Strongest Evidence for Alien Life? (Mars, K2-18b & JWST) (EP. 8)

NASA just dropped what they’re calling the strongest evidence yet for biosignatures on Mars, so we spun up an emergency pod. We break down what the rover actually found in Jezero Crater, why geochemical “life-adjacent” reactions matter, revisit April’s hyped K2-18b claim from Cambridge, and close with brand-new JWST hints of atmospheres on Earth-sized exoplanets. Hosted by Lester Nare and Krishna Choudhary. Summary • NASA’s Mars result — Perseverance, Jezero, Bright Angel Formation, and inorganic proxies for life (iron phosphates/sulfides) plus how instruments like PIXL actually read rocks. • The April headline on K2-18b (“strongest evidence yet”) and what atmospheric retrieval really does and doesn’t prove. • Fresh JWST papers hinting at atmospheres on TRAPPIST-1 worlds — why that’s huge and how transit spectroscopy underpins it. Show Notes • NASA — Mars Biosignature Claim • Cambridge — K2-18b Atmosphere Study • Astrophysical Journal Letters — JWST TRAPPIST-1 • Atmosphere Study (Paper 1) • Astrophysical Journal Letters — JWST TRAPPIST-1 Atmosphere Study (Paper 2)

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:00Lester Nare?

  Hello, Internet. This is your captain speaking, Lester Nare, joined as always by my co-host and our resident PhD, Krishna Choudhary. This is From First Principles, and we are a code red today. As you can see from our background, we had to do this emergency pod as we saw this massive breaking news coming out of NASA of the strongest evidence yet for biosignatures on Mars. So, we are going to do a deep dive on alien life, covering three stories, starting with that latest breaking news in paper from NASA, which has made waves across the media space. And then, we're going to go back for our second story to look at a story from April of this year out of Cambridge, which also claimed to have the strongest evidence yet

• 0:43Lester Nare?

  of life on a distant planet, not Mars. And we'll wrap up with some new discoveries, or at least new analysis from James Webb about the atmosphere on exoplanets that are habitable in the way we think of life. This is going to be a fantastic episode. Let's jump in.

• 1:15Lester Nare?

  My friend.

• 1:16Krishna Choudhary?

  How's it going?

• 1:18Lester Nare?

  Episode eight.

• 1:19Krishna Choudhary?

  We're cooking.

• 1:20Lester Nare?

  A little emergency pod situation.

• 1:22Krishna Choudhary?

  Yeah, yeah, yeah.

• 1:23Lester Nare?

  We both woke up this morning. I immediately texted you as soon as I saw the news.

• 1:27Krishna Choudhary?

  Yeah.

• 1:29Krishna Choudhary?

  Press conference and everything.

• 1:30Lester Nare?

  Everything. Every NASA ex Twitter account posted about this.

• 1:37Krishna Choudhary?

  Yeah.

• 1:38Lester Nare?

  Obviously, it broke on every science blog and everything.

• 1:42Krishna Choudhary?

  Yeah.

• 1:43Lester Nare?

  Because we've sort of had some evidence, but we wanted to make sure, and NASA felt it. Was good enough.

• 1:52Krishna Choudhary?

  Yeah.

• 1:52Lester Nare?

  To now have the acting administrator of NASA, Sean Duffy, uh, come out and do a victory lap.

• 1:59Krishna Choudhary?

  Mm hmm.

• 2:00Lester Nare?

  That we, we, we might've got him.

• 2:01Krishna Choudhary?

  Yeah.

• 2:02Lester Nare?

  We maybe got him.

• 2:03Krishna Choudhary?

  That's what they say.

• 2:05Lester Nare?

  So let's, let's start with the breaking news from today. Um, I watched most of the press conference. Um, I'd been following this particular, let's say, sample because at the time it was brought up and people were like, oh, here we go.

• 2:20Krishna Choudhary?

  Yeah.

• 2:20Lester Nare?

  Um, but at the same time, everyone was telling me, well, the Hillary Clinton administration said there was strong evidence for biosignatures on Mars 20 years ago. So what's actually different?

• 2:30Krishna Choudhary?

  Um, well, this time it seems, it seems to be a little bit better than the one that was 20 years ago, but we're actually going to get back to that as part of our story.

• 2:39Lester Nare?

  Okay.

• 2:39Krishna Choudhary?

  Okay, so it's, it seems to be a landmark discovery.

• 2:43Lester Nare?

  Okay.

• 2:44Krishna Choudhary?

  Um, it is what they're characterizing as a potential biosignature.

• 2:49Lester Nare?

  Ah, potential.

• 2:50Krishna Choudhary?

  And, um, not a full biosignature, a potential biosignature means possibilities that this was a signature of life. But in order to actually really nail it down, what we're going to need is the sample to come back to earth.

• 3:06Lester Nare?

  Fair.

• 3:07Krishna Choudhary?

  And then actually have lab testing with things like electron microscopes and all that other kind of stuff.

• 3:13Lester Nare?

  So we didn't discover the underground cities and ancient structures.

• 3:17Krishna Choudhary?

  No, yeah, no, no channels, no like Martians.

• 3:20Lester Nare?

  Okay.

• 3:20Krishna Choudhary?

  Um, it seems to be a tantalizing sign that there might've been microbial life on Mars way, way back, back when Mars looked kind of like earth, not earth now, but earth prehistoric, like right after formation. So the way the solar system formed, you know, um, there was some giant gas nebula cloud that started spinning. The sun was born, um, there were outcroppings of small nuclei that became the planets, the rocky planets on the inside. The solar radiation kind of blew out all the lighter gases. So the lighter gases of hydrogen and helium formed the outer planets of Jupiter, Neptune, Saturn.

• 4:03Lester Nare?

  The gas giants.

• 4:03Krishna Choudhary?

  Right? And yeah, the gas giants, so. Right after that, you know, for about a billion years, Mars and Earth were both in the habitable zone of the sun, okay? The reason why Mars looks so different today compared to Earth is because it's just smaller. And so it couldn't hang on to its atmosphere for long enough. And if you can't hang on to your atmosphere for long enough, then the atmospheric pressure decreases like crazy. And if the atmospheric pressure decreases, then you're no longer gonna be able to sustain liquid water. Right? And liquid water is something that we're pretty sure is essential for life.

• 4:42Lester Nare?

  Fundamental component.

• 4:42Krishna Choudhary?

  Fundamentally, we need liquid water as this kind of universal solvent that creates the kind of biochemistry that would be required for something as complex as life.

• 4:56Lester Nare?

  Asterix as we know it.

• 4:58Krishna Choudhary?

  As we know it, yes, yes. Obviously, there could be other forms. I mean, there's, there's people talking about life on the clouds of Venus, on the clouds of Jupiter and all sorts of random stuff. But we haven't seen it. There could be life in the methane lakes of Titan, but we haven't seen it.

• 5:13Lester Nare?

  There could be a billion dollars buried in my backyard, but we haven't seen it.

• 5:16Krishna Choudhary?

  But we haven't seen it. And so as far as we can tell, we need life, we need water to create life, right? And anywhere there is liquid water on Earth, there seems to be life. Even if it's like near boiling, like near Yellowstone, there's life there, right? So it seems, it seems like the, the one criteria is liquid water. You don't even need oxygen. You just need liquid water and some source of energy. In the case of Mars, that could have just been the sun or like geological processes on Mars. Or like the already present compounds on Mars that are somehow, you know, packed with energy that life can then exploit to metabolize.

• 5:55Krishna Choudhary?

  So that's sort of the, the Mars that NASA's been obsessed with for the longest time. Okay, this primordial baby Mars that had liquid water. We know that now from our several missions there. Actually, the Curiosity Rover, which was launched in the 2010s. That had a primary mission of trying to find habitable qualities in Mars. It wasn't trying to look for signatures of life. It was just trying to see, okay, was Mars, early in its heyday, was Mars somewhere that could house life? And the Kurashiro rover found signs of liquid water, right? And so everyone was really excited.

• 6:39Krishna Choudhary?

  It's like, okay, there's liquid water. The next thing we should do is try to equip a laboratory on Mars that can run around like a rover and also have all of the tools necessary to sort of do these chemical analyses on the spot and try to look for biosignatures. And that's where the Perseverance rover came in.

• 7:01Lester Nare?

  This, this makes sense because the idea is the sort of the flight time and flight windows from Earth to Mars are both infrequent and it takes very long.

• 7:10Krishna Choudhary?

  Yeah.

• 7:11Lester Nare?

  And so to be able to ascertain, before you spend the time and money

• 7:17Krishna Choudhary?

  Yeah.

• 7:18Lester Nare?

  to send something back, we want to kind of do a spot check on site.

• 7:21Krishna Choudhary?

  Yeah. And honestly, like, you know, when the Mars Perseverance rover was launched, I think it was in 2020, during the first Trump administration, there was, there was a five-year search to figure out where to put it.

• 7:34Lester Nare?

  Okay.

• 7:34Krishna Choudhary?

  Okay?

• 7:34Lester Nare?

  Right.

• 7:35Krishna Choudhary?

  Because you only got one thing. This thing's the size of an SUV. You got one shot. JPL is worried about, okay, once we have a, once we have a spot, how do we get it down there?

• 7:45Lester Nare?

  Jet propulsion lab, for those who don't know.

• 7:46Krishna Choudhary?

  That's the jet propulsion lab out in Pasadena, one of Caltech's little side projects. And, you know, so there was, there were 60 different candidate sites.

• 7:57Lester Nare?

  Okay.

• 7:58Krishna Choudhary?

  That they were trying to figure out.

• 7:59Lester Nare?

  Oh, they had a Mars Love Island.

• 8:01Krishna Choudhary?

  Yeah, yeah. And then, and then there was an international collaboration to try and figure out what is the best place to go. Okay? And what they settled on was this place called the Jezero Crater.

• 8:10Lester Nare?

  Okay.

• 8:11Krishna Choudhary?

  It's this giant crater. It's about 25 miles across and

• 8:17Krishna Choudhary?

  From, we know from the Mars Reconnaissance Orbiter, which is something that just like goes around Mars, has all these like instruments for infrared, visible, from that we can figure out composition of the, of the soil. Yep. That's there, right? The surface chemistry. Yes. From that, we had figured out, okay, this is a pretty promising candidate. Um, also, and I just wanna, because the idea is we're looking for these ingredients that we view as necessary for being valuable to life, being able to exist. Yeah. We have these tools to detect what's there, and then so we look for the perfect match for those two. Exactly, yeah, and we got like, we got about sixty candidates. And then this one was really nice because it's a crater that had, um, that we're pretty sure had like a lake.

• 8:59Krishna Choudhary?

  So it's like one of those crater lakes, you can, you can think of as that. Um, and there was a river delta system. Okay. That was going into it. So there's these beautiful like traces of like, literally valleys and like river valleys going into this crater. So, you know, there's a lot of really nice sedimentary rock that's gonna be there, and you're gonna see, if there's life on Mars, that's a really good place to go. Mm-hmm. Okay, so, um, NASA JPL decided, okay, we're gonna go to the Jezero Crater. They landed it there, which is a feat in itself. In itself. Right? This is a SUV packed with like, a whole building's worth of lab equipment, right? That, that like, you're, you're trying to drop, and the lab equipment has to be resilient to the heartache of getting off the earth. Yes.

• 9:43Krishna Choudhary?

  Going all the way to Mars, then doing a landing on Mars, right? And then everything working. Everything works. And I, it's still just such a testament to our engineering capabilities. Yep. That we are able to do this in one shot. Yep. And like, we're just like really good at it. Mm-hmm. At this point, right? At this point, if like JPL fails and like it crashes, we'd be like, oh, you guys suck, like, you know, like, it's actually insane. Right. How many, how many like? How many failure modes there are and none of them ever fail like James James Space Telescope. There was so many failure modes and it just like didn't fail.

• 10:21Lester Nare?

  Right.

• 10:21Krishna Choudhary?

  Cause like the NASA engineers are that good. Right. And other countries are like, like, you know, they're crashing on the moon.

• 10:28Lester Nare?

  Right, right, right. They're not even.

• 10:30Krishna Choudhary?

  Mars dude with an atmosphere and stuff like it's.

• 10:33Lester Nare?

  M A R S.

• 10:36Krishna Choudhary?

  Red rock.

• 10:39Krishna Choudhary?

  Exactly. So we've been obsessed with Mars for a long time. That's been sort of our, our go to place to try and find um signatures of alien life. Right. Even if it's microbial, we want to see that like, you know, even in terms of life.

• 10:53Lester Nare?

  Right.

• 10:53Krishna Choudhary?

  That we're not alone.

• 10:54Lester Nare?

  I mean, here's the thing, if the part of the point is if we are able to even confirm, which NASA says we're on the road to that. There is microbial life, not intelligent life.

• 11:05Krishna Choudhary?

  Yeah.

• 11:06Lester Nare?

  On the nearest neighbor.

• 11:08Krishna Choudhary?

  Yeah.

• 11:08Lester Nare?

  That we have in the vastness that is the universe.

• 11:12Krishna Choudhary?

  Yeah.

• 11:13Lester Nare?

  That has implications in and of itself, even if it's simply microbial.

• 11:18Krishna Choudhary?

