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 start by picturing something in your
Speaker 2: mind right now. Just close your eyes for a second.
Speaker 3: If you can, well, unless you're drying, right.
Speaker 2: Oh yeah, Please do not close your eyes if you're driving,
Speaker 2: but otherwise, I want you to visualize holding an object
Speaker 2: the exact size of the planet Jupiter.
Speaker 3: That is a massive object to hold in your hand.
Speaker 2: Right. Just picture this massive swirling sphere resting right there
Speaker 2: in your palm, and you're bracing your arm, you know,
Speaker 2: preparing for the crushing incomprehensible weight of a gas.
Speaker 3: Giant, which would be terrifying.
Speaker 2: Exactly your gravitational pressure of a world that size, I mean,
Speaker 2: it should be enough to collapse your entire skeleton instantly
Speaker 2: without a doubt. But instead, when you actually try to
Speaker 2: lift it, you discover that this entire Jupiter sized world
Speaker 2: weighs less than a giant ball of cotton candy.
Speaker 3: Which just doesn't make any sense.
Speaker 2: It totally defies all your expectations. Your brain, it almost
Speaker 2: cannot compute what your hands are feeling because the physical
Speaker 2: laws you rely on every single day are suddenly screaming
Speaker 2: that this object should not exist.
Speaker 3: It creates a complete cognitive short circuit. I mean, our
Speaker 3: brains evolved on a rocky terrestrial world, you know, yeah, Earth, right,
Speaker 3: and here we inherently associate massive volume with massive mass.
Speaker 3: You look at a huge boulder, you know what possesses
Speaker 3: significant density. You don't expect it to float away.
Speaker 2: You expect to break your toe if you kick it.
Speaker 3: Exactly, So, you look at a planet the size of Jupiter,
Speaker 3: and astrophysics dictates that it must possess tremendous gravity driven
Speaker 3: by a deeply compressed core and layers of ultra dense material.
Speaker 3: Because that's what Jukuer is, yes, exactly. Breaking that fundamental
Speaker 3: physical expectation forces us to confront just how limited our
Speaker 3: earth bound common sense intuition actually is when we apply
Speaker 3: it to the broader mechanics of the cosmos.
Speaker 2: Okay, let's unpack this because leaving our common sense at
Speaker 2: the door is the absolute core of our mission.
Speaker 3: Today.
Speaker 2: We are traveling a long way out right, very long, yeah,
Speaker 2: eleven hundred and ten light years away from our Solar system.
Speaker 2: We are heading deep into the southern constellation of Volons,
Speaker 2: which is the flying Fish constellation, the great name, by
Speaker 2: the way, it really is. And we are focusing our
Speaker 2: attention on a newly confirmed pair of planets orbiting a
Speaker 2: sunlike G type main sequence star known as TOI seven
Speaker 2: nine to one.
Speaker 3: And we should clarify these aren't your standard exoplanets.
Speaker 2: No, not at all. They belong to a highly elusive
Speaker 2: category known as superpuffs.
Speaker 3: Superpuffs, which is such a whimsical label for a phenomenon
Speaker 3: that fundamentally challenges our model of planetary formation.
Speaker 2: It sounds like a serial brand, it does.
Speaker 3: But exploring these superpuffs requires us to well completely abandon
Speaker 3: the idea that our own Solar system is the standard
Speaker 3: blueprint for the universe.
Speaker 2: We're not the main character exactly.
Speaker 3: The Cosmos constantly proves that it operates on extreme variables,
Speaker 3: and our goal today is to examine the specific astrophysical
Speaker 3: conditions that allow us star to forge a planet that
Speaker 3: is practically.
Speaker 2: Hollow, which is mind blowing, right, and.
Speaker 3: To understand how these bizarre, fluffy anomalies force us to
Speaker 3: basically rewrite the timeline of cosmic evolution.
Speaker 2: So before we can even touch on the timeline of
Speaker 2: how a cotton candy world forms, we really have to
Speaker 2: ground ourselves in the sheer scale of the environment and
Speaker 2: the staggering physical contradiction of their existence.
Speaker 3: We have to set the scene.
Speaker 2: Right, Let's look at the neighborhood TOI seven ninety one
Speaker 2: is a leveand one hundred and ten light years away.
Speaker 2: For anyone who follows astronomy, you know that distance places
Speaker 2: the system well beyond our immediate stellar neighborhood.
Speaker 3: But it's still than the orion arm of our milky Way.
Speaker 2: Yeah, and what makes that specific distance interesting is, well,
Speaker 2: let's do the math for a second. A single light
Speaker 2: year is nearly six trillion miles, right, or about nine
Speaker 2: point seven trillion kilometers take, So if you multiply eleven
Speaker 2: hun and ten by six.
Speaker 3: Trillion, you're looking at over six point six quadrillion miles away.
Speaker 2: Six point six quadrillion miles That is just a mind
Speaker 2: boggling number. The light we are receiving from the star today.
Speaker 2: It began its journey during the European Middle Ages.
