Speaker 1: Welcome to Bedtime Astronomy. Explore the wonders of the cosmos
Speaker 1: with our soothing Bedtime Astronomie podcast. Each episode offers a
Speaker 1: gentle journey through the stars, planets, and beyond, perfect for
Speaker 1: unwinding after a long day. Let's travel through the mysteries
Speaker 1: of the universe as you drift off into a peaceful
Speaker 1: slumber under the night sky.
Speaker 2: I want you to take a second and like just
Speaker 2: visualize the most likely place we might finally find alien
Speaker 2: life in our solar system.
Speaker 3: Yeah, that's a big question.
Speaker 2: Right, And you know, if you ask one hundred people
Speaker 2: on the street, the vast majority are going to point
Speaker 2: straight to Mars. Oh.
Speaker 3: Absolutely, the red planet.
Speaker 2: Exactly, Mars. I mean it's right next door. We have
Speaker 2: all these rovers like leaving tire tracks in the dirt everywhere.
Speaker 3: We spend so much time looking at those dried up
Speaker 3: river beds.
Speaker 2: Yeah, just hoping to find, you know, a fossilized microbe
Speaker 2: from billions of years ago. But I want you to
Speaker 2: completely bypass Mars today, gipit entirely. Totally. Forget the red dust,
Speaker 2: forget looking for ghosts of a dead biosphere. We are
Speaker 2: heading much further out into deep space, past the.
Speaker 3: Asteroid belt, straight towards you.
Speaker 2: Straight to the gas giant. But you know, we aren't
Speaker 2: looking at the turbulent atmosphere of Jupiter itself. We are
Speaker 2: locking our sights on one of its icy moons, Europa, Europa,
Speaker 2: and like our mission today is to explore this massive,
Speaker 2: brand new reality check in astrobiology.
Speaker 3: It's a huge shift in how we think.
Speaker 2: It really is because, I mean, we've known for a
Speaker 2: while that Europa hides this global ocean beneath its frozen.
Speaker 3: Shell, right, that's not the new part, no, But.
Speaker 2: The new part is that getting to that water and
Speaker 2: you know, whatever complex chemistry might be swimming around in
Speaker 2: it is going to be a much tougher barrier than
Speaker 2: scientists ever assumed.
Speaker 3: It is arguably the most compelling piece of real estate
Speaker 3: in our entire planetary neighborhood.
Speaker 2: Why is that exactly?
Speaker 3: Primarily because it's not a fossil. It is active right now.
Speaker 3: Like when you look at high resolution images.
Speaker 2: Of Europa once from the Galileo probram yeah.
Speaker 3: The Galileo probe in the nineties, or even the more
Speaker 3: recent stuff from Juno, you immediately notice what is missing exactly.
Speaker 3: You don't see craters. If you look at our own Moon,
Speaker 3: it is absolutely pulverized, just covered in impact craters from
Speaker 3: billions of years of cosmic bombardment with the giant golf ball, right,
Speaker 3: But Europa doesn't have that. You see this brilliant, bright
Speaker 3: white sphere heavily scarred with these incredibly long, dark, sort
Speaker 3: of reddish brown fractures.
Speaker 2: It literally looks like a cracked eggshell floating in the void.
Speaker 3: That's a perfect way to describe it, and the lack
Speaker 3: of craters tells us something vital. The surface is young,
Speaker 3: it is constantly refreshing and renewing itself.
Speaker 2: Because beneath that cracked shell, Europa is hiding a massive
Speaker 2: global ocean of liquid water.
Speaker 3: And not just a subterranean lake either, right.
Speaker 2: Not a slushy aquifer. It is a deep, earning ocean
Speaker 2: that wraps around the entire Moon.
Speaker 3: Which brings us to why astrobiologists are just so obsessed
Speaker 3: with this place. It comes down to what we consider
Speaker 3: the holy trinity for habitable environments.
Speaker 2: The three non negotiable ingredients for life.
Speaker 3: Exactly, if you are looking for life as we know it,
Speaker 3: first you need liquid water, not ice. Now, ice is rigid,
Speaker 3: it traps molecules and not vapor because that's too diffuse.
Speaker 3: You need a liquid medium where molecules can float, interact, bond.
Speaker 2: It's the universal solvent. Right.
Speaker 3: Second, you need the right chemistry. You need the building blocks.
Speaker 2: Like carbon, hydrogen, nitrogen.
Speaker 3: Oxygen, phosphorus, and sulfur. Thechnops elements chnops I always like
Speaker 3: that acronym.
Speaker 2: Yeah, And the assumption is that those elements are present
Speaker 2: on the rocky sea floor of Europa, right.
Speaker 3: That's the running theory.
Speaker 2: Yes, so the water is in direct contact with a
Speaker 2: silicate mantle, meaning the ocean is likely dissolving minerals and salts,
Speaker 2: creating this rich chemical soup.
Speaker 3: That direct contact is so crucial. It's what differentiates Europa
Speaker 3: from a moon like say Gannymat.
Speaker 2: Because Gannymat has an ocean too.
Speaker 3: It does, but Gannymat's ocean is likely sandwiched between two
Speaker 3: layers of impenetrable ice.
Speaker 2: Oh, so it never touches the rock exactly.
Speaker 3: Europa's ocean is interacting with the rock. But that brings
Speaker 3: us to the third crucial ingredient for life, energy and
Speaker 3: energy source. You need something to drive the chemical reactions
Speaker 3: to take those basic elements and force them to assemble
Speaker 3: into complex organic molecules.
Speaker 2: And on Earth, I mean, the vast majority of our
Speaker 2: biosphere relies on the Sun.
Speaker 3: Photosynthesis.
Speaker 2: Plants use the Sun, and then everything else basically eats
Speaker 2: the plants. Yeah, but out in the Jupiter system, the
Speaker 2: Sun is just like a bright star in the sky.
Speaker 3: It's incredibly faint out there.
Speaker 2: The solar radiation is just a fraction of what we
Speaker 2: get here on Earth. So the Sun isn't providing the
Speaker 2: energy for life.
Speaker 3: And it certainly isn't providing the heat to keep a
Speaker 3: global ocean from freezing.