  Yeah, yeah. And even if it was something that was there only like three billion years ago, right? The fact that it was there, meaning that like the fact that like a planet that was habitable just had life. That's like two data points.

• 11:29Lester Nare?

  Right, right, right.

• 11:30Krishna Choudhary?

  And all both have.

• 11:32Lester Nare?

  Right.

• 11:32Krishna Choudhary?

  Have life, right? I mean, even with Earth's data point, like the fact, the fact of the matter is as soon as Earth was habitable. We have fossils dating back to like that.

• 11:42Lester Nare?

  Right.

• 11:43Krishna Choudhary?

  Like before photosynthesis, we have fossils that say, yeah, we have, we had life like basically as soon as the earth cooled and we had water.

• 11:50Lester Nare?

  Right. And if we see that now in two locations.

• 11:52Krishna Choudhary?

  Yeah, then it's like, okay, maybe it's actually a pretty ubiquitous phenomenon all across the universe.

• 11:57Lester Nare?

  In that, once you get to the conditions that support life to exist, it does arise not at a low probability, but at a some somewhat higher probability than we may currently. Sort of ascribe to the ability for life to

• 12:12Krishna Choudhary?

  Yeah.

• 12:12Lester Nare?

  Arise.

• 12:12Krishna Choudhary?

  Yeah, yeah. So, so, you know, it'd be, it'd be a huge deal if we find like.

• 12:17Lester Nare?

  The point is, this is going to be a big deal.

• 12:20Krishna Choudhary?

  Yeah, this is gonna be a really big deal. And this is only half the story. Because obviously, you know, however much we pack onto the Perseverance rover, it's not a lab on earth, right? We can't put a scanning tunneling microscope up there. Okay, that's all even JPL guys will be like, guys, come on.

• 12:37Lester Nare?

  Right, right, we can't.

• 12:38Krishna Choudhary?

  It's literally easier to go and get the stuff back.

• 12:41Lester Nare?

  Back, right then.

• 12:41Krishna Choudhary?

  Right? So it's like, okay, we're making this calculation. Like, why don't we just go and get it? And then, and then just do it here.

• 12:47Lester Nare?

  Right, right, right. We'll wait a little longer to get it back.

• 12:51Krishna Choudhary?

  Yeah, so, um, so this is the Jezero Crater.

• 12:55Lester Nare?

  Yes.

• 12:55Krishna Choudhary?

  Um, Perseverance was parked right on the outskirts. Did a little bit of traversing around there, and then it went down this valley, down this river valley towards the crater. Um, it went to the spot called the Bright Angel Formation, which is right in the Nevatera Valley. Okay, it's this like river valley that goes into the crater. Okay, and right over there is something that's really nice because you've got the sedimentary rock on the western edge of this crater. Okay, and because it's a driver river valley, you're gonna have potentially signs of stuff that lived in that water, right? And it's gonna leave its markings in the rock.

• 13:36Krishna Choudhary?

  Okay, now, the best thing to do would be to just search for organic compounds.

• 13:41Lester Nare?

  Okay.

• 13:41Krishna Choudhary?

  Right? That'd be amazing.

• 13:42Lester Nare?

  Right.

• 13:43Krishna Choudhary?

  Like just carbon.

• 13:43Lester Nare?

  Right.

• 13:44Krishna Choudhary?

  Like we, we find glucose, we're like, okay. We got glucose.

• 13:47Lester Nare?

  We got it.

• 13:48Krishna Choudhary?

  Okay, the problem with finding organic compounds on Mars is it's really hard. One is because it's got no atmosphere and very little magnetic field, there's gonna be a lot of radiation from the sun. And that radiation from the sun over the past three billion years is just gonna completely wreck these organic compounds, right? On the other, on top of that, you've got these things called perchlorates, which are chemicals that are highly corrosive. So they're gonna react with organic chemistry and you're not gonna, you're not gonna see like, you're not gonna go see like amino acids like in abundance. You might see them in trace amounts, but you're not gonna like, you know, find

• 14:20Lester Nare?

  Right.

• 14:22Krishna Choudhary?

  Amazing signatures like that.

• 14:23Lester Nare?

  The idea is the environment, because of the atmospheric dissipation, basically will have destroyed any.

• 14:31Lester Nare?

  Active evidence of these organic.

• 14:33Krishna Choudhary?

  Yeah, yeah, exactly. So what you want to do is you want to look for inorganic compounds that have signatures of being made by organic chemistry. Okay, and so that's what this story is.

• 14:47Lester Nare?

  Okay.

• 14:47Krishna Choudhary?

  Okay, this story is focusing on two, um, two classes of compounds. Iron phosphates and iron sulfides. So that's iron with, um, phosphate, which is like an SO4. Or, um, just an S, or you can have, um, like phosphate, sorry, iron and sulfur, which is the SO4. Or you can have iron phosphate, okay, and phosphorus and sulfur, phosphorus specifically, um, very much something that is associated with life on earth.

• 15:19Lester Nare?

  Okay.

• 15:20Krishna Choudhary?

  Okay, so finding these things is very, very nice. And that's what they found.

• 15:24Lester Nare?

  Okay.

• 15:24Krishna Choudhary?

  They found these iron phosphates and iron sulfides in the rock at this Bright Angel Formation. Okay, and the way that they, the way that they found these is very conspicuous. Okay.

• 15:37Lester Nare?

  Okay.

• 15:37Krishna Choudhary?

  It's very weird. It's not like part of the rock itself.

• 15:40Lester Nare?

  Okay.

• 15:40Krishna Choudhary?

  Okay, what they, what they found was, so that you've got this like substrate of rock, which is this mud clay. Okay, it's got a lot of iron and then you have these like little, they, they call them poppy seeds and leopard spots. Okay, they're like little tiny, like, like beads.

• 15:57Lester Nare?

  Yeah.

• 15:57Krishna Choudhary?

  Of stuff.

• 15:58Lester Nare?

  Um, I get if I, for all the New Yorkers, you know, a poppy seed bagel is a heresy when you get your, uh, bacon, egg and cheese, if you put on a bagel, but like it would be like looking at a bagel with these little speckles.

• 16:10Krishna Choudhary?

  Exactly, yeah, it'll be like looking at, except now it's like this clay.

• 16:14Lester Nare?

  Subsurface, right.

• 16:15Krishna Choudhary?

  Yeah, and then you've got these like speckles, right?

• 16:18Lester Nare?

  Yep.

• 16:18Krishna Choudhary?

  And these speckles have these particular minerals. That are very exciting to us.

• 16:24Lester Nare?

  Okay.

• 16:24Krishna Choudhary?

  And the other thing that they found was that, so. These speckles have these minerals, right, of iron sulfide and iron phosphate. And the only way that these things could have really happened is through something called a redox reaction. If you've, um, if you know from, this is basic chemistry, you have this thing called the oxidation reduction process, okay? These reactions are basically ways to transfer electrons from one thing to another. And so you reduce it by taking in electrons, right? Usually it involves oxygen, which is called, why it's called oxidation, but it doesn't always have to. Um, it's really just a transfer of electrons and we know that organic chemistry does this really well.

• 17:04Lester Nare?

  Okay.

• 17:04Krishna Choudhary?

  Okay? And what they found was like in the underlying, so in the underlying clay.

• 17:09Lester Nare?

  Yes.

• 17:09Krishna Choudhary?

  They could actually see, um, carbon. Okay, so there was carbon there.

• 17:14Lester Nare?

  Okay.

• 17:15Krishna Choudhary?

  And the gradient of carbon.

• 17:17Lester Nare?

  Yeah, yeah.

• 17:17Krishna Choudhary?

  Was coinciding with how much of this stuff you were seeing. Okay, do you see what I'm saying? So now it's getting exciting. It's like, it's like there's a gradient of carbon, which means maybe.

• 17:29Lester Nare?

  Yes.

• 17:30Krishna Choudhary?

  There was more life on this side than on this side.

• 17:32Lester Nare?

  Yep.

• 17:32Krishna Choudhary?

  And so, and the density of this.

• 17:34Lester Nare?

  Stuff.

• 17:34Krishna Choudhary?

  Of this, of this iron phosphate, iron phosphate, which is very org, like, you know, on earth, associated with life, is tracking.

• 17:43Lester Nare?

  It, it's correlated to the gradient.

• 17:45Krishna Choudhary?

  Yeah.

• 17:46Lester Nare?

  You know.

• 17:46Krishna Choudhary?

  Of the underlying carbon.

• 17:47Lester Nare?

  Yeah, yeah, yeah, yeah, yeah.

• 17:48Krishna Choudhary?

  So now it's like, okay, this is pretty nice.

• 17:51Lester Nare?

  This looks like two, uh, data points.

• 17:54Krishna Choudhary?

  Yeah, yeah.

• 17:54Lester Nare?

  That are correlating very strongly that we associate with like.

• 17:57Krishna Choudhary?

  With, with organic chemistry. And so, and so that was, and so the idea is you have the starting material, which is this oxidized mudstone. Right, which is rich in iron three, which is an ion of iron, that means that three electrons are missing. And then what you do is you have organic carbon and then that acts like a electron donor to this whole process.

• 18:18Lester Nare?

  Okay.

• 18:18Krishna Choudhary?

  And then you have the iron three and the SO4, which is an ion that's also found in these organic, inorganic compounds. And then that gets converted into iron two and just sulfide, which is just the sulfur atom. So the oxygen goes away. That chemistry is very, very. Organicy.

• 18:36Lester Nare?

  Yeah.

• 18:37Krishna Choudhary?

  Like that chemistry is very life.

• 18:39Lester Nare?

  Life.

• 18:40Krishna Choudhary?

  Life adjacent. If I, if I may say.

• 18:42Lester Nare?

  If I may say.

• 18:43Krishna Choudhary?

  Right? So, so that's, that's the whole point. Everyone's like really excited about this. And, and you know, one of the impressive things is that we can do all of this on Mars, right? All of this toolkit is on that SUV.

• 18:55Lester Nare?

  Right.

• 18:55Krishna Choudhary?

  The Mars Perseverance Rover.

• 18:57Lester Nare?

  Right.

• 18:58Krishna Choudhary?

  Which is crazy. It's got this, um, one instrument called Pixel, P I X L, for planetary instrument for X-ray lithochemistry. Um, basically it's a way to find the chemical makeup of rocks.

• 19:12Lester Nare?

  Yep.

• 19:12Krishna Choudhary?

  Using an X-ray. They've got a little beam of X-rays that goes in, figures out what comes out. So they've got a detector.

• 19:18Lester Nare?

  Yep.

• 19:18Krishna Choudhary?

  And then that tells you.

• 19:19Lester Nare?

  Yep. What's in it?

• 19:20Krishna Choudhary?

  Yeah, what's in it? And then, um, they also have this thing called Sherlock.

• 19:24Lester Nare?

  Oh, yes.

• 19:25Krishna Choudhary?

  Which is scanning habitable environments with Raman and luminescence for organics and chemicals. I think they started with the acronym.

• 19:34Lester Nare?

  Yeah.

• 19:34Krishna Choudhary?

  And they're like, okay, how do we?

• 19:35Lester Nare?

  How do we? How do we make it fit?

• 19:38Krishna Choudhary?

  Yeah, yeah. They do this all the time. It's so funny.

• 19:41Lester Nare?

  Um, cause I don't think chemicals has, it's Sherlock without a K.

• 19:44Krishna Choudhary?

  Yeah, yeah, yeah. It's Sherlock with a C.

• 19:46Lester Nare?

  Yeah.

• 19:46Krishna Choudhary?

  Yeah. Um, but the Sherlock is, um, it does Raman spectroscopy and it's basically a carbon detector. In some sense. So they use the carbon detector to find like carbon on the substrate. And then they used the Pixel instrument to do X-rays on these little tiny poppy seeds and leopard spots to find that, okay, it's iron and sulfur and phosphorus.

• 20:08Lester Nare?

  And the thing is, I want to just reiterate, there are smart people who thought about this on the front end and had a plan in order to be able to like, like, what is the methodology by which you even like ascertain that life was there or not there, et cetera? Very, okay.

• 20:26Krishna Choudhary?

  Yeah, it's really cool that like they could fit all of this.

• 20:30Krishna Choudhary?

  On this giant SUV, pack it into the top of a rocket, have it survive, lift off.

• 20:36Lester Nare?

  Yep.

• 20:36Krishna Choudhary?

  Have it survive landing on Mars.

• 20:38Lester Nare?

  Right.

• 20:38Krishna Choudhary?

  And then now it's like actually giving us all this crazy data.

• 20:41Lester Nare?

  Right.

• 20:42Krishna Choudhary?

  And this this data is like a year old. So they've been they've been going through it because obviously they know this is like a big deal.

• 20:48Lester Nare?

  Right, right, right. I I remember, I believe Administrator Duffy, as part of his speech in the press conference today, made an emphasis on this point. He's like, we found it last year and we sent it all over the world because we wanted to be sure. And everyone looked at it and everyone checked it and they got back to us and they were like, you might be right.

• 21:12Krishna Choudhary?

  Well, so to that point, whenever something like this comes out, this is a big, this is a big deal, right? The great things about nature

• 21:22Krishna Choudhary?

  is that they make their peer review process completely public.

• 21:26Lester Nare?

  Yeah, nature, the publication, not nature.

• 21:29Krishna Choudhary?