Speaker 3: Which is incredible to think about. We're essentially looking at
Speaker 3: a system deeply embedded in the galactic disc, which means
Speaker 3: the star formed from a very specific molecular cloud with
Speaker 3: its own unique ratio of heavy.
Speaker 2: Elements, and that ratio matters a lot, right.
Speaker 3: Oh absolutely. The metallicity of that specific region in the
Speaker 3: orion arm is a crucial piece of the puzzle. It
Speaker 3: directly dictates the raw materials available when TOI seven nine
Speaker 3: to one ignited.
Speaker 2: So if a star system forms in a region depleted
Speaker 2: of heavy elements.
Speaker 3: Stra ms call low metallicity right.
Speaker 2: Low metallicity, the resulting planets are going to be starved
Speaker 2: of the rocky silicates and iron needed to build dense cores.
Speaker 3: You can't build a rocky planet if you don't have
Speaker 3: any row exactly.
Speaker 2: So we are observing a system that had to construct
Speaker 2: Jupiter sized worlds using a radically different material budget than
Speaker 2: our own Sun.
Speaker 3: Had, and that budget deficit leads us directly to the
Speaker 3: density anomaly.
Speaker 2: Which is the craziest part. We see the profile, the
Speaker 2: raw volumetric footprint of a gas giant, but the spale
Speaker 2: is a complete cosmic deception.
Speaker 3: It's all a trick of the light almost.
Speaker 2: To put a massive anchor on this. Our own Jupiter
Speaker 2: is up to thirty five times denser than these two super.
Speaker 3: Puff thirty five times.
Speaker 2: When we think about Jupiter, we are just thinking about
Speaker 2: a big cloud. We are talking about a world so
Speaker 2: massive that the pressure inside it alters the fundamental phase
Speaker 2: states of matter.
Speaker 3: Yes, deep beneath Jupiter's cloud tops, the pressure is millions
Speaker 3: of times greater than Earth's atmosphere. It's violent, very It
Speaker 3: forces hydro and gas to compress so violently that the
Speaker 3: electrons literally detached from their.
Speaker 2: Nuclei, turning the gas into a sloshing ocean of liquid
Speaker 2: metallic hydrogen, which is just insane it is.
Speaker 3: And that generates a magnetic field that acts like a
Speaker 3: lethal radiation shield. Basically, Jupiter is an armored tank.
Speaker 2: A heavily armored tank, and then you look at these
Speaker 2: two planets and volins, and they are practically ghosts.
Speaker 3: The contrast is staggering when you really drill down into
Speaker 3: the thermodynamics of density, because density isn't just about weight.
Speaker 2: Great tells you what's going on inside exactly.
Speaker 3: It is the ultimate indicator of a planet's internal engine.
Speaker 3: Jupiter's high density implies a massive active core generating immense
Speaker 3: internal heat compressing the layers above it.
Speaker 2: So when we observe the superpuffs in the TOI seven
Speaker 2: ninety one system, their extreme lack of density tells us what.
Speaker 3: It tells us that this internal compression engine is either
Speaker 3: completely missing or fundamentally broken.
Speaker 2: Which brings me to this brilliant tactile analogy from George Drandsfield.
Speaker 2: She's an astronomer at the University of Oxford who worked
Speaker 2: on the analysis of these worlds.
Speaker 3: Yes, her work on this is fascinating.
Speaker 2: She described their density as being comparable to a quote
Speaker 2: nice blob of shaving foam fresh from the can.
Speaker 3: The physics behind that analogy are actually surprisingly accurate.
Speaker 2: Really like literal shaving cream.
Speaker 3: Yeah, think about it. When you dispense shaving cream. The
Speaker 3: sudden drop in pressure allows the propellant gas trapped inside
Speaker 3: the gel to rapidly expand. It creates a matrix of
Speaker 3: microscopic bubbles.
Speaker 2: Right, it puffs up in your hand exactly.
Speaker 3: The volume increases exponentially, but the mass remains identical to
Speaker 3: the tiny squirt of gel you started with.
Speaker 2: You press the button, the gel expands into this massive
Speaker 2: puffy cloud in your hand. It has dimension, it blocks light,
Speaker 2: but you can blow on it and it scatters.
Speaker 3: Which is a perfect visual for these planets.
Speaker 2: But this is where the shaving foam analogy creates a
Speaker 2: massive physical paradox for me, and I need you to
Speaker 2: resolve this on to my best. If these planets possess
Speaker 2: a density equivalent to expanded foam, how does a structure
Speaker 2: the size of Jupiter even maintain its cohesion? I mean,
Speaker 2: a planet isn't sitting in a vacuum, right.
Speaker 3: Well, space is a vacuum. But the environment around a
Speaker 3: star is certainly not empty, right.
Speaker 2: It's constantly being blasted by the solar wind of its
Speaker 2: host star. So why doesn't a planet made of literal
Speaker 2: fluff just get shredded and blown out into the interstellar medium.
Speaker 3: What's fascinating here is that the survival of these planets
Speaker 3: hinges entirely on a delicate, almost precarious gravitational truce.
