the
Earth and the Moon, which is about three hundred and
(09:05):
eighty four thousand kilometers, except think of how big Jupiter is.
In the words of Scott Bolton, the Juno principal investigator,
IO is orbiting a monster, and this has many different effects.
We've talked about some of them already, but a big
one is a gravitational effect. Gravity follows the inverse square law,
(09:27):
meaning that the attractive force between two objects in space
is inversely proportional to the square of the distance between them.
And another way of thinking about that is, as you
get closer to a planet, the force of gravity asserted
on you rapidly becomes greater. So get a little bit
closer to Jupiter and you get pulled harder toward it.
(09:49):
A strange thing about IO is that in addition to
being very close in orbit around a very massive planet,
the orbit of this moon is also not circular. It
is slightly elliptical, meaning that if you look down from
above the orbital plane, you're going to see the orbit
being slightly longer in one direction than another. It's a
(10:11):
little bit more oval shaped than a circle. This elliptical
orbit is actually because of regular gravitational influence by two
more of the Galilean moons, Europa and Ganymede. These moons
are in what's called an orbital resonance with Io, which
means that their orbits are sort of like small integer
(10:32):
multiples of the orbits of iOS. They frequently line up
in the same place as Io as they're going around
the planet, and the fact that they continually line up
in the same direction over and over means that they
sort of stretch Io's orbit in that one direction. So
the elliptical orbit of Io means that the distance between
(10:53):
Io and Jupiter keeps changing, and so as the distance
keeps changing, the string of Jupiter's gravitational pull on Io
keeps changing. Two. And this really affects the Moon because
it's always the case that the side of the Moon
facing Jupiter experiences a stronger pull than the side that's
(11:15):
farther away. The nearer side is pulled harder than the
far side, But because of the constantly changing distance between
Io and Jupiter, the difference between the pull on the
far side and the near side of the planet keeps
changing too, And this manifests as what planetary geologists might
call tidal flexing. It's a squeezing, stretching of the solid
(11:38):
material that the Moon is made of in the fluctuating
gravitational field. You can kind of just imagine this by
like holding a rubber ball in your hand and just
like squeezing it over and over again. It's a flexing
of the material that the moon is made of. Now, Rob,
did you ever do the thing in like the school
cafeteria when you were younger, where you you get one
(12:00):
of those, you know, cheap metal forks, cafeteria forks, and
you bend it back and forth a bunch of times,
real fast until it gets hot.
Speaker 2 (12:08):
No, I never did this. I didn't even know this
was a thing. I mean, I mean, physically, I understand
why it's possible, but I didn't know it was a
thing that kids do.
Speaker 3 (12:18):
I guess it was the thing I did. I don't
know sure is that are most forks supposed to bend
like that? You're using your hands right, not your mind? Yes,
just hands, just hands. This this has got to be
possible only with like real bottom shelf cutlery. But yeah,
so you know, you flex a piece of piece of
metal back and forth a bunch of times. Usually what
(12:39):
you will find is that the metal heats up. The
flexing causes a frictional force within the material that excites
the atoms, and it makes the metal hot or at
least warm. Similar principle here, The flexing of the Moon
by the by the changing gravitational field as it gets
closer and farther away from Jupiter causes frictional heat of
(13:00):
the inside of the Moon, and that heat is immense.
It is so immense that it melts parts of the
Moon's interior and this massive build up of internal heat
energy is released to the surface through volcanic eruptions. But
this brings us back to the question we started with,
what is the nature of the subsurface magma source to
(13:22):
read from the paper in Nature quote For decades it
has been speculated that this extreme tidal heating may be
sufficient to melt a substantial fraction of Io's interior, plausibly
forming a global subsurface magma ocean. Many worlds are believed
to have had magma oceans early in their evolution, notably
(13:44):
the early Moon referring to Earth's moon there, notably the
early Moon, which is thought to have had a shallow
magma ocean in the first one hundred million years, caused
by the giant impact that birthed the body, which that
is not new information in this paper, but that on
its own is just a fascinating fact to consider it,
(14:05):
you know. So there is the main theory of the
origin of the current Earth and Moon is the giant
impact hypothesis. So the idea is that roughly four and
a half billion years ago, during the formation of the
Solar System, when the you know, the planets were just accreting,
there was a collision between the early proto Earth and
(14:26):
some kind of roughly Mars sized object, and this collision
caused a fracturing that eventually ended up causing the separation
of the material that became the Earth and became the Moon.