  Not nature, nature. Nature, the Springer publication that's been around, that has published all the big papers over the past hundred years.

• 21:36Lester Nare?

  Yes.

• 21:36Krishna Choudhary?

  Um, very recently, they they didn't used to do this all the time, but very recently they've made their entire peer review process public. So after something gets published.

• 21:44Lester Nare?

  Yeah.

• 21:45Krishna Choudhary?

  Um, you can go to the website.

• 21:47Lester Nare?

  Yeah.

• 21:47Krishna Choudhary?

  And you can go to the peer review file and see what the reviewer said. And, um, you know, it's it's pretty cool because, you know, science should be open.

• 21:56Lester Nare?

  Yes.

• 21:56Krishna Choudhary?

  And just like every grad student knows, in their, there's always one reviewer.

• 22:04Krishna Choudhary?

  For me, it was for me, it was reviewer one. For these guys, it's also reviewer number one.

• 22:08Lester Nare?

  Of course.

• 22:09Krishna Choudhary?

  Okay, because they're they're, um, they're anonymous.

• 22:11Lester Nare?

  Yeah.

• 22:12Krishna Choudhary?

  So if you're anonymous, you can just start saying the most heinous, out of pocket things about about the work. And this guy did not hold back. Reviewer two and reviewer three were pretty nice. They were like, you know, you should you should include. Some of these sources, you should maybe word things differently. Reviewer one was straight up like, this needs to be rejected. He said that multiple times in his first review and he's like, the language is bad. First of all, okay, so. First of all. He was like, first of all, the title. He goes after the title. He's like, I can't believe you put biosignatures on the title. You look now, the title of the paper does not have biosignatures. So reviewer one won that battle.

• 22:54Krishna Choudhary?

  Reviewer one won that battle because they were like, okay, fine, we'll take out biosignatures out of the title because he's like, this is only, you know, you can't say that. The null hypothesis, which is, you know, that this is of abiotic origin, which it totally could be, right? These, these, this chemistry could have formed. We don't know what the chemistry was like 3.5 billion years ago on Mars, right? So it's totally possible that this chemistry could have formed abiotically, right? And so that, that, that was his first qualm. His second qualm was about, well, like, you know, they have this analysis where they're looking at, using the pixel instrument. They're looking at the composition of these nodules and things like that. And he's like, well, you don't have any clean data, right?

• 23:37Krishna Choudhary?

  Because like, it's, it's like you have like iron and sulfur and you're claiming that these are the things that are in it. But there's also all sorts of other stuff, right? And you can look at the rebuttals that the authors. Put back, yeah, yeah, yeah. And so the authors put back the rebuttal being like, no, the beam of the instrument is as big as the nodules, if not bigger. So like you, I can't focus harder than I already have, right? This thing is on, it's not like I can remove a lens and put another one in. Right. Okay. Right. So, okay, so it's like, this is the best data you're gonna get. Okay, so that's, that one's fine. And it also, he, he was also like, the language, I can't believe you call them poppy seeds and leopard spots.

• 24:18Krishna Choudhary?

  You should be calling it by the scientific terminology because otherwise people are gonna get confused. And so they took that out and they started like referring to these things by their scientific thing, which is orthogenic nodules and reaction, reaction fronts. Okay, but, but they also in the rebuttal, they're like, people do this all the time. Yeah. Like, we've heard of Scooby Doo spots, right? Like, like people, it's not like a, it's something that we made up. Right. Like, it's just, it's just a nomenclature. Right. Okay, his main qualm. Okay. Was basically like, you guys are.

• 24:54Krishna Choudhary?

  Like hyping yourselves up way too much, okay? Like, I can't believe you're saying it's a biosignature. And then he brings up what happened in nineteen ninety six. Okay. With McKay and the paper in Science. Yes. Okay, so this is an incredible story because so um nineteen eighties. A team finds a meteorite in Antarctica. Okay, in the ice in Antarctica. That's where the aliens are. That's what the aliens are. Turns out this guy definitely thought so too McKay, right? And his colleagues. So this meteorite is discovered in Antarctica. Yes. And then um we because it's on earth, we can now actually put it under a scanning tunneling microscope. Yep. And things like that. And we can start looking and there's these really weird bacteria looking things.

• 25:39Krishna Choudhary?

  Okay, like they it looks like one of those rod bacterias on this meteorite and things like that. And so low and behold, he's like, this is life, right? It looked like life, honestly. Look at the photos. I'd be like, oh, that's that's a bacteria in a scanning tunneling microscope. If you told me that it was from a Mars meteorite, I'd be like, eh, okay. Okay. I don't know anymore. Yeah. Right? Because if you tell me it's from Mars meteorite, the the the burden of proof has suddenly gone up to here. Right. Okay, um if it's just a rock on earth, then yeah, there's bacteria on it. Mm hmm. Um, so he publishes this thing in Science. It's a huge deal. Okay, Bill Clinton gets in the White House lawn. Right. And calls a press conference. Yes.

• 26:24Krishna Choudhary?

  And he's like, you know, I did not have. No.

• 26:28Krishna Choudhary?

  He was like, he was like, you know, we found, we found, we found a life on Mars and it's great. That's my best uh Bill Clinton impression. The only thing I can do really is the Monica Lewinsky thing. But I'm trying to. But anyways, so it turns out that probably. Right. Not, right? Just not enough evidence to say that this thing is

• 26:49Lester Nare?

  Right.

• 26:49Krishna Choudhary?

  Is um something from Mars. But it became a huge part of the zeitgeist at the time. Because Bill Clinton was also announcing the Human Genome Project. There were all these big wins for American science. And this was gonna be one of them. Um, Dan Brown, the author of Angels and Demons.

• 27:06Lester Nare?

  Yep.

• 27:06Krishna Choudhary?

  He, he wrote a book, yeah, he wrote a book called Deception Point. Where the main, yeah, it's a great book and it's the, the main the crux of the story is that somebody finds fossilized aliens in like an iceberg.

• 27:18Lester Nare?

  Yep.

• 27:19Krishna Choudhary?

  Right?

• 27:19Lester Nare?

  Yep.

• 27:19Krishna Choudhary?

  So it becomes, it becomes like this huge pop culture thing. Um, and what this reviewer one is saying, he's like, you guys are repeating the mistakes of the past. Right? Because the field of astrobiology has already been hurt by um, this sort of fake hype.

• 27:39Lester Nare?

  Mm-hmm.

• 27:40Krishna Choudhary?

  And you guys are quote, the, the, the new dataset is quote, "much weaker" and much less detailed than even what that guy put out in 1996.

• 27:49Lester Nare?

  Those are fine words.

• 27:50Krishna Choudhary?

  Dude, this guy was relentless.

• 27:52Lester Nare?

  That's fine words.

• 27:52Krishna Choudhary?

  Yeah, so, so reviewer two and reviewer three, like reasonable comments. Reviewer one is just going ham. Basically several times he's telling nature not to publish.

• 28:01Lester Nare?

  Right.

• 28:01Krishna Choudhary?

  Okay?

• 28:02Lester Nare?

  Right.

• 28:02Krishna Choudhary?

  Um, the, the authors come back and they say, okay, fine, we refined the language. We're not saying it's, we, we never said it's biosignature. We said it's potential biosignature, which is something that even NASA agrees and, and the, and the greater astrobiology community agrees is what this thing should be called. Because certainly it is a potential biosignature. This is something phosphate and sulfur in iron next to organic compounds. Certainly something that requires further investigation. And that's what a potential biosignature is. Um, well, I just thought it was, I was reading the, the review and it was just like almost personal.

• 28:42Lester Nare?

  This is, this is great.

• 28:43Krishna Choudhary?

  Yeah.

• 28:44Lester Nare?

  And, and so we, we, we are still in a place, because now that we have the understanding of what are we actually talking about? Because a lot of times with these stories of Anything related to biosignatures, life off Earth.

• 28:57Krishna Choudhary?

  Yeah.

• 28:58Lester Nare?

  The news headlines, number one, don't map onto the words in the paper that they cover.

• 29:04Krishna Choudhary?

  Yeah, yeah.

• 29:05Lester Nare?

  Because they're going for clicks.

• 29:06Krishna Choudhary?

  Yeah.

• 29:07Lester Nare?

  And biosignature is like an amorphous word to ninety nine point nine percent of everyday people.

• 29:13Krishna Choudhary?

  Yeah.

• 29:13Lester Nare?

  What does that even mean? But this was actually helpful because now, in this case, specifically to this research path, we understand what we're trying to say or look for when we say potential biosignature.

• 29:28Krishna Choudhary?

  Yeah, it's a potential biosignature. It requires further, um, you know, scrutiny.

• 29:35Lester Nare?

  Yes.

• 29:35Krishna Choudhary?

  And further lab results.

• 29:37Lester Nare?

  Yes.

• 29:38Krishna Choudhary?

  And so actually, um, what the Perseverance Rover did and what it's capable of doing is actually saving samples.

• 29:43Lester Nare?

  Yep.

• 29:43Krishna Choudhary?

  So it took a sample out of this guy, saved it.

• 29:45Lester Nare?

  Yep.

• 29:46Krishna Choudhary?

  And then, you know, in the future, if we get our funding back, we're gonna send stuff there.

• 29:51Lester Nare?

  To pick up the sample.

• 29:52Krishna Choudhary?

  Pick it up and then take it back to Earth.

• 29:54Lester Nare?

  So I think what this means is if we want confirmation that our neighbor, the red planet, remember, we're code red today, uh, does in fact not just have potential evidence of biosignatures, but it is in fact biosignatures, we gotta go get it.

• 30:10Krishna Choudhary?

  Yeah.

• 30:11Lester Nare?

  In order to go get it, we have to fund the programs that are getting us so close to better understanding our place in the universe. And that what we think of as life is potentially.

• 30:24Krishna Choudhary?

  Yeah.

• 30:25Lester Nare?

  Way more abundant than we thought.

• 30:27Krishna Choudhary?

  Yeah.

• 30:28Lester Nare?

  But we have to spend the money.

• 30:28Krishna Choudhary?

  Yeah, we gotta spend the money. And the thing is, I think like SpaceX and Blue Origin are in talks, or at least they were, before the massive spending cuts. They were in talks to like, try to design a mission.

• 30:41Lester Nare?

  Right.

• 30:42Krishna Choudhary?

  To do exactly this.

• 30:43Lester Nare?

  Right.

• 30:44Krishna Choudhary?

  Right?

• 30:44Lester Nare?

  This is a good point. Private aerospace has risen in its, in its, uh, power and its efficacy over the last, let's say, ten, fifteen years.

• 30:53Krishna Choudhary?

  Yeah.

• 30:53Lester Nare?

  Particularly driven by SpaceX's Blue Origin as a close second. Where do they get some, if not a, a large portion of their capital to even do those things?

• 31:06Krishna Choudhary?

  Yeah.

• 31:07Lester Nare?

  Where do they shoot their stuff off from? All government funded.

• 31:10Krishna Choudhary?

  Yeah.

• 31:10Lester Nare?

  All government funded.

• 31:11Krishna Choudhary?

  Yeah. What are they shooting? It's government funded stuff.

• 31:15Lester Nare?

  Stuff.

• 31:15Krishna Choudhary?

  Yeah. It's not all Starlink satellites.

• 31:17Lester Nare?

  When we send astronauts up, right?

• 31:18Krishna Choudhary?

  Yeah.

• 31:19Lester Nare?

  The government is paying SpaceX to build. A capsule to be able to put humans in.

• 31:25Krishna Choudhary?

  Yeah, I mean, and it's following, it's following what the American model for innovation has been for the longest time, which right, which is the government spends the money to do all the hard work.

• 31:34Lester Nare?

  Right.

• 31:35Krishna Choudhary?

  And then, once they figured out all of the little details, now the private sector can come in and be like, oh, okay. I can now, I can now do that and I can do it cheap and I can do it well, right? That's the same thing that happened with silicon transistors.

• 31:48Lester Nare?

  Yes.

• 31:48Krishna Choudhary?

  Right? The government was, gave a blank check during the Apollo missions to a small, small company in Silicon Valley that used to be a bunch of apple orchards and, and orange groves, right? A small company, blank check, I need, I need this size of computer in something like this and I need it to not overheat. And blank check, do it. I just need it. Okay. We gotta beat the Russians. They do it. They're like, well, now I can make computers.

• 32:14Lester Nare?

  Yes.

• 32:16Krishna Choudhary?

  Outcomes, Fairchild Semiconductor, outcomes, Intel, outcomes, all of the Silicon Valley tech.

• 32:21Lester Nare?

  Yes.

• 32:21Krishna Choudhary?

  Right? So i- it's a model that's, that's followed, but again, it needs, like, you still need the government to have that money and have that funding to jumpstart these things.

• 32:30Lester Nare?

  Hundred, hundred percent. This is not to exclude the idea or the fact that the private industry can and has, particularly in aerospace, push the boundaries of innovation.

• 32:41Krishna Choudhary?

  A hundred percent.

• 32:42Lester Nare?

  But these are not mutually exclusive ideas.

• 32:44Krishna Choudhary?

  Yeah, yeah.

• 32:45Lester Nare?

  Like, yes, both things can be true.

• 32:47Krishna Choudhary?

  Yeah.

• 32:47Lester Nare?