Speaker 2: A truce.
Speaker 3: Yes. The extreme lack of density points us toward a
Speaker 3: very specific chemical reality. These planets possess what we call
Speaker 3: hydrogen helium dominated envelopes.
Speaker 2: Okay, hydrogen and helium, right.
Speaker 3: They are the two lightest, most buoyant elements in the universe.
Speaker 3: But even though they are incredibly light, they still possess mass.
Speaker 2: And if they have mass, they have gravity. But the
Speaker 2: gravity of a shaving foam planet must be incredibly weak.
Speaker 3: It is very weak.
Speaker 2: So how is it strong enough to hold on to
Speaker 2: gases that inherently want to expand and dissipate, especially when
Speaker 2: heated by a nearby star.
Speaker 3: The mechanism keeping them intact is a concept known as
Speaker 3: the genes escape parameter.
Speaker 2: Deems a stape.
Speaker 3: Every gas molecule in a planet's atmosphere possesses kinetic energy,
Speaker 3: meaning it is constantly vibrating and bouncing around. The hotter
Speaker 3: the gas, the faster the molecules move.
Speaker 2: That makes sense.
Speaker 3: Heat is energy, right, and if a molecule reaches a
Speaker 3: specific speed, the escape velocity, it overcomes the planet's gravitational
Speaker 3: pull and bleeds off into space.
Speaker 2: So it's a race basically between the planet's gravitational anchor
Speaker 2: and the thermal energy injected by the star trying to
Speaker 2: boil the atmosphere away.
Speaker 3: Precisely that because TOI seven nine to one is a
Speaker 3: sun like star. It is blasting these planets with high
Speaker 3: energy ultraviolet radiation, just baking them. Yeah. This radiation strikes
Speaker 3: the outer layers of the hydrogen helium envelope, heating the
Speaker 3: gas and driving up its kinetic energy. Now, the planet's
Speaker 3: gravity is incredibly weak due to its low mass, so
Speaker 3: the escape velocity is quite low.
Speaker 2: So why hasn't it all evaperated?
Speaker 3: The reason the the entire planet hasn't vanished is that
Speaker 3: the outer envelope absorbs the brunt of this thermal assault,
Speaker 3: swelling outward traumatically rather than instantly boiling off.
Speaker 2: Oh wow, So it inflates like a cosmic hot air
Speaker 2: balloon to absorb the energy.
Speaker 3: Exactly expanding its volume to dissipate the heat, which in
Speaker 3: turn drastically lowers its overall density even further.
Speaker 2: That thermodynamic expansion is exactly why they appear as superpuffs.
Speaker 2: The planet isn't just naturally fluffy. It is actively ballooning
Speaker 2: in response to stellar radiation.
Speaker 3: It's a reaction to the environment. The gravitational pull from
Speaker 3: the core is just barely sufficient to tether the lower
Speaker 3: layers of the envelope, creating this fragile equilibrium.
Speaker 2: It sounds stressful.
Speaker 3: He is a constant agonizing tug of war between the
Speaker 3: star trying to strip the planet naked and the planet's
Speaker 3: weak gravity clinging to its expanding outer shell.
Speaker 2: That fragile equilibrium creates such a vivid, almost haunting image
Speaker 2: of these worlds. But I think we need to bust
Speaker 2: a pervasive myth right now.
Speaker 3: For everyone listening, I know exactly where you're going with this.
Speaker 2: Because we use terms like cotton candy, it's incredibly easy
Speaker 2: to visualize these super puffs as giant, glowing pink carnival
Speaker 2: treats floating in the void, which.
Speaker 3: Would look cool but is entirely wrong.
Speaker 2: Right If a probe we're actually flying past these planets,
Speaker 2: the visual reality dictated by atmospheric physics would be entirely different.
Speaker 2: They are not pink, not at all.
Speaker 3: The optical properties of a hydrogen rich envelope completely rule
Speaker 3: out any neon pink aesthetics. The visual appearance of a
Speaker 3: gas giant is dictated entirely by how its atmosphere interacts
Speaker 3: with incoming.
Speaker 2: Starlight, and that's based on the chemicals in the air, exactly.
Speaker 3: A process largely governed by Raleigh scattering and the presence
Speaker 3: of specific cloud condensates.
Speaker 2: Okay, let's break that down. So if we have a deep,
Speaker 2: relatively clear atmosphere dominated by hydrogen and helium, we're likely
Speaker 2: looking at a world that scatters short wavelength.
Speaker 3: Light, which is the blue end of the spectrum.
Speaker 2: Right, That would give it a deep, translucent blue hue
Speaker 2: functioning on the exit act same basic optical principles that
Speaker 2: make our own sky blue on.
Speaker 3: Earth, though likely much more profound given the sheer depth
Speaker 3: of the envelope. A pure hydrogen atmosphere would indeed scatter
Speaker 3: blue light very efficiently.
Speaker 2: But it might not be pure hydrogen right.