Speaker 2: Solid because space is unimaginably So how does a moon
Speaker 2: floating hundreds of millions of miles away from the Sun
Speaker 2: out in the freezing depths of the outer Solar System
Speaker 2: actually managed to stay liquid?
Speaker 3: Well, if Europa were just floating out there in isolation,
Speaker 3: it would be a solid, inert block of ice all
Speaker 3: the way through to its.
Speaker 2: Core, just a giant ice cube.
Speaker 3: Literally. The surface temperature at europe A's equator never gets
Speaker 3: warmer than about minus two hundred and sixty degrees fahrenheit. Wow,
Speaker 3: And at the Poles it drops down to an agonizing
Speaker 3: minus three hundred and seventy degrees.
Speaker 2: That is just I can't even comprehend that level of cold.
Speaker 3: Any ambient heat from its formation of billions of years
Speaker 3: ago should have radiated away into the vacuum of space
Speaker 3: a long time ago.
Speaker 2: So the heat keeping that ocean liquid has to be
Speaker 2: continually generated from the inside out.
Speaker 3: Exactly. It's the engine keeping Europa alive.
Speaker 2: And that engine is driven entirely by gravity. Like we
Speaker 2: have to picture the sheer, overwhelming gravitational pull of Jupiter.
Speaker 3: Jupiter is a monster. It's three hundred and eighteen times
Speaker 3: more massive than Earth.
Speaker 2: Right, So Jupiter's gravity it completely dictates the physical reality
Speaker 2: of its moons.
Speaker 3: And Europa is caught in this very specific gravitational dance.
Speaker 3: It is in what we call an orbital resonance with
Speaker 3: two of Jupiter's other large moons, Io and Ganymede.
Speaker 2: Orbital resonance, so they are synced up.
Speaker 3: Yes, for every one time Ganymate orbits Jupiter Europa orbits
Speaker 3: twice and Io orbits four times.
Speaker 2: Okay, the four to two to one resonance.
Speaker 3: Right, This laplace resonance forces Europa's orbit to be elliptical
Speaker 3: or oval shaped rather than a perfect circle.
Speaker 2: So the distance between Europa and Jupiter is constantly changing exactly.
Speaker 3: Sometimes Europa swings in relatively close to the gas giant,
Speaker 3: and other times it swings much further out, And.
Speaker 2: That changing distance means a constantly changing gravitational pull.
Speaker 3: Yes, When Europa makes its closest approach to Jupiter, known
Speaker 3: as the parajove, Jupiter's gravity pulls on the Moon with
Speaker 3: immense force.
Speaker 2: It literally stretches the Moon, doesn't it.
Speaker 3: It does. The solid rock of the mantle and the
Speaker 3: thick ice shell actually bulge outward toward Jupiter by as
Speaker 3: much as thirty meters.
Speaker 2: It's like one hundred feet solid rock and ice bulging
Speaker 2: up one hundred feet right.
Speaker 3: And then as Europa swings further away in its orbit,
Speaker 3: reaching up a jove, that gravitational grip relaxes.
Speaker 2: And the moon shape settles back down exactly. So an
Speaker 2: entire planetary body is being physically stretched and compressed one
Speaker 2: hundred feet up and one hundred feet down every single orbit.
Speaker 3: Which takes about three and a half earthdays.
Speaker 2: That is insane. Just think about the mechanical stress of that.
Speaker 2: I mean, it's like, okay, if you take a thick
Speaker 2: metal paper clip, Okay, and you just hold it, nothing happens. Yeah,
Speaker 2: But if you start bending it back and forth rapidly
Speaker 2: and repeatedly.
Speaker 3: The metal right at the bend gets hot.
Speaker 2: Right, you can actually burn your fingers on it. The
Speaker 2: friction of the metallic crystalline structure grinding against itself generates internal.
Speaker 3: Heat that translates perfectly to a planetary scale.
Speaker 2: So Jupiter is basically bending Europa like a paper clip.
Speaker 3: The continuous squeezing and stretching is bending that planetary paper clip.
Speaker 3: The massive amounts of rock deep in the Moon's silicate
Speaker 3: mantle are grinding against each other, and.
Speaker 2: The layers of deep ice are flexing too.
Speaker 3: Yes, all of that incredible internal friction generates an enormous
Speaker 3: amount of thermal energy deep within the Moon's interior tidal heating,
Speaker 3: exactly tidal heating. It is a ceaseless, powerful geologic engine.
Speaker 2: So this immense heat is radiating outward from the rocky core.
Speaker 2: It hits the bottom of the frozen crust, melting it
Speaker 2: from the.
Speaker 3: Inside out, creating this massive, warm global ocean hidden in
Speaker 3: the dark.
Speaker 2: Right, the ocean exists in this state of tension. Its
Speaker 2: sandwiched between the hot, volcanically active rocky seafloor below and
Speaker 2: the frozen ice shell above. Yes, but wait, I have
Speaker 2: to push back here. If there is so much heat
Speaker 2: being generated inside this moon, enough to melt a volume
Speaker 2: of water twice the size of all of Earth's oceans combined,
Speaker 2: why doesn't the heat just melt the rest of the ice.
Speaker 3: That's a great question.
Speaker 2: Why is the outside still frozen solid? It seems like
Speaker 2: it should.
Speaker 3: Just be a water world because you are witnessing a
Speaker 3: stalemate between two extreme thermodynamic forces.
Speaker 2: Okay, stalemate.
Speaker 3: You have the intense, constant tidal heating pushing up from
Speaker 3: the seafloor, but you also have the brutal, unforgiving cold
Speaker 3: of deep space pressing down from above.
Speaker 2: Right, The minus two hundred and sixty.
Speaker 3: Degrees thorodynamics dictates that heat will always move to where
Speaker 3: it is cold. The thermal energy from the ocean is
Speaker 3: constantly trying to bleed away into the vacuum of space.
Speaker 2: And as a result, the outermost layer of the water freezes.
Speaker 3: Creating the thick ice shell.
Speaker 2: And once that ice forms, it changes the dynamic Right.
Speaker 2: Because ice is a remarkably good insulator.