  Both things are true, particularly as we talk about these deeper space missions in particular, where there is no commercial value.

• 32:56Krishna Choudhary?

  No.

• 32:57Lester Nare?

  For a private aerospace company, for these more, again, fundamental discovery.

• 33:03Krishna Choudhary?

  Yeah, exactly. I mean, maybe you're trying to colonize Mars, but that's like several hundred years away.

• 33:08Lester Nare?

  Yeah, and not in our lifetime.

• 33:09Krishna Choudhary?

  Right? Yeah.

• 33:09Lester Nare?

  And unless we figure out the longevity issue, which we talked about in last episode, we won't be around for that.

• 33:14Krishna Choudhary?

  Yeah, I won't be around for that.

• 33:15Lester Nare?

  So this was the announcement today, September 10th, took the internet by storm.

• 33:22Lester Nare?

  But this is not the first time even this year that we've seen a headline with some version of the language strongest evidence yet.

• 33:32Krishna Choudhary?

  Yes.

• 33:32Lester Nare?

  And so our second story uh is coming out of the BBC with the headline scientists find quote strongest evidence yet of life on distant planet. This is from April 17.

• 33:46Krishna Choudhary?

  That's right.

• 33:47Lester Nare?

  So almost an identical headline.

• 33:50Krishna Choudhary?

  Yeah.

• 33:50Lester Nare?

  Different location, potential buyer signatures, strongest evidence yet of life interchangeable. This in this case for the April story, not on Mars.

• 34:00Krishna Choudhary?

  No.

• 34:01Lester Nare?

  But on a very, very distant planet.

• 34:03Krishna Choudhary?

  Yeah.

• 34:03Lester Nare?

  And this research was coming from a Cambridge team studying the atmosphere of a planet called K 218 B.

• 34:10Krishna Choudhary?

  Yeah.

• 34:10Lester Nare?

  So as a layman, I don't understand what the difference between these two things are when the article just says strongest evidence yet. Which one is stronger? Is this one stronger? Is that one stronger?

• 34:21Krishna Choudhary?

  Yeah.

• 34:21Lester Nare?

  Is it the strongest?

• 34:22Krishna Choudhary?

  In in my opinion, I would say the NASA one is stronger.

• 34:25Lester Nare?

  Okay.

• 34:25Krishna Choudhary?

  Okay, because you can literally see the stuff.

• 34:27Lester Nare?

  Yes.

• 34:28Krishna Choudhary?

  Okay, um, and at least what we see, we know we see.

• 34:32Lester Nare?

  Right.

• 34:33Krishna Choudhary?

  Okay, with this one, it turns out that the paper that came out in on April 17th that was purporting to have seen the things that it sees might not have been seeing those things.

• 34:45Lester Nare?

  So you're saying don't trust the headlines?

• 34:47Krishna Choudhary?

  Yes, I'm saying definitely don't trust the headlines and in this case also maybe take the scientific paper with a grain of salt. There was a lot of pushback after the scientific paper came out.

• 34:57Lester Nare?

  Okay.

• 34:58Krishna Choudhary?

  From the from the um, community. Saying don't, don't say that.

• 35:04Lester Nare?

  So what's interesting about this April story is unlike the rover perseverance being the source of the sort of discovery quote unquote, uh, it was the James Webb Space Telescope.

• 35:14Krishna Choudhary?

  That's right.

• 35:15Lester Nare?

  Another NASA product.

• 35:16Krishna Choudhary?

  So there's no tactile evidence.

• 35:17Lester Nare?

  Right.

• 35:17Krishna Choudhary?

  This thing's just looking at stuff.

• 35:18Lester Nare?

  It's just looking at stuff. Really, really far away.

• 35:22Krishna Choudhary?

  Yeah, yeah. This one's, this one's honestly one hundred and twenty light years away. So in our neighborhood.

• 35:27Lester Nare?

  Yeah, okay.

• 35:27Krishna Choudhary?

  Yeah, James Webb is capable of looking, you know, towards the beginning of the Big Bang.

• 35:32Lester Nare?

  The Benninging.

• 35:32Krishna Choudhary?

  Yeah, so, so this thing is looking at a hundred and twenty light years away. It's a, it's a star called K two eighteen. It was discovered by the Kepler um space observatory. And um this is K two eighteen B, so it's the second planet to have been discovered there.

• 35:52Lester Nare?

  The star is K two eighteen.

• 35:53Krishna Choudhary?

  Yeah.

• 35:53Lester Nare?

  Planet's K two eighteen B.

• 35:54Krishna Choudhary?

  B, yeah. And so um the, the planet is a little peculiar for stuff that we talk about in terms of

• 36:04Krishna Choudhary?

  being potentially habitable because it's not an Earth-like planet. It's, it's a, it's bigger than Earth. It's got the radius of two Earths. It's got the mass of eight. So it's one of these like mini Neptunes. Um, what we call Hyssian worlds. We, we think that there is a giant ocean on this planet.

• 36:25Lester Nare?

  Okay, like in that interstellar scene where they went on the ocean planet and they had the giant tidal wave.

• 36:30Krishna Choudhary?

  Yeah, yeah, yeah. Except this would be a lot, a lot deeper ocean.

• 36:35Lester Nare?

  You wouldn't be able to stand.

• 36:36Krishna Choudhary?

  Yeah, you wouldn't be able to stand and stuff like that. Um, it, it kind of reminds me of the um planet from Dune. That was the home world of the Atreides.

• 36:47Lester Nare?

  Yes.

• 36:48Krishna Choudhary?

  Family, you know?

• 36:48Lester Nare?

  Yes.

• 36:49Krishna Choudhary?

  Like the beautiful blue planet.

• 36:50Lester Nare?

  Yes.

• 36:51Krishna Choudhary?

  Uh, yeah, it's kind of like that. It's a water world.

• 36:55Krishna Choudhary?

  And it's, it's what we call Hyssian worlds um in the astrobiology community.

• 37:00Lester Nare?

  Okay.

• 37:01Krishna Choudhary?

  Right? Um, and so what they think they found is traces of a gas called dimethyl sulfide. This is the gas that you get with like um, you know, cooked cabbage.

• 37:16Lester Nare?

  Yes.

• 37:16Krishna Choudhary?

  The smell.

• 37:17Lester Nare?

  Yes.

• 37:17Krishna Choudhary?

  That's dimethyl sulfide. Also like um.

• 37:19Lester Nare?

  Particular smell.

• 37:20Krishna Choudhary?

  Yeah, also like if you're brewing beer.

• 37:23Lester Nare?

  Yes.

• 37:23Krishna Choudhary?

  And then it goes wrong.

• 37:24Lester Nare?

  Yes.

• 37:24Krishna Choudhary?

  There's a smell.

• 37:25Lester Nare?

  Yes.

• 37:26Krishna Choudhary?

  That's dimethyl sulfide.

• 37:26Lester Nare?

  Okay.

• 37:27Krishna Choudhary?

  Okay, and that's mostly just made by like phytoplankton on Earth.

• 37:33Lester Nare?

  Okay.

• 37:33Krishna Choudhary?

  Okay, so when we found that on this distant planet.

• 37:38Lester Nare?

  Fido Plankton must be there.

• 37:40Krishna Choudhary?

  Yeah, it's like, oh dope. And honestly, if we found DMS there and there were, there was no doubt of DMS, then it's a pretty strong, it's, it's pretty strong evidence. It's not everything, because again, it can happen abiotically, and that's part of the story that we're gonna get to. So, first let's, first let's try to figure out how we would even like try to find gases on another planet.

• 38:03Lester Nare?

  Right.

• 38:03Krishna Choudhary?

  Okay, um, you know, on Mars, you can like literally just like see it.

• 38:08Lester Nare?

  Right.

• 38:08Krishna Choudhary?

  Right? And then with the Mars Perseverance Rover, today's news, it can just go and like, oh, it's like, it's shooting X-rays and then.

• 38:15Lester Nare?

  Yeah, it's right there.

• 38:16Krishna Choudhary?

  It's right there. I'm shooting an X-ray. I get the signature.

• 38:19Lester Nare?

  Not a hundred twenty light years.

• 38:20Krishna Choudhary?

  Right. It's this thing is, this thing is extremely far. So how do we actually determine, um, what is in its atmosphere?

• 38:26Lester Nare?

  Right. That's my first question. How, how can we even know that from like a, you know, from a sensor system?

• 38:31Krishna Choudhary?

  Yeah, from a sensor, and that's, and that's one of the big reasons why everyone was so excited about the James Webb Space Telescope is because it would have this capability.

• 38:40Lester Nare?

  Okay.

• 38:40Krishna Choudhary?

  So here's the idea. Um, the way we find a lot of these planets is through this thing called the transit technique.

• 38:46Lester Nare?

  Okay.

• 38:46Krishna Choudhary?

  Okay. What you do is you stare at a star for a very long time. In this case, Kepler did it for, um, for a month. You stare at a single patch of the sky and you look at all the stars, and what the star's gonna do is it's gonna dim every once in a while for, for a few hours. It's gonna dim. And then maybe two weeks later, it's gonna dim again.

• 39:07Lester Nare?

  Okay.

• 39:07Krishna Choudhary?

  And then you're gonna wait two weeks later, it's gonna dim again. And there's gonna be a rhythmic dimming.

• 39:11Lester Nare?

  Mm-hmm.

• 39:11Krishna Choudhary?

  Okay? And what's happening is you're getting an eclipse of the, of the, of the planet in front of the star.

• 39:18Lester Nare?

  Because it's basically like if, if, if I'm JWST looking this way.

• 39:21Krishna Choudhary?

  Yeah.

• 39:22Lester Nare?

  Uh, the star is in the center of my field of view.

• 39:24Krishna Choudhary?

  Yeah.

• 39:25Lester Nare?

  And the planet is orbiting around. It's eventually gonna pass in between me, JWST, looking at the star.

• 39:32Krishna Choudhary?

  Yeah.

• 39:32Lester Nare?

  Okay, two eighteen. And it's gonna be the whoop. And so the dips you're talking about.

• 39:38Krishna Choudhary?

  That's good. That's gonna be a transit. That's why we call it a transit method of finding it. And the way that this thing dips is called a transit curve. Right? You're gonna see the brightness because these stars are stars are so far away and they're so small for how far away they are. That they're basically points of light. You can't really um resolve a circle.

• 39:59Lester Nare?

  Right.

• 39:59Krishna Choudhary?

  Okay, you just resolve a tiny point of light and all you can tell is its brightness.

• 40:03Lester Nare?

  Okay.

• 40:04Krishna Choudhary?

  Okay, and so the brightness goes down and then it goes back up.

• 40:07Lester Nare?

  Yeah.

• 40:07Krishna Choudhary?

  And then it's this rhythmic pattern that tells you that there's something orbiting that star.

• 40:12Lester Nare?

  Right.

• 40:12Krishna Choudhary?

  That's happening every, you know, two weeks to a month or whatever and has some cadence. And then you can be very sure that there that that's a planet that I'm looking at. Okay? Now, the the nice thing about the transit method is, okay, so you're getting a transit curve. For the light, right? The light is dimming. But if you have a spectrograph, which is what the James Webb Space Telescope has, it's got a really nice spectrograph. Okay, especially in the infrared region.

• 40:39Lester Nare?

  Mm hmm.

• 40:40Krishna Choudhary?

  Which is um where a lot of gases do quantum.

• 40:45Lester Nare?

  Stuff.

• 40:45Krishna Choudhary?

  Stuff. Okay?

• 40:46Lester Nare?

  Yes.

• 40:47Krishna Choudhary?

  So if you've got this spectrograph. What you can do is you can get a transit curve for every color.

• 40:54Lester Nare?

  Okay.

• 40:55Krishna Choudhary?

  And the trick is that if there is an atmosphere with stuff in it. Then the transit curve for different colors is going to be different.

• 41:04Lester Nare?

  It's gonna have a different.

• 41:05Krishna Choudhary?

  Right? Because if suppose there's a bunch of oxygen on this planet. There's gonna be a certain wavelength of light that oxygen really likes. And it's gonna absorb a lot of. So what you're gonna see is a transit curve for ever for every um you're gonna see a dip.

• 41:22Lester Nare?

  Yes.

• 41:23Krishna Choudhary?

  In every single wavelength.

• 41:24Lester Nare?

  Yes.

• 41:24Krishna Choudhary?

  But there's gonna be one wavelength that you're gonna see an even bigger dip.

• 41:28Lester Nare?

  Ah.

• 41:28Krishna Choudhary?

  Because the atmosphere is gonna be taking out more of that star.

• 41:31Lester Nare?

  Yes.

• 41:32Krishna Choudhary?

  Light.

• 41:33Lester Nare?

  Yes.

• 41:33Krishna Choudhary?

  Right?

• 41:33Lester Nare?

  Yes.

• 41:35Krishna Choudhary?

  That is fundamentally how we use transit method.

• 41:39Lester Nare?

  Yes.

• 41:39Krishna Choudhary?

  To find atmospheres on these planets.

• 41:42Lester Nare?

  The the comp the chemical composition.

• 41:44Krishna Choudhary?

  Yeah.

• 41:45Lester Nare?

  Of the of the atmosphere.

• 41:46Krishna Choudhary?

  Yeah, the chemical composition becomes a kind of barcode across wavelength.

