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<v Speaker 1>Welcome to Bedtime Astronomy. Explore the wonders of the cosmos

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<v Speaker 1>with our soothing Bedtime Astronomie podcast. Each episode offers a

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<v Speaker 1>gentle journey through the stars, planets, and beyond, perfect for

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<v Speaker 1>unwinding after a long day. Let's travel through the mysteries

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<v Speaker 1>of the universe as you drift off into a peaceful

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<v Speaker 1>slumber under the night sky.

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<v Speaker 2>So, if you are listening to this right now, I

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<v Speaker 2>want you to just imagine standing in the middle of

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<v Speaker 2>the Pacific Ocean. Okay, and it is the pitch black of.

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<v Speaker 3>Night sounds terrifying on it.

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<v Speaker 2>Yeah, And you are holding just a standard every day flashlight,

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<v Speaker 2>oh wow. Okay, and your task is to find a single,

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<v Speaker 2>specific microscopic organism floating somewhere out there in the water,

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<v Speaker 2>just by wildly waving that beam of light around in.

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<v Speaker 3>The dark, which is pretty much impossible, exactly.

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<v Speaker 2>But for a very long time, that is exactly what

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<v Speaker 2>the search for life outside our Solar system is felt like.

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<v Speaker 2>I mean, humanity has managed to confirm over six thousand

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<v Speaker 2>exoplanets so far.

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<v Speaker 3>Yeah, over six thousand. It's a massive number, it is, But.

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<v Speaker 2>Until recently, trying to find realistic, actual candidates for biology

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<v Speaker 2>among all those churning gas giants and freezing rocks. It's

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<v Speaker 2>just been completely overwhelming. You are basically wandering the cosmos

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<v Speaker 2>hoping to bump into an alien microbe.

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<v Speaker 3>Right, It's a sheer numbers game.

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<v Speaker 2>Yeah, But today our mission is to understand a monumental

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<v Speaker 2>shift in this entire field, a completely groundbreaking development that

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<v Speaker 2>basically takes the flashlight out of our hands, drains the ocean,

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<v Speaker 2>and hands us a highly specific, mathematically rigorous VIP guest

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<v Speaker 2>list for the universe.

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<v Speaker 3>That's a great way to put it.

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<v Speaker 2>Thank you. It's a meticulously curated catalog of exactly forty

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<v Speaker 2>five potentially habitable rocky exoplanets. It was published in March

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<v Speaker 2>twenty twenty six by a team at Cornell University.

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<v Speaker 3>It's a fundamental paradigm shift. We really need to emphasize

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<v Speaker 3>the phrase mass discovery versus extreme precision.

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<v Speaker 2>Here, Okay, unpack that for us.

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<v Speaker 3>Well, if you look back over the last twenty or

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<v Speaker 3>thirty years of astronomy, the headline was always about adding

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<v Speaker 3>another planet.

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<v Speaker 2>To the tally, like we found fifty more today exactly.

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<v Speaker 3>The sheer volume of discoveries was the story. But this milestone.

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<v Speaker 3>It's about the complete opposite. It is entirely about filtering the.

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<v Speaker 2>Noise, filtering out the junk.

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<v Speaker 3>Right, the team at Cornell didn't just look at the

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<v Speaker 3>sky and make optimistic guesses. They took an incredibly vast,

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<v Speaker 3>almost incomprehensible data set from the European Space Agency's GUY emission.

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<v Speaker 4>That's the Data Release three, right, yes, specifically Data Release three,

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<v Speaker 4>and they combined it with the NASA Exo Planet Archive,

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<v Speaker 4>And by doing that they applied such rigorous, unforgiving physical

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<v Speaker 4>and chemical.

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<v Speaker 3>Constraints that they managed to just throw out thousands.

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<v Speaker 2>Of worlds, leaving only the absolute most promising target.

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<v Speaker 3>Exactly the best targets for future life detection missions.

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<v Speaker 2>I want to pause on that phrase filtering the noise,

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<v Speaker 2>because if you aren't deeply entrenched in planet tis very science,

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<v Speaker 2>it is really hard to overstate how chaotic that noise

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<v Speaker 2>actually is.

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<v Speaker 3>Oh, it's incredibly chaotic.

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<v Speaker 2>Right, six thousand confirmed worlds isn't a list of six

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<v Speaker 2>thousand earths. We are talking about gas giants the size

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<v Speaker 2>of Jupiter, but they orbit so close to their star

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<v Speaker 2>that they are just burning at thousands of degrees jupiters

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<v Speaker 2>yet or we are talking about planets where it literally

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<v Speaker 2>rains molten glass sideways because the winds are moving at

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<v Speaker 2>supersonic speeds.

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<v Speaker 3>It's a very violent universe.

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<v Speaker 2>Just totally hostile environments. And out of all of that chaos,

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<v Speaker 2>this team, led by Professor Lisa Koltenegger, whittled the entire

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<v Speaker 2>known universe down to forty five specific.

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<v Speaker 3>Names, forty five very special places.

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<v Speaker 2>Forty five places where you could theoretically look for something

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<v Speaker 2>looking back. But here's my immediate question, how do you

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<v Speaker 2>confidently throw away nine hundred and fifty five planets.

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<v Speaker 3>It's a brutal process, honestly, right.

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<v Speaker 2>If we are sitting here on Earth making sweeping judgments

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<v Speaker 2>about rocks billions of miles away, what is the actual

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<v Speaker 2>mechanism for saying yes to one and no to five

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<v Speaker 2>thousand others?

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<v Speaker 3>Well, the very first sweep of that cosmic sieve is

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<v Speaker 3>based entirely on density and radius. They instantly eliminate anything

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<v Speaker 3>that isn't rocky.

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<v Speaker 2>So gas giants are just out completely on.

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<v Speaker 3>If a planet has a thick, crushing gaseous envelope like Jupiter, Saturn,

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<v Speaker 3>or even Neptune, it is immediately off the list.

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<v Speaker 2>Because we need a surface exactly.

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<v Speaker 3>We are looking for a specific type of surface habitability,

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<v Speaker 3>meaning a solid surface where liquid water could actually pool.

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<v Speaker 3>But the real heavy lifting of this filtering process it

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<v Speaker 3>comes from a concept called the empirical habitable zone.

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<v Speaker 2>Okay, I have to jump in here, because whenever the

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<v Speaker 2>phrase habitable zone or goldilock zone gets tossed around, it

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<v Speaker 2>always sounds so, I don't know, aggressively cozy.

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<v Speaker 3>Right, like a nice galactic suburb.

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<v Speaker 2>Exactly, not too hot, not too cold, just right. But

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<v Speaker 2>the word empirical implies we are basing this on hard evidence, right,

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<v Speaker 2>So what is the actual hard evidence anchoring this zone?

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<v Speaker 3>The evidence this is our own solar system. That is

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<v Speaker 3>what makes it empirical.

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<v Speaker 2>Oh I see yeah.

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<v Speaker 3>Instead of just running purely theoretical thermodynamic models, we use

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<v Speaker 3>our immediate planetary neighbors as the ultimate undeniable benchmark.

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<v Speaker 2>So Earth is the baseline.

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<v Speaker 3>Erse is obviously the perfect baseline. We know for a

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<v Speaker 3>fact that liquid water and biology exist here. But to

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<v Speaker 3>define the inner edge, the absolute too hot boundary, we

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<v Speaker 3>look toward the sun to Venus.

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<v Speaker 2>Because Venus is a nightmare.

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<v Speaker 3>Precisely, Venus represents the extreme limit of a runaway greenhouse effect.

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<v Speaker 3>And to define the outer edge the two cold boundary,

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<v Speaker 3>we look outward to Mars.

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<v Speaker 2>Which is essentially a frozen desert.

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<v Speaker 3>Right, Mars represents a world with a severely thin atmosphere

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<v Speaker 3>where water simply cannot exist in a stable liquid state

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<v Speaker 3>on the surface for any meaningful geological timeframe.

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<v Speaker 2>I'm going to push back heavily on the cozy aspect

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<v Speaker 2>of this, then, because if we are using Venus and

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<v Speaker 2>Mars as our benchmarks, well, both of those planets are

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<v Speaker 2>technically in our son's general neighborhood.

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<v Speaker 3>There are literal nextdoor neighbors. Right.

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<v Speaker 2>Yet, if you were to stand on the surface of

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<v Speaker 2>Venus right now, you would be simultaneously crushed by atmospheric

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<v Speaker 2>pressure ninety times heavier than Earth's, and you would be

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<v Speaker 2>boiled alive by temperatures hot enough to melt lead.

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<v Speaker 3>It is not a pleasant place, not at all.

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<v Speaker 2>And if you magically teleported to Mars, your blood would

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<v Speaker 2>boil from the low pressure while you simultaneously froze to death,

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<v Speaker 2>and you wouldn't be able to draw a single breath

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<v Speaker 2>of oxygen.

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<v Speaker 3>Which is a very grim picture, but very accurate.

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<v Speaker 2>So if these two completely dead violently hostile worlds are

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<v Speaker 2>the boundaries of this zone. The traditional concept of a

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<v Speaker 2>habitable zone feels wildly generous. The margins for life must

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<v Speaker 2>be incredibly, unforgivingly tight.

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<v Speaker 3>You've hit on the exact reason why this catalog is

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<v Speaker 3>such a towering achievement. The margins are razor thin, I

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<v Speaker 3>can imagine, and frankly, the astronomical community has struggled with

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<v Speaker 3>this exact problem for a long time. Historically, we might

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<v Speaker 3>spot an exoplanet and say, well, it's roughly in the

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<v Speaker 3>habitable zone, but our measurements were fuzzy.

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<v Speaker 2>We were just guessing.

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<v Speaker 3>Basically, we're making very educated approximations. But this is where

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<v Speaker 3>the Guy emissions data Release three becomes the absolute lynchpin

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<v Speaker 3>of this entire endeavor. How So, we cannot know if

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<v Speaker 3>a planet is walking that impossible tightrope between becoming a

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<v Speaker 3>Venus or a Mars unless we know exactly, and I

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<v Speaker 3>mean down to the decimal point, how much energy is

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<v Speaker 3>hitting its surface.

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<v Speaker 2>And to know how much energy is hitting the planet,

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<v Speaker 2>you have to know exactly what the star is doing exactly.

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<v Speaker 2>But how does a satellite like Gaya actually figure that out?

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<v Speaker 2>If we are looking at a star that is fifty

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<v Speaker 2>light years away. It's just a blurry pixel of light.

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<v Speaker 2>How do we move from a pixel to knowing the

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<v Speaker 2>exact radiation environment of a planet orbiting it.

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<v Speaker 3>It all comes down to solving the distance problem through

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<v Speaker 3>something called astrometry.

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<v Speaker 2>Okay, astrometry.

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<v Speaker 3>Let me give you an example. Okay. Imagine you are

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<v Speaker 3>holding your thumb out at arm's length.

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<v Speaker 2>All right, I'm picturing it.

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<v Speaker 3>If you close your left eye and then open it

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<v Speaker 3>and close your right eye, your thumb appears to jump

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<v Speaker 3>back and forth against the background of the wall.

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<v Speaker 2>Right, Yeah, it shifts.

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<v Speaker 3>That apparent shift is parallax. Guya does exactly that, but

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<v Speaker 3>on a cosmic scale. It measures the precise position of

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<v Speaker 3>a star in the sky. Then, six months later, when

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<v Speaker 3>Earth and Gaya, which orbits out at the l to

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<v Speaker 3>lagrange point, has moved halfway across the Solar System, it

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<v Speaker 3>measures the star's position again.

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<v Speaker 2>Oh wow.

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<v Speaker 3>By measuring that incredibly tiny apparent shift against the distant

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<v Speaker 3>background galaxies, Gaya calculates the exact geometric distance to that star.

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<v Speaker 2>So it's literally just high school trigonometry just scaled up

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<v Speaker 2>to billions of miles essentially.

