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: Imagine for just a second that you are standing outside
Speaker 2: on like a perfectly clear, crisp night You're just looking
Speaker 2: up at the vast, sprawling expanse of the night sky right.
Speaker 3: Right, getting that full cosmic.
Speaker 2: Perspective exactly, And the stars they appear completely fixed. The
Speaker 2: planets are slowly silently tracing these ancient, mathematically predictable paths.
Speaker 3: It's basically orbital mechanics doing its thing.
Speaker 2: Yeah, and everything just feels ordered. Like the universe from
Speaker 2: our terrestrial vantage point, anyway, it looks like a flawless,
Speaker 2: frictionless clock.
Speaker 3: A very large, very cold clock.
Speaker 2: Right now, I want you to imagine locking your eyes
Speaker 2: onto a specific celestial object that's just hurtling through the darkness.
Speaker 3: Okay, I'm picturing it.
Speaker 2: It has mass, it has momentum, it has been traveling
Speaker 2: on this massive elliptical track for centuries, literally doing exactly
Speaker 2: what the laws of thermodynamics and gravity demand that it do.
Speaker 3: Because that's how physics works. You can't argue with inertia,
Speaker 3: you can't.
Speaker 2: But then, right as you're watching it, the impossible happens.
Speaker 2: This ancient object completely slams on the brakes.
Speaker 3: Which is wild.
Speaker 2: The rotation just grinds to a dead stop, and then,
Speaker 2: completely defying everything we intuitively understand about momentum inertia and
Speaker 2: you know, the absolute vacuum of space, it starts violently
Speaker 2: spinning in the exact opposite direction.
Speaker 3: Yeah, it fundamentally breaks the brain's intuitive physics engine totally,
Speaker 3: because when an object with that much mass and that
Speaker 3: much established inertia suddenly reverses course in a frictionless environment,
Speaker 3: it feels like glitch. In reality, it.
Speaker 2: Really does, like someone just hit reverse under remote control.
Speaker 3: Exactly. It goes against our fundamental understanding of how large
Speaker 3: celestial bodies are supposed to behave. I mean, you expect
Speaker 3: a planet or a moon to gradually slow down over say,
Speaker 3: billions of years due to tidal.
Speaker 2: Forces, billions of years, not not over a week end.
Speaker 3: Exactly, a sudden, violent mechanical reversal on a human timescale
Speaker 3: that requires a localized application of force so massive and
Speaker 3: so chaotic that it almost seems engineered, which is.
Speaker 2: Why this is arguably one of the most fascinating astronomical
Speaker 2: anomalies on record. We aren't just talking about like a
Speaker 2: theoretical model or a broken piece of video game physics here.
Speaker 3: No, this is heavily documented.
Speaker 2: It's a very real event surrounding a specific object known
Speaker 2: to astronomers as comment forty one pe total Giacobini krisoc
Speaker 2: quite the mouthful. Yeah, we are definitely gonna call it
Speaker 2: forty one p to save oxygen.
Speaker 3: Good call.
Speaker 2: Okay, let's unpack this because our mission today is to
Speaker 2: entirely break down on this unprecedented event. We're talking about
Speaker 2: the first ever observed instance of a comet throwing itself
Speaker 2: into a reverse spin.
Speaker 3: And what makes this story truly brilliant isn't just the
Speaker 3: violent physics of the reversal itself.
Speaker 2: Oh right, it's how we found out about it exactly
Speaker 2: because we didn't catch this happening live.
Speaker 3: The evidence of this impossible cosmic spin out was just
Speaker 3: sitting quietly in a digital database.
Speaker 2: Like a ghost in the machine.
Speaker 3: Yeah, completely unnoticed until someone decided to sift through the
Speaker 3: archives and actually do the math. The archival nature of
Speaker 3: the discovery is perhaps the most compelling part of the narrative.
Speaker 2: Here because it completely recontextualizes how we view modern astronomy.
Speaker 2: We aren't just looking up.
Speaker 3: Anymore, right, we're looking back through the hard drives.
Speaker 2: So we're going to explore the chaotic physics of the
Speaker 2: inner Solar System, the rapid, almost violent life and death
Speaker 2: cycles of short period comets, and basically the hidden treasures
Speaker 2: buried inside decades of data.
Speaker 3: Because to really grasp the magnitude of what happened to
Speaker 3: for p, you have to understand the specific structural vulnerabilities
Speaker 3: of the comet itself.
Speaker 2: Yeah, it's not just a generic space rock.
Speaker 3: No, it is a remarkably fragile piece of primordial architecture.
Speaker 2: So let's start with that architecture. Yeah, Because if a
Speaker 2: solid object stops spinning in a vacuum, the kinetic energy
Speaker 2: doesn't just magically disappear, right right.
Speaker 3: Physics demands an equal and opposite reaction exactly.
Speaker 2: So before we can identify where that massive counterforce came from,
Speaker 2: we need to understand exactly what kind of object is
Speaker 2: receiving the blow. Let's meet our protagonist.
Speaker 3: Let's do it.
Speaker 2: Where does a rock like forty one pe actually come from?
Speaker 2: Like initially, Well.
Speaker 3: To find the true origin of forty one P you
Speaker 3: have to look outward, like far past the orbits of
Speaker 3: Neptune and Urinus. Way out there, Yeah, to the absolute
Speaker 3: freezing dark edges of our solar neighborhood. We're talking about
Speaker 3: the Kuiper Belt.