• 41:50Lester Nare?

  Because the idea is is the lights passing through the atmosphere of the planet on its way to JWST. The atmosphere, if it has certain stuff, is gonna absorb that light. So that's what causes. On the transit curve, the dip to be lower than everything else.

• 42:05Krishna Choudhary?

  Exactly.

• 42:06Lester Nare?

  There's a high abundance of that particular.

• 42:08Krishna Choudhary?

  Exactly. Like, like, for example, suppose we had a spectrometer in the UV range. I don't think the James Webb Space Telescope does, but for sake of argument, suppose there's an alien world out there, right? And it's got a telescope pointed at us and they're just lucky enough that the earth is transiting. They gotta wait a whole year.

• 42:27Lester Nare?

  Yeah, it's a bird to come back around.

• 42:28Krishna Choudhary?

  For it to come back around, but let's just say they're super patient.

• 42:31Lester Nare?

  Yes.

• 42:33Krishna Choudhary?

  When the earth goes in front of that star, they're gonna see a giant dip in the UV. Because there's a bunch of ozone, right? And the ozone is what keeps us from having skin cancer.

• 42:45Lester Nare?

  Right.

• 42:45Krishna Choudhary?

  Right? But that's fundamentally because it's shielding us from all of this UV radiation. That alien planet, when it's watching the earth go in front, it's gonna see the rest of the light go down because the earth is blocking it. But the ozone is just gonna be completely obliterated.

• 42:59Lester Nare?

  Right, right.

• 43:00Krishna Choudhary?

  Right?

• 43:00Lester Nare?

  Because it's so present in the atmosphere.

• 43:01Krishna Choudhary?

  Yeah, because it's so, it's so present, right? And so, from that, they can then be like, oh, this planet has a lot of ozone. Similarly, that's what we can do with these planets.

• 43:10Lester Nare?

  So that, that's how we can understand the atmospheric makeup, which then from that, we can draw conclusions.

• 43:16Krishna Choudhary?

  Yes, yeah. So, so that's what these guys did, right? They, they, they, they got this transit from the JWST.

• 43:23Lester Nare?

  Yes.

• 43:24Krishna Choudhary?

  And then what they wanna do is they wanna try to figure out what kind of atmosphere would give me that barcode? Where this wavelength is a little lower, this wavelength is fine, this wavelength is a little lower, so on and so forth.

• 43:34Lester Nare?

  Right.

• 43:35Krishna Choudhary?

  Right?

• 43:37Krishna Choudhary?

  To do that, now, we have to use something like a probabilistic model. This thing called like Bayesian analysis. It's called atmospheric retrieval because we're trying to retrieve the possible atmosphere that created this signature.

• 43:52Lester Nare?

  This, this, let's, let's, let's say like, like a barcode.

• 43:54Krishna Choudhary?

  Yeah, yeah. So, so what you do is you simulate a bunch of different atmospheres with a bunch of different density profiles, temperature profiles, pressure profiles, heights, so on and so forth, where the, the, the gas is, on what part of the atmosphere. And then you simulate what that would look like on a planet with that particular star. Because we know what the star. Looks like, right? We have the spectrum of the star when the, when the planet is not in the way. And so from that, we then subtract this candidate atmosphere, one, one by one, right? And you, you create this Bayesian model of all the possible scenarios. Yes. And you try to see what model best fits. The barcode we see in real life. This barcode that we see in real life, right?

• 44:37Krishna Choudhary?

  And so, um, this team out of Cambridge from Nikumadusudan. Yes. He fit a bunch of different atmospheres and he found that the atmosphere that had, um, DMS and DMDS, which is dimethyl disulfide. So dimethyl sulfide is just, um, CH3, two of these with a sulfur in the middle. And then the dimethyl disulfide is two sulfurs with CH3, CH3. Okay. Um, and what he found was that the best model that fit it was something that had a bunch of DMS and a thousand percent more DMDS than we find on earth. And both of these compounds are very much of biotic origin on earth. Okay.

• 45:16Krishna Choudhary?

  So he publishes this thing and immediately the BBC, um, you know, they love tooting UK's horn. So they're like, oh, strongest evidence yet. We did it. Right? We did it. Even though it was with our stuff. Yeah, yeah, yeah, exactly. Yeah, like, I'd like you try to, I'd like to see you try and make a JWST. Anyways, so here's the deal though. You read the paper. Okay. And the significance level that these guys are saying is at three point, three sigma. Okay. Three standard deviations, meaning the null hypothesis is there's no DMS and DMDS. This, um, barcode that we saw is a fluke. Okay.

• 45:57Krishna Choudhary?

  And this thing is saying that with about 99.7% certainty, three sigma, meaning you've got this Gaussian distribution of all the possible things that it can be. And we're three standard deviations away from that null hypothesis. Okay. So we're at, we're 99.7% certainty. Might seem like a lot.

• 46:15Lester Nare?

  I mean, if I got a nine nine point seven with the grade deflation we had at Princeton, I'd be pretty happy.

• 46:19Krishna Choudhary?

  Yeah, yeah, yeah. Now, you don't even need grade deflation at that point, right?

• 46:23Lester Nare?

  Right.

• 46:23Krishna Choudhary?

  Nowadays, that's a, that's an A plus plus plus plus plus plus. Um, actually, back then, that was a B minus.

• 46:32Krishna Choudhary?

  But, um, so ninety nine point seven percent certainty seems like quite a bit.

• 46:37Lester Nare?

  It's in science.

• 46:38Krishna Choudhary?

  In science, especially in physics and in astrophysics, that is not a lot. The gold standard is, um, five sigma.

• 46:45Lester Nare?

  Okay.

• 46:45Krishna Choudhary?

  Which is ninety nine point nine nine nine nine percent. Okay?

• 46:49Lester Nare?

  Okay.

• 46:50Krishna Choudhary?

  Um, five sigma is the gold standard for things like the Higgs boson. I mean, if we had three si- if, if three sigma was the bar for announcing a discovery, we would have discovered the Higgs boson.

• 47:04Lester Nare?

  Before CERN?

• 47:04Krishna Choudhary?

  Before CERN.

• 47:05Lester Nare?

  Yeah.

• 47:05Krishna Choudhary?

  Because Fermilab was doing these experiments already.

• 47:08Lester Nare?

  Right.

• 47:08Krishna Choudhary?

  And we were seeing the signature.

• 47:11Lester Nare?

  Yeah, yeah.

• 47:11Krishna Choudhary?

  Of the Higgs boson, but we didn't do it because we didn't have the.

• 47:15Lester Nare?

  Five sigma.

• 47:15Krishna Choudhary?

  The five sigma level.

• 47:17Lester Nare?

  Right.

• 47:17Krishna Choudhary?

  To like actually announce it.

• 47:18Lester Nare?

  Yes.

• 47:18Krishna Choudhary?

  So this isn't good practice to announce something at three sigma.

• 47:22Lester Nare?

  So, so there, there's a bar.

• 47:24Krishna Choudhary?

  There's a bar.

• 47:24Lester Nare?

  So that's sort of like, that's mutually agreed upon.

• 47:26Krishna Choudhary?

  By, by everyone in the community.

• 47:28Lester Nare?

  You don't publish.

• 47:29Krishna Choudhary?

  Yeah.

• 47:30Lester Nare?

  Unless you reach this bar.

• 47:32Krishna Choudhary?

  Mm hmm.

• 47:33Lester Nare?

  But then.

• 47:34Krishna Choudhary?

  These guys did it at three sigma.

• 47:35Lester Nare?

  It's funny because I'm looking at this quote in the BBC article from the lead researcher, um, who, who said, this is the strongest evidence yet there is possibly life out there. I can realistically say that we can confirm the signal within one to two years.

• 47:52Krishna Choudhary?

  Okay, so he's saying that we can confirm the signal, but then why are you publishing it?

• 47:57Lester Nare?

  That's, that's the kind of.

• 47:57Krishna Choudhary?

  Here, the, the other, the other thing is like a year before that, a year before, like in twenty twenty four, I believe.

• 48:03Lester Nare?

  Yeah, yeah.

• 48:04Krishna Choudhary?

  It, there was a thing that came out in the BBC that like, it, it's a tantalizing signs of possible life on a faraway world.

• 48:12Lester Nare?

  I love the language.

• 48:13Krishna Choudhary?

  And that was at one sigma, sixty six percent.

• 48:17Lester Nare?

  Yeah.

• 48:18Krishna Choudhary?

  At sixty-six percent, I can't believe you're even talking to the BBC. And, okay, here's, here's the funny part. That BBC article is written by the same guy who wrote this. So, I'm not saying what you think I'm saying. But I'm saying that maybe these two guys are like friends. Okay, and, and like, they had dinner and he's, and he said, hey, I got, like, dude, at one sigma, I, I've, I, I, in science, at one sigma, you talk to your lab mates about how to improve the sigma. Okay, you maybe talk to like, close collaborators. You don't talk to the media at one sigma. That's insane to me, okay?

• 48:59Lester Nare?

  Sixty-six percent.

• 49:00Krishna Choudhary?

  Yeah, sixty-six percent, dude, like, that's, that's like a bad coin.

• 49:06Krishna Choudhary?

  Like, that's so close to fif- in- okay, anyways, but, um, understandably, seventeenth of April, this, this paper comes out. Understandably, there's a lot of backlash from the community.

• 49:18Lester Nare?

  A lot of reviewer number ones.

• 49:19Krishna Choudhary?

  Yeah, yeah, a lot of, a lot of like, so, a week later, um, this guy Jake Taylor from Oxford, a week later, so Oxford, Oxford and Cambridge, they've always had beef. This guy comes out and he's like, actually with, uh, five sigma, I'm telling you, um, well, actually, like, so he did six different other models with the same data.

• 49:41Lester Nare?

  For, th- th- this is the model of the potential atmospheres that could match to the barcode. So the idea is Cambridge said, we looked at a bunch of possible barcodes. We found one that's a really close match.

• 49:53Krishna Choudhary?

  Yeah.

• 49:54Lester Nare?

  Now Oxford came back.

• 49:55Krishna Choudhary?

  Oxford came back and it's like, well, I did like, six different methods of doing this, and only one of them showed DMS. But five of them don't.

• 50:05Lester Nare?

  So what are you talking about?

• 50:06Krishna Choudhary?

  So what are you talking about, right? Five of these fits don't have any DMS, but they're fitting. With this guy pretty The actually it's kind of you cherry picked one. Yeah. And you really didn't do. Like an exhaustive search. Right. Right? Right. Um, and that was, that was a week after this, this guy published, right? He's a postdoc. He was just like, no. About a week ago. A week is crazy. A week, right? And then, and then about three weeks later, the Americans start coming. Ah, we always do. Okay. Cause we, we want to live a more time. Um, so the Welbanks Group at the University of Arizona, they show pretty conclusively that like propane, which is C three H four, abiotic, can also produce the same signature. Hmm. Okay. So it's like, well, you have, you, you had like certain constraints on your atmospheric retrieval,

• 50:49Krishna Choudhary?

  but now like, once we expand the search, there's all these other molecules that sort of fit the bill. Mm hmm. University of Chicago does the same thing with all the data and they're like, mm, I don't, I don't see it. So everybody was like. Everybody's like, bro, what are you doing? And then actually I looked up, the most recent one is the 18th of July, 2025. Hmm. Um, UCLA, Caltech, and actually Nikomad Sudan, who is the original. Leader. Leader, author of the April 17th paper. He's also a co-author in this. Okay. And, um, they say that there's probably water on this thing, like, um, a liquid ocean. Given that, given the, um,

• 51:28Krishna Choudhary?

  the levels of ammonia and nitrogen and methane that we see, like that level suggests that there's liquid ocean. But he also like pulled back on the DMS. I was gonna say, that's a totally different argument. Yeah. So, so he's like, he's like, there's this. And then, and then like, and then like the one little sentence of the abstract is like, ah, but the DMS could have been, could have been made abiotically, actually. So maybe the BBC article needs a slight correction. Yeah. And they really should like put out a little, you know, disclaimer. Because. Like, or a little asterisk at the bottom being like. Funny, the UK always runs to the Americans. Yeah. You need the help. Funny, yeah. But, but so it's, so they, they're sort of in a pivot. Yeah.

• 52:11Lester Nare?

  In the, in the claim.

• 52:13Krishna Choudhary?

  Yeah.

• 52:13Lester Nare?

  Which is like, oh, it's probably a liquid planet.

• 52:15Krishna Choudhary?

  Yeah.

• 52:15Lester Nare?

  Okay.

• 52:16Krishna Choudhary?

  Okay, but the DMS stuff, let's, let's, let's just.

• 52:20Lester Nare?

  So the evidence was not the strongest.

• 52:22Krishna Choudhary?

  No, no.

• 52:23Lester Nare?

  Um, so that's a great way to distinguish. When you see headlines and it's like tantalizing.

• 52:30Krishna Choudhary?

  Yeah.

• 52:30Lester Nare?

  Strongest potential evidence of life. What is evidence of, what type of life? Is it microbial life? Is it intelligent life? Is it a bio-signature? Is it a techno-signature? There's all these.

• 52:41Krishna Choudhary?

  Yeah, is it a potential?

• 52:42Lester Nare?

  Is it a potential? Or is it a direct?

• 52:44Krishna Choudhary?