So that's the common origin of the Earth we have now,
and where the Moon came from. And so the idea
here is that for the first one hundred million years
or so after that, the Moon probably had a global
(14:51):
shallow magma ocean surrounded by liquid by molten rock. Wow
would have been cool to see. Perhaps not physically cool,
but anyway. So the authors cite that as an example
of a global shallow magma ocean surrounding a planetary body
or a moon, and then the quote goes on to
(15:13):
say Io's extreme volcanism strongly suggests the existence of at
least a partially molten interior. Whether the interior contains a
shallow global magma ocean has been an outstanding question since
the discovery of Io's volcanism. Now, beyond these theoretical models,
were there any recent experiments that would have provided support
(15:36):
for the idea of a global magma ocean. I was
looking into this and it appears yes, there were some
good reasons from findings that pointed in this direction. Apparently,
the Galileo mission took some magnetic measurements that were thought
to be consistent with a shallow, shallow reserve of global magma,
(15:56):
and I also wanted to flag another argument for the
magma ocean, and I came across in a space dot
Com article by Keith Cooper, which pointed out that previous
data collected by the JUNO mission had actually enabled researchers
to create the first global map of Io's volcanic activity.
(16:17):
Rob actually pasted a picture of this global map in
the outline for you to look at here. And so
it's got little color coded polka dots of different energy
levels of volcanic corruptions all over Io's surface. The authors
here assembled this map based on near infrared signatures of
iOS polar regions. In particular, data collected by previous missions
(16:38):
had already done some of this mapping, I think, but
had left us with an incomplete picture of volcanic activity
near the poles. And I was reading a space dot
com article that quoted study author Ashley Davies, a volcanologist
at NASA, JPL and Calteche, Pasadena, and Davies explained their
findings by saying, quote before this anal it was thought
(17:00):
that Iowe's polar volcanoes were fewer and more powerful than
at lower latitudes. We show that polar volcanoes are about
as prevalent as at lower latitudes, and actually with lower
emitted power. Suggesting smaller eruptions. And another thing the researchers
found is that these findings were interpreted by computer modeling
(17:22):
to lend support to the hypothesis of a global subsurface
magma ocean. So it seemed like this looked good for
the for the magma ocean.
Speaker 2 (17:31):
Did they consider connecting these dots and seeing if it
made a pentagram or not, because that's that's generally what
you do in detective movies.
Speaker 3 (17:39):
It really does look like people should be putting tax
in and putting string between them, doesn't it.
Speaker 2 (17:44):
Yeah, yeah, see it all lines up with that unnamed island.
Speaker 3 (17:47):
Yeah, well, that unnamed island is I'm sure going to
be right around one of the yellow dots here. In fact,
I think I see where Loki Ptera is, and yes,
it is, in fact one of the It is one
of the hottest types of dots. Any pentangle, I'm not
really seeing it.
Speaker 2 (18:02):
If you want them bad enough, they will manifest.
Speaker 3 (18:05):
But anyway, coming back to the new Jono experiment park
it all from twenty twenty four, so the authors use
the Doppler data from the JUNO flybys and the Deep
Space Network radio telescopes, as well as data previously collected
by the Galileo mission to try to look at the
tidal deformation of Io. And again, remember they're looking for
(18:26):
if it's more if it's stretching more, if it seems
more easily deformed, that probably means liquid magma ocean underneath.
And if it's more rigid, that probably means that it
is more solid underneath. And they concluded, based on their
findings that Io could not have a global magma ocean
underneath its surface. Instead, the Moon must be mostly solid,
(18:47):
with individual magma chambers driving the hundreds of volcanoes. The
authors of the paper right quote our results indicate that
tidal forces do not universally create global magma oceans, which
may be prevented from forming owing to rapid melt ascent
intrusion and eruption. So even strong tidal heating, such as
(19:08):
that expected on several known exoplanets and super earths, may
not guarantee the formation of magma oceans on moons or
planetary bodies. And Rob, I've got a little artist's rendition
for you to look at here. This is an artist's
impression of the interior of Io informed by these new findings,
does not show a global magma ocean instead shows these
(19:30):
the pockets, these magma chambers that are leading up to
the volcanoes on the surface, some of these volcanoes being
connected to plumes that we see erupting far over the
surface of the planet. This has more the look of
you know, it's like when you see superheroes and movies
that like have the fire inside and you see their
(19:51):
skin kind of cracking and then the fire is ready
to come out. It looks like it's about to go
supermode exactly.