Speaker 3: Transfield's research team suspects that these envelopes might not be
Speaker 3: clear at all. The thermodynamic profile of these superpuffs suggests
Speaker 3: that their upper atmospheres are likely cool enough to support
Speaker 3: massive global cloud decks.
Speaker 2: But obviously these wouldn't be water clouds like we have
Speaker 2: on Earth right, No, or.
Speaker 3: Even the ammonia clouds that ban Jupiter.
Speaker 2: So what kind of chemistry are we talking about for
Speaker 2: clouds on a shaving foam planet.
Speaker 3: Depending on the specific temperature, we could be looking at
Speaker 3: clouds composed of photochemical hazes like smog kinda yeah, or
Speaker 3: even exotic condensates like salt crystals or silicate dust suspended
Speaker 3: high in the atmosphere.
Speaker 2: Wait, really salt clouds, yeah.
Speaker 3: Salt, or even tiny grains of sand. Essentially yeah. And
Speaker 3: if the atmosphere is choked with these high altitude hazes,
Speaker 3: the optical effect shifts from Raleigh scattering to me scattering.
Speaker 2: Okay, me scattering. That's where the particles are large enough
Speaker 2: to scatter all wavelengths of visible light equally right.
Speaker 3: Exactly, so instead of just scattering blue, it scatters everything.
Speaker 2: Which means, rather than a translucent blue sphere, we might
Speaker 2: be looking at a brilliant, blindingly white world. Just a
Speaker 2: stark white orb like an impossibly massive snowball suspended in
Speaker 2: the darkness, but with edges that are incredibly soft and diffuse,
Speaker 2: fading seamlessly into the vacuum of space.
Speaker 3: The lack of a sharp limb, the distinct edge we
Speaker 3: normally see when we look at a planet, is a defining.
Speaker 2: Characteristic here because it's so puffy, right.
Speaker 3: The atmosphere is so extended and so diffuse that there
Speaker 3: is no hard boundary, just a gradual, hazy transition from
Speaker 3: the intense white reflection of the cloud tops out into
Speaker 3: the blackness of the Volan's constellation.
Speaker 2: Visualizing a hazy edgeless white giant is beautiful. But what
Speaker 2: absolutely staggers me is the technological gauntlet we had to
Speaker 2: run just to prove these soft edged ghosts exist.
Speaker 3: It wasn't easy.
Speaker 2: Finding a superpuff isn't a matter of just pointing a
Speaker 2: telescope and taking a picture. It requires a relentless, multi
Speaker 2: stage photometric and spectroscopic relay race.
Speaker 3: Or relay race is the perfect way to describe it.
Speaker 2: Let's break down the timeline, starting with the transit detection
Speaker 2: by NASA's test satellite Test.
Speaker 3: The Transiting Exoplanet Survey satellite. It operates on a brilliantly
Speaker 3: simple geometric principle, but executed with terrifying precision.
Speaker 2: It's just watching for shadows basically.
Speaker 3: Essentially, yes, it watches for transits, which occur when a
Speaker 3: planet's orbit carries it directly between its host star and
Speaker 3: our vantage.
Speaker 2: Point, like an eclipse.
Speaker 3: Exactly as the planet crosses the face of the star,
Speaker 3: it blocks a microscopic fraction of the star's light.
Speaker 2: But wait, because these planets have such a low density,
Speaker 2: they don't have a solid silhouette. Does that diffuse, hazy
Speaker 2: edge make the transit harder for tests to detect?
Speaker 3: That is a very good question.
Speaker 2: I mean, if the edges are base sickly transparent gas,
Speaker 2: does the stars light just bleed through, muddying the data.
Speaker 3: That is an excellent complication to highlight. The diffuse nature
Speaker 3: of the atmosphere absolutely does affect the light curve.
Speaker 2: The light curve is the graph of the star's brightness
Speaker 2: over time.
Speaker 3: Right. Instead of a sharp, sudden dip in starlight as
Speaker 3: a solid, rocky edge crosses the star, a superpuff can
Speaker 3: create a slightly softer, more gradual curve because a light
Speaker 3: is filtering through the haze exactly the tenuous outer atmosphere
Speaker 3: begins to filter the light before the opaque main body
Speaker 3: fully blocks it. However, the core photometric dip is still
Speaker 3: governed by the sheer cross sectional area of the planet,
Speaker 3: and tests can handle that oh easily. Yeah. Test is
Speaker 3: equipped with four wide field CCD cameras that are sensitive
Speaker 3: enough to measure changes in stellar brightness on the order
Speaker 3: of parts per million.
Speaker 2: That is absurdly precise.
Speaker 3: It really is so.
Speaker 2: Even with a soft edge, test measures the total drop
Speaker 2: in photons and calculates the physical diameter of the blockage.
Speaker 2: Test runs the number and says, we have an object
Speaker 2: here that has the exact volumetric radius of Jupiter.
Speaker 3: But knowing the size is only half the battle right.
Speaker 2: Because tess gives us the geometry, but it is completely
Speaker 2: blind to the mass.
Speaker 3: And geometry without mass leaves you entirely in the dark.
