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