Speaker 2 (19:56):
Yeah, yeah, these kind of yeah, these deep the I
want to describe them as veins because they don't really
have that kind of rooting pattern. But deep fissures, I
guess would be more glowing fissures would be the way
to describe them.
Speaker 3 (20:11):
And so perhaps one reason Io doesn't have a magma
ocean would be all of its volcanoes. They may in
fact be dissipating the heat that would otherwise melt the mantle,
the author's write in their conclusion quote. On Earth, deep
melts can be denser than the surrounding mantle and thus
remain sequestered. In a basal magma ocean. On Io, pressures
(20:34):
are much lower, so mantle melts are expected to be
always less dense than the surrounding solid mantle. The melts
will tend to ascend, making maintenance of a deep magma
ocean dynamically problematic. Conversely, if the melts are dense, for example,
if sufficiently iron rich, although a deep magma ocean could
then form, it would be hard to explain how any
(20:57):
such melt would ascend and erupt. Thus, we conclude that
the volcanism scene on iosurface is not sourced from a
global magma ocean. So it seems like that interesting idea
is likely put to rest unless something causes us to
really reinterpret these results. But despite the magma reserves not
being part of a sort of global shared ocean in nature,
(21:21):
I still think that leaves the volcanoes and the plumes
and the eruptions and the lava lakes no less fascinating
and charismatic.
Speaker 2 (21:29):
Yeah. Yeah, Plus, you know that if you miss that,
if you miss that vision of what iowe is, it's
probably out there somewhere else in the universe. So you
can just imagine that it's out there somewhere waiting for you.
Speaker 3 (21:42):
Used to be present on our moon.
Speaker 2 (21:45):
Yeah, yeah, it's somewhere else in time and space, and
in time maybe a lot closer than you thought. Now.
One of the features of the illustration that you showed me,
(22:06):
and certainly listeners can find various images that either depict
this or are actual captures of this. One of the
distinguishing features that you often see with IO is that
of these plumes coming up from its surface volcanic eruption
that is ejecting material into space, and it is always
(22:28):
kind of weird to look at because it feels completely
out of scale, like we're not used to seeing. You know,
we've all seen images of volcanic eruptions, and yes they
can actually they can look quite alarming from orbit, but
this just looks These just look amazing because the Moon
in profile has this plume coming off of it, just
this ridiculously far reaching plume of volcanic eruption. And so
(22:55):
that's what I want to explore here in this next section,
getting into like what exactly this is, what is it
mean for not only IO, but for the the basically
the entire orbital realm of Jupiter itself.
Speaker 3 (23:09):
I totally agree with what you say about looking at
these plumes, that the plumes even in real. Direct images
taken from reality look fake. They look like they look
like art. The word photo can be misleading because the
instruments used to capture these images can be different in nature,
and it's not always just visual light. But but yeah,
like direct images of reality that we're looking at, but
(23:32):
they're that they look like a cartoon.
Speaker 2 (23:34):
Yeah, yeah, like this is grotesque and ridiculous, But I'm
reminded of of pimples. You know, usually in profile, you
are not going to notice a pimple, And if a
pimple were to burst on a person, you wouldn't see
that in profile. You wouldn't see like the silhouette of
the eruption. And if you were to see that, well,
(23:55):
you would be watching like an Itchy and scratchy cartoon
or a SpongeBob cartoon or something. It be a cartoon
exaggeration of reality. And that's what the scale of these
things really looks like.
Speaker 3 (24:06):
Yeah, that's right. We see plumes on io that are
like somebody with a three inch high pimple that when
you pop it, it squirts like six feet off their body.