Speaker 2: Okay, the Kuiper Belt.
Speaker 3: It's this massive, incredibly sparse ring of primordial frozen debris.
Speaker 3: The objects out there are basically the leftover building blocks
Speaker 3: from the very formation of the Solar system, so.
Speaker 2: Roughly four point six billion years ago exactly.
Speaker 3: They are essentially preserved in a deep frieze, totally untouched
Speaker 3: by solar radiation, just drifting in a state of near
Speaker 3: perfect cryogenic suspension.
Speaker 2: So it basically spends billions of years just floating in
Speaker 2: the dark, like a dormant time capsule of ice and.
Speaker 3: Rock yep, just waiting.
Speaker 2: So, how does something locked in the deep frieze of
Speaker 2: the outer Solar System end up zooming past Earth? Like?
Speaker 2: How does it get hot enough to fundamentally alter its
Speaker 2: own mechanics.
Speaker 3: Well, it encounters the ultimate gravitational bully of our Solar system, Jupiter.
Speaker 3: It is so staggeringly massive that its immense gravity will
Speaker 3: dictates the architecture of basically everything around it.
Speaker 2: It's kind of cosmic vacuum cleaner, right, a vacum.
Speaker 3: Cleaner and a gravitational slingshot. Because at some point in
Speaker 3: forty one p's ancient history, it's slow, lazy orbit drifted
Speaker 3: just a fraction too close to Jupiter's sphere of influence,
Speaker 3: and the giant planet's gravity caught it, warped its trajectory
Speaker 3: and fundamentally flung it inward toward the Sun.
Speaker 2: It's basically orbital resonance, acting as an eviction notice permanent.
Speaker 3: One Yeah. That interaction completely rewrote the comet's destiny. It
Speaker 3: left forty one P locked into a brand new, highly
Speaker 3: elliptical path.
Speaker 2: Right.
Speaker 3: It became what astronomers classify as a Jupiter family comet.
Speaker 3: So its orbit now brings it swinging through the inner
Speaker 3: Solar System relatively close to the Sun and Earth every
Speaker 3: five point four years.
Speaker 2: Okay, five point four years.
Speaker 3: And based on dynamic orbital modeling, researchers believe it has
Speaker 3: actually been trapped in this exact five point four year
Speaker 3: loop for approximately fifteen hundred years.
Speaker 2: That is wild a millennium and a half of doing
Speaker 2: the exact same lap round and round five point four
Speaker 2: years out toward the cold Jupiter, then whipping back around
Speaker 2: into the searing heat of the Sun. But when I
Speaker 2: picture a comet surviving that kind of extreme thermal cycling
Speaker 2: for fifteen hundred years, I picture something the size of
Speaker 2: a city.
Speaker 3: Yeah, that's the standard mental imag.
Speaker 2: Right, Like I picture a massive apocalyptic mountain of ice,
Speaker 2: you know, like Hailbop or Haley's Comet.
Speaker 3: And that assumption is exactly why forty one P is
Speaker 3: such a profound mechanical anomaly. Okay, because the nucleus of
Speaker 3: commet forty one P, and I mean the actual solid
Speaker 3: core of rock, dust and ice beneath the glowing coma
Speaker 3: you see in photographs, it is almost unimaginably small.
Speaker 2: How small are we talking?
Speaker 3: It measures only about one kilometer.
Speaker 2: Across one kilometer. Okay. Just to give you a concrete
Speaker 2: visual anchor for that scale, picture the Eiffel Tower in Paris.
Speaker 3: Okay.
Speaker 2: Now imagine stacking three Eiffel towers and to end, that
Speaker 2: total height is roughly the diameter of this entire comet.
Speaker 3: It's a tiny on a human scale.
Speaker 2: Sure, looking up at three stacked Eiffel Towers floating in
Speaker 2: the sky would be.
Speaker 3: Massive, terrifying really, right, But.
Speaker 2: In the arena of orbital mechanics, in a space populated
Speaker 2: by moons and gas giants, that is essentially a microscopic
Speaker 2: speck of.
Speaker 3: Dust, it is remarkably diminutive, and that lack of physical
Speaker 3: volume translates directly to a severe lacks makes sense because
Speaker 3: four one P is so small its own self gravity
Speaker 3: is incredibly went. In fact, the escape velocity on a
Speaker 3: one kilometer commet is so low that if you were
Speaker 3: standing on its surface, you could simply jump and your
Speaker 3: leg muscles would provide enough kinetic energy to break the
Speaker 3: comet's gravitational hold entirely.
Speaker 2: Wait, really, you just jump into orbit.
Speaker 3: You would just float away into space. You've never come
Speaker 3: back down.
Speaker 2: That is insane, which means the comet itself barely has
Speaker 2: the internal cohesive strength to hold its own material together,
Speaker 2: let alone resist external forces.
Speaker 3: Exactly, it is highly susceptible to torque.
Speaker 2: Right.
Speaker 3: Torque, Yeah, torque is simply the measure of force that
Speaker 3: can cause an object to rotate about an access. When
Speaker 3: you have an object with substantial mass, say a fifty
Speaker 3: kilometer wide comet, it possesses a massive moment of inertia.
Speaker 3: It's heavy, right, It takes a staggering amount of energy
Speaker 3: to alter its rotation. It can essentially shrug off environmental forces.
Speaker 3: Forty one p does not have that luxury. It is
Speaker 3: a lightweight.
Speaker 2: Think of it like a quad copter drone.