  Yeah.

• 52:45Lester Nare?

  And so with, with the rover Mars, the reason why Mars is a great laboratory or great research arena is because we can touch and feel and look, it's right there.

• 52:54Krishna Choudhary?

  It's right there, yeah.

• 52:55Lester Nare?

  It's tangible.

• 52:56Krishna Choudhary?

  And we can bring it back.

• 52:56Lester Nare?

  And we can bring it back.

• 52:58Krishna Choudhary?

  Yeah.

• 52:58Lester Nare?

  If we fund.

• 52:59Krishna Choudhary?

  Yeah.

• 52:59Lester Nare?

  The trip back, which we should, because we want to know that there's, uh, aliens out there.

• 53:04Krishna Choudhary?

  Yeah.

• 53:04Lester Nare?

  But this is a, this is a very good co- uh, contrast. Because, you know, as many viewers know, and I know you know, like, I work in, at a nonprofit that's sort of addressing this unidentified anomalous phenomena issue. It's funny, I actually tweeted earlier today, X posted whatever people want to say. Uh, yeah, uh, yesterday.

• 53:25Krishna Choudhary?

  Yeah.

• 53:25Lester Nare?

  Um, was this UFO hearing in Congress.

• 53:28Krishna Choudhary?

  Yeah, I heard about that.

• 53:29Lester Nare?

  In the House Oversight Committee.

• 53:30Krishna Choudhary?

  And there was like that crazy video.

• 53:32Lester Nare?

  And there's a crazy video.

• 53:34Krishna Choudhary?

  That looked crazy, I was like, I don't know about this.

• 53:36Lester Nare?

  It's a crazy video of a Hellfire missile being fired at this object flying over the ocean. It makes contact, but it does nothing to the flight path of the thing that is flying. Mind you, like Hellfire missiles are one of our most sophisticated, advanced, like, i- i- it's a problem if it's prosaic or not, or anomalous, it's a problem regardless. But the, the, the juxtaposition or the sort of fast follow of like that hearing happening, and then I woke up and then NASA's like, oh wait, we might have found life on Mars. It's like, what are you hiding? No, kidding.

• 54:10Krishna Choudhary?

  Yeah, and, and like understandably, like. This kind of research and and this kind of claim requires an extraordinary amount of evidence because this would be one of the biggest discoveries in human history.

• 54:23Lester Nare?

  Finding out that life exists elsewhere is it's I mean, it's in the top three.

• 54:28Krishna Choudhary?

  Yeah, it's in the top three.

• 54:30Lester Nare?

  You could argue about whether it's LeBron or Michael Jordan as the GOAT.

• 54:32Krishna Choudhary?

  Yeah, but like it's it's up there. Yeah, it's either Kobe, LeBron or Jordan.

• 54:36Lester Nare?

  Yeah, right. It's it's so it's kind of like that situation.

• 54:39Krishna Choudhary?

  Like, we can all agree that this is gonna be a huge deal if it comes out, which is why there's some scrutiny every time somebody says something, right? And which is why I think reviewer one on that last paper was so pissed off.

• 54:50Lester Nare?

  Went ham.

• 54:50Krishna Choudhary?

  Right?

• 54:51Lester Nare?

  Went absolutely ham. So this is so, okay, so this is good because we're gonna go to the last story, which kind of creates a nice bookend.

• 54:59Krishna Choudhary?

  Yeah.

• 54:59Lester Nare?

  For all the fans of the new TV show on Apple TV, the studio, we need a nice bookend. I love a good bookend. Um, and so the last story is out of both Scientific American and CBS News. This is also sort of like a brand new breaking story.

• 55:14Krishna Choudhary?

  Yeah.

• 55:15Lester Nare?

  Which is, again, another word, hints of atmosphere on Earth-sized exoplanets raises hopes for life in a new, another W W James Webb Space Telescope finding.

• 55:27Krishna Choudhary?

  Yep.

• 55:28Lester Nare?

  Um, what's interesting about this one is like Halo, they came out guns blazing, dual wielding research papers.

• 55:33Krishna Choudhary?

  Yeah.

• 55:33Lester Nare?

  There wasn't one.

• 55:34Krishna Choudhary?

  Yeah.

• 55:34Lester Nare?

  It was two in the Astrophysical Journal Letters.

• 55:37Krishna Choudhary?

  Yeah.

• 55:37Lester Nare?

  Related to this hints of atmosphere. So it's sort of great that we just talked through the transit map.

• 55:45Krishna Choudhary?

  Yes, yeah.

• 55:46Lester Nare?

  And understanding like how like how would JWST like detect the atmosphere from using sensor technology?

• 55:52Krishna Choudhary?

  Exactly, yeah.

• 55:53Lester Nare?

  So we have that.

• 55:53Krishna Choudhary?

  So we have that grounding now. And now we are looking, so this this came out September 8th, um, very recent.

• 56:00Lester Nare?

  This was two days ago.

• 56:01Krishna Choudhary?

  Um, everyone's excited about this because this is a paper on the Trappist.

• 56:07Lester Nare?

  Ah, Trappist one.

• 56:09Krishna Choudhary?

  Trappist one. Have you heard about this?

• 56:10Lester Nare?

  So Trappist has been, again, because I did the UAP stuff, a lot of people are like, that's where they that's where the aliens are.

• 56:16Krishna Choudhary?

  That's where the aliens are. Everyone's like, that's where the aliens are, right? Trappist one is um, is a great little micro lab for solar system research, okay? The reason for it is, um, it's it's got a bunch of rocky planets.

• 56:31Lester Nare?

  Mm hmm.

• 56:31Krishna Choudhary?

  That are all transiting.

• 56:33Lester Nare?

  Oh, in front of like we just talked about.

• 56:35Krishna Choudhary?

  The sun, right? The the problem with like finding. Planets is it's incredibly hard to detect, right? Think about like, I mean, think about, think about how we find um the planets, right? You were saying that you you gotta look at this thing.

• 56:48Lester Nare?

  Yes.

• 56:48Krishna Choudhary?

  You gotta look at the star and you gotta look for the star's brightness to dim.

• 56:52Lester Nare?

  Yes.

• 56:52Krishna Choudhary?

  And then you gotta wait for it to dim again. And then you have two and you gotta wait for that third because then you know that it's rhythmic.

• 56:57Lester Nare?

  Yeah, it's rhythmic.

• 56:57Krishna Choudhary?

  Right? If it's just two, it could just be two random things going in front.

• 57:00Lester Nare?

  Right.

• 57:00Krishna Choudhary?

  Or whatever. And then, you know, um, so you you have to wait for that.

• 57:04Lester Nare?

  Yes.

• 57:05Krishna Choudhary?

  The other thing is you gotta get lucky, right?

• 57:06Lester Nare?

  Right.

• 57:07Krishna Choudhary?

  The the solar system has to be on edge to our field of view.

• 57:12Lester Nare?

  Hmm.

• 57:12Krishna Choudhary?

  If you've got a star over here and the solar system is doing this.

• 57:15Lester Nare?

  We it won't pass in front.

• 57:16Krishna Choudhary?

  It's no never gonna pass in front and I'm never gonna see it.

• 57:19Lester Nare?

  Right.

• 57:19Krishna Choudhary?

  Right? And so the solar system has to have that exact angle.

• 57:23Lester Nare?

  Right, right.

• 57:23Krishna Choudhary?

  Of being like in our line of sight.

• 57:25Lester Nare?

  Yeah, yeah, yeah.

• 57:26Krishna Choudhary?

  Right?

• 57:26Lester Nare?

  Can't be up here like angle.

• 57:27Krishna Choudhary?

  So you've got to be incredibly lucky. This thing is not only on edge.

• 57:31Lester Nare?

  Yeah.

• 57:32Krishna Choudhary?

  Right? It's got like a bunch of planets.

• 57:35Lester Nare?

  Yes.

• 57:35Krishna Choudhary?

  That are all on edge that are that are doing this transiting.

• 57:38Lester Nare?

  Yes.

• 57:39Krishna Choudhary?

  Also, the transits are very, very short. From one and a half days to nineteen days.

• 57:45Lester Nare?

  This goes back to what we were talking about earlier for there's an alien species looking at Earth, our transit times a year.

• 57:49Krishna Choudhary?

  A year. They'd they'd have to keep staring at the sun. They'd probably see Mercury.

• 57:54Lester Nare?

  Right.

• 57:54Krishna Choudhary?

  And and then they'd be like, oh, there's no, there's no atmosphere on this thing.

• 57:57Lester Nare?

  Right, and then give up.

• 57:58Krishna Choudhary?

  And then give up, right? But then they maybe they'd see Venus and they'd be like, that's got a hell of an atmosphere, you know?

• 58:04Lester Nare?

  Right.

• 58:05Krishna Choudhary?

  But like, yeah, Earth, they'd have to wait three hundred and sixty-five days.

• 58:08Lester Nare?

  Just for once and then they'd have to wait two more years to get the three.

• 58:11Krishna Choudhary?

  Two more years to get all three.

• 58:12Lester Nare?

  So the fact that the transit's just a couple of days.

• 58:15Krishna Choudhary?

  Couple of days till like twenty days.

• 58:17Lester Nare?

  It's hu- cuz it's like, it's cuz it's this is a resource allocation issue. If we had a bunch of these tools.

• 58:22Krishna Choudhary?

  Yeah.

• 58:22Lester Nare?

  We could just point wherever or leave them forever. It doesn't matter.

• 58:25Krishna Choudhary?

  Yeah.

• 58:25Lester Nare?

  But there's limited time and everyone wants to look at different things for different reasons. And so that's a really good point that the transit time.

• 58:32Krishna Choudhary?

  Is so short.

• 58:33Lester Nare?

  Is so short, which is me- a meaningful variable.

• 58:35Krishna Choudhary?

  Yeah, and the other, the other great thing is, so Trappist has a bunch of these planets, right?

• 58:39Lester Nare?

  Yes.

• 58:40Krishna Choudhary?

  So imagine you've got a star like this and you've got a bunch of planets, right? Now, where the habitable zone is.

• 58:46Lester Nare?

  Yeah, yeah.

• 58:46Krishna Choudhary?

  Is kind of. Nebulous, right? It's like, we don't know exactly the, there's no like, hard line of that Goldilocks zone. But because we've got all of these in a line, even if the habitable zone is here, there's gonna be a few planets in there. Even if the habitable zone is out here, there's gonna be a few planets in there. So it's like hedging our bets on all of these planets. Right? That's why Trappist 1 is very exciting to us. Um, it was, it was found by the Trappist system, which is this transitory planetary project in La Silla, Chile. Um, really quite small telescopes, to be honest, that are just doing this thing where they just stare at a bunch of stars and then try to do astromet- um, ph- photometry on them to figure out brightness.

• 59:31Krishna Choudhary?

  And, um, it found this thing, I think in like, um, 2016. And ever since, it's been, it's been, it's been a big part of the, um, exoplanet Research community. Research community. Um, so a bunch of planets have been found. As we've looked at it for longer and longer, we know that some of these inner planets do not have an atmosphere. Okay. Okay? Um, it makes sense because this solar system is extremely small. It's a condens- It's condensed. The, the star itself is an M dwarf. The, the classification of stars goes O B A F G K M. We are a G-type star, the sun. Yep. Um, M is all the way on the right-hand side of the Hertz-Brung-Russell diagram. It's tiny, it's red. It's tiny. Okay?

• 1:00:15Krishna Choudhary?

  Um, and so th- this entire planetary system is condensed in sta- inside of the orbit of Mercury. Oh, wow, wow. So the distance between our sun and Mercury. Yeah. All of these planets are in that- Are inside there, okay? Now, that's a good thing because if you've got a really dim star, you wanna be close to it in order to like, have liquid water and all this other kinda stuff. On the other hand, if you're that close to a star, the star's gonna act up. Right. Right? There's gonna be solar flares. Yep. It's gonna be random, like, it's gonna like, vomit. Yes. And then, and then you just get a giant dose of radiation. Right. Right? So that's probably why the, the inner planets don't have an atmosphere anymore. Because like, okay, like, you're too close to the star.

• 1:00:57Krishna Choudhary?

  Like, even, even though the star is like, small, it's still gonna be volatile. It's still gonna have all these like, little outbursts. And so, and so you're kinda screwed there. But the Trappist 1 E, which is, E is the planet. Yes. Now, this is- I believe the fourth planet that's out there. Um, that's something that is kind of earth-like.

• 1:01:16Lester Nare?

  Yes.

• 1:01:16Krishna Choudhary?

  Okay, it's about um ninety percent the radius of the earth, so about sixty percent the mass.

• 1:01:22Lester Nare?

  Yeah.

• 1:01:22Krishna Choudhary?

  Which means it's like, you know, if we're on there, we can like at least like hang out.

• 1:01:25Lester Nare?

  Yeah.

• 1:01:26Krishna Choudhary?

  Um, we'd we'd be jumping a little bit higher.

• 1:01:28Lester Nare?

  A little moon-like.

• 1:01:29Krishna Choudhary?

  Yeah, a little moon-like-ish, but it's it's not like something that is completely foreign to us.

• 1:01:34Lester Nare?

  Okay.

• 1:01:34Krishna Choudhary?

  Right? The moon, the moon is a sixth of earth's gravity. This is, you know, gonna be like sixty percent.