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<v Speaker 3>Yes, but the precision required is mind boggling. We are

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<v Speaker 3>talking about measuring angles so small it's like trying to

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<v Speaker 3>measure the width of the human hair from miles away.

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<v Speaker 2>That is insane.

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<v Speaker 3>It is. Now, why does distance matter so much? Because

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<v Speaker 3>of the inverse square law of light.

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<v Speaker 2>Meaning the further away something is the dimmer it look.

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<v Speaker 3>Right, if you see a star in the sky, you

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<v Speaker 3>know it's apparent brightness, how bright it looks to your telescope.

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<v Speaker 3>But a star could look dim because it's a small,

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<v Speaker 3>weak star right next door. Or it could look dim

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<v Speaker 3>because it's an absolute monster of a star that is

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<v Speaker 3>incredibly far away. Oh, I say, once Gaya gives you

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<v Speaker 3>the exact distance, yeah, you can calculate its true intrinsic luminosity.

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<v Speaker 3>You know exactly how much energy that star is actually

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<v Speaker 3>pumping out into space.

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<v Speaker 2>Which means the Cornell team finally have the missing variable.

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<v Speaker 3>Yeah.

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<v Speaker 2>Before Guya, they might have been guessing, uh, we think

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<v Speaker 2>this planet gets enough light to be warm. But with

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<v Speaker 2>Gaya's data they could say, we know for a mathematical

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<v Speaker 2>fact that this specific planet receives exactly one three hundred

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<v Speaker 2>and sixty watts per square meter or whatever.

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<v Speaker 3>The exact number is correct. They calculate the exact stellar

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<v Speaker 3>energy flux, and if that mathematical flux pushes the planet

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<v Speaker 3>even a fraction of a percent towards the Venus extreme,

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<v Speaker 3>they mercifully cut it from the list.

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<v Speaker 2>Just totally ruthless.

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<v Speaker 3>Very ruthless. If it drops toward the Mars extreme, it's out.

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<v Speaker 3>They ran thousands of planets through this mathematical formula, and

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<v Speaker 3>that is how they found the forty five that actually

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<v Speaker 3>sit perfectly within that mathematical sweet spot.

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<v Speaker 2>It really paints a picture of extreme planetary fragility, doesn't it.

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<v Speaker 3>It really does.

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<v Speaker 2>Imagine being a planet hunter looking at a distant star

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<v Speaker 2>and realizing the planet orbiting it has to walk this

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<v Speaker 2>absolute tightrope.

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<v Speaker 3>A very precarious tightrope.

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<v Speaker 2>A tiny fraction too much radiation, the oceans boil off

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<v Speaker 2>into space, the hydrogen escapes, and you have venus A

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<v Speaker 2>fraction too little, The carbon dioxide freezes out, the atmosphere collapses,

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<v Speaker 2>and the whole world turns into a giant snowball.

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<v Speaker 3>Which is why finding forty five planets that survived that

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<v Speaker 3>math is staggering.

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<v Speaker 2>It is, but as I understand it, the researchers didn't

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<v Speaker 2>even stop there.

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<v Speaker 3>Did they No, they did not.

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<v Speaker 2>They looked at these forty five ideal candidates and decided

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<v Speaker 2>the empirical habitable zone wasn't strict enough. They added an

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<v Speaker 2>even more unforgiving filter.

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<v Speaker 3>They did for the sake of maximum conservatism. They applied

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<v Speaker 3>a three D habitable zone filter.

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<v Speaker 2>Okay, what does that mean?

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<v Speaker 3>Well, the initial empirical zone we just discussed is incredibly useful,

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<v Speaker 3>but it fundamentally relies on generalized one dimensional assumptions.

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<v Speaker 2>Like treating the planet as a flat circle.

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<v Speaker 3>Basically, it treats the planet almost like a flat, uniform sphere,

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<v Speaker 3>absorbing energy evenly. But reality is infinitely more complex. The

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<v Speaker 3>three D filter accounts for atmospheric dynamics, planetary rotation, and

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<v Speaker 3>how heat actually moves around a three dimensional globe.

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<v Speaker 2>Wow.

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<v Speaker 3>When they ran the forty five planets through this hyper

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<v Speaker 3>strict three dimensional gauntlet, the list narrowed down even further

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<v Speaker 3>to just twenty four ultra high priority worlds.

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<v Speaker 2>Okay, so treating a planet like a flat sphere is

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<v Speaker 2>like well, it's like looking at a static two D

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<v Speaker 2>photo of a house and trying to guess if it's

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<v Speaker 2>warm inside.

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<v Speaker 3>That's a good analogy.

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<v Speaker 2>You see the sun hitting the roof in the photo,

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<v Speaker 2>and you guess, sure, it looks cozy. But the three

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<v Speaker 2>D model is like actually walking through the house.

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<v Speaker 3>Right.

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<v Speaker 2>In the three D model, you aren't just looking at

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<v Speaker 2>the sun. You are checking the insulation in the walls.

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<v Speaker 2>You are kneeling down to feel for drafts under the door,

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<v Speaker 2>you are seeing how the air conditioning ducts circulate the air,

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<v Speaker 2>and you're checking the actual thermostat. Yes, a flat photo

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<v Speaker 2>might show a house bathed in sunshine, but the three

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<v Speaker 2>D walk through tells you if the living room is

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<v Speaker 2>freezing because all the heat escapes through a drafty window.

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<v Speaker 3>I like the house analogy, but I'm going to complicate

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<v Speaker 3>it a bit. Please do, because planetary climate is far

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<v Speaker 3>more chaotic than a drafty window. Imagine that house is

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<v Speaker 3>also spinning at one thousand miles an hour.

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<v Speaker 2>Okay, now I'm dizzy.

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<v Speaker 3>And the heater isn't just a furnace in the basement,

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<v Speaker 3>It's a massive nuclear reactor hanging in the sky, bombarding

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<v Speaker 3>the house with radiation. Planets are dynamic, rotating fluid systems.

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<v Speaker 3>They have varied topographies, massive oceans that act as heat sinks,

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<v Speaker 3>and swirling atmosphere currents governed by the Coriolis effect.

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<v Speaker 2>So how does a three D model actually simulate all

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<v Speaker 2>of that? Because that sounds like an unbelievable amount of math.

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<v Speaker 3>It requires General circulation models or GCMs.

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<v Speaker 2>Are those like weather simulators Exactly.

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<v Speaker 3>They are essentially the same supercomputer models we use to

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<v Speaker 3>predict weather and climate change here on Earth. They chop

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<v Speaker 3>the planet's atmosphere and oceans into a three dimensional grid

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<v Speaker 3>millions of little boxes. Okay, then they calculate the thermodynamics,

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<v Speaker 3>the fluid dynamics, and the radiative transfer, how light bounces

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<v Speaker 3>around in every single box, and how each box interacts

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<v Speaker 3>with its neighbors. What's fascinating here is that this is

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<v Speaker 3>absolutely critical because of a phenomenon called tidal locking.

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<v Speaker 2>Right tidal locking, I've heard of this. That's when a

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<v Speaker 2>planet orbits so close to its star that the star's

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<v Speaker 2>gravity basically grabs hold of the planet's uneven mass and

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<v Speaker 2>forces it to stop spinning relative to the star. Yes,

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<v Speaker 2>the rotation matches the orbit, so one side is always

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<v Speaker 2>facing the sun in perpetual daylight and the other side

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<v Speaker 2>is staring out into the blackness of space in perpetual

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<v Speaker 2>freezing night.

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<v Speaker 3>Exactly. Our Moon is tidally locked Earth, which is why

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<v Speaker 3>we always see the same face. Oh right, now, if

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<v Speaker 3>you have an exoplanet that is tidally locked to a

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<v Speaker 3>red dwarf star, a simple one D or two D

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<v Speaker 3>model might take the scorching heat of the day side,

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<v Speaker 3>average it with the freezing cold of the night side,

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<v Speaker 3>and spit out a number that says, hey, the average

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<v Speaker 3>global temperature is sixty five degrees It's perfectly habitable.

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<v Speaker 2>But no one actually experiences the average Precisely, half the

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<v Speaker 2>planet is an absolute furnace and the other half is

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<v Speaker 2>a solid ice block.

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<v Speaker 3>Exactly. But a three D model asks the vital question,

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<v Speaker 3>how does the atmosphere transport the scorching heat from the

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<v Speaker 3>day side to the freezing night side?

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<v Speaker 2>Oh, so the wind carries the heat.

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<v Speaker 3>Does the heat rise at the substellar point the exact

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<v Speaker 3>spot where the Sun is directly overhead, and flow high

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<v Speaker 3>in the atmosphere to the night side, creating massive planet

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<v Speaker 3>wide hurricane force winds.

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<v Speaker 2>That sounds terrifying.

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<v Speaker 3>It is does the ocean have currents that can distribute

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<v Speaker 3>that thermal energy? If the atmosphere is too thin, it

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<v Speaker 3>can't transport the heat, and the atmosphere on the dark

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<v Speaker 3>side might literally freeze solid and collapse onto the ground

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<v Speaker 3>a snow.

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<v Speaker 2>Wait, the air itself freezes.

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<v Speaker 3>Yes, atmosphere it collapse. Yeah, Well, if it's too thick,

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<v Speaker 3>the heat transport might be so efficient that the whole

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<v Speaker 3>planet just cooks. That global circulation of heat absolutely makes

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<v Speaker 3>or breaks a planet's ability to hold onto liquid water.

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<v Speaker 2>And that really makes you stop and wonder about the

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<v Speaker 2>planet sitting right on the razor's edge of this three

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<v Speaker 2>D boundary.

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<v Speaker 3>It does.

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<v Speaker 2>You could have a world that is, by all accounts,

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<v Speaker 2>a lush, beautiful paradise. It has flowing water, thick clouds,

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<v Speaker 2>stable temperatures. But because it's sitting right on the absolute

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<v Speaker 2>extreme margin of that three D habitable zone, what happens

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<v Speaker 2>if there's a slight orbital.

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<v Speaker 3>Shift the tiny wabble, yeah.

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<v Speaker 2>Or what if there's a minor atmosphere change, like a

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<v Speaker 2>slight natural increase in a greenhouse gas from a volcano.

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<v Speaker 2>It feels like it wouldn't take much to tip one

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<v Speaker 2>of these paradise worlds completely over the edge.

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<v Speaker 3>It really wouldn't.

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<v Speaker 2>It could trigger a positive feedback loop where the water

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<v Speaker 2>starts evaporating. Water vapor acts as a greenhouse gas traps

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<v Speaker 2>more heat, evaporates more water, and suddenly your paradise is

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<v Speaker 2>just a barren Venus like wasteland, which.

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<v Speaker 3>Tells us a very sobering truth about the universe. Habitability

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<v Speaker 3>isn't necessarily a permanent state.

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<v Speaker 2>It's temporary.

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<v Speaker 3>It can be a highly temporary, fleeting phase in a

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<v Speaker 3>planet's long geological evolution. We know Mars was likely habitable

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<v Speaker 3>billions of years ago.

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<v Speaker 2>It had rivers and stuff.

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<v Speaker 3>It had river deltas and lakes, but it lost its

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<v Speaker 3>magnetic field, the solar wind stripped its atmosphere, and it died.

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<v Speaker 3>Venus may have had oceans, but the sun grew brighter

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<v Speaker 3>over billions of years and it boiled away.

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<v Speaker 2>Wow.

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<v Speaker 3>Establishing this three D boundary is a massive leap forward

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<v Speaker 3>because it strips away the overly optimistic candidates. It leaves

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<v Speaker 3>us with twenty four worlds that have the most robust,

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<v Speaker 3>resilient potential for maintaining stable, life supporting climates despite the

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<v Speaker 3>chaotic nature of stellar evolution.