Speaker 3: Regarding density.
Speaker 2: You can't know how heavy something is just by looking
Speaker 2: at its shadow.
Speaker 3: Precisely. To weigh a planet eleven and ten light years away,
Speaker 3: we have to shift our methodology entirely. We have to
Speaker 3: look at the gravitational influence the planet exerts on its
Speaker 3: host star.
Speaker 2: And this is where the astronomical relay rays handed the
Speaker 2: baton down to ground based observatories.
Speaker 3: Specifically utilizing the ASTEP telescope.
Speaker 2: Down in Antarctica. And I have to ask why Antarctica.
Speaker 2: That seems like an incredibly hostile place to put a
Speaker 2: delicate astronomical instrument when you could just, I don't know,
Speaker 2: build it in Hawaii or Chile.
Speaker 3: It is hostile, but Antarctica offers a very specific observational
Speaker 3: advantage the polar night ah.
Speaker 2: Of course, the sun doesn't rise right.
Speaker 3: When you are trying to measure incredibly subtle gravitational interactions
Speaker 3: over long orbital periods, you need continuous, uninterrupted observation.
Speaker 2: Because if you miss a piece of the orbit, your
Speaker 2: math is wrong.
Speaker 3: Exactly. A telescope in Chili is blind for twelve hours
Speaker 3: a day when the sun is up, but a step
Speaker 3: positioned at the Concordius station on the Antarctic Plateau can
Speaker 3: stare at the Volan's constellation continuously for months at a
Speaker 3: time during the Antarctic winter.
Speaker 2: Without the diurnal cycle breaking the data stream.
Speaker 3: It just stares into the dark, gathering data.
Speaker 2: And that continuous data stream is hunting for radial velocity shifts. Right,
Speaker 2: walk us through the mechanics of how we use that
Speaker 2: to weigh a planet, because we know gravity is a
Speaker 2: two way street. It is the star pulls the planet
Speaker 2: into orbit, but the planet's mass also tugs back on
Speaker 2: the star, causing the star to wobble slightly around the
Speaker 2: system's center of mass.
Speaker 3: The radial velocity method measures that precise stellar wobble by
Speaker 3: analyzing the star's light through a spectrograph.
Speaker 2: So we're looking at the light again, but differently.
Speaker 3: Right as the unseen planet's gravity pulls the star slightly
Speaker 3: toward Earth. The light waves emitted by the star are compressed.
Speaker 3: This shifts them slightly toward the blue end of the electromagnetic.
Speaker 2: Spectrum, and then it swings around.
Speaker 3: As the planet orbits to the other side and pulls
Speaker 3: the star away from us. The light waves stretch out,
Speaker 3: shifting toward the red end.
Speaker 2: The Doppler effect exactly like the pitch of an ambulance siren,
Speaker 2: rising as it approaches you and falling as it speeds away,
Speaker 2: except here we are measuring the changing pitch of starlight.
Speaker 3: That's a perfect analogy.
Speaker 2: But wait. If these super puffs have the mass of
Speaker 2: just a few earths spread out over the massive volume
Speaker 2: of Jupiter, their gravitational tug must be microscopic. It is
Speaker 2: incredibly faint, because the star TOI seven ninety one is massive.
Speaker 2: Getting a shaving foam planet to make it wobble must
Speaker 2: be like ah a mosquito trying to drag a bowling ball.
Speaker 3: The signal to noise ratio is punishing, truly punishing. We
Speaker 3: are talking about detecting a star moving in a velocity
Speaker 3: of perhaps a few meters per second from a distance
Speaker 3: of over a thousand light years away.
Speaker 2: That's walking speed. We're detecting a star walking.
Speaker 3: Yes. Ground based spectrographs have to isolate that tiny rismic
Speaker 3: Doppler shift from the chaotic, turbulent boiling of the star's
Speaker 3: own surface plasma. It's an immense data challenge.
Speaker 2: But they did it.
Speaker 3: They did, and when the ASTEP data was finally analyzed,
Speaker 3: the math revealed the paradox. Tests provided a massive volume,
Speaker 3: a step provided an agonizingly tiny mass.
Speaker 2: You divide the tiny mass by the massive volume, and
Speaker 2: the resulting density equation spits out a number that makes
Speaker 2: planetary scientists question.
Speaker 3: Their own instruments because it just feels wrong.
Speaker 2: Here's where it gets really interesting. We've solved the density equation,
Speaker 2: but we are still blind to the actual chemical inventory
Speaker 2: of that extended atmosphere. We've hypothesized the hydrogen helium envelope
Speaker 2: based on the mass, and we've guessed at the photochemistry
Speaker 2: of the clouds.
Speaker 3: The guessing isn't science. We need definitive proof.
Speaker 2: And that requires a tool that tests and a step
Speaker 2: cannot provide.
Speaker 3: The final leg of this observational marathon requires transmission spectroscopy,
Speaker 3: which is arguably the most complex technique in modern astrophysics.
Speaker 2: And to execute it with the precision required for a superpuff, we.