Speaker 2 (24:15):
Yes, so what's going on here? Well, you know, here
on Earth, we certainly have powerful volcanic eruptions as well.
We have in the past, and they occur periodically, and
they will continue to occur. But we also have some
other things going for us that you don't find on
IO and you don't find everywhere else in our solar system.
(24:37):
We have a robust atmosphere, We have resulting wind resistance
and sufficient gravity to place the necessary escape velocity beyond
what even a very powerful terrestrial eruption is capable of reaching.
Speaker 3 (24:51):
Right, So that escape velocity number is going to mean
that our volcanoes they might erupt quite powerfully, but they're
not blasting stuff out into space so that it never
comes back, or not much stuff certainly.
Speaker 2 (25:02):
Yeah. I've read that while terrestrial volcanoes can't really blast
things into orbit, they can reach really high into the atmosphere,
in arguably touching space. For instance, the twenty twenty two
Hanga Tonga volcanic eruption supposedly shot water vapor up that
high to where it was essentially touching space. But it's
(25:24):
not quite what we're seeing with IO at all.
Speaker 3 (25:27):
Right, And even if it were to go into space
and go into orbit, that still wouldn't be escape velocity.
Speaker 2 (25:32):
Right, right, Yeah, you've got to get all the way
out of there. You got to it's got to be
a complete breakup with the planet, not one of these things.
We'll continue to see each other socially. No, no, no,
you've got to be out of there.
Speaker 3 (25:42):
Volcanoes are not doing that.
Speaker 2 (25:46):
So this thinking about this led me to, you know,
get into escape velocity here on Earth and elsewhere, and
ways to escape it. You know, the most obvious way
to do it is, of course, in a rocket. That's
what we're used to seeing with our Earth space technology.
The escape velocity on Earth is eleven point one eighty
(26:09):
six kilometers per second. That is, that's going to be
a higher velocity than is necessary for any of the
other inner planets. On Earth's own moon it's two point
thirty eight kilometers per second, and on Io the number
I've seen is two point five five eight. So just
(26:29):
to give you a little frame of reference for what
we're talking about here again coming back to what does
Earth have that a lot of these other suspects don't
you know? It has. It has the gravity, it has
the robust atmosphere and so forth. So this all adds
up to a greater necessary escape velocity for anything that
is leaving the surface of the planet or any point
(26:51):
within the atmosphere of the planet, and hoping to free
itself of our orbital dominion. Now one thing I want
to go ahead, get out of the at the top here there.
I think a lot of people have probably heard the
legendary manhole shot into space story via Operation plumb Bob.
(27:12):
These were atomic tests in nineteen fifty seven. The idea
here was that you had these test wells for atomic
detonations with a metal cap on the top, essentially a
manhole cover, and at least one of these blasted the
cap off, and it was said that it achieved such velocity.
(27:33):
In fact, I think the number that is often cited
is six times the necessary escape velocity and therefore flew
off into space and is potentially still out there well.
According to a twenty twenty two Snop's article by Bethania Palma,
there's nothing actual actually out there to back this up.
This all seems to stem from a comment by Robert Brownly,
(27:57):
who worked on the project, who remarked that the manhole
cover in question would have been blasted off at six
times the necessary escape velocity. It apparently went flying, but
that's all that's really known. We don't know if it
was launched into space, and if it was, we have
no records or recording of it. I think it's also
been mentioned that it's possible that it would have burnt
(28:20):
burnt up on the way up as well. So you know,
we have to consider all these options. But there's no
like clear evidence that this thing actually made it into
orbit or beyond orbit and so forth.
Speaker 3 (28:32):
Yeah, all we actually know is that this was a piece,
a solid piece of metal that was hit from below
with tremendous energy. But we don't know exactly what happened
to that matter and energy afterwards, what its journey was
question mark right now.
Speaker 2 (28:49):
Of course we already mentioned rockets. Rockets are you know,
we can compare rockets to volcanoes in that, you know,
the rocket is taking advantage of a very explosive chemical
reaction in order to propel this you know, tower of
steel and so forth upwards through the atmosphere. And you know,
it's and rocket science has come a long way. It's
(29:11):
ultimately a lot more dependable than trying to blast into
space on a volcano, which again probably wouldn't give you
the exactly the push you needed anyway.