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<v Speaker 2>So, with the list completely whittled down to the forty

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<v Speaker 2>five overall candidates and the twenty four absolute ultra high

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<v Speaker 2>priority world, I want to talk about the actual names

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<v Speaker 2>on this cosmic VIP list, let's do it. Who are

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<v Speaker 2>the neighbors we might actually be visiting or at least

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<v Speaker 2>staring at very intensely, because if you are listening to

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<v Speaker 2>this and you follow astronomy at all, some of these

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<v Speaker 2>names are going to jump out at you.

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<v Speaker 3>Definitely.

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<v Speaker 2>You have Proxima Sentry B, which is incredibly exciting because

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<v Speaker 2>it's our absolute closest stellar neighbor. It's literally the star

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<v Speaker 2>next door, and it has a rocky world in.

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<v Speaker 3>The zone, a fascinating target.

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<v Speaker 2>You've got several members of the famous Trappist one system.

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<v Speaker 2>There's Kepler one to eighty six, which was a huge

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<v Speaker 2>deal when it was discovered because it was the first

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<v Speaker 2>Earth sized planet found in a habitable zone.

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<v Speaker 3>That was a historic fine.

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<v Speaker 2>And there's LHS eleven forty B. But beyond the planets themselves,

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<v Speaker 2>I find the team behind this catalog just absolutely fascinating.

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<v Speaker 3>Great group.

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<v Speaker 2>You have Professor Koltenegger who directs the Carl Sagan Institute

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<v Speaker 2>at Cornell, but she co authored this massive paradigm shifting

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<v Speaker 2>catalog with an undergraduate student, Abigail Bowl and recent alumni

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<v Speaker 2>Lucas Lawrence and Gillis Lowry. Yes, we're literally talking about

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<v Speaker 2>college students and recent grads who are fundamentally riding the

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<v Speaker 2>road map for the future of humanity's space exploration.

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<v Speaker 3>It's a wonderful aspect of modern astronomy. It speaks volumes

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<v Speaker 3>about the accessibility and the sheer quality of the data.

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<v Speaker 2>We now have, meaning anyone can look at it.

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<v Speaker 3>Essentially. Yes, decades ago, obtaining this kind of data required

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<v Speaker 3>a lifetime of lobbying for telescope time. Now massive surveys

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00:18:21.960 --> 00:18:25.799
<v Speaker 3>like GAYA and the NASA Exoplanet Archive are democratized.

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00:18:25.920 --> 00:18:26.640
<v Speaker 2>That's incredible.

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00:18:26.680 --> 00:18:30.519
<v Speaker 3>They allow a dedicated team combining seasoned expertise with brilliant,

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00:18:30.680 --> 00:18:35.400
<v Speaker 3>highly motivated young minds to synthesize decades of observations into

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00:18:35.440 --> 00:18:39.440
<v Speaker 3>a precise, actionable database. And it's important to note that

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<v Speaker 3>they did just list these planets arbitrarily. They purposefully categorize

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<v Speaker 3>them to test very specific boundaries of planetary physics.

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00:18:47.400 --> 00:18:50.200
<v Speaker 2>Right, because if you just wanted forty five Earth clones,

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00:18:50.279 --> 00:18:52.559
<v Speaker 2>you might miss out on understanding how life works an

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00:18:52.599 --> 00:18:54.079
<v Speaker 2>extreme environment exactly.

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00:18:54.279 --> 00:18:57.680
<v Speaker 3>For instance, some planets on the list have irradiation environments

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<v Speaker 3>that are practically identical to modern Earth. They are the

398
00:19:00.640 --> 00:19:04.000
<v Speaker 3>safe bets the easy ones, but others sit right on

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00:19:04.039 --> 00:19:07.519
<v Speaker 3>the very edges of the habitable zone specifically chosen so

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00:19:07.559 --> 00:19:10.920
<v Speaker 3>we can test where exactly those boundaries fail. If we

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00:19:10.960 --> 00:19:12.880
<v Speaker 3>look at a planet on the inner edge and see

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00:19:12.920 --> 00:19:15.880
<v Speaker 3>it hasn't turned into venus, our models need to adjust.

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00:19:16.359 --> 00:19:18.960
<v Speaker 2>Now here's where it gets really interesting for me. This

404
00:19:19.000 --> 00:19:22.039
<v Speaker 2>is something I genuinely don't fully understand, but it sounds wild.

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00:19:22.480 --> 00:19:27.680
<v Speaker 2>The catalog specifically includes planets with highly eccentric orbits. Ah So,

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00:19:27.759 --> 00:19:31.640
<v Speaker 2>instead of a nice, neat relatively circular path around their

407
00:19:31.680 --> 00:19:35.359
<v Speaker 2>star like Earth has, their orbits are stretched out into.

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00:19:35.160 --> 00:19:36.920
<v Speaker 3>Long ovals, highly elliptical.

409
00:19:37.000 --> 00:19:39.200
<v Speaker 2>They are swinging in violently close to the star and

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00:19:39.240 --> 00:19:41.880
<v Speaker 2>then getting flung far out into the freezing depths of

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00:19:41.920 --> 00:19:45.680
<v Speaker 2>their solar system. What on Earth, or rather what out there,

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00:19:45.839 --> 00:19:48.119
<v Speaker 2>would the climate dynamics actually look like on.

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00:19:48.079 --> 00:19:50.680
<v Speaker 3>A planet like that? It would be extreme, to say

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00:19:50.720 --> 00:19:51.119
<v Speaker 3>the least.

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00:19:51.400 --> 00:19:53.559
<v Speaker 2>If I'm standing on a rocky world with a highly

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00:19:53.599 --> 00:19:58.599
<v Speaker 2>eccentric orbit, am I just experiencing extreme whiplash inducing seasons

417
00:19:59.160 --> 00:20:02.400
<v Speaker 2>like a summer where the oceans are practically steaming, followed

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00:20:02.440 --> 00:20:04.720
<v Speaker 2>a few months later by a winter where the entire

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00:20:04.759 --> 00:20:07.440
<v Speaker 2>atmosphere is freezing onto the ground as solid ice.

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00:20:07.839 --> 00:20:11.559
<v Speaker 3>Orbital mechanics dictate that you absolutely would experience those extremes.

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00:20:11.839 --> 00:20:15.319
<v Speaker 3>According to Kepler's laws of planetary motion, a planet moves

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00:20:15.359 --> 00:20:19.039
<v Speaker 3>fastest when it is closest to its star. That's periapsis, right, yes,

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00:20:19.079 --> 00:20:22.319
<v Speaker 3>at periapsis, and it moves slowest when it is farthest away,

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00:20:22.640 --> 00:20:26.480
<v Speaker 3>at apoapsis. So let's play out the scenario you just described.

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00:20:26.839 --> 00:20:29.680
<v Speaker 3>As the planet swings deeply into the inner Solar System,

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00:20:30.039 --> 00:20:34.480
<v Speaker 3>the sudden, violent spike in stellar irradiation could trigger massive,

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00:20:34.680 --> 00:20:38.279
<v Speaker 3>rapid evaporation of surface water. Oh wow, The latent heat

428
00:20:38.319 --> 00:20:42.119
<v Speaker 3>of vaporization would pump enormous amounts of energy into the atmosphere,

429
00:20:42.319 --> 00:20:47.720
<v Speaker 3>creating incredibly dense, chaotic planet wide storm systems hurricanes that

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00:20:47.799 --> 00:20:49.079
<v Speaker 3>dwarf anything on Earth.

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00:20:49.240 --> 00:20:51.920
<v Speaker 2>And because it's moving fastest at that close point, that

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00:20:52.039 --> 00:20:54.559
<v Speaker 2>hellish summer might actually be quite sure exactly.

433
00:20:54.640 --> 00:20:56.720
<v Speaker 3>It whips around the star and then begins the long,

434
00:20:56.799 --> 00:20:58.720
<v Speaker 3>slow climb back out in the deep space.

435
00:20:58.799 --> 00:21:00.680
<v Speaker 2>And then it gets cold cold.

436
00:21:01.039 --> 00:21:03.279
<v Speaker 3>As it swings back out to the farthest reaches of

437
00:21:03.319 --> 00:21:06.759
<v Speaker 3>its orbit, the solar radiation drops off a cliff. All

438
00:21:06.799 --> 00:21:09.599
<v Speaker 3>that water vapor that got pumped into the atmosphere, it

439
00:21:09.640 --> 00:21:13.160
<v Speaker 3>would begin to condense and eventually precipitate out as global rain,

440
00:21:13.559 --> 00:21:16.680
<v Speaker 3>then snow, and perhaps even solid sheets of ice covering

441
00:21:16.720 --> 00:21:17.240
<v Speaker 3>the oceans.

442
00:21:17.519 --> 00:21:21.319
<v Speaker 2>That sounds completely inhospitable. Why on Earth would the Cornell

443
00:21:21.400 --> 00:21:24.079
<v Speaker 2>team put a planet like that on a VIP list

444
00:21:24.160 --> 00:21:24.960
<v Speaker 2>for life?

445
00:21:25.440 --> 00:21:28.440
<v Speaker 3>Because studying these weird oh's, as we might call them,

446
00:21:28.920 --> 00:21:32.559
<v Speaker 3>is vital for understanding the absolute limits of biology. What

447
00:21:32.559 --> 00:21:35.480
<v Speaker 3>do you mean, Well, life on Earth is remarkably adaptable.

448
00:21:35.759 --> 00:21:39.039
<v Speaker 3>We find extremophiles in the boiling acidic hydro thermal vents

449
00:21:39.039 --> 00:21:41.039
<v Speaker 3>at the bottom of the ocean, and we find them

450
00:21:41.119 --> 00:21:42.400
<v Speaker 3>locked in the ice of Antarctica.

451
00:21:42.519 --> 00:21:43.519
<v Speaker 2>True life finds a way.

452
00:21:43.680 --> 00:21:46.000
<v Speaker 3>If a planet has a deep ocean, the sheer thermal

453
00:21:46.039 --> 00:21:49.079
<v Speaker 3>mass of that water might buffer the extreme temperature swings.

454
00:21:49.440 --> 00:21:52.240
<v Speaker 3>The surface might freeze, but deep down the water remains

455
00:21:52.240 --> 00:21:53.480
<v Speaker 3>liquid and stable.

456
00:21:53.119 --> 00:21:55.480
<v Speaker 2>So the aliens are just hiding under the ice during winter.

457
00:21:55.920 --> 00:22:00.599
<v Speaker 3>Essentially, yes, if we find biological cigus nature is on

458
00:22:00.640 --> 00:22:05.640
<v Speaker 3>a planet with whiplash seasons, it completely broadens our understanding

459
00:22:05.880 --> 00:22:09.240
<v Speaker 3>of the extreme conditions under which life can persist. It

460
00:22:09.319 --> 00:22:12.319
<v Speaker 3>forces us to abandon our earth centric biases.

461
00:22:12.519 --> 00:22:15.160
<v Speaker 2>That makes a lot of sense. It's about testing the

462
00:22:15.279 --> 00:22:20.039
<v Speaker 2>extremes and speaking of testing boundaries, the researchers also specifically

463
00:22:20.119 --> 00:22:23.400
<v Speaker 2>highlighted some of the oldest known habitable zone rocky.

464
00:22:23.119 --> 00:22:25.559
<v Speaker 3>Planets on the list, yes, the ancient ones.

465
00:22:25.319 --> 00:22:27.799
<v Speaker 2>Which if you think about it from an evolutionary perspective,

466
00:22:27.920 --> 00:22:31.599
<v Speaker 2>makes perfect sense. Time is arguably the most important factor

467
00:22:31.599 --> 00:22:32.240
<v Speaker 2>in the universe.