Speaker 3: Oh that's a good comparison.
Speaker 2: Yeah, Like, if you have a massive military grade helicopter,
Speaker 2: a sudden gust of wind or a minor mechanical hiccup
Speaker 2: isn't going to flip it upside down. Its sheer mass
Speaker 2: anchors its momentum. But if you have a cheap, lightlyight,
Speaker 2: palm sized plastic drone and one of the four rotors
Speaker 2: suddenly fires at three hundred percent capacity while the others
Speaker 2: remain normal, the drone doesn't just drift.
Speaker 3: Sideways, No, it completely wipes out.
Speaker 2: Exactly the massive asymmetry and thrust against its low mass
Speaker 2: throws the entire machine into an uncontrollable, violent flat spin.
Speaker 2: In the grand chaotic mechanics of our solar system, comet
Speaker 2: forty one P is that tiny unbalanced drone.
Speaker 3: The drone analogy captures the mechanical vulnerability perfectly. It is
Speaker 3: structurally at the mercy of the thermodynamic environment.
Speaker 2: Around it, and that extreme vulnerability is really what sets
Speaker 2: the stage for the deeply bizarre sequence of events that
Speaker 2: astronomer David Jewett eventually uncovered.
Speaker 3: Yes, the entire time timeline a forty one p's twenty
Speaker 3: seventeen approach to the Sun basically reads like a forensic
Speaker 3: reconstruction of a mechanical failure.
Speaker 2: So let's trace that twenty seventeen timeline because it really
Speaker 2: is a detective story.
Speaker 3: It really is.
Speaker 2: We are following the breadcrumbs left in the digital archives,
Speaker 2: and it starts in March at twenty seventeen, when forty
Speaker 2: one P was making its standard five point four year
Speaker 2: swing toward the Sun.
Speaker 3: Right in March, the astronomical community had their eyes on it.
Speaker 3: Astronomers utilize the Discovery Channel telescope, which is a very
Speaker 3: powerful ground based optical observatory located at the Lowell Observatory
Speaker 3: in Arizona.
Speaker 2: Very famous telescope.
Speaker 3: Oh yeah, so they took standard photometric observations basically measuring
Speaker 3: the light curve of the comet as it tumbled through space.
Speaker 2: So a solid baseline measurement exactly.
Speaker 3: The March data established the comet's starting parameters. They calculated
Speaker 3: how fast it was spinning as it came in toward perihelion,
Speaker 3: which is its closest approach to the Sun, and what
Speaker 3: was it doing at that moment. It was behaving like
Speaker 3: a perfectly standard, albeit very small, Jupiter family comet. Its
Speaker 3: rotation was normal, its momentum was steady.
Speaker 2: Okay, But the narrative fractures just two months later. Right
Speaker 2: fast forward to May of twenty seventeen. If I'm David
Speaker 2: Jewett looking at this archival data, what am I seeing
Speaker 2: in the May files?
Speaker 3: You are seeing an inexplicable deceleration. In May researchers pulled
Speaker 3: data gathered from space, specifically from NASA's Neil Garrel's Swift Observatory. Now,
Speaker 3: SWIFT is primarily designed to hunt for gamma ray bursts
Speaker 3: deep in the cosmos.
Speaker 2: Oh really, not comets, right.
Speaker 3: But its ultraviolet and optical telescopes are occasionally pointed at
Speaker 3: local targets like commets, and the ultraviolet data from Swift
Speaker 3: reveals something entirely baffling.
Speaker 2: What did it true?
Speaker 3: In just an eight week span, the comet had experienced
Speaker 3: a massive, dramatic slowdown in its repational period.
Speaker 2: A slowdown in a vacuum implies a massive counter force.
Speaker 2: I mean, there's a no air resistance to bleed off
Speaker 2: that momentum right now.
Speaker 3: None.
Speaker 2: So what kind of deceleration are the swift numbers actually showing?
Speaker 3: The object was suddenly spending three times more slowly than
Speaker 3: its baseline measurement in March.
Speaker 2: Three times.
Speaker 3: Yeah, The rotation period had stretched out to a sluggish,
Speaker 3: agonizing crawl, taking anywhere from forty six to sixty hours
Speaker 3: to complete a single rotation. It was literally grinding to
Speaker 3: a halt.
Speaker 2: A comet that has been doing the same lap carrying
Speaker 2: the exact same momentum for fifteen hundred years suddenly loses
Speaker 2: two thirds of its rotational velocity in sixty days.
Speaker 3: It's unheard of.
Speaker 2: That alone is a terrifying display of localized force. It's
Speaker 2: a massive physics anomaly. But that isn't the climax of
Speaker 2: the archive, isit.
Speaker 3: No, the actual shot comes at the end of the year.
Speaker 2: Okay, let's get into that.
Speaker 3: We're moved to December twenty seventeen. This is the crucial
Speaker 3: file that Jewett eventually cracked open. The observations this time
Speaker 3: came from the Hubble Space telescope.
Speaker 2: Oh the big guns, the biggest.
Speaker 3: Hubble's optics are pristine. It operates entirely above the distortion
Speaker 3: of Earth's atmosphere, providing incredibly high resolution imaging. Right when
Speaker 3: the December light curves from Hubble were finally analyzed, they
Speaker 3: showed that the sluggish sixty hour crawl was totally gone.
Speaker 2: So the rotation sped back up.
Speaker 3: It accelerated wildly. It went from that sixty hour crawl
Speaker 3: back down to completing a full rotation in just fourteen hours.