Speaker 3: It acts as planetary armour. The ice shell traps the
Speaker 3: remaining heat inside, preventing the rest of the ocean from
Speaker 3: freezing solid. Wow, it is a delicate equilibrium. The ice
Speaker 3: shell is estimated to be anywhere from ten to fifteen
Speaker 3: miles thick fifteen miles, perhaps even thicker in certain regions,
Speaker 3: depending on the localized heat flow from the mantle.
Speaker 2: So we have this incredible, potentially life bearing ocean, complete
Speaker 2: with the care, chemistry, and the energy needed to sustain
Speaker 2: a biosphere. Yes, but it is locked inside a planetary
Speaker 2: vault with walls made of miles thick rock hard.
Speaker 3: Ice, which creates an absolute nightmare for planetary scientists and engineers.
Speaker 2: I can imagine, how do you sample an ocean you
Speaker 2: can't reach. We don't have the technology to pack a
Speaker 2: fifteen mile long drill onto a rocket, No, we definitely don't,
Speaker 2: and then fly it to Jupiter, land it softly on
Speaker 2: the ice, and power it for years as it grinds
Speaker 2: through cryogenic ice. That's just science fiction.
Speaker 3: Completely, which is exactly why the scientific community has spent
Speaker 3: the last few decades clinging to the dream of the shortcut.
Speaker 2: The shortcut. Okay, let's unpack this. What was the assumption here?
Speaker 3: The shortcut was a highly optimistic yet theoretically grounded assumption
Speaker 3: about the mechanics of the ice shell, hoping.
Speaker 2: We wouldn't need a gargantuan drilling operation. Right.
Speaker 3: The hope was that the ocean was actively doing the
Speaker 3: hard work for us, that the ocean might be migrating
Speaker 3: up to meet us.
Speaker 2: Because we're looking at a surface covered in thousands of
Speaker 2: miles of caaotic fractures, ridges.
Speaker 3: And bands, the shell is clearly active.
Speaker 2: So the theory was that deep ocean water could travel
Speaker 2: upward through narrow vertical fractures in.
Speaker 3: The ice geological features known as dikes, yes.
Speaker 2: And that this pressurized water would pool in shallow reservoirs
Speaker 2: much closer to the surface, like maybe just a few
Speaker 2: dozen meters down.
Speaker 3: That was the dream. The scientific framework for this is cry.
Speaker 2: Volcanism ice vulcanism.
Speaker 3: Exactly to conceptualize it, scientists naturally look at the geologic
Speaker 3: processes we understand.
Speaker 2: Best traditional vulcanism.
Speaker 3: Here on Earth, right beneath our feet, we have incredibly hot,
Speaker 3: pressurized molten rock magma moving through the lithosphere.
Speaker 2: And when this magma encounters weak points, faults or tectonic
Speaker 2: fractures in the Earth's crust.
Speaker 3: The immense lithostatic pressure forces it upward. Sometimes it erupts
Speaker 3: explosively on the surface as.
Speaker 2: Lava, or it pools in shallow magma chambers just below
Speaker 2: the crust, creating geothermal anomalies.
Speaker 3: Exactly, cry vulcanism takes that entire Earth based plumbing system
Speaker 3: and applies it to an ice world.
Speaker 2: So instead of molten silicate rock moving through a rocky
Speaker 2: granite crust, you have liquid water moving through cracks in
Speaker 2: a solid water ice crust.
Speaker 3: Yes, the deep ocean is highly pressurized by the weight
Speaker 3: of the.
Speaker 2: Ice above it, the ice shell flexes, a crack opens
Speaker 2: up at the bottom, and that pressure squeezes the liquid
Speaker 2: water up into the fracture.
Speaker 3: That was the prevailing model for a long time. If
Speaker 3: cryovulcanism operates on Europa with the same fundamental mechanics as
Speaker 3: vulcanism on Earth, you would expect these vertical dikes to
Speaker 3: act as natural.
Speaker 2: Pipelines, continuously ferrying deep, mineral rich ocean water up into
Speaker 2: shallow pockets just beneath the surface.
Speaker 3: Or even erupting onto the surface to create the smooth,
Speaker 3: renewed planes we see in the orbital imagery.
Speaker 2: I mean, this would be the ultimate game changer for exploration.
Speaker 2: If this shortcut exists, future space missions wouldn'tne a fifteen
Speaker 2: mile drill.
Speaker 3: They could simply use ground penetrating radar from orbit to
Speaker 3: map out these shallow pockets.
Speaker 2: Right then, you land a relatively small, simple probe equipped
Speaker 2: with like a thermal melt probe.
Speaker 3: You melt through maybe ten, twenty or fifty feet of ice.
Speaker 2: And suddenly you are sampling the deep ocean. You're tasting
Speaker 2: the exact chemical environment where life might be thriving without
Speaker 2: having to breach the primary fifteen mile vault.
Speaker 3: It was an incredibly elegant solution to an impossible engineering problem. Look, but,
Speaker 3: as we often find in planetary science, mapping the mechanics
Speaker 3: of one planet directly onto another is fraught with peril.
Speaker 2: I mean, wait, ice and liquid water are fundamentally different
Speaker 2: materials from solid rock and molten lava.
Speaker 3: Completely different.
Speaker 2: Can we really assume they behave the same way under pressure?
Speaker 3: No, we can't. They possess completely different thermodynamic properties, different densities,
Speaker 3: and they transfer heat in entirely different ways.
Speaker 2: And this is where the dream of the shortcut collides
Speaker 2: with a massive, sobering reality check.
Speaker 3: A major twenty twenty six study has completely dismantled the
Speaker 3: system yeah.
Speaker 2: Led by lejendro Oshaw, a planetary scientist at the Rutger
Speaker 2: School of Arts and Sciences.
Speaker 3: They finally ran the brutal, unfiltered physics on this concept.
Speaker 2: Because they didn't want to rely on Earth based analogies anymore.
Speaker 2: They wanted to know exactly what happens when liquid water
Speaker 2: tries to force its way through deep.
Speaker 3: Space ice, and their methodology was focused entirely on the
Speaker 3: journey itself. The core question they tackled was whether liquid
Speaker 3: water could realistically rise from Europa's deep, highly pressurized ocean,
Speaker 3: travel vertically through narrow fractures in the ice shell, and
Speaker 3: reach the shallow subsurface without freezing solid along the way.