468
00:22:32.559 --> 00:22:35.319
<v Speaker 3>It is the most crucial ingredient for complexity. If we

469
00:22:35.359 --> 00:22:38.079
<v Speaker 3>connect this to the bigger picture of evolutionary biology, we

470
00:22:38.160 --> 00:22:39.920
<v Speaker 3>have to look at our own history. We know that

471
00:22:40.000 --> 00:22:43.240
<v Speaker 3>on Earth life didn't just appear fully formed overnight. Right

472
00:22:43.359 --> 00:22:46.240
<v Speaker 3>The Earth is roughly four and a half billion years old.

473
00:22:46.359 --> 00:22:48.720
<v Speaker 3>For the first billion years, it was a hellscape of

474
00:22:48.799 --> 00:22:53.480
<v Speaker 3>magma and asteroid bombardments. Once it cooled, simple single celled

475
00:22:53.559 --> 00:22:57.519
<v Speaker 3>organisms emerged, but they stayed simple for billions.

476
00:22:57.039 --> 00:22:58.799
<v Speaker 2>Of years, just floating blobs.

477
00:22:59.200 --> 00:23:01.839
<v Speaker 3>It took an unam measurably long time for cells to

478
00:23:01.839 --> 00:23:06.119
<v Speaker 3>develop nuclei, to form multicellular life, and eventually to trigger

479
00:23:06.160 --> 00:23:09.039
<v Speaker 3>the Cambrian Explosion where complex animals emerged.

480
00:23:09.279 --> 00:23:12.160
<v Speaker 2>So if a planet is relatively young, say just a

481
00:23:12.240 --> 00:23:16.519
<v Speaker 2>billion years old, even if it has water and perfect temperatures,

482
00:23:16.799 --> 00:23:19.079
<v Speaker 2>we might just be looking at a global ocean full

483
00:23:19.160 --> 00:23:20.279
<v Speaker 2>of invisible slime.

484
00:23:20.720 --> 00:23:23.759
<v Speaker 3>Correct slime is life, and finding it would be the

485
00:23:23.799 --> 00:23:27.039
<v Speaker 3>greatest discovery in human history, but it's not complex life.

486
00:23:27.440 --> 00:23:31.559
<v Speaker 3>By actively identifying these ancient, rocky world's planets that age

487
00:23:31.640 --> 00:23:35.319
<v Speaker 3>estimates suggests are six, seven, or even eight billion years old,

488
00:23:36.000 --> 00:23:39.039
<v Speaker 3>the catalog provides us with targets that offer the absolute

489
00:23:39.200 --> 00:23:41.960
<v Speaker 3>longest available runway for biology to have taken hold.

490
00:23:42.039 --> 00:23:42.839
<v Speaker 2>That is profound.

491
00:23:43.000 --> 00:23:45.240
<v Speaker 3>If a planet has been sitting in a stable, habitable

492
00:23:45.240 --> 00:23:48.480
<v Speaker 3>configuration for eight billion years without suffering a runaway greenhouse

493
00:23:48.480 --> 00:23:51.440
<v Speaker 3>effect or losing its atmosphere, the complexity of the chemistry

494
00:23:51.480 --> 00:23:54.319
<v Speaker 3>and potentially the biology could be staggering compared to a

495
00:23:54.319 --> 00:23:57.119
<v Speaker 3>younger world. We are looking at environments that have had

496
00:23:57.200 --> 00:23:59.519
<v Speaker 3>nearly double the evolutionary time of Earth.

497
00:24:00.160 --> 00:24:03.119
<v Speaker 2>So we have this incredible VIP list. We have the

498
00:24:03.160 --> 00:24:06.759
<v Speaker 2>oldest planets, the weirdest eccentric planets, the most earth like

499
00:24:06.880 --> 00:24:11.759
<v Speaker 2>safe bets, and our literal nextdoor neighbors. The map is drawn,

500
00:24:11.920 --> 00:24:14.000
<v Speaker 2>it is, But if I'm listening to this, my next

501
00:24:14.000 --> 00:24:17.640
<v Speaker 2>logical question is what do we actually do with a

502
00:24:17.720 --> 00:24:20.960
<v Speaker 2>list of forty five planets that are trillions of miles away.

503
00:24:21.279 --> 00:24:23.519
<v Speaker 2>We have the names, we have the coordinates, but we

504
00:24:23.559 --> 00:24:26.640
<v Speaker 2>can't exactly send a probe there, not right now, No yet.

505
00:24:26.640 --> 00:24:30.079
<v Speaker 2>According to the researchers, this isn't just a fun theoretical streadsheet.

506
00:24:30.240 --> 00:24:34.000
<v Speaker 2>This is a highly practical, literal roadmap for the most

507
00:24:34.039 --> 00:24:37.279
<v Speaker 2>advanced technology humanity has ever built or will build in

508
00:24:37.319 --> 00:24:38.119
<v Speaker 2>the next century.

509
00:24:38.599 --> 00:24:42.200
<v Speaker 3>Professor Koldnikker actually summarize the utility of this catalog perfectly.

510
00:24:42.720 --> 00:24:45.839
<v Speaker 3>She stated, our paper reveals where you should travel to

511
00:24:45.839 --> 00:24:49.400
<v Speaker 3>find life if we ever build a project Hail Mary's Spacecraft.

512
00:24:49.440 --> 00:24:50.359
<v Speaker 2>Oh, I love that book.

513
00:24:50.400 --> 00:24:52.759
<v Speaker 3>It's a great reference. Now, obviously that is a reference

514
00:24:52.799 --> 00:24:56.279
<v Speaker 3>to science fiction. We do not currently possess interstellar spacecraft

515
00:24:56.319 --> 00:24:58.359
<v Speaker 3>capable of traveling at fractions of the speed of light

516
00:24:58.400 --> 00:25:03.000
<v Speaker 3>to proximusentry the Trappist one system. Setting a physical object

517
00:25:03.000 --> 00:25:05.039
<v Speaker 3>there is for now impossible.

518
00:25:05.319 --> 00:25:06.880
<v Speaker 2>So what's the practical use today?

519
00:25:07.160 --> 00:25:11.400
<v Speaker 3>The practical reality is that this catalog optimizes observing time

520
00:25:11.440 --> 00:25:14.680
<v Speaker 3>for our current and future technological marvels. We are talking

521
00:25:14.720 --> 00:25:17.079
<v Speaker 3>about humanity's greatest eyes in the sky, and.

522
00:25:17.039 --> 00:25:18.839
<v Speaker 2>When we say eyes in the sky, we are talking

523
00:25:18.880 --> 00:25:22.359
<v Speaker 2>about machines that cost billions of dollars and take decades

524
00:25:22.359 --> 00:25:25.839
<v Speaker 2>to build. We're talking about the James Webb Space Telescope

525
00:25:25.920 --> 00:25:29.920
<v Speaker 2>or JWST, which is operational right now. Yes, we're talking

526
00:25:29.920 --> 00:25:34.759
<v Speaker 2>about massive ground based projects currently under construction, like the

527
00:25:34.839 --> 00:25:38.880
<v Speaker 2>extremely Large Telescope the ELT. And we're talking about proposed

528
00:25:38.960 --> 00:25:43.519
<v Speaker 2>future missions like the Habitable World's Observatory the HWO and

529
00:25:43.559 --> 00:25:46.759
<v Speaker 2>the large Interferometer for exoplanets known as Life.

530
00:25:46.839 --> 00:25:49.799
<v Speaker 3>Exactly, and to understand why this catalog is so critical,

531
00:25:50.000 --> 00:25:53.599
<v Speaker 3>you have to understand the brutal economics of astronomy. Telescope

532
00:25:53.599 --> 00:25:55.880
<v Speaker 3>times is not something as scientists can just casually sign

533
00:25:55.920 --> 00:25:57.920
<v Speaker 3>out like a library book. I can imagine it is

534
00:25:58.039 --> 00:26:01.480
<v Speaker 3>arguably the most scarce and fiercely competitive scientific resource on

535
00:26:01.519 --> 00:26:02.079
<v Speaker 3>the planet.

536
00:26:02.160 --> 00:26:05.519
<v Speaker 2>I imagine every astronomer on Earth has a pet project

537
00:26:05.519 --> 00:26:08.160
<v Speaker 2>they want to point JWST at they do.

538
00:26:08.799 --> 00:26:12.839
<v Speaker 3>Astronomers from all over the world submit incredibly detailed proposals

539
00:26:13.200 --> 00:26:16.319
<v Speaker 3>detailing exactly what they want to look at, why it matters,

540
00:26:16.680 --> 00:26:19.519
<v Speaker 3>and exactly how many hours of telescope time it will take.

541
00:26:20.119 --> 00:26:21.720
<v Speaker 3>The over subscription rate is.

542
00:26:21.839 --> 00:26:24.480
<v Speaker 2>Massive, meaning everyone wants time and there's none left.

543
00:26:24.880 --> 00:26:27.519
<v Speaker 3>Far more requests for time than there are hours in

544
00:26:27.559 --> 00:26:30.400
<v Speaker 3>a year. The committees that allocate this time are ruthless.

545
00:26:31.119 --> 00:26:34.039
<v Speaker 3>You simply cannot afford to point a ten billion dollar

546
00:26:34.119 --> 00:26:37.160
<v Speaker 3>machine at a random patch of sky and just hope

547
00:26:37.160 --> 00:26:41.960
<v Speaker 3>something interesting happens. You need absolute mathematical certainty that the

548
00:26:41.960 --> 00:26:44.440
<v Speaker 3>patch of sky you are scaring at holds the highest

549
00:26:44.480 --> 00:26:47.960
<v Speaker 3>possible probability of yielding a significant scientific return.

550
00:26:48.160 --> 00:26:51.160
<v Speaker 2>So this Cornell catalog acts as the ultimate filter. Yes,

551
00:26:51.279 --> 00:26:53.640
<v Speaker 2>it's the ultimate trump card in a proposal. You don't

552
00:26:53.640 --> 00:26:55.799
<v Speaker 2>have to say I think this planet might be habitable.

553
00:26:56.000 --> 00:26:59.160
<v Speaker 2>You can say this planet has survived the empirical habitable

554
00:26:59.240 --> 00:27:02.079
<v Speaker 2>zone filter, the thread climate model filter, and it is

555
00:27:02.079 --> 00:27:04.480
<v Speaker 2>officially one of the twenty four best candidates in the

556
00:27:04.519 --> 00:27:05.160
<v Speaker 2>known universe.

557
00:27:05.559 --> 00:27:09.400
<v Speaker 3>It tells these incredibly expensive machines exactly where to look.

558
00:27:09.920 --> 00:27:14.279
<v Speaker 3>It equips observers with clear, heavily vented priorities, and depending

559
00:27:14.279 --> 00:27:18.400
<v Speaker 3>on the telescope, they will use incredibly complex techniques like

560
00:27:18.440 --> 00:27:22.599
<v Speaker 3>what future telescopes might use direct imaging, where they literally

561
00:27:22.599 --> 00:27:24.480
<v Speaker 3>try to block out the light of the host star

562
00:27:24.720 --> 00:27:26.880
<v Speaker 3>with a protograph to see the faint glimmer of the

563
00:27:26.880 --> 00:27:31.200
<v Speaker 3>planet itself. Others might use light curve analysis, but most

564
00:27:31.240 --> 00:27:35.359
<v Speaker 3>importantly for our current capabilities with JWST. The catalog provides

565
00:27:35.400 --> 00:27:39.039
<v Speaker 3>the perfect targets for a technique called transmission spectroscopy.

566
00:27:39.240 --> 00:27:42.079
<v Speaker 2>I am so glad you brought up transmission spectroscopy because

567
00:27:42.079 --> 00:27:45.279
<v Speaker 2>we don't have to wait thirty years for futuristic telescopes

568
00:27:45.319 --> 00:27:48.279
<v Speaker 2>to see this in action. The James Web Space Telescope

569
00:27:48.359 --> 00:27:50.920
<v Speaker 2>is up there right now, parked a million miles from Earth,

570
00:27:51.000 --> 00:27:53.319
<v Speaker 2>staring down one of the most famous systems on this

571
00:27:53.440 --> 00:27:56.519
<v Speaker 2>newly minted VIP list, the Trappist one system.