Speaker 3: Ral it was whipping around. What's fascinating here is the
Speaker 3: direction of the rotation had flipped. It was spinning in
Speaker 3: the completely opposite direction from its March baseline.
Speaker 2: A violent, massive mechanical reversal over a span of just
Speaker 2: nine months. Think about the energy required to execute that maneuver.
Speaker 2: It had to continue slowing down after the May observation,
Speaker 2: eventually coming to an absolute dead mechanical stop in the
Speaker 2: vacuus space before being forcefully continuously pushed to accelerate backward.
Speaker 3: It really forces a complete reevaluation of the thermodynamic forces
Speaker 3: at play on the surface of these small bodies. I
Speaker 3: bet because to fundamentally alter the angular momentum of a
Speaker 3: one kilometer wide solid object, you need a continuous, targeted
Speaker 3: and immense application of force. You literally need engine.
Speaker 2: Which brings us to the mechanics of the vacuum itself.
Speaker 2: We have the forensic timeline right, normal spin, sudden deceleration,
Speaker 2: dead stop, violent reverse acceleration.
Speaker 3: The whole sequence.
Speaker 2: We know the mass is low, but where is the engine?
Speaker 2: Like what massive force in the solar SYSM could possibly
Speaker 2: act as a localized thruster system capable of throwing three
Speaker 2: Eiffel Towers into reverse.
Speaker 3: The engine is fueled by a very specific phase transition
Speaker 3: called sublimation.
Speaker 2: Okay, sublimation, let's break that down.
Speaker 3: When we interact with ice on Earth, we are dealing
Speaker 3: with atmospheric pressure. If you take an ice cube out
Speaker 3: of your freezer, the ambient heat causes the solid H
Speaker 3: two O to melt into liquid water. Right, it melts,
Speaker 3: and if you apply enough heat, that liquid water eventually
Speaker 3: boils and evaporates into a gas That is the standard
Speaker 3: thermodynamic progression solid liquid gas.
Speaker 2: But a comet operates in the deep vacuum of space.
Speaker 2: The atmospheric pressure is essentially zero.
Speaker 3: Exactly, and without atmospheric pressure, the liquid state of water
Speaker 3: simply cannot exist. Yeah, the physics won't allow it. So
Speaker 3: as Comet forty one P approaches the Sun, it is
Speaker 3: subjected to incredibly intense unshielded solar radiation.
Speaker 2: It's getting baked, baked.
Speaker 3: The surface of the comet heats up rapidly the frozen
Speaker 3: volatile things like water, ice, carbon monoxide, carbon dioxide. They
Speaker 3: react to this extreme thermal shock by instantly flashing from
Speaker 3: a solid state directly into a gaseous state. Wow, they
Speaker 3: bypass the liquid phase entirely.
Speaker 2: So it's flash boiling from a frozen rock straight into
Speaker 2: a violent cloud of vapor.
Speaker 3: Yes, and that vapor doesn't just passively float away like
Speaker 3: a morning mist, because it expands incredibly rapidly upon transitioning
Speaker 3: to a gas. It violently, forcefully ejects outward into the
Speaker 3: vacuum like get explosion. Very much so. This violent expulsion
Speaker 3: creates localized outgassing jets right on the surface of the
Speaker 3: comet's nucleus.
Speaker 2: This is where David Jewett's analysis of the Hubble data
Speaker 2: becomes so brilliant because he looked at these outgassing jets
Speaker 2: and just applied absolute foundational Newtonian physics to them.
Speaker 3: Newton's third law right.
Speaker 2: For every action, there is an equal and opposite reaction.
Speaker 2: As the sublimating gas violently fires outward into space, the
Speaker 2: physical force of that ejection pushes back against the solid
Speaker 2: surface of the comet.
Speaker 3: It is the exact same mechanical principle that propels a
Speaker 3: SpaceX rocket off a launch pad.
Speaker 2: That's a great way to picture it.
Speaker 3: The rocket forces combustion gases downward, and the equal opposite
Speaker 3: reaction pushes the massive physical structure of the rocket upward.
Speaker 3: On forty one p the sublimating ice is acting identically
Speaker 3: to chemical propellant. The comet has essentially grown a series
Speaker 3: of organic, entirely uncontrollable rocket thrusters all over its surface.
Speaker 2: The wait, if you have thrusters covering the entire surface
Speaker 2: of a sphere pushing equally in all directions, the forces
Speaker 2: would just cancel each.
Speaker 3: Other out, you would think, so, yes, the comet.
Speaker 2: Would just sit inside a glowing ball of its own gas. Yeah,
Speaker 2: I mean it might get pushed slightly outward away from
Speaker 2: the sun by solar wind, but its spin would violently
Speaker 2: throw itself into reverse.
Speaker 1: Right.
Speaker 3: But you are assuming a comet is a perfect smooth sphere,
Speaker 3: and they almost never are because forty one P is
Speaker 3: so small it lacks the necessary mass to achieve hydrostatic equilibrium,
Speaker 3: which is what that's the gravitational force that pulls planets
Speaker 3: and large moons into perfect round shapes. Forty one P
Speaker 3: is lumpy, irregular, scarred, and completely asymmetrical. It looks more
Speaker 3: like a battered potato than a billiard ball.
Speaker 2: Ah okay, And because the shape is asymmetrical, the distribution
Speaker 2: of the ice is asymmetrical.