Speaker 3 (29:20):
I wonder if it's been tried.
Speaker 2 (29:23):
You'd have to be you'd have to be so patient.
I don't think. I don't think it's just maybe there's
some sort of sci fi scenario, or it would make
sense if you know of a science fiction tale in
which someone uses a volcano to escape a planet's orbit,
do write in and tell us about it. Now. In
terms of just using explosions though, and explosive events to
(29:46):
potentially transfer into orbit or beyond orbit, we do have
to mention Project Ryan here. This has come up on
the show in the past because it is, you know,
it's an early concept of how we might achieve interplanetary travel.
It was a nuclear pulse spaceship concept from the nineteen
(30:10):
fifties and sixties. I think a lot of you may
be familiar with this. Essentially built around the idea was
built around the concept you could propel a craft through
space via a series of nuclear detonations behind the craft.
Not to be confused with nuclear thermal rockets such as
(30:30):
the Nerva project, in that you'd have a nuclear reaction
that was heating fuel rather than depending on a chemical
reaction to do so.
Speaker 3 (30:42):
So the Nerv rocket would still be a reaction drive,
but it would just be the heating is from nuclear sources.
Speaker 2 (30:48):
Correct, Yeah, And that one was never tested in space,
nor was Orion. But the Orion program is like, let's
keep throwing atomic bombs behind the ship, allowing them to explode,
thus propelling our ship onward and onward through space with
each blast like pushing up against a blast plate on
the rear of the vessel, an idea that I've just
(31:11):
always found. I mean, it's it's it's preposterous and yet reasonable,
amazing in its own right, and you know, in Inner
Yourself to the Stars, Yeah, yeah, and uh yeah, it's it's.
It's one that I've come back to a few different times.
But it's one of Sagan wrote about as well. Actually
(31:34):
looked up an old like press briefing where someone asked
Sagan about it, and you know, he pointed out he'd
written about it in Cosmos or I don't remember if
you'd written about it in Cosmos or if you just
discussed it on the television series, but you know, pointed
out that like, Okay, well, this is actually not a
bad way to go ahead and get rid of some
of our atomic weapons. Let's use them to propel a spaceship.
(31:56):
But of course there are all these various hazards to
such a technique as well. Some of these we'll get
into here in the discussion. So I was, you know,
I was mostly familiar with the concepts involved here, the
potential benefits and the downsides. But one thing that I
didn't quite realize is that early models of the project
(32:17):
Orion nuclear pulse spaceship during the fifties and sixties actually
considered it not only for propelling a vehicle through space,
but for using it in liftoff in order to achieve
escape velocity from Earth.
Speaker 3 (32:32):
WHOA, I don't think I'd ever thought of it that way.
Speaker 2 (32:35):
Yeah, I was reading about this in a couple of sources.
One was in a nuclear pulse Propulsion Oriyan and Beyond
by Schmidt at All for NASA, and they pointed out
that early drafts of the proposal called for a bullet
light capsule to be launched from the ground. From the
ground via an atomic detonation, likely from a Nevada nuclear
(32:56):
test site. The mass of the vehicle on takeoff would
have been on the order of ten thousand tons, most
of which would have gone into orbit at takeoff, the
zero point one kiloton yield pulse units would be ejected
at a frequency of one per second. As the vehicle accelerated,
the rate would slow down and the yield would increase
(33:16):
until twenty kiloton pulses would have been detonated every ten seconds.
The vehicle would fly straight up until it cleared the
atmosphere so as to minimize radioactive contamination. This is one
of the big hazards and downsides to this whole concept
is that you would it would entail detonating multiple multiple
(33:37):
atomic weapons in this model within the atmosphere. But even
if you weren't using that within its atmosphere to achieve liftoff,
if you were going to the program where okay, once
you get your spaceship away from Earth, then you can
start dropping bombs in order to accelerate. Even then you're
still causing all of these detonations. And then what happens
(33:59):
when you reach sure destination. There are some models that
were outlined that would call for detonating bombs as you landed,
thus like nuking the landing site ahead of your arrival.
And if there are people on board, well they're gonna
have to deal with the literal fallout of all of that.