• 1:01:40Lester Nare?

  It's like, it's like a trampoline world.

• 1:01:41Krishna Choudhary?

  Yeah, yeah, and it's got an equilibrium temperature, they say, of about two hundred and fifty Kelvin. Okay, so it's a little bit out of the where the earth would be to get earth's um equilibrium temperature, which is what around like two eighty Kelvin? This is at two fifty Kelvin, which is what negative twenty degrees Celsius.

• 1:02:01Lester Nare?

  Okay.

• 1:02:01Krishna Choudhary?

  That's the equilibrium temperature. Now, the thing is, you can have, if you've got an atmosphere like Venus. You can have a massive greenhouse effect.

• 1:02:11Lester Nare?

  Okay.

• 1:02:12Krishna Choudhary?

  And then that greenhouse effect can keep

• 1:02:14Lester Nare?

  Heat.

• 1:02:15Krishna Choudhary?

  Heat.

• 1:02:15Lester Nare?

  In.

• 1:02:15Krishna Choudhary?

  In, and if you have a massive greenhouse effect, the pressure is also higher. So then you can have liquid water. Right? So there's a possibility that we could have liquid water on this thing. And we could have types of um habitable like qualities on this thing, right? So so trying to trying to figure this out is is uh is a big problem. Okay, the other cool thing about um all of these planets are because they're so close to the to their sun.

• 1:02:44Lester Nare?

  Yes.

• 1:02:44Krishna Choudhary?

  Right? Um, they're within the the within the orbit of mercury.

• 1:02:48Lester Nare?

  Yes.

• 1:02:48Krishna Choudhary?

  Right? They do this thing called tidal locking, which is something that the mercury does to the sun and something that the moon does to the earth.

• 1:02:54Lester Nare?

  Yes.

• 1:02:54Krishna Choudhary?

  Whenever we look at the moon, we see the same face of the moon.

• 1:02:57Lester Nare?

  Right.

• 1:02:58Krishna Choudhary?

  And that's because as it rotates, it's also rotating.

• 1:03:02Lester Nare?

  Yes.

• 1:03:02Krishna Choudhary?

  Itself.

• 1:03:03Lester Nare?

  Yes.

• 1:03:03Krishna Choudhary?

  Right? And the rate of rotation.

• 1:03:05Lester Nare?

  Match.

• 1:03:06Krishna Choudhary?

  Is matching the rate at which it rotates the earth.

• 1:03:08Lester Nare?

  Yeah.

• 1:03:09Krishna Choudhary?

  Right? The earth doesn't do that, right? The earth spins once every twenty four hours.

• 1:03:13Lester Nare?

  Yeah.

• 1:03:13Krishna Choudhary?

  Once a day.

• 1:03:14Lester Nare?

  Yeah.

• 1:03:14Krishna Choudhary?

  And then it takes three hundred sixty five days to go all the way around. That's why we have three hundred sixty five days. A day on the moon is also a year on the moon, if the earth is like kind of its center. You know what I mean?

• 1:03:25Lester Nare?

  I know.

• 1:03:25Krishna Choudhary?

  A day on mercury is also a year on mercury.

• 1:03:28Lester Nare?

  Yeah, yeah.

• 1:03:29Krishna Choudhary?

  Right?

• 1:03:29Lester Nare?

  Yeah.

• 1:03:30Krishna Choudhary?

  All of these planets, because they're so close to the sun, they also have this tidal locking, right? Which means they also always face their sun.

• 1:03:38Lester Nare?

  The, the, the point is there's one side of the rock is always in the sun.

• 1:03:43Krishna Choudhary?

  And the other side is always in the dark.

• 1:03:45Lester Nare?

  This is why when people say the dark side of the moon, we never see the dark side of the moon. The Chinese can, because they landed something.

• 1:03:51Krishna Choudhary?

  Cause they, yeah.

• 1:03:52Lester Nare?

  And they're over there and we don't know what they're doing and the national security state is freaking out about that.

• 1:03:56Krishna Choudhary?

  Freaking out, yeah.

• 1:03:57Lester Nare?

  But, but that, that's as, as like.

• 1:03:58Krishna Choudhary?

  But that's the idea.

• 1:03:59Lester Nare?

  That's the idea.

• 1:03:59Krishna Choudhary?

  That's the idea, yeah. So, like, you know, um, that actually causes some problems for like, cause the earth has this dynamic climate.

• 1:04:08Lester Nare?

  Mm-hmm.

• 1:04:08Krishna Choudhary?

  A lot of it is because we've got all parts of the, the, the earth getting some sunlight.

• 1:04:14Lester Nare?

  Mm-hmm.

• 1:04:14Krishna Choudhary?

  Right? Now imagine like you've got, you've got something like this. What kind of world would that be?

• 1:04:19Lester Nare?

  Right.

• 1:04:19Krishna Choudhary?

  Um, and I was reading about this. It's really cool. They call it the staring eyeball planet.

• 1:04:23Lester Nare?

  Okay.

• 1:04:24Krishna Choudhary?

  Okay? So what's happening is you've got one part of the, the, the planet looking at the sun, right?

• 1:04:29Lester Nare?

  Yes.

• 1:04:30Krishna Choudhary?

  If this thing is really cold.

• 1:04:31Lester Nare?

  Yeah.

• 1:04:31Krishna Choudhary?

  Then, okay, fine. The dark side is just gonna be frozen.

• 1:04:34Lester Nare?

  Yeah, yeah.

• 1:04:34Krishna Choudhary?

  But the part that's looking at the sun, there's gonna be a central part.

• 1:04:38Lester Nare?

  Yeah.

• 1:04:38Krishna Choudhary?

  That is sort of hot.

• 1:04:39Lester Nare?

  Yeah, yeah, yeah.

• 1:04:40Krishna Choudhary?

  And like maybe has liquid water, if it has water.

• 1:04:42Lester Nare?

  Yeah.

• 1:04:43Krishna Choudhary?

  And then as you go towards the, the outer parts, you're gonna have this, these, this middle region where it's like freezing.

• 1:04:49Lester Nare?

  Yeah, yeah, yeah.

• 1:04:49Krishna Choudhary?

  And so you're gonna have this eyeball.

• 1:04:50Lester Nare?

  Yeah, yeah, yeah.

• 1:04:51Krishna Choudhary?

  Staring at that sun the whole time, right? Where the central part that is, that is where the sun is always overhead all the time.

• 1:04:58Lester Nare?

  Yes.

• 1:04:58Krishna Choudhary?

  That's gonna be the part that's gonna be where.

• 1:05:00Lester Nare?

  Where you wanna look.

• 1:05:01Krishna Choudhary?

  There's gonna be this temperate zone, right? Where we would wanna live if we ever went there.

• 1:05:04Lester Nare?

  Yep.

• 1:05:05Krishna Choudhary?

  Um, which is kinda cool to think about, like a planet that looks like a staring eyeball.

• 1:05:09Lester Nare?

  Yeah, yeah.

• 1:05:09Krishna Choudhary?

  Um, anyways, so they're trying to find the atmosphere on this thing.

• 1:05:14Lester Nare?

  Right.

• 1:05:14Krishna Choudhary?

  Okay? So you wanna do the same thing that you did with the K two eighteen B.

• 1:05:18Lester Nare?

  Yes.

• 1:05:18Krishna Choudhary?

  Right? You wanna look at this thing. You wanna look at the star on its own. Then you wanna look at the, the planet transiting it. And you wanna see which wavelengths does the atmosphere, if it has one. Absorb.

• 1:05:29Lester Nare?

  Mm hmm.

• 1:05:29Krishna Choudhary?

  Okay, if it had no atmosphere, every single wavelength would be absorbed at exactly the same amount. And you would just have a flat line, no barcode, right?

• 1:05:38Lester Nare?

  Yep.

• 1:05:38Krishna Choudhary?

  No barcode, just um, flat absorption across the spectrum.

• 1:05:43Lester Nare?

  Right. Okay. To to take the bar, just to like really emphasize the barcode analogy, it would it would be like just having a barcode where all the bars are exactly the same. Like some barcodes like have a little like jigger pattern and this and that, but it would just be like no.

• 1:05:54Krishna Choudhary?

  It would just be black.

• 1:05:55Lester Nare?

  Yes, yeah.

• 1:05:55Krishna Choudhary?

  There would be no, no, no white, black markings, right?

• 1:05:59Lester Nare?

  Right.

• 1:05:59Krishna Choudhary?

  Yeah, so it would just, there would be no barcode.

• 1:06:01Lester Nare?

  That's the no atmosphere barcode.

• 1:06:02Krishna Choudhary?

  Yeah, that's the no atmosphere barcode, okay, so um, they they get data from four transits, because again, this thing, you know, twenty days.

• 1:06:10Lester Nare?

  Yeah.

• 1:06:10Krishna Choudhary?

  So quick, we're like, all right, let's just stare at it.

• 1:06:13Lester Nare?

  Right.

• 1:06:13Krishna Choudhary?

  Um, they they get this thing for um, four different transits. And what you want to do is you want to average them out, so that you get like higher signal to noise, right? You you um, and it was weird.

• 1:06:27Lester Nare?

  Okay.

• 1:06:28Krishna Choudhary?

  Because the first two times, the transits look way different than the next two times.

• 1:06:34Lester Nare?

  Hmm.

• 1:06:35Krishna Choudhary?

  Okay, and that's very strange.

• 1:06:37Lester Nare?

  It's, would it be especially strange, like because it's tidally locked? That would mean we would get, in theory, some more somewhat of consistency.

• 1:06:45Krishna Choudhary?

  Yeah, yeah, because you're getting that same slice, right?

• 1:06:47Lester Nare?

  Every time.

• 1:06:48Krishna Choudhary?

  Slice every time, and you're thinking that there's not a lot of circulation because this thing is so tidally locked, right? Um, there's not like the the thing isn't like revolving underneath where where there's like mixing and stuff going on.

• 1:06:59Lester Nare?

  Right.

• 1:06:59Krishna Choudhary?

  Um, so you would expect that the atmosphere, the atmospheric signature.

• 1:07:05Lester Nare?

  Right.

• 1:07:05Krishna Choudhary?

  Should be static.

• 1:07:06Lester Nare?

  Right.

• 1:07:07Krishna Choudhary?

  Okay, this is not, so what's happening here? And it turns out that the star itself is pretty volatile.

• 1:07:15Lester Nare?

  Okay.

• 1:07:15Krishna Choudhary?

  Okay, and so when it's, like if the star has, let's say, like a sunspot on it.

• 1:07:20Lester Nare?

  Yeah.

• 1:07:21Krishna Choudhary?

  At some point.

• 1:07:22Lester Nare?

  Yeah.

• 1:07:22Krishna Choudhary?

  And then I do a transit.

• 1:07:23Lester Nare?

  Yeah.

• 1:07:23Krishna Choudhary?

  Versus when the star is just like a normal star, doesn't have a flare, right?

• 1:07:28Lester Nare?

  Ah, yeah.

• 1:07:28Krishna Choudhary?

  Then you're gonna get these different, the the the initial background radiation.

• 1:07:33Lester Nare?

  Yeah, yeah.

• 1:07:33Krishna Choudhary?

  Has signatures.

• 1:07:34Lester Nare?

  Yes.

• 1:07:35Krishna Choudhary?

  That then are getting confounded by the thing in front.

• 1:07:38Lester Nare?

  Yep.

• 1:07:38Krishna Choudhary?

  Right, and that's why this thing required two papers.

• 1:07:42Lester Nare?

  I see.

• 1:07:42Krishna Choudhary?

  Okay, so the first paper, which is by Espinoza and the colleagues, um, that one was trying to mitigate something called stellar contamination.

• 1:07:53Lester Nare?

  Mm hmm.

• 1:07:53Krishna Choudhary?

  Okay, that's the idea of, okay, how do we model? The starlight.

• 1:07:57Lester Nare?

  Right.

• 1:07:58Krishna Choudhary?

  And try to get a clean spectrum out.

• 1:08:00Lester Nare?

  It's basically, we want to remove the, the star's radiation effects. Like, how do we get rid of that noise to get just the planet's atmospheric barcode?

• 1:08:10Krishna Choudhary?

  And so that was, um, the Espinoza paper.

• 1:08:13Lester Nare?

  Okay.

• 1:08:13Krishna Choudhary?

  Then there's the, uh, Glidden paper.

• 1:08:15Lester Nare?

  Yes.

• 1:08:16Krishna Choudhary?

  And that one does a detailed analysis of the spectrum that comes out of the Espinoza.

• 1:08:21Lester Nare?

  Uh, so, so, so, okay. So someone created a model to get rid of the radiation.

• 1:08:23Krishna Choudhary?

  There's a techniques paper.

• 1:08:24Lester Nare?

  Yeah, yeah.

• 1:08:25Krishna Choudhary?

  And then there's a, there's a paper about, okay, now that, now that the tech, cause the technique, like, already like the, you know, to do this.

• 1:08:32Lester Nare?

  Yeah.

• 1:08:33Krishna Choudhary?

  Required so much stuff that they're like, this needs to be its own thing.

• 1:08:36Lester Nare?

  Yeah.

• 1:08:37Krishna Choudhary?

  I need a first author on this. All right.

• 1:08:40Lester Nare?

  I love, I love research.