Speaker 3: Exactly, the active areas, the exposed patches of volatilized that
Speaker 3: create the strongest jets, were unevenly distributed across its irregular.
Speaker 2: Surface, so it's not a uniform push, not at all.
Speaker 3: So when the sun hit those patches, the thrusters didn't
Speaker 3: fire symmetrically. They fired off center, they fired at odd angles,
Speaker 3: and the dominant force of those asymmetrical jets happened to
Speaker 3: push directly against the comet's original rotational motion.
Speaker 2: Here's where it gets really interesting because Jewett used a
Speaker 2: brilliant analogy in his analysis to make sense of this torque.
Speaker 2: He compared the comet to a playground merry go round.
Speaker 3: Such a helpful visual it really is.
Speaker 2: Imagine a heavy metal merry go round spinning steadily to
Speaker 2: the left. If you run up to it and start
Speaker 2: aggressively pushing against the metal bars, forcing them to the right,
Speaker 2: the merry go round doesn't just instantly snap into reverse.
Speaker 3: No, as momentum right.
Speaker 2: The first thing that happens is it begins to aggressively decelerate.
Speaker 2: Your pushing is fighting against the established angular momentum.
Speaker 3: And that deceleration is exactly what the Swift observatory captured
Speaker 3: in May of twenty seventeen AH the slowdown. Yes, the
Speaker 3: Sun's intense heat had activated the comet's asymmetrical thrusters, and
Speaker 3: the physical force of those gas ejections started pushing continuously
Speaker 3: against the comet's natural forward spin. The spin was bleeding
Speaker 3: off energy, slowing to that sluggish sixty hour crawl.
Speaker 2: But the Sun doesn't just turn off. The thermal shot continues.
Speaker 2: As the comet gets closer to perihelion, the sublimation doesn't stop.
Speaker 3: It actually accelerates.
Speaker 2: Right, so back to the playground. You don't stop pushing
Speaker 2: the merry go round to the right. You keep applying force.
Speaker 2: Eventually the forward momentum is entirely depleted. The merry go
Speaker 2: round grounds to a dead stop.
Speaker 3: It is your own momentum.
Speaker 2: And then, because you are still leaning your entire weight
Speaker 2: into it pushing right, it begins to accelerate into a
Speaker 2: right word spin exactly.
Speaker 3: The continuous, wildly uneven outgassing eventually overpowered the entirety of
Speaker 3: the comet's original angular momentum.
Speaker 2: It's mind boggling, it really is.
Speaker 3: It applied enough counter torque to stop a one kilometer
Speaker 3: rock dead in its tracks, and then functioned as a
Speaker 3: retrograde engine, spinning it up until it was whipping around
Speaker 3: every fourteen hours by December. The physics are totally sound,
Speaker 3: but witnessing the sheer scale of thermodynamic energy required to
Speaker 3: execute that maneuver on a solid body is staggering.
Speaker 2: It's an incredible display of mechanics. But as Jewett dug
Speaker 2: deeper into the data, this violent spin reversal started to
Speaker 2: look less like a quirky physics trick and more like
Speaker 2: a meta symptoms Sadly, yes, it points to something much
Speaker 2: darker regarding the structural integrity and the overall life span
Speaker 2: of forty one P. The comet is essentially experiencing a
Speaker 2: violent terminal crisis.
Speaker 3: Yes, we have to zoom out from the twenty seventeen
Speaker 3: event and look at the comet's historical health, because to
Speaker 3: contextualize the violence of the spin reversal, you have to
Speaker 3: look at the volume of gas the comet was actually producing, right,
Speaker 3: and the archives provide a chilling point of comparison.
Speaker 2: So let's pull up the data from its previous closed passes.
Speaker 2: Forty one P loops the Sun every five point four years.
Speaker 2: What did it look like in the past.
Speaker 3: The most vital comparison point is its perihelium passage in
Speaker 3: the year two thousand and one, sorry two thousand one.
Speaker 3: During that approach sixteen years prior to the spin reversal,
Speaker 3: astronomers recorded that forty one P was exceptionally active for
Speaker 3: a comet of its diminutive size. Oh yeah, it was
Speaker 3: venting brilliantly. The volatile ice was reacting violently to the Sun,
Speaker 3: producing a massive, dense coma of gas and dust. It
Speaker 3: was a robust, highly healthy textbook commet.
Speaker 2: But when we ask forward back to the twenty seventeen passage,
Speaker 2: the exact same orbital path, the exact same proximity to
Speaker 2: the Sun, the health metrics just collapse.
Speaker 3: You fall off a cliff.
Speaker 2: The overall gas production of forty one P didn't just dip,
Speaker 2: It plummeted by roughly in order of magnitude. It dropped
Speaker 2: by a factor of ten. Yeah, it was producing only
Speaker 2: ten percent of the gas that it produced just sixteen
Speaker 2: years prior. Ninety percent of its activity simply vanished.
Speaker 3: That kind of severe, almost instantaneous drop in outcasting is alarming.
Speaker 3: Astronomers generally accept two primary hypotheses for why a short
Speaker 3: period COMMET would undergo such a massive and rapid loss
Speaker 3: of activities.
Speaker 2: So let's unpack the first hypothesis. What's the main idea?
Speaker 3: The first is simple volatile depletion. Okay, the comet is
Speaker 3: fundamentally running out of fuel. You have to remember forty
Speaker 3: one P has been running this exact inner solar system
Speaker 3: loop for fifteen hundred years.