The original concept was created by Ted Taylor and Freeman Dyson,
(34:22):
and Freeman Dyson's son, George Dyson, claims, historian of science,
wrote about all this in the book project Orion, The
True Story of the Atomic Spaceship, and he points out
quote these early four thousand ton ground launched versions of
Orion specified the ejection of about eight hundred bombs raging
(34:45):
and yield from zero point fifteen kilotons at sea level
to five kilotons in space to reach a three hundred
mile orbit around Earth. Points out that each bomb would
have weighed around half a ton. Less yield would be
necessary at lower out tod since the thicker air itself
would absorb energy and add to the kick against that plate.
(35:06):
But then you would need more yield. You'd have to
steadily increase the yield of the detonations as the vessel
was propelled upwards. And this would have all required like
tight precision and exactly how you're detonating these bombs and
even how you're getting them back there underneath the ship,
like is it a trapdoor or is there some sort
(35:26):
of a you know, some sort of a targeted rocket
system that launches them alongside the vessel and then back
underneath it. You know, you would have to work out
all of those problems. So that's about eight hundred bombs.
The original design called for about two thousand bombs or
two thousand pulse units, far more than needed to reach
orbit according to their calculations, but that was because they'd
(35:47):
set their sites pretty high. Their slogan was Mars by
nineteen sixty five, Saturn by nineteen seventy, and they were
talking about like crews of one hundred and fifty people.
So this was a really ambitious concept. Obviously, this is
not the way it all worked out.
Speaker 3 (36:05):
I mean I said this in a totally different context earlier.
But there's a cartoonishness to this. It kind of reads
like a joke.
Speaker 2 (36:12):
Yeah, it does, and I think that's one of the
reasons it resonates so well. It's like this interesting perversion
of the accumulation of atomic weapons, though not necessarily a
negative pervert, like the accumulation of atomic weapons is already
a perversion in many respects, but the idea of then
taking them all and using them to propel a spaceship
(36:34):
to another planet, you know, with such ambition it, you know,
it's ultimately more attractive. Like Sagan said, it's like, well,
that's one way to get rid of the weapons, or
at least that's the way he put it at one point.
(36:58):
Now the concept here continued to again they ended up
moving away from the idea of it potentially blasting off
of the surface of the Earth like this via atomic
weapon detonations. It had many powerful supporters, but it never
came to fruition for a variety of reasons, including cost,
including risk, and of course including international treaties about nuclear testing.
(37:21):
George Dyson points out that, yeah, you had these various
drawbacks to such a program, including the idea that if
you were going to use detonations while potentially a landing
a ship in another world, again, you would be pre
contaminating the landing site. So even if you even if
that wasn't going to make it too you know, radioactive
for then humans to venture out on the surface of
(37:43):
this destination world, you're still messing with what you were
going to explore to begin with. You know, so so
many different reasons to not go in this direction. Now
you might be wondering was there another way to get
something into orbit from Earth's surface without some sort of
an explosion. Well, there has been research into the use
of centrifugal force, and such research actually continues at least
(38:07):
as a rocket aid to decrease the dependence on traditional rockets.
You know, you can think essentially like slingshots in terms
of like the basic fundamentals here, this is the sort
of thing we could potentially come back and do a
more dedicated episode on this idea, because again there as
(38:27):
at least one company out there that continues doing a
lot of well funded work in this area. Now elsewhere
in speculation and in science fiction, there are some ideas
related to directed panspermia to consider, so directed PAMs spermias.
Of course, this would entail the intentional seeding of other
worlds with life, and in some creative takes on what
(38:51):
this might look like, it might entail some manner of
biological propulsion, maybe some sort of biocanon that enables a
seed of some sort to escape from one world's gravity,
drift through space and find another world. And we actually
saw a vision of what this might look like in
a recent film that we discussed on Weird House Cinema,
(39:11):
Beyond the Mind's Eye.
Speaker 3 (39:13):
Oh that's right with the Yon Homer soundtrack, It's like
the second or third track on there is the one
that the seed's blasting into space and then we see
them form, and what was the deal with that?
Speaker 1 (39:24):
It?
Speaker 3 (39:25):
Like, why do I associate that with a cover of
Black Sabbath's Planet Caravan.