Speaker 3: Have to utilize NASA's James Web Space telescope.
Speaker 2: So if we can't physically send a probe to scoop
Speaker 2: up the gas, Web has to rely on the starlight
Speaker 2: passing through the atmosphere during a transit. It's almost like
Speaker 2: looking for the molecular shadows cast by the chemicals.
Speaker 3: That's exactly what it is.
Speaker 2: How does Web separate those shadows from the blinding glare
Speaker 2: of the star itself.
Speaker 3: It operates on the principles of quantum mechanics. When the
Speaker 3: starlight from TOI seven nine to one filters through the
Speaker 3: wispy outer edges of the superpuff's atmosphere, the photons interact
Speaker 3: with the gas molecule.
Speaker 2: They bump into each other, right.
Speaker 3: But molecules don't just absorb light randomly. The chemical bonds
Speaker 3: in a molecule of water or methane or carbon dioxide
Speaker 3: will only absorb photons that carry a very specific quantized
Speaker 3: amount of energy.
Speaker 2: And because the energy of a photon dictates its wavelength
Speaker 2: or its color, a specific molecule will only ever absorb
Speaker 2: a specific color of light correct.
Speaker 3: So as the starlight passes through the atmosphere, the specific
Speaker 3: molecules present in the gas will absorb their corresponding colors,
Speaker 3: essentially removing them from the light beam.
Speaker 2: So the light that reaches us is missing pieces.
Speaker 3: Yes, when that filtered light finally hits the spectrographs on
Speaker 3: the WEB telescope, we don't see a continuous rainbow. We
Speaker 3: see a spectrum crossed by dark missing bands.
Speaker 2: The missing colors act like a chemical.
Speaker 3: Barcode, exactly like a barcode.
Speaker 2: If we see a missing band at say one point
Speaker 2: four microns, we know the starlight bumped into water vapor.
Speaker 2: If there's a gap at three point three microns, we
Speaker 2: know it hit methane.
Speaker 3: Web is essentially reading the absorption barcode from across.
Speaker 2: The galaxy, which is just staggering when you think about it.
Speaker 3: And this barcode is going to do far more than
Speaker 3: just confirm the presence of hydrogen, the specific ratios of
Speaker 3: carbon to oxygen where the isotopic signature trapped in that gas.
Speaker 3: They act as a forensic time machine.
Speaker 2: A time machine, how so, because.
Speaker 3: The chemical inventory the atmosphere today contains the fossilized evidence
Speaker 3: of exactly where and how this planet formed billions of years.
Speaker 2: Ago, which provides the perfect narrative bridge to the ultimate question.
Speaker 2: Webb's barcode will tell us the what, but we really
Speaker 2: need to understand the.
Speaker 3: How right the origin story?
Speaker 2: How does a star system cook up something so fundamentally weird?
Speaker 2: And why are they so incredibly scarce?
Speaker 3: They are very, very rare.
Speaker 2: If we look at the exoplanet census, we have confirmed
Speaker 2: roughly six three hundred worlds, give or take. We have
Speaker 2: massive hot jupiters skimming the surface of their stars. We
Speaker 2: have rocky super earths, we have rogue planets drifting in the.
Speaker 3: Dark, a huge variety of planets.
Speaker 2: But out of those sixty three hundred, fewer than forty
Speaker 2: are classified as superpuffs. That's a statistical anomaly so extreme
Speaker 2: it demands an explanation.
Speaker 3: Their extreme rarity is the loudest clue we have about
Speaker 3: their origin. If superpuffs were a standard by product is
Speaker 3: stellar evolution, our surveys would be flooded with them.
Speaker 2: Because they're huge. They cast big shadows right.
Speaker 3: Their massive size makes them incredibly easy for telescopes like
Speaker 3: test to spot. The fact that we have found so
Speaker 3: few tells us that the astrophysical recipe for a superpuff
Speaker 3: requires a highly specific, transient and delicate set of initial conditions.
Speaker 2: Conditions within the protoplanetary disk exactly. Let's rewind the clock
Speaker 2: to that stellar nursery. A star is born and it
Speaker 2: is surrounded by this chaotic, swirling accretion disk of gas
Speaker 2: and dust.
Speaker 3: Standard planetary formation.
Speaker 2: Right the core accretion model. It dictates that dust grains collide,
Speaker 2: stick together, form pebbles, then planetesimals, and eventually build a solid, rocky.
Speaker 3: Core, building a planet from the ground up.
Speaker 2: Once that core hits a critical mass, maybe ten times
Speaker 2: the mass of Earth, its gravity triggers runaway gas accretion,
Speaker 2: vacuuming up the surrounding hydrogen to become a dense gas giant.
Speaker 3: That's how Jupiter formed.
Speaker 2: But for a form, that standard assembly line has to
Speaker 2: completely derail, and.
Speaker 3: The derailment occurs in the ratio of solid building materials
Speaker 3: to available gas.
Speaker 2: So too much gas, not enough rock.
Speaker 3: More or less.