Speaker 2: And to answer a question like that, you can't just
Speaker 2: rely on telescope observations. You have to build the environment
Speaker 2: in a computer.
Speaker 3: They utilized advanced computational fluid dynamics to simulate the localized
Speaker 3: physics of this upward journey, modeling.
Speaker 2: The pressure, the temperature gradient of the ice shell, the
Speaker 2: specific heat capacity of the water.
Speaker 3: And the geometry of the fractures.
Speaker 2: And in doing so they exposed a critical flaw in
Speaker 2: the older models, the models that it generated so much optimism.
Speaker 3: Yes, the previous models relied heavily on a mathematical simplification.
Speaker 3: They treated the rising water as if it moved in
Speaker 3: a laminar flow.
Speaker 2: Laminar flow. Okay, let's make sure we have a vivid
Speaker 2: picture of this, because it is the lynchpin of the
Speaker 2: old theory. It is Laminar flow is smooth, It's highly orderly,
Speaker 2: like if you turn on your kitchen fauce. It just
Speaker 2: a tiny bit and the water glides out in this
Speaker 2: perfect clear glass like cylinder where all the water molecules
Speaker 2: are moving perfectly parallel to.
Speaker 3: One another with no class currents or mixing.
Speaker 2: Right. That is laminar flow.
Speaker 3: The old models effectively assumed that water from the deep
Speaker 3: ocean would behave like that faucet. It would gently and
Speaker 3: smoothly slide up these fractures.
Speaker 2: In the ice, which sounds nice in theory.
Speaker 3: In a laminar flow regime, the water maintains its thermal
Speaker 3: energy relatively well because the fluid isn't mixing, so only
Speaker 3: the very.
Speaker 2: Outer layer of the water touches the freezing ice walls exactly.
Speaker 3: It acts as an insulating buffer for the warmer water
Speaker 3: in the center of the flow.
Speaker 2: But Ojcha's team realized there was a fundamental physics element
Speaker 2: missing from those assumptions.
Speaker 3: Applying laminar flow to a highly pressurized extrusion event on
Speaker 3: an active moon was a mathematically convenient, but physically impossible assumption.
Speaker 2: Because space isn't to controlled laboratory. You can't expect millions
Speaker 2: of gallons of pressurized water to flow up a jagged,
Speaker 2: dynamic freezing pipe in a smooth straight line.
Speaker 3: The older models were completely ignoring the chaotic, unpredictable nature
Speaker 3: of fluid dynamics.
Speaker 2: They were ignoring turbulence.
Speaker 3: Purbulence dictates the reality of the flow. When you factor
Speaker 3: in the intense pressures at the bottom of the ocean,
Speaker 3: the narrow, jagged constraints of these tectonic fractures, and the
Speaker 3: immense vertical distance the water must traverse.
Speaker 2: A gentle laminar stream is physically impossible.
Speaker 3: The fluid dynamics simulations proved that the water wouldn't rise peacefully.
Speaker 3: It would be injected into the fracture at high velocity,
Speaker 3: resulting in violently turbulent flow.
Speaker 2: And if the water is turbulent, the molecules aren't moving
Speaker 2: in a straight parallel line anymore. The fluid is tearing
Speaker 2: itself apart.
Speaker 3: It is moving left and right, surging up and dropping down.
Speaker 2: It is swirling aggressively, creating massive eddies and vortices inside
Speaker 2: the crack.
Speaker 3: Picture a raging whitewater river violently rushing through a narrow,
Speaker 3: jagged slot canyon. Oh wow, Yeah, the water is crashing
Speaker 3: against the rock walls, folding over on itself, constantly churning
Speaker 3: and mixing.
Speaker 2: Now take that chaotic energy and place it inside a
Speaker 2: vertical crack in Europa's ice shell.
Speaker 3: You have a churning, swirling mass of liquid water violently
Speaker 3: scraping and mixing against the walls of the fracture, and.
Speaker 2: We have to focus on the thermal reality of those walls.
Speaker 2: This isn't a rocky canyon in Arizona.
Speaker 3: No, And it isn't the relatively warm ice you'd find
Speaker 3: in an Earth glacier either.
Speaker 2: This is deep space ice. As you move up through
Speaker 2: the shell, the temperature of the ice drops precipitously, plunging
Speaker 2: down toward that surface temperature of minus two hundred and
Speaker 2: sixty degrees fair.
Speaker 3: It is a cryogenic environment which triggers the fatal mechanism
Speaker 3: that destroys the shortcut right catastrophic heat loss.
Speaker 2: Yes.
Speaker 3: In our earlier laminar flow example, the water in the
Speaker 3: center was insulated, but in a turbulent flow there.
Speaker 2: Is no center because it's constantly mixing.
Speaker 3: The swirling motion constantly takes the relatively warm water from
Speaker 3: the interior of the crack and violently throws it outward,
Speaker 3: smashing it directly against the freezing cryogenic walls.
Speaker 2: So the water rapidly surrenders its thermal energy into the
Speaker 2: surrounding ice.
Speaker 3: The rate of heat transfer is staggering, far faster than
Speaker 3: any of the older simplified models had accounted for.
Speaker 2: The water is rushing up, furiously, churning and rapidly harringing
Speaker 2: its heat into the walls of the fracture. It cools
Speaker 2: down at a phenomenal rate as it climbs towards the surface.
Speaker 3: And this rapid cooling in a chaotic environment leads to
Speaker 3: a state of matter that dictates the final outcome super
Speaker 3: cooling super cooling. It is a fascinating thermodynamic.
Speaker 2: State because, as we generally assume that the instant water
Speaker 2: reaches thirty two degrees fahrenheit or zero degree celsius. It
Speaker 2: immediately transitions into a solid state.
Speaker 3: Right, But the phase change from liquid to solid requires
Speaker 3: a starting point, a nucleation site for the ice crystals
Speaker 3: to begin forming.
Speaker 2: And if it doesn't have one, if.
Speaker 3: The water cools down rapidly enough, it can actually drop
Speaker 3: below its standard freezing temperature and temporarily remain in a
Speaker 3: liquid state.