Speaker 2 (39:34):
Because it was used as a music video for that
cover the Planet Caravan. Yeah, which kind of shakes out
kind of makes sense. Now is this at all feasible?
I don't know. Again, I think it comes down to
what sort of world are you attempting to escape with
this seed? You know, what's the gravity like, what's the
atmosphere like? And so forth. Now I haven't seen this
(39:57):
movie in ages, but I believe the bugs in the
eteen ninety seven Starship Troopers movie also have something like this.
I think they're called plasma bugs in that, and these
are some sort of organic cannon system.
Speaker 3 (40:09):
Right, biological artillery. Yeah, there's some big bugs that kind
of bend over and they like eject something out of
their backside that goes up into orbit and it takes
out the capital ships.
Speaker 2 (40:21):
All right, So some maybe some sort of weaponized version
of something that might otherwise be used for pan spermic.
Speaker 3 (40:29):
Purposes, possibly, who knows.
Speaker 2 (40:32):
Now there's another major player in the world of science
fiction biothreats, and that's the Tyranids in the Warhammer forty
thousand universe. These are if you're not familiar with these,
they're kind of there's a little bit of xenomorph to them,
except they are a spacefaring species. They have big, big
leviathan bioships and they arrive on worlds and they invade
them and eventually like turn all the bio they convert
(40:55):
all the biomass on the planet, But then they have
to get it off the planet. And interestingly enough, unless
I'm mistaken, they don't have any kind of way of
like launching it directly back up with their you know,
entirely biological civilization. Instead, they depend on something called capillary towers,
(41:16):
which are like organic space elevators. So they just have
the big ships in orbit suck it all up back
off the surface of the planet, which I guess is
one way to potentially do this.
Speaker 3 (41:27):
Sounds kind of Necromonger style, Yeah, yeah, yeah, there's a
certain necromongernous to them, or there's a certain Tyranid nature
to the Necromongers.
Speaker 2 (41:36):
One way or the other, including an image an illustration
here of what this might look like, you know, the
big coiling ambilical cord going from the planet's surface up
to some sort of you know, horrifying living alien vessel.
Speaker 3 (41:52):
Yikes, give me out.
Speaker 2 (41:53):
But anyway, back to the real world, back to volcanoes. Yeah, so,
while Earth volcanoes can't blast things in orbit space, volcanoes,
including ice volcanoes, which I think we've talked about on
the show before, absolutely can and the volcanoes of Io,
dealing with much less gravity and atmosphere, can easily jet
their contents into orbit, and not only into their orbit,
(42:17):
but into the orbit of Jupiter. Ah.
Speaker 3 (42:19):
Well, this actually brings us back to the one of
the first things we talked about in the series, when
we were discussing Carl Sagan's comments about what scientists knew
as the voyager probe was approaching Jupiter before they actually
had direct evidence of the volcanoes. One of the indications
that there might be something strange going on with Io
(42:40):
was he said that they had already detected a huge
doughnut shaped tube of atoms in orbit around Jupiter basically
within the sort of the same position as the orbit
of the moon Io made up of just like just
isolated atoms of things like sulfur and potassium and sodium,
and for some reason that's just going around the planet.
Speaker 2 (43:02):
Why that's right. Yeah, These eruptions create a terroidal or
doughnut shaped cloud of charged particles that follow Io's orbit
and wraps part of the way around Jupiter. It's also
referred to as a plasma taurus, and it produces ultra
violet light, intense radiation, and as Io orbits Jupiter, it
(43:24):
travels through the torrent, generating an enormous electrical current, thus
amplifying Jupiter's magnetosphere. So the ioplasma Taurus plays a major
role in strengthening the most powerful magnetosphere in the Solar System.
I mean, the magnetosphere of Jupiter almost reaches the orbit
of Saturn.
Speaker 3 (43:44):
Wow.
Speaker 2 (43:45):
Now, there are other sources of charge particles in Jupiter's orbit,
including other Jovian moons and the Solar wind, But according
to the ESA, Jupiter's magnetosphere captures all of these particles
and then speeds them up like it's a literal part
article accelerator, creating intense radiation belts out of these accelerated
particles and I owe as a major contributor. These radiation
(44:07):
belts pose an additional obstacle to missions to any missions
to the Jovian moons, particularly any possible future missions that
might feature live crew members, because this would expose them
to lethal doses of radiation for like hours at a
time potentially, and it poses a risk to equipment as well.