572
00:27:56.640 --> 00:27:59.000
<v Speaker 3>It is actively gathering data as we speak.

573
00:27:59.079 --> 00:28:01.960
<v Speaker 2>But to really appreciate what JAST is finding, we have

574
00:28:02.039 --> 00:28:04.640
<v Speaker 2>to unpack how it's actually looking at them. Because it's

575
00:28:04.640 --> 00:28:07.440
<v Speaker 2>not taking a photograph, is it. It's not zooming in

576
00:28:07.480 --> 00:28:10.599
<v Speaker 2>with a super high resolution lens until it sees continents

577
00:28:10.640 --> 00:28:11.279
<v Speaker 2>and oceans.

578
00:28:12.039 --> 00:28:15.759
<v Speaker 3>No, taking a direct photograph of a rocky exoplanet with

579
00:28:15.839 --> 00:28:19.960
<v Speaker 3>current technology is virtually impossible. The host star is simply

580
00:28:20.000 --> 00:28:23.720
<v Speaker 3>too blindingly bright. It completely washes out the tiny, faint

581
00:28:23.759 --> 00:28:24.720
<v Speaker 3>reflection of the planet.

582
00:28:24.839 --> 00:28:26.559
<v Speaker 2>It's like trying to see a firefly next to a

583
00:28:26.559 --> 00:28:27.759
<v Speaker 2>searchlight exactly.

584
00:28:27.960 --> 00:28:32.480
<v Speaker 3>Instead, JWST is probing the atmospheres of these distant exoplanets

585
00:28:32.839 --> 00:28:35.480
<v Speaker 3>using transmission spectroscopy during transits.

586
00:28:35.720 --> 00:28:39.200
<v Speaker 2>Okay, let's break that down mechanically. What is a transit?

587
00:28:39.599 --> 00:28:43.480
<v Speaker 3>The mechanics of a transit are relatively straightforward. From our

588
00:28:43.559 --> 00:28:46.680
<v Speaker 3>specific vantage point here in the Solar System, the orbital

589
00:28:46.720 --> 00:28:49.960
<v Speaker 3>plane of the exoplanet happens to be perfectly aligned edge

590
00:28:50.000 --> 00:28:50.359
<v Speaker 3>on with.

591
00:28:50.400 --> 00:28:52.920
<v Speaker 2>Us, so we're looking at it from the side.

592
00:28:53.079 --> 00:28:56.079
<v Speaker 3>Yes, this means that as the planet orbits its star,

593
00:28:56.759 --> 00:28:59.039
<v Speaker 3>we can watch as it passes directly in front of

594
00:28:59.039 --> 00:29:02.640
<v Speaker 3>the stellar disc. When that happens, the solid rocky body

595
00:29:02.640 --> 00:29:05.000
<v Speaker 3>of the planet blocks a tiny fraction of the starlight,

596
00:29:05.279 --> 00:29:08.039
<v Speaker 3>causing a slight dip in the stars overall brightness, and.

597
00:29:07.960 --> 00:29:10.039
<v Speaker 2>That dip is how we know the planet is there.

598
00:29:10.359 --> 00:29:13.759
<v Speaker 3>Right, But the magic of transmission spectroscopy happens at the

599
00:29:13.880 --> 00:29:15.119
<v Speaker 3>very edges of the planet.

600
00:29:15.240 --> 00:29:18.240
<v Speaker 2>Because the entire planet isn't just solid rock. If it

601
00:29:18.240 --> 00:29:21.920
<v Speaker 2>has an atmosphere, there is a tiny, incredibly thin halo

602
00:29:22.200 --> 00:29:24.039
<v Speaker 2>of gas surrounding the rock.

603
00:29:24.240 --> 00:29:26.880
<v Speaker 3>Exactly when the planet passes in front of the star,

604
00:29:27.640 --> 00:29:31.839
<v Speaker 3>a minute fraction of the starlight doesn't hit the solid rock. Instead,

605
00:29:32.039 --> 00:29:34.960
<v Speaker 3>it grazes the edge of the planet and filters through

606
00:29:34.960 --> 00:29:38.960
<v Speaker 3>that incredibly thin sliver of atmospheric gas on its way

607
00:29:39.039 --> 00:29:40.680
<v Speaker 3>to JWST's mirrors.

608
00:29:41.079 --> 00:29:43.599
<v Speaker 2>I always try to visualize this because the scales are

609
00:29:43.599 --> 00:29:46.920
<v Speaker 2>so insane. I think the easiest way to imagine transmission

610
00:29:46.960 --> 00:29:50.000
<v Speaker 2>spectroscopy is to picture yourself trying to guess what color

611
00:29:50.039 --> 00:29:51.480
<v Speaker 2>sunglasses someone is wearing.

612
00:29:51.599 --> 00:29:52.480
<v Speaker 3>Okay, let's hear it.

613
00:29:52.640 --> 00:29:55.519
<v Speaker 2>But this person is standing five miles away. Obviously, you

614
00:29:55.519 --> 00:29:57.960
<v Speaker 2>can't just look and see the lenses from five miles away.

615
00:29:58.000 --> 00:29:58.920
<v Speaker 2>They're way too small.

616
00:29:59.000 --> 00:29:59.240
<v Speaker 3>Right.

617
00:30:00.119 --> 00:30:02.400
<v Speaker 2>If you have that person stand directly in front of

618
00:30:02.440 --> 00:30:05.400
<v Speaker 2>an incredibly bright and tense search light, and that searchlight

619
00:30:05.440 --> 00:30:07.960
<v Speaker 2>shines directly through the lenses of their sunglasses and right

620
00:30:08.000 --> 00:30:10.960
<v Speaker 2>into your eyes, the beam of light hitting your eyes

621
00:30:11.039 --> 00:30:13.000
<v Speaker 2>is going to be altered. Ah. Yes, If the light

622
00:30:13.079 --> 00:30:15.920
<v Speaker 2>suddenly looks tinted green, you know for a fact they

623
00:30:15.920 --> 00:30:19.559
<v Speaker 2>are wearing green lenses. The material of the lenses absorbs

624
00:30:19.599 --> 00:30:22.039
<v Speaker 2>certain colors of the light spectrum and let other colors

625
00:30:22.079 --> 00:30:22.720
<v Speaker 2>pass through.

626
00:30:23.000 --> 00:30:26.400
<v Speaker 3>Your analogy captures the basic mechanism beautifully, But let's make

627
00:30:26.440 --> 00:30:31.559
<v Speaker 3>it more scientifically accurate. Because JWST's job is exponentially harder

628
00:30:31.599 --> 00:30:34.160
<v Speaker 3>than that I figured as much. Imagine that search light

629
00:30:34.279 --> 00:30:37.079
<v Speaker 3>is constantly fluctuating in brightness. You only get to look

630
00:30:37.079 --> 00:30:39.240
<v Speaker 3>at the thung glasses for a few hours every couple

631
00:30:39.279 --> 00:30:41.599
<v Speaker 3>of weeks, and the lenses are microscopic.

632
00:30:41.680 --> 00:30:42.119
<v Speaker 2>Yikes.

633
00:30:42.160 --> 00:30:46.119
<v Speaker 3>Okay, when starlight passes through the exoplanet's atmosphere, it isn't

634
00:30:46.160 --> 00:30:50.119
<v Speaker 3>just being tinted a single color. The specific molecules floating

635
00:30:50.160 --> 00:30:53.759
<v Speaker 3>in that gas, whether it's water, vapor, carbon dioxide, methane,

636
00:30:53.920 --> 00:30:57.599
<v Speaker 3>or ozone, interact with the light photons on a quantum level.

637
00:30:57.680 --> 00:31:00.200
<v Speaker 2>Wait, on a quantum level, how does a photon of

638
00:31:00.279 --> 00:31:02.359
<v Speaker 2>light interact with a molecule of water.

639
00:31:02.640 --> 00:31:05.519
<v Speaker 3>When a photon of light carrying a very specific amount

640
00:31:05.519 --> 00:31:08.680
<v Speaker 3>of energy hits a molecule, it can cause the chemical

641
00:31:08.720 --> 00:31:12.279
<v Speaker 3>bonds of that molecule to vibrate or rotate. But a

642
00:31:12.359 --> 00:31:15.799
<v Speaker 3>water molecule will only absorb a photon if the photon

643
00:31:15.880 --> 00:31:19.839
<v Speaker 3>has the exact specific wavelength that matches the water molecule's

644
00:31:19.920 --> 00:31:22.400
<v Speaker 3>vibrational frequency. It's like a tuning fork.

645
00:31:22.480 --> 00:31:23.319
<v Speaker 2>Oh, that makes sense.

646
00:31:23.359 --> 00:31:26.200
<v Speaker 3>If it absorbs that photon, that specific wavelength of light

647
00:31:26.279 --> 00:31:28.480
<v Speaker 3>goes missing from the beam. So when the rest of

648
00:31:28.519 --> 00:31:32.640
<v Speaker 3>the starlight eventually reaches JWST's spectrograph, it gets split up

649
00:31:32.640 --> 00:31:34.599
<v Speaker 3>into a rainbow like a prism.

650
00:31:34.359 --> 00:31:35.559
<v Speaker 2>And there are chunks missing.

651
00:31:35.720 --> 00:31:38.920
<v Speaker 3>Yes, scientists look at that rainbow and they see dark

652
00:31:39.240 --> 00:31:42.559
<v Speaker 3>vertical bands where light is missing. Those dark bands are

653
00:31:42.599 --> 00:31:45.519
<v Speaker 3>a chemical fingerprint. If they see a dark band at

654
00:31:45.519 --> 00:31:48.799
<v Speaker 3>a specific wavelength, they can say a water molecule absorbed

655
00:31:48.799 --> 00:31:51.759
<v Speaker 3>that light. Therefore there is water in that atmosphere.

656
00:31:51.839 --> 00:31:54.839
<v Speaker 2>That is just phenomenal. We are literally reading the shadows

657
00:31:54.880 --> 00:31:58.279
<v Speaker 2>of molecules cast across trillions of miles of space. And

658
00:31:58.400 --> 00:32:01.799
<v Speaker 2>JWST is specifically built for this, isn't it. It doesn't

659
00:32:01.839 --> 00:32:04.400
<v Speaker 2>look at visible light like our eyes do. It looks

660
00:32:04.519 --> 00:32:05.680
<v Speaker 2>at infrared light.

661
00:32:05.799 --> 00:32:11.480
<v Speaker 3>Yes, JWST is equipped with massive, incredibly sensitive infrared sensors.

662
00:32:12.039 --> 00:32:15.880
<v Speaker 3>Infrared is the absolute perfect spectrum for finding these specific

663
00:32:16.000 --> 00:32:16.960
<v Speaker 3>chemical signatures.

664
00:32:17.119 --> 00:32:17.799
<v Speaker 2>Why infrared.

665
00:32:17.960 --> 00:32:23.480
<v Speaker 3>The molecular bonds of biologically interesting compounds, things like water, methane,

666
00:32:23.599 --> 00:32:27.799
<v Speaker 3>and carbon dioxide vibrate and absorb light very strongly at

667
00:32:27.839 --> 00:32:32.079
<v Speaker 3>infrared wavelengths. The absorption bands in the infrared are deep

668
00:32:32.119 --> 00:32:35.720
<v Speaker 3>and clear, making them much easier to detect than invisible light.

669
00:32:35.880 --> 00:32:38.079
<v Speaker 2>And this brings us back to why the Trappist one

670
00:32:38.119 --> 00:32:41.680
<v Speaker 2>system is the ultimate testing ground for this technology. Because

671
00:32:41.720 --> 00:32:45.440
<v Speaker 2>earlier we mentioned how telescope time is fiercely competitive. If

672
00:32:45.480 --> 00:32:47.200
<v Speaker 2>you want to catch a transit, you have to wait

673
00:32:47.200 --> 00:32:49.319
<v Speaker 2>for the planet to actually cross in front of the star.