Speaker 2: This is super cooled liquid. We see this on Earth
Speaker 2: under very specific conditions. Right. They like, if you leave
Speaker 2: a perfectly sealed bottle of highly purified water in the
Speaker 2: freezer just a little too long, you can pull it
Speaker 2: out and it still looks completely liquid. It might be
Speaker 2: like twenty five degrees fahrenheit, but it's flowing. However, the
Speaker 2: moment you flick the bottle with your finger or twist
Speaker 2: the cap and release the pressure.
Speaker 3: You introduce a mechanical disturbance.
Speaker 2: You provide a nucleation point, and the entire bottle flashes
Speaker 2: into solid ice right in front of your eyes in
Speaker 2: a matter of seconds.
Speaker 3: The water in that bottle is is thermode dynamically unstable.
Speaker 3: It desperately wants to freeze. It just needs a trigger.
Speaker 2: Now apply that to Europa. The turbulent water rushing up
Speaker 2: the fracture becomes deeply super cooled by the constant contact
Speaker 2: with the cryogenic walls.
Speaker 3: And in that violently churning, highly pressurized environment, there is
Speaker 3: no shortage of mechanical disturbances or nucleation sites.
Speaker 2: The ice walls themselves provide infinite points for crystallization to begin.
Speaker 3: So the supercooled water starts to flash freeze.
Speaker 2: But because it's moving so violently, it doesn't freeze into
Speaker 2: a single smooth sheet of solid ice from the outside in.
Speaker 3: It forms something entirely different. It forms frizil ice.
Speaker 2: For zil ice, that's a specific term.
Speaker 3: Yes, frazil ice is the nail in the coffin for
Speaker 3: the cryovulcanism theory on Europa.
Speaker 2: What exactly is it?
Speaker 3: When this highly agitated supercooled fluid begins to freeze, it
Speaker 3: instantly forms billions of tiny needle like microscopic ice crystals
Speaker 3: suspended directly within the liquid column.
Speaker 2: So it stops being a fluid and turn into a thick, gritty,
Speaker 2: abrasive slush exactly.
Speaker 3: The consistency of slush. And as the turbulent flow continues
Speaker 3: to bleed heat into the walls, more and more of
Speaker 3: these frizil ice crystals precipitate out of the liquid, so.
Speaker 2: The concentration of ice crystal sky rockets.
Speaker 3: They begin to clump and stick together, increasing the viscosity
Speaker 3: of the fluid. More importantly, they aggressively stick to the
Speaker 3: incredibly cold, jagged walls of the fracture.
Speaker 2: They start to accumulate. They're actively paving the inside of
Speaker 2: the crack with sticky slush, narrowing the pathway by the second.
Speaker 3: It's like trying to pump rapidly set in concrete through
Speaker 3: a pipe.
Speaker 2: The more it flows, the thicker it gets, until it
Speaker 2: chokes itself out.
Speaker 3: The timeline generated by Oshaw's computer simulations is the most
Speaker 3: sobering aspect of the.
Speaker 2: Study because of how fast this happens.
Speaker 3: Given the rapid turbulence driven heat loss and the explosive
Speaker 3: formation of Frazil ice, these vertical dikes simply cannot sustain flow.
Speaker 2: The models demonstrated that these narrow cracks wouldn't stay open
Speaker 2: for years or months or even weeks.
Speaker 3: They would violently freeze shut within a matter of mere hours.
Speaker 2: Hours a massive Techti fracture rips open at the bottom
Speaker 2: of the ice shell. The pressurized liquid ocean rushes in,
Speaker 2: hoping to find a path.
Speaker 3: To the surface, it immediately becomes turbulent.
Speaker 2: It's super cools. The Frazil ice forms a dense slush,
Speaker 2: and within a few hours the entire fracture cements itself shut.
Speaker 3: The fluid never even gets close to the surface.
Speaker 2: Nature essentially slams the vault door shut the moment the
Speaker 2: ocean tries to escape.
Speaker 3: The physics of the environment make the process brutally self defeating.
Speaker 3: The very act of the pressurized water forcing its way
Speaker 3: upward generates the fluid turbulence that rapidly seals its own
Speaker 3: exit pathway.
Speaker 2: The mechanics of the ice shell actively prevent cryovulcanism from
Speaker 2: functioning the way vulcanism functions.
Speaker 3: On Earth exactly.
Speaker 2: Okay, but I have a question. Looking at the scale
Speaker 2: of Europa, a moon subjected to the immense gravitational torture
Speaker 2: of Jupiter. Couldn't we just assume the.
Speaker 3: Cracks are bigger, You mean, wider fractures?
Speaker 2: Yeah, if a narrow pipe freezes shut in hours, what
Speaker 2: if the fracture is a massive gaping chasm in the ice.
Speaker 2: Surely a massive fracture could survive the cold.
Speaker 3: It's the logical next step in the hypothesis.
Speaker 2: Right, If the pathways wide enough, wouldn't sheer volume allow
Speaker 2: at least some of the water in the center to
Speaker 2: survive the journey and pool near the surface before the
Speaker 2: edge is managed to freeze.
Speaker 3: Oshaw's team rigorously tested that exact scenario. They adjusted the
Speaker 3: simulations to account for significantly wider fractures, pushing the boundaries
Speaker 3: of what is geologically plausible for the ice shell. The
Speaker 3: results were incredibly stubborn. Even under the most idealized generous
Speaker 3: conditions maximizing the width of the fractures, the upward migration
Speaker 3: still fails.
Speaker 2: Wait, really, why does scaling up the width fail to
Speaker 2: solve the thermal problem?
Speaker 3: Because fluid turbulence does not scale linearly in a way
Speaker 3: that protects the heat.
Speaker 2: Okay, unpack that for me.
Speaker 3: Yes, a much wider fracture possesses a greater volume of water,
Speaker 3: and technically it takes slightly longer to freeze completely shut
Speaker 3: compared to a narrow crack. Makes sense, But the chaotic
Speaker 3: energy of the turbulence scales up alongside the volume. The
Speaker 3: violent mixing continues to throw the interior heat against the
Speaker 3: cryogenic walls.
Speaker 2: Ah, so it's just mixing even more aggressively.
Speaker 3: To successfully transport enough liquid water to the upper crust
Speaker 3: to carve out the vast geological features we observe on
Speaker 3: the surface, the massive lenticularate, the sprawling chaotic terrain, the
Speaker 3: fractures would need to be unrealistically massive.