So any mission through these belts requires, on one hand,
(44:29):
additional navigation precision to avoid, as the ESA points out,
low latitude orbital paths around Jupiter. And also you just
need to have additional shielding and protection for any gear
because I've read that it essentially would be it would
be a case where whatever kind of equipment was aboard
one of these craft, it would encounter as much radiation
(44:53):
as a terrestrial satellite would endure over the course of
multiple decades.
Speaker 3 (44:57):
And Joe I.
Speaker 2 (44:57):
Included a couple images here in the notes for you.
Here the sort of highlight iOS Plasma Taurus and shows
shows us like how it sort of features into the
complex magnetosphere and orbital ecosystem of Jupiter.
Speaker 3 (45:14):
Ah yeah, okay, so branching out from the poles, we
see the magnetic field lines, but then closer in to
of course those extend out really far into space. But
then in closer to the planet we see the gold ring,
we see the ring of the the the atom or
the ion Taurus. And this is a lot of this,
as you said, is stuff that is actually being ejected
(45:37):
from the thin atmosphere and uh, an orbit of Io
bi volcanic eruptions and just goes off into space and
ends up in orbit not around Io but around Jupiter.
Speaker 2 (45:48):
Yeah. Yeah, so I I found found this. This is
not just another way in which Io stands out and
I think is rather fascinating. It's it's again, it's easy
to to consider Io and think, okay, well it's not
It's maybe not a top consideration for extraterdustrial life. It's
not a top consideration for some sort of uh, you know,
(46:09):
distant future human colony.
Speaker 3 (46:11):
Uh.
Speaker 2 (46:12):
And it's not even like the biggest moon. Maybe in
your opinion, it's not the most impressive moon in the
Jovian System. But when you look at details like this,
it's clear that it is a major player in the
Jovian System, like it contributes quite a bit. So it
would be you would be in great error if you
were to completely dismiss IO and be like, oh, it's
not interesting it it doesn't really do anything, et cetera. Like, no,
(46:35):
it's it's it's of extreme importance.
Speaker 3 (46:38):
I want to meet the person who says it's not
interesting because it's not the biggest size matters not. Come on,
look at the volcanoes. Yeah, I know, it's that island.
Speaker 2 (46:50):
There's a lot going on here, you know, maybe maybe
not life, but maybe life. As we discussed in the
last episode, we just don't know. There's a lot more
to learn from Io, that's for sure.
Speaker 3 (47:02):
Did I tell you I've been thinking about that big
island in the middle of Loki Potera as the Island
of Death.
Speaker 2 (47:07):
That would be something if it had they like the
signature booklan topography going on there. Once we get some
more detailed imagery. All right, well, we're going to go
ahead and close the book on Io here, you know,
at least until more data presents itself and provokes us
to come back and take another look. But in the meantime,
(47:29):
we'd love to hear from all of you out there
if you have feedback in anything we've discussed in these episodes. Likewise,
are there other moons that we've covered in the past,
Jovian moons, the moons of Saturn, and so forth that
you think deserve a second, more detailed examination on the show.
If so, right in, let us know and we will
(47:49):
consider giving it a go.
Speaker 3 (47:51):
I feel like the obvious candidate is tighten right. Yeah,
here we go deep on Titan.
Speaker 2 (47:57):
Yeah, or you know whatever, the biggest one is, right,
all right? Just a reminder to everybody. It' 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 (48:14):
Huge thanks as always to our regular audio producer JJ Posway,
and shout out special thanks today to our guest producer
Max Williams. Thank you so much. Max. If you would
like to get in touch with us with feedback on
this episode or any other, to suggest a topic for
the future, or just to say hello, you can email
us at contact at stuff to Blow your Mind dot com.
Speaker 1 (48:44):
Stuff to Blow Your Mind is production of iHeartRadio. For
more podcasts from My Heart radio, visit the iHeartRadio app,
Apple podcasts, or wherever you're listening to your favorite shows.
Speaker 2 (49:04):
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