Speaker 2: Yeah.
Speaker 3: We hypothesize that superpuffs form in highly specialized zones of
Speaker 3: the disc, often further out beyond what we call the snow.
Speaker 2: Line, where volatile compounds like water and ammonia freeze into
Speaker 2: solid grains.
Speaker 3: Right. However, in the specific case of a superpuff, the
Speaker 3: disk in that region is somehow starved of solid dust
Speaker 3: and pebbles, but remains heavily saturated with cold hydrogen gas.
Speaker 2: Okay, it's like trying to build a snowman in a dense,
Speaker 2: freezing fog bank.
Speaker 3: Okay, I like this. Let's hear it.
Speaker 2: If you roll a snowball down a snowy hill, it
Speaker 2: packs on dense heavy snow and ice, growing into a solid,
Speaker 2: heavy mass. That's a standard gas.
Speaker 3: Giant, right, gathering solid material.
Speaker 2: But if you roll a small snowball through a freezing fog,
Speaker 2: it can't pack on solid mass. It just gathers a massive,
Speaker 2: uncompressed crystalline halo of frost. The volume expands dramatically, but
Speaker 2: the weight barely changes.
Speaker 3: That is a phenomenal analogy for the fluid dynamics at
Speaker 3: play here.
Speaker 2: Thanks, it just makes sense in my head. That way.
Speaker 3: The small planetary core forms, but because the local environment
Speaker 3: is dust pour, the core never reaches the critical mass
Speaker 3: required to trigger violent, compacting runaway accretion.
Speaker 2: It never gets heavy enough to crush the gas exactly.
Speaker 3: Instead, its weak gravity slowly gathers the surrounding frigid low
Speaker 3: density gas. Because the gas is cold, it lacks the
Speaker 3: thermal energy to resist the weak gravitational pull, so it
Speaker 3: just piles up right, allowing the planet to accumulate a
Speaker 3: massive atmosphere without compressing it.
Speaker 2: It slowly wraps itself in this massive, extended halo of
Speaker 2: freezing fog. But that begs a massive evolutionary question for me.
Speaker 2: Because the universe is dynamic, very.
Speaker 3: Dynamic, things don't stay still.
Speaker 2: The protoplanetary disk eventually dissipates, the star fully ignites, and
Speaker 2: suddenly this delicate freezing fog bank of a planet is
Speaker 2: exposed to the searing reality of stuffe radiation.
Speaker 3: The star wakes up and starts cooking everything.
Speaker 2: Right, and you mentioned that these planets shed their material
Speaker 2: over time. This makes me seriously question our entire classification system. Also,
Speaker 2: are we actually looking at a distinct, permanent class of
Speaker 2: planets or is a superpuff just a fleeting, awkward teenage
Speaker 2: phase in a planet's evolution.
Speaker 3: A cosmic phase.
Speaker 2: Basically, Yeah, if we observe TOI seven ninety one, a
Speaker 2: billion years from now, will that fluffy blue exterior have
Speaker 2: completely boiled away? Leaving behind a naked barren core.
Speaker 3: You are tapping into one of the most contentious debates
Speaker 3: in planetary science right now. Really well, absolutely, the theory
Speaker 3: of atmospheric photo evaporation strongly supports your suspicion. The sheer
Speaker 3: volume of a superpuff makes it incredibly.
Speaker 2: Vulnerable because it's so spread out.
Speaker 3: Yes, the stellar ultraviolet X ray radiation that we call
Speaker 3: the XUV flux, it acts like a cosmic blow torch.
Speaker 2: Heating that upper envelope until the kinetic energy of the
Speaker 2: molecules violently shatters the genes escape parameter we talked about.
Speaker 3: Exactly, We're very likely observing a transient phenomenon. Hydro dynamic escape.
Speaker 2: Takes over hydro dynamic escape.
Speaker 3: That's where the upper atmosphere heats up and expands so
Speaker 3: rapidly that it creates an outward wind. It physically drags
Speaker 3: heavier molecules along with the escaping.
Speaker 2: Hydrogen like a rip current in the sky.
Speaker 3: Yes, over hundreds of millions of years, the planet bleeds
Speaker 3: its mass into space, trailing a comet like tail of
Speaker 3: escaping gas.
Speaker 2: So the shaving foam is actively melting in the heat
Speaker 2: of the star.
Speaker 3: Yes, and if TOI seven to ninety one's planets are
Speaker 3: migrating inward, getting closer to the star, that evaporation will
Speaker 3: accelerate exponentially.
Speaker 2: It'll just melt faster.
Speaker 3: Over a deep geological time, a Jupiter sized superpuff will
Speaker 3: likely be eroded down to a mini Neptune, and eventually
Speaker 3: the stellar wind will strip the envelope entirely, leaving behind
Speaker 3: a dense terrestrial super.
Speaker 2: Earth just the pit of the peach exactly.
Speaker 3: So classifying them as a permanent planetary type might actually
Speaker 3: be a mistake. We are likely just catching a breeched
Speaker 3: napshot of a violent cosmic diet.