Speaker 2: They would require a width or a frequency that simply
Speaker 2: defies the structural integrity and the physical limits of Europa's
Speaker 2: ice shell exactly. It's like a battle of thermal mass
Speaker 2: versus environmental hostility. Like if you take a standard garden hose,
Speaker 2: fill it with warm water and snak it through a
Speaker 2: frozen snowbank while violently shaking it, the water freezes almost instantly.
Speaker 2: If you upgrade to a massive, high volume fire hose
Speaker 2: and do the same thing, the sheer volume means more
Speaker 2: water gets through initially, But if the walls of that
Speaker 2: fire hose are minus two hundred degrees and the water
Speaker 2: inside is churned violently, that fire hose is still going
Speaker 2: to freeze solid before the water can establish a sustained
Speaker 2: long term flow.
Speaker 3: The cyogenic environment is just too overwhelming. The thermodynamic reality
Speaker 3: is absolute.
Speaker 2: So no matter how much water you pump, the cold
Speaker 2: walls and the chaotic slow are going to freeze its
Speaker 2: solid before it reaches the other end.
Speaker 3: The ice shell is too thick, the ambient temperature is
Speaker 3: too low, and the fluid dynamics are too chaotic for
Speaker 3: any localized volume of deep ocean water to punch its
Speaker 3: way through to the surface without surrendering all of its
Speaker 3: heat and freezing solid in the attempt.
Speaker 2: This realization forces us into a very uncomfortable corner regarding
Speaker 2: our maps of Europa. It does because planetary geologists have
Speaker 2: spent decades analyzing the images from the Galilee emission. We
Speaker 2: see vast regions of chaotic terrain where the ice looks
Speaker 2: like it has been shattered, melted, and refrozen into massive,
Speaker 2: jagged blocks.
Speaker 3: We see these features that unequivocally look like they are
Speaker 3: formed by liquid water interacting with the shallow crust.
Speaker 2: In fact, based on radar and gravitational data, many scientists
Speaker 2: are heavily invested in the idea that there are distinct
Speaker 2: shallow lenses of liquid water trapped in the ice just
Speaker 2: below the surface right now. Yes, But if OSHA's physics
Speaker 2: are correct and the deep ocean absolutely cannot make the
Speaker 2: vertical journey, where did that shallow water come from?
Speaker 3: This leads to the most critical and perhaps most disappointing
Speaker 3: astrobiological consequence of the study, the concept of the false hope.
Speaker 2: The false hope of shallow reservoirs.
Speaker 3: If we identify pockets of liquid water residing in the
Speaker 3: shallow subsurface of Europa, the physics dictate that they almost
Speaker 3: certainly did not originate from the deep global ocean.
Speaker 2: If they didn't migrate up from the bottom, the only
Speaker 2: logical conclusion is that they were generated right there inside
Speaker 2: the upper layers of the crust.
Speaker 3: Precisely the conclusion we are forced to draw. The alternative
Speaker 3: origin mechanism is localized heating and melting, occurring entirely within
Speaker 3: the confined matrix of the ice shell itself.
Speaker 2: But how do you generate enough thermal energy to melt
Speaker 2: massive pockets of liquid water entirely within a cryogenic ice shell,
Speaker 2: completely isolated from the hot, rocky core.
Speaker 3: We return to the primary engine, tidal heating from Jupiter.
Speaker 3: The gravitational squeezing and stretching from Jupiter doesn't just affect
Speaker 3: the rocky mantle, it flexes the entire fifteen mile thick
Speaker 3: ice shell.
Speaker 2: As the Moon orbits. The ice is subjected to immense
Speaker 2: tectonic stress. It bends, it shears, and it grinds against
Speaker 2: itself along massive fault.
Speaker 3: Lines, and in certain concentrated areas, perhaps where the ice
Speaker 3: is structurally deformed, the mechanical friction of the ice aggressively
Speaker 3: grinding against itself sheer heating can generate enough localized thermal
Speaker 3: energy to literally melt the surrounding ice in situ.
Speaker 2: So the mechanical friction melts the ice right where it sits.
Speaker 2: It's like it's the planetary equivalent of vigorously rubbing your
Speaker 2: hands together when you're out in the cold.
Speaker 3: That's exactly what it is.
Speaker 2: The friction generates a small pocket of heat right between
Speaker 2: your palms, entirely independent of your body's core temperature. Right
Speaker 2: so youru rope's crust is constantly rubbing together, generating enough
Speaker 2: friction to melt localized pockets of slush and liquid water
Speaker 2: miles above the actual ocean.
Speaker 3: It creates a shallow, isolated reservoir of liquid and to
Speaker 3: a remote sensing instrument like a radar sander looking down
Speaker 3: from a spacecraft in orbit, a pocket of liquid water
Speaker 3: simply registers as a pocket of liquid water.
Speaker 2: But the distinction between those two origins is an absolute
Speaker 2: heartbreak for anyone designing a mission to find life. It
Speaker 2: completely changes the value of the target.
Speaker 3: It alters the astrobiological potential of that water from a
Speaker 3: prime target to a virtually sterile puddle.
Speaker 2: Because if we go back to the holy trinity of life, water, chemistry,
Speaker 2: and energy, we know life needs the complex, nutrient rich
Speaker 2: chemistry that is only happening down in the deep ocean,
Speaker 2: where the water is actively dissolving minerals from the rocky seafloor.
Speaker 3: That is where the hydrothermal vents would be. That is
Speaker 3: where the organic building blocks are churning.
Speaker 2: If a space probe samples a shallow puddle that just
Speaker 2: melted locally, it's completely disconnected from the deep ocean environment.
Speaker 2: If a future multi billion dollar space probe lands on Europa,
Speaker 2: manages to melt its way through fifty feet of ice
Speaker 2: and successfully samples one of these shallow reservoirs, and it
Speaker 2: turns out that reservoir was just created by mechanical friction
Speaker 2: melting a block of pure sterile ice, it is.
Speaker 3: Completely disconnected from the biosphere. The scientific return would be
Speaker 3: profoundly limited.