674
00:32:49.640 --> 00:32:52.000
<v Speaker 2>If you are looking at Earth from another star system,

675
00:32:52.039 --> 00:32:54.880
<v Speaker 2>you only get one transit a year. You'd have to

676
00:32:54.920 --> 00:32:57.880
<v Speaker 2>stare at our Sun for a decade to get enough data.

677
00:32:57.640 --> 00:33:00.240
<v Speaker 3>Which nobody has time for, right if this.

678
00:33:00.240 --> 00:33:03.200
<v Speaker 2>One is different. It's an incredibly compact group of seven

679
00:33:03.319 --> 00:33:07.319
<v Speaker 2>Earth sized worlds, all orbiting a cool red dwarf star

680
00:33:07.559 --> 00:33:10.559
<v Speaker 2>just forty light years away. Forty light years is practically

681
00:33:10.559 --> 00:33:12.000
<v Speaker 2>down the street in cosmic terms.

682
00:33:12.160 --> 00:33:15.119
<v Speaker 3>It is remarkably close, which gives us an excellent signal

683
00:33:15.119 --> 00:33:18.039
<v Speaker 3>to noise ratio. But the most crucial factor is that

684
00:33:18.079 --> 00:33:21.079
<v Speaker 3>Trappis one is an m dwarf star, a red dwarf,

685
00:33:21.440 --> 00:33:24.519
<v Speaker 3>meaning it's small. It is vastly smaller and cooler than

686
00:33:24.559 --> 00:33:28.000
<v Speaker 3>our Sun. Because the star is so cool, its habitable

687
00:33:28.079 --> 00:33:31.599
<v Speaker 3>zone is pulled in very, very close the planet's orbit tightly.

688
00:33:32.279 --> 00:33:35.000
<v Speaker 3>Trappis one, for instance, completes an entire orbit a full

689
00:33:35.079 --> 00:33:37.519
<v Speaker 3>year in just about six earth days.

690
00:33:37.559 --> 00:33:39.680
<v Speaker 2>Six days. That means it transits in front of the

691
00:33:39.720 --> 00:33:40.599
<v Speaker 2>star once a.

692
00:33:40.599 --> 00:33:45.200
<v Speaker 3>Week, exactly Frequent transits mean frequent opportunities for JWST to

693
00:33:45.240 --> 00:33:49.640
<v Speaker 3>catch that starlight filtering through the atmosphere. Scientists can't just

694
00:33:49.680 --> 00:33:52.160
<v Speaker 3>look at one transit and get a perfect picture. The

695
00:33:52.240 --> 00:33:54.200
<v Speaker 3>signal is too incredibly.

696
00:33:53.680 --> 00:33:55.119
<v Speaker 2>Faint, so they have to add them up.

697
00:33:55.279 --> 00:33:57.759
<v Speaker 3>Yes, they have to stack the data. They record dozens

698
00:33:57.799 --> 00:34:00.559
<v Speaker 3>of transits over months and years, overlaying the data on

699
00:34:00.599 --> 00:34:03.640
<v Speaker 3>top of each other to amplify the true atmospheric signal

700
00:34:03.799 --> 00:34:06.720
<v Speaker 3>and cancel out the random noise. The tight orbits of

701
00:34:06.799 --> 00:34:09.920
<v Speaker 3>red dwarf systems make this stacking process feasible within a

702
00:34:10.000 --> 00:34:11.360
<v Speaker 3>human timeframe.

703
00:34:10.920 --> 00:34:14.079
<v Speaker 2>Which means we actually have real data. We aren't just

704
00:34:14.119 --> 00:34:15.360
<v Speaker 2>talking in theories anymore.

705
00:34:15.440 --> 00:34:17.000
<v Speaker 3>No, the data has been pouring in.

706
00:34:17.360 --> 00:34:22.159
<v Speaker 2>JAWST has been staring intently at one specific incredibly promising

707
00:34:22.280 --> 00:34:26.079
<v Speaker 2>candidate in the system, Trappist one, and the data from

708
00:34:26.079 --> 00:34:28.920
<v Speaker 2>the observations taken between twenty twenty three and twenty twenty

709
00:34:28.960 --> 00:34:32.639
<v Speaker 2>five has been analyzed and the results are completely upending

710
00:34:32.679 --> 00:34:35.719
<v Speaker 2>what scientists thought they would find. They're forcing a total

711
00:34:35.800 --> 00:34:37.599
<v Speaker 2>rethink of atmospheric models.

712
00:34:37.679 --> 00:34:41.360
<v Speaker 3>They really are. The recent observations of Trappis one are

713
00:34:41.400 --> 00:34:44.559
<v Speaker 3>a masterclass in science progressing by the process.

714
00:34:44.119 --> 00:34:45.719
<v Speaker 2>Of elimination, process of elimination.

715
00:34:45.880 --> 00:34:48.599
<v Speaker 3>OK, when you have a rocky world the size of Earth,

716
00:34:49.119 --> 00:34:52.639
<v Speaker 3>there are several hypothetical types of atmospheres it could hold.

717
00:34:53.239 --> 00:34:56.480
<v Speaker 3>The JST data analyzes have largely ruled out the most

718
00:34:56.519 --> 00:35:00.400
<v Speaker 3>extreme scenarios by looking for those deep absorption bands and

719
00:35:00.440 --> 00:35:02.079
<v Speaker 3>crucially by not finding them.

720
00:35:02.280 --> 00:35:04.360
<v Speaker 2>Let's walk through what they crossed off the list, because

721
00:35:04.360 --> 00:35:06.079
<v Speaker 2>if I remember correctly, there are a lot of fears

722
00:35:06.119 --> 00:35:08.480
<v Speaker 2>that all these red dwarf planets would just be baked

723
00:35:08.599 --> 00:35:09.400
<v Speaker 2>dead husks.

724
00:35:09.519 --> 00:35:12.400
<v Speaker 3>The first major scenario they ruled out was a thick

725
00:35:12.519 --> 00:35:17.119
<v Speaker 3>carbon dioxide dominated atmosphere. The spectral signature is completely disfavor it.

726
00:35:17.360 --> 00:35:20.159
<v Speaker 3>This is a massive relief because it means Trappist one

727
00:35:20.559 --> 00:35:23.400
<v Speaker 3>is not a Venus like world suffering from a runaway

728
00:35:23.400 --> 00:35:26.599
<v Speaker 3>greenhouse effect. If it added a thick CO two atmosphere,

729
00:35:26.960 --> 00:35:31.519
<v Speaker 3>JWST would have seen massive, unmistakable absorption bands at specific

730
00:35:31.559 --> 00:35:32.719
<v Speaker 3>infrared wavelengths.

731
00:35:32.920 --> 00:35:35.719
<v Speaker 2>They weren't there, So we can confidently scratch Venus off

732
00:35:35.719 --> 00:35:38.960
<v Speaker 2>the list of possibilities for Trappist one. That's a huge win.

733
00:35:39.159 --> 00:35:41.599
<v Speaker 3>It is a huge win. But the data also doesn't

734
00:35:41.599 --> 00:35:45.039
<v Speaker 3>match the signature of a thin, completely CO two heavy

735
00:35:45.079 --> 00:35:47.880
<v Speaker 3>atmosphere either, like Mars. Right, it doesn't have the spectral

736
00:35:47.880 --> 00:35:51.719
<v Speaker 3>footprint of Mars. Furthermore, the data has excluded the possibility

737
00:35:51.920 --> 00:35:55.559
<v Speaker 3>of a puffy hydrogen rich primordial atmosphere.

738
00:35:55.599 --> 00:35:58.360
<v Speaker 2>Wait, a puffy hydrogen atmosphere, what does that even look

739
00:35:58.400 --> 00:36:01.079
<v Speaker 2>like physically? A rocky planet with hydrogen gas.

740
00:36:01.159 --> 00:36:04.000
<v Speaker 3>Well, when planets form out of the potoplanetary disk of

741
00:36:04.079 --> 00:36:06.960
<v Speaker 3>gas and dust surrounding a young star, they can sometimes

742
00:36:06.960 --> 00:36:10.519
<v Speaker 3>sweek up and retain massive envelopes of hydrogen and helium gas.

743
00:36:10.719 --> 00:36:12.199
<v Speaker 3>This is a primordial atmosphere.

744
00:36:12.280 --> 00:36:12.519
<v Speaker 2>Okay.

745
00:36:12.960 --> 00:36:15.719
<v Speaker 3>If a small rocky planet holds onto that hydrogen, it

746
00:36:15.800 --> 00:36:18.599
<v Speaker 3>ends up looking somewhat like a miniature gas giant, a

747
00:36:18.719 --> 00:36:19.480
<v Speaker 3>Meani Neptune.

748
00:36:19.559 --> 00:36:19.760
<v Speaker 2>Oh.

749
00:36:19.800 --> 00:36:22.840
<v Speaker 3>Interesting, The hydrogen envelope is very light, so it puffs

750
00:36:22.840 --> 00:36:27.079
<v Speaker 3>out far into space. A puffy atmosphere creates a very large,

751
00:36:27.239 --> 00:36:31.320
<v Speaker 3>easy to see transit signal. But the incredibly flat spectral

752
00:36:31.400 --> 00:36:34.719
<v Speaker 3>lines for trapis one m tell us unequivocally that this

753
00:36:34.880 --> 00:36:37.280
<v Speaker 3>thick hydrogen rich scenario is off the table.

754
00:36:37.440 --> 00:36:39.679
<v Speaker 2>So if I am a planetary scientist looking at this

755
00:36:39.760 --> 00:36:43.119
<v Speaker 2>JATABST data and I realize the atmosphere isn't a crushing

756
00:36:43.239 --> 00:36:46.280
<v Speaker 2>hot venus, it isn't a freezing thin Mars, and it

757
00:36:46.320 --> 00:36:51.199
<v Speaker 2>isn't a puffy, gaseous hydrogen ball. What exactly is left

758
00:36:51.280 --> 00:36:54.039
<v Speaker 2>if we've eliminated all the extremes, what is tropis ONEm

759
00:36:54.119 --> 00:36:54.880
<v Speaker 2>actually made of?

760
00:36:55.239 --> 00:36:58.079
<v Speaker 3>By ruling out those extremes, the data leaves open two

761
00:36:58.239 --> 00:37:02.480
<v Speaker 3>incredibly thrilling possibilities. We must be intellectually honest and state

762
00:37:02.519 --> 00:37:05.559
<v Speaker 3>the first possibility. The planet might simply be a bare,

763
00:37:05.719 --> 00:37:09.000
<v Speaker 3>lifeless rock in space, completely stripped of any atmosphere whatsoever

764
00:37:09.039 --> 00:37:10.639
<v Speaker 3>by the intense radiation of its star.

765
00:37:10.840 --> 00:37:13.199
<v Speaker 2>A dead rock. Thrilling for a geologist maybe, but not

766
00:37:13.239 --> 00:37:15.800
<v Speaker 2>for someone looking for life. But what is the second possibility?

767
00:37:15.920 --> 00:37:18.559
<v Speaker 3>The second possibility is what keeps astronomers awake at night.

768
00:37:19.000 --> 00:37:22.360
<v Speaker 3>Trapis one am could possess a thinner secondary atmosphere.

769
00:37:22.360 --> 00:37:23.440
<v Speaker 2>A secondary atmosphere.

770
00:37:23.480 --> 00:37:26.119
<v Speaker 3>This means an atmosphere that wasn't gathered from the stellar

771
00:37:26.159 --> 00:37:30.000
<v Speaker 3>nebula during formation, but was generated later by the planet itself,

772
00:37:30.599 --> 00:37:35.280
<v Speaker 3>likely through massive geological processes like volcanic outgassing, or brought

773
00:37:35.320 --> 00:37:37.119
<v Speaker 3>in by comet impacts.