Speaker 2: That's a lot of trips around the Sun.
Speaker 3: It is every five point four years the Sun burns
Speaker 3: off a layer of its near surface ice after a
Speaker 3: millennium and a half, the tank is simply hit empty. Wow,
Speaker 3: The accessible ice that is actually capable of sublimating has
Speaker 3: been exhausted, leaving behind mostly inert rock and deep core
Speaker 3: ice that the sun's heat just can't easily reach.
Speaker 2: So it's drying out. It's transitioning from a vibrant comet
Speaker 2: into just a dead, inert asteroid.
Speaker 3: Exactly.
Speaker 2: So if the tank isn't simply empty, what's the alternative?
Speaker 2: Is the fuel somehow trapped?
Speaker 3: You're hitting on the second hypothesis Mantling Mantling, Yes. Mantling
Speaker 3: suggests that the volatile ice is still present beneath the surface,
Speaker 3: but it is being aggressively smothered.
Speaker 2: Smothered out well.
Speaker 3: When a comet sublimates, the gas expanding into space carries dirt, dust,
Speaker 3: and heavier silicate particles with it. But because forty one
Speaker 3: Peter has such weak gravity, not all of that debris
Speaker 3: reaches escape velocity.
Speaker 2: Ah, so it doesn't all blow away, right.
Speaker 3: A lot of the heavier dust eventually falls back down
Speaker 3: onto the nucleus over hundreds of orbits. This fallback creates
Speaker 3: a thick, highly insulating crust of dust and burt over
Speaker 3: the active ice patches.
Speaker 2: Wait, hold on, let me push back on the antling
Speaker 2: theory for a second. Sure, if the comet is building
Speaker 2: up this thick insulating crust of dust, wouldn't that actually
Speaker 2: act as a heat shield, Like if the crust prevents
Speaker 2: the sun's thermal radiation from reaching the ice, the sublimation stops. True,
Speaker 2: and if the sublimation stops, the rogue outgassing thrusters shut down.
Speaker 2: So doesn't the dust crust actually save the comet from
Speaker 2: continuing to spin out of control? It seems like mantling
Speaker 2: would stabilize the rotation, not make it worse.
Speaker 3: It's a brilliant deduction, and in a perfectly uniform system
Speaker 3: that might be true. A perfectly even mantle would shut
Speaker 3: down the commet entirely, turning it into a dormant rock.
Speaker 3: But again, forty one P is heavily asymmetrical and chaotic.
Speaker 3: The mantle doesn't build up evenly. You get thick crusts
Speaker 3: in some areas and exposed highly active vents in others.
Speaker 3: Oh I see this extreme variance in surface insulation actually
Speaker 3: exacerbates the asymmetrical thruster problem. You have concentrated hyper pressurized
Speaker 3: jets firing from the few remaining weak points in the crust.
Speaker 2: So instead of a dozen small thrusters pushing evenly, you
Speaker 2: have one or two massive concentrated geysers fighting against the
Speaker 2: entire mass of the comet. Exactly, it makes the torque
Speaker 2: even more violent.
Speaker 3: Furthermore, even belief the mantle, the heat slowly permeates, the
Speaker 3: ice beneath the crust still sublimates, but the gas is trapped.
Speaker 2: Oh a pressure cooker.
Speaker 3: Yes, it creates localized high pressure subsurface pockets that eventually
Speaker 3: explode through the crust, creating sudden, violent bursts of momentum,
Speaker 3: whether it is depleting its fuel or choking on its
Speaker 3: own debris. The timeline is what truly shocks the astronomical community.
Speaker 2: Right the sixteen year gap.
Speaker 3: Yes, the structural evolution of comets, the gradual building of
Speaker 3: a thick mantle, or the complete exhaustion of volatile reserves.
Speaker 3: These are processes that standard models dictate should take centuries
Speaker 3: or millennia.
Speaker 2: Right, space time is deep time.
Speaker 3: We assume these changes happen on deep cosmic timescales. But
Speaker 3: with forty one p the data proves it dropped ninety
Speaker 3: percent of its activity in just sixteen years. We are
Speaker 3: watching cosmic evolution, the actual aging and dying of a
Speaker 3: celestial body unfolding on a human timescale.
Speaker 2: Which naturally forces us to look at the math of
Speaker 2: its future. We have a rapidly deteriorating comet. We have
Speaker 2: a wildly fluctuating asymmetrical rotational spin. We have a structurally
Speaker 2: compromised weak body of ice.
Speaker 3: And rock, a recipe for disaster.
Speaker 2: When David Jewett ran the predictive modeling on these specific
Speaker 2: torques and mass loss rates, what does the physics say
Speaker 2: happens next? How does the story of forty one p end?
Speaker 3: The physics point toward a mathematically inevitable and highly violent conclusion.
Speaker 3: The continuous radical changes in angular momentum are subjecting the
Speaker 3: comet to extreme mechanical stress I can imagine. And the
Speaker 3: ultimate threat here isn't the Sun's heat melting it away.
Speaker 3: The threat is centrifical force.
Speaker 2: Okay, let's make sure the mechanics a centrifugal force are
Speaker 2: perfectly clear for everyone. If you take a wet tennis ball,
Speaker 2: soak it in a bucket of water, and then spin
Speaker 2: it incredibly fast, the water violently flies outward in all directions.
Speaker 3: Exactly.