Speaker 2: It won't tell us what's happening in Europa's most intriguing,
Speaker 2: potentially life bearing zone.
Speaker 3: It would be akin to a marine biologist attempting to
Speaker 3: study the bizarre complex hydrothermal vent ecosystems of the Mariana
Speaker 3: Trench by analyzing a puddle of melted snow sitting on
Speaker 3: top of a glacier in Greenland.
Speaker 2: Wow. Yeah, physically they are both liquid water, yes.
Speaker 3: But one is a rich, dynamic chemical ecosystem and the
Speaker 3: other is just melted precipitation.
Speaker 2: A shallow reservoir on Europa, if formed entirely by localized
Speaker 2: sheer heating within the crust, tell us absolutely nothing about
Speaker 2: the chemical conditions, the potential habitability, or the presence of
Speaker 2: life in the deep ocean.
Speaker 3: It's a brutal bait and switch. We spend decades hoping
Speaker 3: these shallow pockets were a convenient window into the deep ocean, but.
Speaker 2: This research suggests they are just a mirror reflecting only
Speaker 2: the isolated, frozen, sterile reality of the crust itself.
Speaker 3: While it is undeniably a sobering realization for our immediate
Speaker 3: exploration goals, it is also a vital timely piece of
Speaker 3: scientific course.
Speaker 2: Correction because this discovery isn't just theoretical, is it.
Speaker 3: No, This theoretical modeling isn't just an academic exercise confined
Speaker 3: to a university server. This new understanding of fluid dynamics
Speaker 3: and Frazil ice has immediate massive implications for billions of
Speaker 3: dollars of space hardware currently flying through the void of
Speaker 3: the Solar System.
Speaker 2: We're looking at the incoming fleet. The stakes here are
Speaker 2: incredibly high because we have two flagship missions already launched,
Speaker 2: already on their way to the Jupiter.
Speaker 3: System, and they were designed, funded, and built based largely
Speaker 3: on the older, more optimistic assumptions about Europa's ice shell.
Speaker 2: Let's break down the timeline. First, we have the European
Speaker 2: Space Agency.
Speaker 3: The European Space Agency launched the Jupiter Icy Moons Explorer
Speaker 3: universally known as jew IC in April of twenty twenty three.
Speaker 2: Okay, so that's already out there.
Speaker 3: It is currently executing a complex looping trajectory through the
Speaker 3: inner Solar System to build up speed, and it is
Speaker 3: scheduled to finally arrive in the Jupiter System in July
Speaker 3: of twenty thirty one.
Speaker 2: And right on its heels we have NASA's massive contribution
Speaker 2: to the effort the Europa Clipper. It launched recently in
Speaker 2: October of twenty twenty four. It is taking a more
Speaker 2: direct gravitational trajectory and is slated to arrive at Jupiter
Speaker 2: ahead of Juicy in April of twenty thirty.
Speaker 3: These are monumental engineering achievements. The Europa Clipper, for example,
Speaker 3: is the largest spacecraft NASA has ever developed for a
Speaker 3: planetary mission. It's huge, It will enter a highly elliptical
Speaker 3: orbit around Jupiter designed to sweep past Europa and make
Speaker 3: forty nine incredibly close low altitude flyby, and.
Speaker 2: It carries a massive payload of nine highly sophisticated scientific
Speaker 2: instruments designed to map the Moon's surface, composition, and interior
Speaker 2: structure in unprecedented detail.
Speaker 3: And one of the most critical instruments on that Tale
Speaker 3: of the Reason instrument, which stands for radar for Europa
Speaker 3: Assessment and sounding ocean to near surface, is directly impacted
Speaker 3: by ocha's research.
Speaker 2: This is a powerful ice penetrating radar. Its primary directive
Speaker 2: is to fire radio waves down into the ice shell,
Speaker 2: measure how those waves bounce back and map out the
Speaker 2: internal structure.
Speaker 3: It is specifically hunting for the dielectric signature of liquid water.
Speaker 3: It is looking for those shallow reservoirs.
Speaker 2: Without the sobering reality check provided by the fluid dynamics modeling.
Speaker 2: Consider the scenario when Clipper arrives and powers up that radar.
Speaker 3: The potential for a massive false positive is glaring right.
Speaker 2: Clipper conducts its low altitude flybys, the radar pings the
Speaker 2: upper layers of the ice shell, and the data lights up.
Speaker 3: The radar waves hit a boundary transition from solid iceed
Speaker 3: to liquid water and bounce back.
Speaker 2: The science teams back at the jet propulsion laboratory look
Speaker 2: at the telemetry. They see a massive pocket of liquid
Speaker 2: water just a few miles down, and they celebrate. They
Speaker 2: announce to the world that they have found it.
Speaker 3: They'd think the deep ocean is venting upward, just like
Speaker 3: the old cryo vulcanism models predicted.
Speaker 2: But they would be wrong.
Speaker 3: They would look at a localized, sheer, melted pocket of
Speaker 3: sterile water and fundamentally misinterpret it as a direct, active
Speaker 3: chemical window into the deep global ocean.
Speaker 2: And the danger of that misinterpretation extends far beyond a
Speaker 2: single press conference.
Speaker 3: It dictates the future of space exploration for decades. They
Speaker 3: might use that flawed interpretation to lobby for fund and
Speaker 3: design a subsequent astronomically expensive lander mission targeted directly at
Speaker 3: that specific reservoir.
Speaker 2: Fully believing they're about to drill down and sample the
Speaker 2: habitable zone.
Speaker 3: A lander mission that would take another twenty years to
Speaker 3: build and fly.
Speaker 2: They would finally land on the ice, deploy a thermal drill,
Speaker 2: melt their way down to the water, activate their mass
Speaker 2: spectrometers to look for complex organic.
Speaker 3: Molecules, and find absolutely nothing.
Speaker 2: Sterile, isolated, friction, melted water.
Speaker 3: It would be a catastrophic generational waste of time, engineering,
Speaker 3: and scientific funding.
Speaker 2: This highlights why theoretical modeling, simulation, and constantly challenging our
Speaker 2: own assumptions are the bedrock of planetary science. Oscha's research
Speaker 2: acts as a preemptive, critical guidebook for the scientists who
Speaker 2: will be analyzing the data from Clipper and JUC.