774
00:37:36.679 --> 00:37:38.719
<v Speaker 2>Like it made its own air exactly.

775
00:37:39.400 --> 00:37:43.000
<v Speaker 3>This secondary atmosphere wouldn't be dominated by primordial hydrogen or

776
00:37:43.039 --> 00:37:47.400
<v Speaker 3>overwhelming carbon dioxide. Instead, it could be nitrogen rich, perhaps

777
00:37:47.480 --> 00:37:50.360
<v Speaker 3>with traces of water, vapor, oxygen, or methane.

778
00:37:50.559 --> 00:37:55.400
<v Speaker 2>A nitrogen rich secondary atmosphere that basically describes Earth exactly.

779
00:37:55.559 --> 00:37:59.800
<v Speaker 3>Earth's atmosphere is roughly seventy eight percent nitrogen. Saturn's moon Titan,

780
00:38:00.079 --> 00:38:03.679
<v Speaker 3>also has a thick nitrogen rich secondary atmosphere. If Trappist

781
00:38:03.679 --> 00:38:06.239
<v Speaker 3>one m has an atmospheer akin to Earth or Titan,

782
00:38:06.679 --> 00:38:10.360
<v Speaker 3>it drastically elevates its status as a primary candidate for astrobiology.

783
00:38:10.480 --> 00:38:13.639
<v Speaker 2>It is just a staggering thought, a rocky planet forty

784
00:38:13.719 --> 00:38:16.519
<v Speaker 2>light years away potentially wrapped in a blanket of nitrogen

785
00:38:16.559 --> 00:38:19.039
<v Speaker 2>and methane orbiting a red sun. I know we are

786
00:38:19.079 --> 00:38:21.719
<v Speaker 2>focusing heavily on this one specific planet, but I have

787
00:38:21.800 --> 00:38:23.920
<v Speaker 2>to assume that what we learn from Trappis ONEm applies

788
00:38:23.960 --> 00:38:24.920
<v Speaker 2>to the rest of the universe.

789
00:38:25.000 --> 00:38:25.239
<v Speaker 4>Right.

790
00:38:25.360 --> 00:38:28.840
<v Speaker 3>The importance of this stretches far, far beyond just Trappist One.

791
00:38:29.639 --> 00:38:33.800
<v Speaker 3>By eliminating these specific extreme scenarios, the Venus, Mars and

792
00:38:33.840 --> 00:38:38.079
<v Speaker 3>puffy hydrogen models, we are radically refining our foundational models

793
00:38:38.079 --> 00:38:40.400
<v Speaker 3>for atmospheric evolution across the cosmos.

794
00:38:40.679 --> 00:38:42.599
<v Speaker 2>Oh, because there's so many of these.

795
00:38:42.519 --> 00:38:47.039
<v Speaker 3>Red dwarfs specifically, yes, for planets orbiting M dwarf stars

796
00:38:47.159 --> 00:38:50.280
<v Speaker 3>or red dwarfs. And this is critical because red dwarfs

797
00:38:50.280 --> 00:38:53.119
<v Speaker 3>are by a vast margin, the most common type of

798
00:38:53.159 --> 00:38:56.480
<v Speaker 3>star in our entire galaxy. Upwards of seventy percent of

799
00:38:56.519 --> 00:38:59.280
<v Speaker 3>all stars are red dwarfs seventy percent. If we want

800
00:38:59.280 --> 00:39:01.880
<v Speaker 3>to understand the capitability, we have to understand what happens

801
00:39:01.920 --> 00:39:05.880
<v Speaker 3>to rocky planets orbiting these specific stars. Gawst's work on

802
00:39:05.920 --> 00:39:09.119
<v Speaker 3>trappis one m is literally writing the textbook on what

803
00:39:09.239 --> 00:39:11.880
<v Speaker 3>kinds of atmospheres are physically and chemically plausible in the

804
00:39:11.920 --> 00:39:14.440
<v Speaker 3>absolute most common planetary environments in the universe.

805
00:39:15.000 --> 00:39:18.280
<v Speaker 2>But as with all great scientific endeavors, there is a massive,

806
00:39:18.360 --> 00:39:22.599
<v Speaker 2>frustrating cosmic wildcard that threatens to muddy all of this pristine,

807
00:39:22.679 --> 00:39:23.480
<v Speaker 2>beautiful data.

808
00:39:23.800 --> 00:39:25.119
<v Speaker 3>There's always a catch.

809
00:39:25.119 --> 00:39:28.159
<v Speaker 2>And ironically enough, the problem comes directly from the very

810
00:39:28.199 --> 00:39:30.400
<v Speaker 2>star that provides the light we need to see the

811
00:39:30.440 --> 00:39:33.360
<v Speaker 2>planets in the first place. The red dwarf itself isn't

812
00:39:33.400 --> 00:39:37.519
<v Speaker 2>just sitting there being a passive flashlight. It's actively fighting us.

813
00:39:37.639 --> 00:39:41.119
<v Speaker 3>Yes, this is known as the red dwarf dilemma. Researchers

814
00:39:41.119 --> 00:39:45.400
<v Speaker 3>continually urge extreme caution when interpreting any spectral data from

815
00:39:45.440 --> 00:39:49.679
<v Speaker 3>planets like traptist one M because of severe stellar activity,

816
00:39:49.800 --> 00:39:53.719
<v Speaker 3>they're unstable. Red dwarfs are notoriously volatile. They are not calm,

817
00:39:53.800 --> 00:39:57.079
<v Speaker 3>steady burning spheres of plasma like our Sun. They are

818
00:39:57.159 --> 00:40:00.639
<v Speaker 3>fully convective stars, meaning the boiling place asma from their

819
00:40:00.639 --> 00:40:04.119
<v Speaker 3>core churns all the way to the surface. This creates intense,

820
00:40:04.199 --> 00:40:05.800
<v Speaker 3>chaotic magnetic fields.

821
00:40:05.920 --> 00:40:07.039
<v Speaker 2>Hows they flare a lot.

822
00:40:07.159 --> 00:40:12.000
<v Speaker 3>They are prone to incredibly violent stellar flares, massive eruptions

823
00:40:12.000 --> 00:40:14.639
<v Speaker 3>of radiation that can bay their close orbiting planets in

824
00:40:14.840 --> 00:40:16.920
<v Speaker 3>X rays and ultraviolet light, which.

825
00:40:16.679 --> 00:40:19.639
<v Speaker 2>Sounds terrible for life on the surface obviously, But how

826
00:40:19.679 --> 00:40:22.880
<v Speaker 2>does a flare mess up er data? If JWST is

827
00:40:22.920 --> 00:40:26.159
<v Speaker 2>looking for the shadow of water molecules in the planet's atmosphere,

828
00:40:26.519 --> 00:40:28.639
<v Speaker 2>how does the stars tantrum ruin.

829
00:40:28.440 --> 00:40:31.440
<v Speaker 3>That It's not just the flares, it's the star spots.

830
00:40:31.000 --> 00:40:32.360
<v Speaker 2>Star spots like sunspots.

831
00:40:32.599 --> 00:40:36.000
<v Speaker 3>Much like sunspots on our Sun, Red dwarfs are frequently

832
00:40:36.039 --> 00:40:39.679
<v Speaker 3>covered in massive star spots areas where the intense magnetic

833
00:40:39.719 --> 00:40:43.679
<v Speaker 3>fields temporarily suppress the convection of heat, creating patches on

834
00:40:43.719 --> 00:40:46.519
<v Speaker 3>the star's surface that are cooler and darker than the

835
00:40:46.559 --> 00:40:50.440
<v Speaker 3>surrounding plasma. Okay, because they are cooler, the chemistry of

836
00:40:50.440 --> 00:40:54.920
<v Speaker 3>the star in those spots actually changes. Molecules can temporarily

837
00:40:54.960 --> 00:40:57.119
<v Speaker 3>form in the cooler regions of the star itself.

838
00:40:57.159 --> 00:41:00.079
<v Speaker 2>Fait hold on, molecules can form on the star. I

839
00:41:00.119 --> 00:41:02.559
<v Speaker 2>thought stars were too hot for molecules, that everything was

840
00:41:02.639 --> 00:41:05.480
<v Speaker 2>just ripped apart into atoms and plasma.

841
00:41:04.960 --> 00:41:08.440
<v Speaker 3>In a star like our sun. Yes, but red dwarfs

842
00:41:08.440 --> 00:41:11.400
<v Speaker 3>are cool enough and their starspots are even cooler that

843
00:41:11.480 --> 00:41:15.679
<v Speaker 3>simple molecules like water or titanium oxide can briefly form

844
00:41:15.760 --> 00:41:19.199
<v Speaker 3>in the star's outer layers, and this creates a devastating

845
00:41:19.199 --> 00:41:21.119
<v Speaker 3>problem for transmission spectroscopy.

846
00:41:21.519 --> 00:41:24.039
<v Speaker 2>Let me guess. If water molecules are forming on the

847
00:41:24.039 --> 00:41:26.280
<v Speaker 2>surface of the star, they're absorbing light before it even

848
00:41:26.360 --> 00:41:27.159
<v Speaker 2>hits the planet.

849
00:41:27.360 --> 00:41:30.519
<v Speaker 3>You've hit the nail on the head. This is stellar contamination.

850
00:41:31.119 --> 00:41:34.360
<v Speaker 3>When the starlight passes through the planet's atmosphere, it carries

851
00:41:34.360 --> 00:41:36.960
<v Speaker 3>the chemical signature of the star spot with it. Earlier

852
00:41:36.960 --> 00:41:39.400
<v Speaker 3>in the decade, there were some hints or whispers in

853
00:41:39.440 --> 00:41:43.320
<v Speaker 3>the data of methane and water on some exoplanets, which

854
00:41:43.320 --> 00:41:47.599
<v Speaker 3>cause massive excitement, but later, rigorous studies came out suggesting

855
00:41:47.639 --> 00:41:51.119
<v Speaker 3>that maybe that molecular signature wasn't coming from the planet's

856
00:41:51.119 --> 00:41:52.039
<v Speaker 3>atmosphere at all.

857
00:41:52.119 --> 00:41:52.840
<v Speaker 2>It was an illusion.

858
00:41:52.920 --> 00:41:55.559
<v Speaker 3>It was an illusion. The water signature was coming from

859
00:41:55.599 --> 00:42:00.679
<v Speaker 3>a massive, cool star spot rotating into view. Exactly is

860
00:42:00.760 --> 00:42:02.039
<v Speaker 3>the planet transitd So.

861
00:42:02.039 --> 00:42:05.400
<v Speaker 2>The star is essentially faking the data. It is projecting

862
00:42:05.440 --> 00:42:09.000
<v Speaker 2>a hologram of water onto the planet. How do scientists

863
00:42:09.039 --> 00:42:11.719
<v Speaker 2>even begin to solve that? If the signature for water

864
00:42:11.760 --> 00:42:13.880
<v Speaker 2>looks exactly the same, whether it's from the star or

865
00:42:13.920 --> 00:42:16.159
<v Speaker 2>the planet, how do you disentangle the two.

866
00:42:16.719 --> 00:42:19.960
<v Speaker 3>That is the defining question the astronomical community is actively

867
00:42:20.000 --> 00:42:23.599
<v Speaker 3>grappling with right now. How do we definitively separate the

868
00:42:23.639 --> 00:42:27.280
<v Speaker 3>biological or chemical footprint of a planet from the magnetic

869
00:42:27.400 --> 00:42:29.480
<v Speaker 3>temper tantrums of its host star.

870
00:42:29.840 --> 00:42:31.079
<v Speaker 2>It sounds impossible.