Speaker 2: The spinning motion creates an outward push, pulling mass away
Speaker 2: from the center of rotation. If you spin something fast enough,
Speaker 2: the outward centrifical force becomes stronger than the internal bonds
Speaker 2: holding the object together, and.
Speaker 3: We return to the core vulnerability of forty one p
Speaker 3: its diminutive size. Because it is only one kilometer wide,
Speaker 3: its self gravity is incredibly weak.
Speaker 2: Right, you could jump right off it.
Speaker 3: Furthermore, comets are not solid blocks of granite. They are
Speaker 3: highly porous, structurally fragile agglomerations of ice, dust, and loose rock.
Speaker 3: They are essentially giant, loosely packed dirty snowballs.
Speaker 2: That's a great way to put it, dirty snowballs.
Speaker 3: Their internal tensile strength is remarkable low, so it's.
Speaker 2: Barely holding itself together under normal circumstances.
Speaker 3: So as these rogue outgassing jets continue to misfire. If
Speaker 3: they push the kana's rotational velocity just slightly past a
Speaker 3: critical threshold, the outward centrifical forces will completely overpower are
Speaker 3: the comets weak gravity and its fragile internal cohesion. All
Speaker 3: man the force attempting to fling the material outward into
Speaker 3: space will become greater than the gravity pulling it inward.
Speaker 2: It hits the rotational equivalent of the roch limit. The
Speaker 2: internal physics just give up. And what does that look like?
Speaker 2: Does it just crack an half?
Speaker 3: It looks like catastrophic disintegration. The nucleus will literally tear
Speaker 3: itself apart from the inside out, unbelievable. It will shatter
Speaker 3: into a massive debris feel of expanding ice, dust and boulders,
Speaker 3: completely dissolving its physical form and spreading its remains across
Speaker 3: its five point four year orbital track. David Jewett looked
Speaker 3: at the torque calculations and was completely unambiguous about the prognosis.
Speaker 2: What did he say?
Speaker 3: He stated, I expect this nucleus will very quickly self destruct.
Speaker 2: Wow, very quickly self destruct. It's chilling to hear an
Speaker 2: ascophysicist use that kind of definitive, violent language regarding a
Speaker 2: celestial body.
Speaker 3: It's rare.
Speaker 2: It paints a profoundly different picture of the Solar System
Speaker 2: than the one we usually imagine. You have this object
Speaker 2: that survived the chaotic formation of the Solar System four
Speaker 2: point six billion years ago. It survived being violently ejected
Speaker 2: by Jupiter. It successfully navigated the thermal shock of the
Speaker 2: Sun for fifteen hundred years, and now suddenly it is
Speaker 2: being ripped apart by its own internal gases, literally spinning
Speaker 2: itself to death because it can't handle the physics of
Speaker 2: its own sublimation.
Speaker 3: It highlights how utterly fragile these small bodies actually are.
Speaker 3: They aren't permanent fixtures in the sky. They are temporary,
Speaker 3: delicate structures, entirely at the mercy of the thermodynamic environment.
Speaker 2: It is a stark reminder of the dynamic violence of
Speaker 2: orbital mechanics. But you know, the entire narrative of forty
Speaker 2: one p's impending destruction is underscored by the methodology of
Speaker 2: the discovery itself. Absolutely, we wouldn't know any of this.
Speaker 2: We wouldn't understand the violent torque of asymmetrical jets or
Speaker 2: the incredibly rapid sixteen year aging process if it weren't
Speaker 2: for the philosophy of modern astronomical data archiving. It's true,
Speaker 2: this is the part of the story that I find
Speaker 2: most inspiring. The unsung hero here isn't a new multi
Speaker 2: billion dollar piece of hardware launched in orbit yesterday.
Speaker 3: No, not at all.
Speaker 2: The hero is the digital filing cabinet. The hero is
Speaker 2: the patient meticulous mining of old, ignored data.
Speaker 3: Consider the timeline of discovery again. The baseline observation was
Speaker 3: March twenty seventeen, the swift slowdown was May twenty seventeen,
Speaker 3: and the shocking violent spin reversal was captured by the
Speaker 3: Hubble Space Telescope in December twenty seventeen. But the incredible
Speaker 3: truth is that when Hubble captured that light curve in
Speaker 3: December of twenty seventeen, no one on Earth realized what
Speaker 3: they just photographed.
Speaker 2: That blows my mind. The telescope recorded the impossible physics,
Speaker 2: downloaded the telemetry to servers on Earth, and it was
Speaker 2: just quietly filed away. No alarm bells went off, no
Speaker 2: one was watching the live feed shouting eureka.
Speaker 3: It simply became another data point in an impossibly vast
Speaker 3: ocean of information. To understand how a discovery this massive
Speaker 3: gets buried, you have to look at the sheer, overwhelming
Speaker 3: output of modern observatories.
Speaker 2: It's a lot of data.
Speaker 3: The Hubble Space Telescope has been gazing into the deep
Speaker 3: universe collecting high resolution imaging and complex spectroscopic data for
Speaker 3: over three decades. It is an absolute fire hose of
Speaker 3: cosmic telemetry.
Speaker 2: It's capturing infinitely more data than the global astronomical community
Speaker 2: can possibly analyze in real time.
Speaker 3: Precisely, and because of that immense volume, NASA and the
Speaker 3: Space Telescope Science Institute established the mcculski Archive for Space Telescopes,
Speaker 3: commonly known as mass mast okay. This is a massive,
Speaker 3: centralized repository that holds the raw and calibrated data not
Speaker 3: just from Hubble, but from over a dozen different space
Speaker 3: based and ground based astronomical missions. Every photon captured, every
Speaker 3: light curve measured, is uploaded into this archive and made
Speaker 3: freely available to researchers.