Speaker 2: And if they are just a temporary phase, that raises
Speaker 2: the ultimate why for me?
Speaker 3: Why study them?
Speaker 2: Yeah? Why do we dedicate decade long satellite missions, brave
Speaker 2: the polar night of Antarctica and aim a ten billion
Speaker 2: dollar quantum space telescope just to look at an awkward
Speaker 2: teenage planet that won't even exist in its current form
Speaker 2: of billion years from now.
Speaker 3: If we connect this to the bigger picture, the answer
Speaker 3: lies in the philosophical foundation of the scientific method itself.
Speaker 3: Dransfield expressed it perfectly by studying exotic systems and rare anomalies.
Speaker 3: We add the missing pieces to the grand puzzle of
Speaker 3: planetary formation.
Speaker 2: It's the anomalies that stress test our models. If a
Speaker 2: theory of physics only works for the planets in our backyard,
Speaker 2: it's not a universal law.
Speaker 3: No, it's just a localized coincidence. If we restrict our
Speaker 3: observations to the norm, our understanding stagnates.
Speaker 2: We get comfortable.
Speaker 3: Exactly before we deservered exoplanets. We assumed our solar system
Speaker 3: was the rigid template for the galaxy, rocky planets close
Speaker 3: to the star gas giants far.
Speaker 2: Away, because that's all we knew.
Speaker 3: But then we looked out into the Orion arm and
Speaker 3: found hot jupiters practically touching their host stars. We found
Speaker 3: rogue planets with no stars at all, just drifting. And
Speaker 3: we found superpuffs, hollow ghosts made of uncompressed gas. Every
Speaker 3: time we encounter an anomaly that breaks our mathematical models,
Speaker 3: it forces us to rebuild those models with greater complexity
Speaker 3: and accuracy.
Speaker 2: We have to write better math.
Speaker 3: Yes, superpuffs are the extreme boundary condition that tests our
Speaker 3: understanding of fluid dynamics, orbital mechanics, and quantum spectroscopy.
Speaker 2: So what does this all mean for you listening right now?
Speaker 2: It means that understanding the bizarre world's orbiting TOI sevven
Speaker 2: nine to one isn't just an exercise in cataloging weird
Speaker 2: cosmic trivia.
Speaker 3: It's far more important than that.
Speaker 2: It is a fundamental stress test of reality. We journeyed
Speaker 2: thousands of light years today, looking back through centuries of
Speaker 2: sterlite to find planets the massive size of Jupiter, but
Speaker 2: with the paradoxical density of a fresh squirt of shaving phone.
Speaker 3: A cosmic paradox.
Speaker 2: We use the physics of light scattering to paint a
Speaker 2: vivid picture of hazy edgeless, white and blue skies, and
Speaker 2: we unpacked the agonizing gravitational tug of war that keeps
Speaker 2: them from blowing away in the solar wind.
Speaker 3: It's a delicate balance.
Speaker 2: We tracked the incredible human ingenuity required to weigh a
Speaker 2: ghost using the Doppler shift of a wobbling star, and
Speaker 2: most importantly, we learned how their rare cold birth in
Speaker 2: the dust starved regions of a stellar nursery helps scientists
Speaker 2: piece together the brutal mechanics of cosmic evolution.
Speaker 3: We're watching it happen by observing.
Speaker 2: Them now before the stellar winds strip them down to
Speaker 2: barren rock. We are quite literally watching the relentless engine
Speaker 2: of the universe actively sculpting a world.
Speaker 3: It is a profound realization that the cosmos is a dynamic,
Speaker 3: evolving laboratory. And it leaves me with one final provocative
Speaker 3: thought for you to carry with you today.
Speaker 2: Oh I'm ready, let's hear it.
Speaker 3: Just explore it. How a highly specific imbalance of cold
Speaker 3: gas and low gravity can forge a massive planet that
Speaker 3: perfectly mimics the density of shaving foam. It is an
Speaker 3: extreme physical state that challenged our core assumptions of what
Speaker 3: a planet could.
Speaker 2: Be, right, it broke the rules.
Speaker 3: So if the universe is capable of engineering something that bizarre,
Speaker 3: what others seemingly impossible extreme physical states are currently orbiting
Speaker 3: the billions of stars we haven't analyzed yet?
Speaker 2: Oh? Wow?
Speaker 3: Could there be entire worlds out there constructed from exotic
Speaker 3: states of matter like superionic water, ice that is simultaneously
Speaker 3: solid and liquid, or matter compressed so strangely it literally
Speaker 3: defies our current periodic table. What other impossible things are
Speaker 3: just waiting for a telescope to catch their shadow?
Speaker 2: It makes you look up at the night sky and
Speaker 2: realize that the dark, silent spaces between the stars are
Speaker 2: hiding secrets that our physics textbooks haven't even dreamed up yet.
Speaker 2: Thank you for joining the conversation today, for opening your
Speaker 2: mind to the impossible, and for matching our curiosity step
Speaker 2: for st step. We will catch you on the next one.