871
00:42:31.199 --> 00:42:35.239
<v Speaker 3>It requires incredibly sophisticated modeling of the star's magnetic activity.

872
00:42:35.280 --> 00:42:37.519
<v Speaker 3>We have to map the star spots and subtract their

873
00:42:37.559 --> 00:42:41.320
<v Speaker 3>spectrum from the planet spectrum. It requires continuous monitoring.

874
00:42:41.000 --> 00:42:42.599
<v Speaker 2>So it's just really really hard mass.

875
00:42:42.920 --> 00:42:46.519
<v Speaker 3>But we have to be honest. The current data sets,

876
00:42:46.960 --> 00:42:51.039
<v Speaker 3>while absolutely revolutionary, are not quite sensitive enough to perfectly

877
00:42:51.159 --> 00:42:55.400
<v Speaker 3>untangle the stellar contamination from the planetary signal. In every

878
00:42:55.440 --> 00:42:58.519
<v Speaker 3>single case, the air bars are still too wide. We

879
00:42:58.559 --> 00:43:01.360
<v Speaker 3>cannot yet give a definitive, undred percent certain answer on

880
00:43:01.440 --> 00:43:04.719
<v Speaker 3>whether a world like Trappis one M has that sin

881
00:43:04.840 --> 00:43:08.519
<v Speaker 3>gaseous envelope, or if it's just a bare rock reflecting

882
00:43:08.519 --> 00:43:10.159
<v Speaker 3>a very noisy, spody star.

883
00:43:10.440 --> 00:43:13.559
<v Speaker 2>It is such a cruel cosmic irony. The most common

884
00:43:13.599 --> 00:43:16.239
<v Speaker 2>stars in the universe, the red dwarfs, are the ones

885
00:43:16.320 --> 00:43:19.599
<v Speaker 2>statistically most likely to harbor these rocky planets in tight

886
00:43:19.719 --> 00:43:22.519
<v Speaker 2>observable orbits. They offer the best targets, they offer the

887
00:43:22.519 --> 00:43:25.360
<v Speaker 2>best chance to stack transit data. But they are also

888
00:43:25.480 --> 00:43:28.239
<v Speaker 2>the exact stars that are most actively trying to blind

889
00:43:28.239 --> 00:43:32.119
<v Speaker 2>our instruments and confuse our data with their chaotic magnetic fields.

890
00:43:32.559 --> 00:43:34.960
<v Speaker 2>It's like trying to listen to a tiny, faint whisper

891
00:43:34.960 --> 00:43:37.480
<v Speaker 2>from a planet, but its sun is constantly screaming into

892
00:43:37.519 --> 00:43:40.039
<v Speaker 2>the microphone, and the sun happens to be whispering the

893
00:43:40.119 --> 00:43:42.239
<v Speaker 2>exact same words you are trying to listen for.

894
00:43:42.320 --> 00:43:42.880
<v Speaker 3>It's maddening.

895
00:43:43.079 --> 00:43:46.719
<v Speaker 2>But even with these stellar tantrums, even with the extreme

896
00:43:46.840 --> 00:43:50.440
<v Speaker 2>difficulty of separating the signal from the noise, the sheer

897
00:43:50.519 --> 00:43:55.199
<v Speaker 2>combination of the Cornell Catalog in JWST's ongoing, relentless mission

898
00:43:55.719 --> 00:43:59.760
<v Speaker 2>represents an absolute monumental leap forward. I feel like we

899
00:43:59.800 --> 00:44:03.639
<v Speaker 2>are closer than ever to answering humanity's biggest, most existential question.

900
00:44:04.039 --> 00:44:06.159
<v Speaker 3>We truly are. If you look at the arc of

901
00:44:06.199 --> 00:44:10.760
<v Speaker 3>this entire endeavor, the field of exoplanet astronomy has fundamentally

902
00:44:10.800 --> 00:44:14.639
<v Speaker 3>and irreversibly moved from an era of pure discovery we're

903
00:44:14.679 --> 00:44:17.320
<v Speaker 3>simply counting the number of worlds and proving they existed

904
00:44:17.440 --> 00:44:21.719
<v Speaker 3>was the primary goal, to an era of deep, rigorous characterization.

905
00:44:21.920 --> 00:44:23.400
<v Speaker 2>We're not just counting anymore.

906
00:44:23.480 --> 00:44:25.199
<v Speaker 3>No, we are no longer just asking is there a

907
00:44:25.239 --> 00:44:28.000
<v Speaker 3>planet there? We know they are everywhere. We are now

908
00:44:28.039 --> 00:44:31.000
<v Speaker 3>asking what is the detailed thermodynamic and chemical makeup of

909
00:44:31.039 --> 00:44:34.880
<v Speaker 3>its atmosphere and what is its true mathematical potential for

910
00:44:34.920 --> 00:44:36.000
<v Speaker 3>supporting biology?

911
00:44:36.039 --> 00:44:37.679
<v Speaker 2>And the Cornell Catalog is the key.

912
00:44:37.840 --> 00:44:40.760
<v Speaker 3>The Cornell Catalog, providing those forty five and the strictly

913
00:44:40.800 --> 00:44:44.440
<v Speaker 3>modeled twenty four VIP candidates, provides the exact where to look.

914
00:44:44.760 --> 00:44:48.280
<v Speaker 3>It acts as the ultimate filter for our most precious resources.

915
00:44:47.719 --> 00:44:49.599
<v Speaker 2>And JWST provides the how.

916
00:44:49.920 --> 00:44:56.400
<v Speaker 3>Yes, JWST with its incredibly powerful infrared transmission. Spectroscopy provides

917
00:44:56.440 --> 00:45:01.199
<v Speaker 3>the how to look Future observatories. The the multi billion

918
00:45:01.239 --> 00:45:04.840
<v Speaker 3>dollar massive machines currently being drafted and built will take

919
00:45:04.880 --> 00:45:07.599
<v Speaker 3>this exact roadmap and build upon it. They won't be

920
00:45:07.599 --> 00:45:11.440
<v Speaker 3>flying blind. They will be specifically scanning these prioritized candidates

921
00:45:11.519 --> 00:45:13.079
<v Speaker 3>for genuine biosignatures.

922
00:45:13.360 --> 00:45:15.880
<v Speaker 2>And when we say biosignatures, we aren't just looking for water.

923
00:45:16.079 --> 00:45:19.599
<v Speaker 2>Water is everywhere. We're looking for things like unusual ratios

924
00:45:19.599 --> 00:45:22.440
<v Speaker 2>of water, oxygen, and methane existing in the atmosphere at

925
00:45:22.480 --> 00:45:25.559
<v Speaker 2>the same time, gases that actively react with each other

926
00:45:25.599 --> 00:45:28.199
<v Speaker 2>and shouldn't exist together in large quantities for very long

927
00:45:28.599 --> 00:45:32.719
<v Speaker 2>unless something like a massive biosphere of life is actively

928
00:45:32.800 --> 00:45:36.079
<v Speaker 2>continuously producing them to replenish the atmosphere. And if you

929
00:45:36.159 --> 00:45:38.199
<v Speaker 2>are listening to this, I really want you to take

930
00:45:38.239 --> 00:45:40.679
<v Speaker 2>a second and think about the sheer scale of what

931
00:45:40.719 --> 00:45:44.320
<v Speaker 2>we've walked through today. We aren't guessing anymore. We aren't

932
00:45:44.360 --> 00:45:46.800
<v Speaker 2>throwing darts at a massive map of the Milky Way

933
00:45:46.880 --> 00:45:50.280
<v Speaker 2>hoping to hit something interesting. Thanks to GAYA, thanks to

934
00:45:50.360 --> 00:45:54.920
<v Speaker 2>extreme three D climate modeling, and thanks to relentless data analysis,

935
00:45:55.360 --> 00:45:59.960
<v Speaker 2>we possess a prioritized mathematically rigorous list of forty five.

936
00:46:00.039 --> 00:46:03.480
<v Speaker 2>I have actual physical places in the universe where the

937
00:46:03.519 --> 00:46:04.760
<v Speaker 2>spark of life.

938
00:46:04.920 --> 00:46:06.800
<v Speaker 3>Might have ignited the profound thought.

939
00:46:06.920 --> 00:46:09.159
<v Speaker 2>Earth might be a total fluke, We might be a

940
00:46:09.199 --> 00:46:12.880
<v Speaker 2>cosmic rarity and anomaly of geology and timing. Or Earth

941
00:46:12.960 --> 00:46:15.840
<v Speaker 2>might just be one incredibly small part of a vibrant,

942
00:46:15.960 --> 00:46:19.400
<v Speaker 2>bustling galactic community of living worlds. And for the very

943
00:46:19.440 --> 00:46:21.719
<v Speaker 2>first time in all of human history, we aren't just

944
00:46:21.800 --> 00:46:24.440
<v Speaker 2>philosophizing about it. We have the map, we have the list,

945
00:46:24.440 --> 00:46:26.440
<v Speaker 2>and we have the tools to finally find out.

946
00:46:26.519 --> 00:46:29.599
<v Speaker 3>The transition is complete. The search for life has moved

947
00:46:29.599 --> 00:46:32.239
<v Speaker 3>out of the realm of science fiction and theoretical philosophy,

948
00:46:32.480 --> 00:46:36.000
<v Speaker 3>and it has become a deeply structured, achievable, data driven

949
00:46:36.039 --> 00:46:40.039
<v Speaker 3>scientific endeavor. It's happening right now, one transit, one photon,

950
00:46:40.360 --> 00:46:42.599
<v Speaker 3>and one carefully selected planet at a time.

951
00:46:42.800 --> 00:46:44.519
<v Speaker 2>And as we wrap up this discussion, I want to

952
00:46:44.559 --> 00:46:46.559
<v Speaker 2>leave you with a final thought to really all over.

953
00:46:47.159 --> 00:46:50.039
<v Speaker 2>We talked extensively about how the Cornell Catalog didn't just

954
00:46:50.119 --> 00:46:52.880
<v Speaker 2>look for Earth clones. They specifically highlighted some of the

955
00:46:52.920 --> 00:46:56.199
<v Speaker 2>oldest rocky planets in the habitable zone to act as

956
00:46:56.239 --> 00:47:00.239
<v Speaker 2>extreme evolutionary test cases. I want you to think about time.

957
00:47:00.480 --> 00:47:01.480
<v Speaker 3>Time is everything.

958
00:47:01.559 --> 00:47:04.679
<v Speaker 2>Life on Earth took roughly four billion years to get

959
00:47:04.719 --> 00:47:08.840
<v Speaker 2>from simple single cells floating in geothermal muk to complex

960
00:47:08.920 --> 00:47:12.679
<v Speaker 2>creatures capable of building space telescopes, mapping the stars, and

961
00:47:12.679 --> 00:47:17.320
<v Speaker 2>debating the nuances of red dwarf magnetic flares. Now imagine

962
00:47:17.320 --> 00:47:21.159
<v Speaker 2>a rocky, ocean filled planet on this new VIP list,

963
00:47:21.480 --> 00:47:23.760
<v Speaker 2>a planet that has been sitting in its star's perfect

964
00:47:23.840 --> 00:47:27.320
<v Speaker 2>stable temperature zone, insulated by a thick atmosphere, not for

965
00:47:27.400 --> 00:47:28.920
<v Speaker 2>four billion years, but for eight or.

966
00:47:28.960 --> 00:47:30.760
<v Speaker 3>Nine billion years, double the time we've had.

967
00:47:30.880 --> 00:47:33.559
<v Speaker 2>Exactly if the spark of life took hold in those

968
00:47:33.599 --> 00:47:36.679
<v Speaker 2>alien oceans all those eons ago, with more than double

969
00:47:36.719 --> 00:47:40.000
<v Speaker 2>the evolutionary runway that life on Earth had, what on Earth,

970
00:47:40.079 --> 00:47:42.039
<v Speaker 2>or rather what out there, would it look like today