Speaker 2: It is the ultimate open source library of the cosmos.
Speaker 2: And it was inside this specific digital library that David
Speaker 2: Jewett was simply browsing years after the fame. He was
Speaker 2: just looking, He wasn't comment during telescope time. He was
Speaker 2: sifting through the MAAST records, pulled at the files on
Speaker 2: forty one p from late twenty seventeen and realized that
Speaker 2: the specific Hubble light curves from December had never been
Speaker 2: fully modeled.
Speaker 3: No one had done the complex mathematical work to extract
Speaker 3: the rotational period from those specific pixels. Jewett applied the
Speaker 3: math to the archival data, and the ghost emerged from
Speaker 3: the machine. Incredible, the spin reversal revealed itself on a
Speaker 3: computer monitor, years after the physical event had already occurred
Speaker 3: in the vacuum of space.
Speaker 2: This completely upends the romanticized Hollywood version of science, doesn't it.
Speaker 2: We always picture the lone genius peering through a frosted
Speaker 2: eyepiece on a mountaintop, gasping as a new comet streaks
Speaker 2: across the lens.
Speaker 3: A very dramatic image, but not very accurate.
Speaker 2: Right. The reality of modern astrophysics is often much quieter,
Speaker 2: and in many ways much more profound. It is the
Speaker 2: realization that the truth of the universe, the evidence of
Speaker 2: a dying comet spinning violently backward, was sitting on a hard.
Speaker 3: Drive the entire time, hidden in plain sight.
Speaker 2: It was like finding a winning lottery ticket in the
Speaker 2: pocket of a winter coat you haven't worn in three years.
Speaker 2: The data didn't change, the stars didn't change. The only
Speaker 2: thing that changed was a human being deciding to ask
Speaker 2: the right question and having the curiosity to look at
Speaker 2: the old data in the new way.
Speaker 3: The philosophy of open science is rapidly becoming the most
Speaker 3: powerful tool in astronomy. Space exploration is no longer solely
Speaker 3: defined by the massive, multi billion dollar engineering challenges of
Speaker 3: launching new mirrors into the void.
Speaker 2: Right, the hardware is just step one exactly.
Speaker 3: It is equally defined by data mining. The archive itself
Speaker 3: is a universe waiting to be explored. By ensuring that
Speaker 3: petabytes of raw astronomical data are open, preserved, and accessible,
Speaker 3: we guarantee that observations can be endlessly revisited to answer
Speaker 3: questions that scientists in twenty seventeen didn't even know they
Speaker 3: needed to ask.
Speaker 2: It's a phenomenal synthesis of human curiosity and raw computational physics.
Speaker 2: If we trace the entire narrative arc of commat forty one,
Speaker 2: we start with a fragile, microscopic rock Asian just three
Speaker 2: Eiffel towers cross born billions of years ago in the
Speaker 2: crygenic deep frieze of the Kuiper Belt. It gets gravitationally
Speaker 2: bullied by Jupiter, permanently evicted into a fifteen hundred year
Speaker 2: loop of thermal torture. Then, in a span of just
Speaker 2: sixteen years, it rapidly ages, losing ninety percent of its
Speaker 2: activity as it either exhausts its fuel or suffocates under.
Speaker 3: Its own debris, a tragic end.
Speaker 2: And finally, the sun superheats its remaining asymmetrical ice patches,
Speaker 2: turning them into rogue rocket thrusters that violently break the
Speaker 2: commet's momentum and hurl it into an unprecedented, catastrophic reverse spin.
Speaker 3: It really sounds like science fiction when you summarize.
Speaker 1: It like that.
Speaker 2: It does. Now plagued by the immense stress of centrifugal force,
Speaker 2: it is mathematically destined to tear its own fragile body apart,
Speaker 2: leaving nothing but a ghost trail of dust in its wake.
Speaker 2: And the entire violent saga was decoded from a forgotten
Speaker 2: computer file.
Speaker 3: It perfectly dismantles the illusion of a static universe. The
Speaker 3: night sky is not a calm, predictable tapestry. It is
Speaker 3: a highly volatile, violently shifting thermodynamic engine constant motion. Celestial
Speaker 3: bodies are constantly reacting, decaying, and being destroyed by the
Speaker 3: invisible forces of gravity and radiation, and.
Speaker 2: Our ability to comprehend that beautiful, terrifying chaos relies on
Speaker 2: our willingness to meticulously preserve and re examine our own.
Speaker 3: Records, which leaves us with a rather profound implication to consider.
Speaker 3: If a single unanalyzed file from twenty seventeen could fundamentally
Speaker 3: shift our understanding of comet mechanics and reveal a completely unprecedented,
Speaker 3: violent rotational reversal hiding in plain sight, what else is
Speaker 3: in the archive?
Speaker 2: That's a huge question.
Speaker 3: What other universe breaking anomalies, dying stars, or silent cosmic
Speaker 3: catastrophes are sitting quietly on a server right now, completely undetected,
Speaker 3: simply waiting for someone curious enough to open the file.
Speaker 2: The answers to the universe's greatest mysteries might not require
Speaker 2: a new telescope. They might just require us to look
Speaker 2: close at the light we've already captured.
Speaker 3: U