Speaker 3: It shatters the easy dream, but it sharpens the actual science.
Speaker 3: It forces the teams to be far more rigorous in
Speaker 3: their analysis.
Speaker 2: When Clipper and je arrive in the early twenty thirties
Speaker 2: and start beaming back petabytes of radar and gravitational data,
Speaker 2: the mission scientists now possess a crucial piece of the puzzle.
Speaker 3: They know that the ice shell is a much more formidable,
Speaker 3: actively defensive barrier than they ever assumed, so the.
Speaker 2: Data won't trick them into a false sense of victory.
Speaker 3: We will know to treat any evidence of shallow liquid
Speaker 3: water with extreme skepticism regarding its origin.
Speaker 2: It completely redefines the parameters of the search. If they
Speaker 2: find a shallow pocket, they can't just assume its ocean water.
Speaker 3: They have to analyze the surrounding geologic context. Is there
Speaker 3: evidence of massive sheer faulting nearby that could explain it
Speaker 3: as localized melt?
Speaker 2: They will know they either have to calibrate their instruments
Speaker 2: to look much much deeper, trying to penetrate the full
Speaker 2: fifteen miles.
Speaker 3: Or they have to look for incredibly rare catastrophic geological anomalies,
Speaker 3: perhaps massive impact basins where a comet punched a temporary
Speaker 3: hole through the Brazil ice barrier.
Speaker 2: It forces the scientific community to be much smarter and
Speaker 2: much more discerning about the data they are about to collect.
Speaker 3: Science is just as much about closing doors as it
Speaker 3: is about opening them. Proving that a specific pathway is
Speaker 3: physically impossible is a highly valuable scientific return.
Speaker 2: It prevents the entire field of astrobiology from wandering down
Speaker 2: a theoretical blind alley for the next twenty years.
Speaker 3: Exactly so.
Speaker 2: Synthesizing this entire reality check, we began with a vision
Speaker 2: of Europa that was deeply appealing. We pictured an accessible oasis,
Speaker 2: a dynamic, cracked icy shell that was constantly bleeding its deep, warm,
Speaker 2: potentially life filled ocean out towards the surface.
Speaker 3: Offering up its secrets for us to easily scoop up.
Speaker 2: We banked entirely on the dream of the shortcut.
Speaker 3: We relied heavily on terrestrial analogies. Assuming that the mechanics
Speaker 3: of magma and rock would neatly translate to water and
Speaker 3: cryogenic ice.
Speaker 2: We envisioned a complex plumbing system of dikes and fractures
Speaker 2: driven by the pressure of the ocean.
Speaker 3: But then the brutal, unforgiving reality of computational fluid dynamics
Speaker 3: was applied.
Speaker 2: The researchers at Rutgers pulled back the curtain on the
Speaker 2: actual mechanics of an alien moon. We were forced to
Speaker 2: abandon the calm, orderly, mathematically convenient assumption of laminar flow
Speaker 2: and plunge into the chaotic, violent, and thermally destructive reality
Speaker 2: of high velocity turbulence.
Speaker 3: We saw how that fluid turbulence aggressively strips the thermal
Speaker 3: energy away from the water, violently transferring the heat into
Speaker 3: the cryogenic walls of the tenttonic fractures.
Speaker 2: We witness the rapid onset of supercooling, and.
Speaker 3: We saw the fatal mechanism the super cooled water flashing
Speaker 3: into billions of needles of brazil ice.
Speaker 2: Instantly creating a highly viscous, gritty slush that aggressively adheres
Speaker 2: to the walls, cementing the massive fractures shut within a
Speaker 2: matter of hours.
Speaker 3: It is nature's own impenetrable failsafe mechanism. The very act
Speaker 3: of the pressurized ocean trying to violently force its way
Speaker 3: to the surface generates the exact chaotic conditions that seal
Speaker 3: its own fate.
Speaker 2: The vault actively locks itself, and because of that physical reality,
Speaker 2: the shallow reservoirs we are hunting for with the upcoming
Speaker 2: radar instruments on Clipper and Jewsies are likely just phantoms.
Speaker 3: They are localized milk pockets generated by tantonic friction, entirely
Speaker 3: disconnected from the rich, complex habitable zone of the deep ocean.
Speaker 2: The barrier remains intact and the ocean remains profoundly isolated.
Speaker 3: Which leaves us with a linger r'aring immensely daunting thought
Speaker 3: for the future of astrobiology and human engineering. What's that
Speaker 3: We now understand precisely how formidable Europa's ice shell truly is.
Speaker 3: It is not a passive layer of frozen water. It
Speaker 3: is an active, self sealing, dynamic armoor that brutally shuts
Speaker 3: down even nature's own immense gravitational and thermodynamic forces attempting
Speaker 3: to push water to the surface.
Speaker 2: If an entire pressurized ocean, driven by the relentless grinding
Speaker 2: tidal forces of the largest planet in our Solar system,
Speaker 2: cannot physically punch a hole through that cryogenic.
Speaker 3: Armor, If nature cannot break the vault, what kind of radical,
Speaker 3: out of the box, entirely unprecedented engineering will humanity eventually
Speaker 3: need to invent to pierce that armor ourselves?
Speaker 2: That is a staggering thought. If we are truly committed
Speaker 2: to touching that dark ocean below, we can no longer
Speaker 2: rely on the hope of a natural shortcut.
Speaker 3: We cannot waste for the ocean to come to us.
Speaker 3: We are going to have to figure out how to
Speaker 3: break the planetary vault ourselves.
Speaker 2: It forces us to ask just how badly we want
Speaker 2: to know what is swimming in the dark down there.
Speaker 2: When we started, we wanted to find an easy path
Speaker 2: to alien life. We thought Europa was going to cooperate.
Speaker 3: We thought we could just skim the surface and find
Speaker 3: the answers.
Speaker 2: But Europa is fiercely protective of its environment. The diagnostic
Speaker 2: landscape here isn't just murky. It is actively sealed under
Speaker 2: fifteen miles of the hardest, coldest, most defensive ice in
Speaker 2: the Solar System. The shortcut is closed.
Speaker 3: The real, grueling work of exploration is just beginning.
Speaker 2: Keep looking up and keep questioning what you think you know.