• 1:08:41Krishna Choudhary?

  Put, get, make me a minor author on the other one, but this one, I got a career to think about.

• 1:08:48Krishna Choudhary?

  So, but it's, it's a, it's a really cool, it's a really cool way of doing things. They, they did this, again, it's a probabilistic framework.

• 1:08:55Lester Nare?

  Right.

• 1:08:55Krishna Choudhary?

  They did this thing called, um, Gaussian processes. Okay. Which is basically like, it's a probabilistic solution where what you're doing is you're like varying all these functions on all the things that the stars could be. And like what you're seeing, and then you try to match. And then you try to get like a sort of single combined decontaminated transmission spectrum.

• 1:09:15Lester Nare?

  Right, right.

• 1:09:16Krishna Choudhary?

  Out, right, of that Trappist one E.

• 1:09:19Lester Nare?

  So the idea is we were originally just getting, uh, this like initial barcode that included the contamination.

• 1:09:25Krishna Choudhary?

  Yeah, from the star just doing weird stuff.

• 1:09:27Lester Nare?

  So now we have like a remixed barcode.

• 1:09:30Krishna Choudhary?

  Yeah, to try to get that static atmosphere out.

• 1:09:33Lester Nare?

  Just the atmosphere.

• 1:09:34Krishna Choudhary?

  Out of those four transits.

• 1:09:35Lester Nare?

  So it's, it's like, we wanted to, we wanted to, you know, it's like a rap song. It's like no features.

• 1:09:40Krishna Choudhary?

  Yeah.

• 1:09:40Lester Nare?

  This is J. Cole album.

• 1:09:41Krishna Choudhary?

  Yeah.

• 1:09:42Lester Nare?

  We just want J. Cole, no, no features.

• 1:09:44Krishna Choudhary?

  No features, exactly. But you're giving me this.

• 1:09:47Lester Nare?

  We got, we got Young Thug, we got Drake, we got all those other people here. I just want J. Cole.

• 1:09:52Krishna Choudhary?

  I just want J. Cole. So once they got J. Cole, then the J. Cole went to the Glidden team. And then they're the ones who are like, okay, this is what J. Cole's like.

• 1:09:59Lester Nare?

  Yeah, right, right, right, right, right, right. Okay, yep.

• 1:10:01Krishna Choudhary?

  Yeah. So, so the Glidden team then gets this atmosphere out, which is this decontaminated. Spectrum and from that they do some analysis. So again, they're gonna do the same thing where they have this atmosphere of Bayesian retrieval. Where they're gonna try and fit all these atmospheres. One of the other cool things they did was actually, uh, one of them is this model agnostic. So before even involving the model and like trying to fit like all these different models. They just did like a fundamental physics type of thing, which is like.

• 1:10:29Krishna Choudhary?

  Let's try to figure out how big the molecules are. Okay. In atomic units, atomic units are basically like one proton, one neutron. Okay. So like hydrogen would have a molecular weight of two. Because there's one proton, one proton, H two, right? Oxygen would have a molecular weight of thirty two. Because it's sixteen and sixteen, eight protons, eight neutrons, eight protons, eight neutrons to make the O two molecule. C O two would be even more, that would be thirty two plus um twelve, which is uh forty four, forty four, right? Um, so you, one can figure out the molecular weight. Yes. Of that atmosphere by modeling the height of the atmosphere, okay?

• 1:11:11Krishna Choudhary?

  Because if the dominant gas, let's say the dominant gas is of some molecular weight.

• 1:11:17Krishna Choudhary?

  The higher the molecular weight, the lower the atmosphere is gonna be. Because it's heavier. Right. Right? Um, also, we know the temperature, right? The, the higher the temperature, the higher the atmosphere is gonna be because there's gonna be more energy for it to go higher. Also, the, the higher gravity is, the lower the atmosphere is. But the gravity, we can kind of tell based on the density metrics to be like, okay, it's about, you know, sixty percent of earth. Um, temperature, we can tell based on um its distance. Yes. From the thing, so we can say it's two hundred fifty Kelvin. Yes. And then the height, we can tell by looking at the, the way that this transit works. Right, right, right. By the way that the transit works. Yes. And so now we can fit the molecular species.

• 1:11:59Krishna Choudhary?

  And they found that the, the lower bound on the mole- molecular weight is about nine molecular units. Okay. Crucially, that means it can't be hydrogen. Okay. And that's huge. Okay. Okay, if it's night, if it's not a hydrogen dominated atmosphere. That's a very good thing because that means you've got higher pressures. You've got potentially greenhouse effects going on, right? And you've already just from fundamental physics ruled out. That there's probably not hydrogen there. So it's not like one of these Jupiter's.

• 1:12:30Lester Nare?

  Yeah.

• 1:12:30Krishna Choudhary?

  Right? Jupiter is just like all hydrogen effectively.

• 1:12:33Lester Nare?

  Right, right.

• 1:12:33Krishna Choudhary?

  Like a bunch of helium.

• 1:12:35Lester Nare?

  That's so clever.

• 1:12:36Krishna Choudhary?

  It's a nice one, right?

• 1:12:37Lester Nare?

  No, that's.

• 1:12:38Krishna Choudhary?

  I thought it was cool.

• 1:12:39Lester Nare?

  No, that's really, and again, it's, it's sometimes, I, I, I just, I keep coming back to this point every time we talk about these, these experimental designs is like, sometimes it's just about reframing the problem set.

• 1:12:50Krishna Choudhary?

  Yeah.

• 1:12:51Lester Nare?

  Right? It's not necessarily that you need the new shiny thing.

• 1:12:54Krishna Choudhary?

  Yeah.

• 1:12:54Lester Nare?

  Sometimes you have the data and you just need to kind of come at it at a different.

• 1:12:58Krishna Choudhary?

  Yeah.

• 1:12:59Lester Nare?

  Entry point and then your follow-ons. Cause now, I know you're gonna continue. So now that we know that like, it, it, it creates a different context by which you're then analyzing all the other downstream.

• 1:13:09Krishna Choudhary?

  Yeah.

• 1:13:10Lester Nare?

  Steps in the process.

• 1:13:10Krishna Choudhary?

  Exactly, yeah. Yeah. So now you can, now you can start simulating atmospheres that don't have.

• 1:13:14Lester Nare?

  Right, which removes a whole.

• 1:13:17Krishna Choudhary?

  And so then you, so what they did was they simulated a bunch of atmospheres. What they're figuring out is, um, there's probably also not a, not a lot of CO2.

• 1:13:26Lester Nare?

  Okay.

• 1:13:27Krishna Choudhary?

  Okay. Um, which means that it's not like Mars or Venus. Venus and Mars are basically all CO2. So this one's not like Venus or Mars. They say, at this point, what they're saying is it's either it's got no atmosphere and we're seeing just noise. Or it's got an atmosphere, not hydrogen, not CO2, but perhaps a lot of nitrogen, kinda like the earth. Also kinda like Titan.

• 1:13:54Lester Nare?

  Right.

• 1:13:55Krishna Choudhary?

  And it's got signatures of a lot of methane. We don't see a lot of oxygen, I don't think.

• 1:13:58Lester Nare?

  Okay.

• 1:13:59Krishna Choudhary?

  Okay? Um, so there's no like photosynthesis going on, which kinda makes sense. I mean, the star is.

• 1:14:04Lester Nare?

  Yeah.

• 1:14:04Krishna Choudhary?

  So dim.

• 1:14:05Lester Nare?

  Yeah, yeah, yeah, yeah.

• 1:14:06Krishna Choudhary?

  Um.

• 1:14:06Lester Nare?

  It's not a big enough power source.

• 1:14:07Krishna Choudhary?

  Yeah, yeah. I mean, if, if, if, if it was doing photosynthesis, perhaps it's doing a much different kind of photosynthesis. Because the spectrum of the star is so different from the sun's, right?

• 1:14:15Lester Nare?

  Sure.

• 1:14:15Krishna Choudhary?

  Um, but nitrogen and methane, which is kinda like Titan, which is very exciting because Titan is also a candidate for, you know, potential life.

• 1:14:25Lester Nare?

  Tantalizing signs.

• 1:14:27Krishna Choudhary?

  Tantalizing signs, right? And so it also gives credence to like perhaps studying Titan a bit more, right? To see if. If if worlds like Titan are very common in the galaxy, then studying Titan more is gonna give us more clues into how this would work.

• 1:14:44Lester Nare?

  Right.

• 1:14:45Krishna Choudhary?

  Right?

• 1:14:45Lester Nare?

  Um. And Titan's closer. The point is, if it's closer, we can do more there. And then we can extrapolate what we learned from that to them farther.

• 1:14:52Krishna Choudhary?

  Exactly, yeah, yeah. And so tha- that's the that's the whole idea. I mean, they're they're looking forward to more transits in the future.

• 1:14:59Lester Nare?

  Mm hmm.

• 1:14:59Krishna Choudhary?

  And um, actually, what they're gonna do that's kind of really cool is they're gonna see what a transit on the B planet looks like.

• 1:15:07Lester Nare?

  Mm hmm.

• 1:15:07Krishna Choudhary?

  Because the B planet doesn't have any atmosphere. We know that for sure, right? And so then i- i- if if we can figure out what what a transit for B looks like and just like get a bunch of that data, then we can model the star transiting a bare rock.

• 1:15:22Lester Nare?

  Mm hmm.

• 1:15:23Krishna Choudhary?

  Really well.

• 1:15:23Lester Nare?

  Mm hmm.

• 1:15:24Krishna Choudhary?

  And then we can have an even better idea on what the transit on the E planet would look like, right? And then and then we get better data, better signal to noise, better model fitting.

• 1:15:34Lester Nare?

  Mm hmm.

• 1:15:35Krishna Choudhary?

  Higher confidence on whatever's out there.

• 1:15:38Lester Nare?

  Ah, I love, we need to do Alien Week like Shark Week.

• 1:15:42Krishna Choudhary?

  Yeah.

• 1:15:42Lester Nare?

  Yeah.

• 1:15:43Krishna Choudhary?

  Um. Every once in a while, whenever there's something cool, like we gotta do it.

• 1:15:46Lester Nare?

  I mean, that literally.

• 1:15:47Krishna Choudhary?

  This one was cool, right? Mars was, the Mars story is very cool.

• 1:15:49Lester Nare?

  This week, we had not only this hint of atmosphere on Earth-sized exoplanets, which came out two days ago on September eighth. We also had the NASA announcement, totally separate.

• 1:16:00Krishna Choudhary?

  Yeah.

• 1:16:00Lester Nare?

  Totally different context for for Mars.

• 1:16:03Krishna Choudhary?

  Um, and all four stories are um, American.

• 1:16:08Lester Nare?

  Yeah, look.

• 1:16:08Krishna Choudhary?

  Right?

• 1:16:09Lester Nare?

  Look, you can't avoid us.

• 1:16:09Krishna Choudhary?

  You can't avoid us, right? The Mars story is is obviously the Perseverance Rover and JPL and then the other three papers.

• 1:16:18Lester Nare?

  Yep.

• 1:16:18Krishna Choudhary?

  All James Webb, baby.

• 1:16:19Lester Nare?

  Webb, which again, you know, this is why we need to continue to fund science. If you want aliens.

• 1:16:27Lester Nare?

  We have to fund.

• 1:16:28Krishna Choudhary?

  Yeah.

• 1:16:29Lester Nare?

  The fundamental reason.

• 1:16:29Krishna Choudhary?

  Yeah, even if the aliens are looking at us, right? And and we give up on science.

• 1:16:34Lester Nare?

  Yeah, they're gonna be like, ah.

• 1:16:35Krishna Choudhary?

  They're gonna be like, ah, man, they almost had us.

• 1:16:38Lester Nare?

  Almost had us. Almost had us. And so to do a real quick, quick recap, we started off with the massive breaking news of strongest, strongest evidence yet of biosignatures on Mars, announced by NASA, huge press conference, all the things. We then compared that to the April story in the BBC out of Cambridge, uh, which had follow on papers from Oxford, University of Arizona, University of Chicago. Um, and lastly, the Caltech, UCLA combo about strongest evidence yet of life on a distant planet, which we under we sort of broke down why they've now pivoted to saying, maybe it's a water world.

• 1:17:16Krishna Choudhary?

  Yeah.

• 1:17:16Lester Nare?

  And we ended with another follow up on how we are trying to understand the atmospheres on exoplanets, which is on the path to basically being able to identify what targets really makes sense for us to look for life. Um, very informative, very clarifying.

• 1:17:35Lester Nare?

  I I just.

• 1:17:37Lester Nare?

  I I I wish we got this kind of clarity in the articles.

• 1:17:44Krishna Choudhary?

  Yeah.

• 1:17:44Lester Nare?

  That most people read.

• 1:17:45Krishna Choudhary?

  Yeah.

• 1:17:46Lester Nare?

  So if you are watching this and this was super helpful, please share it with your friends.

• 1:17:50Krishna Choudhary?

  Yes, please do.

• 1:17:51Lester Nare?

  Be interested in this subject because again, like understanding, like, what are we actually saying?

• 1:17:56Krishna Choudhary?

  Yeah.

• 1:17:56Lester Nare?

  When we say, what is the evidence?

• 1:17:58Krishna Choudhary?

  Yeah.

• 1:17:59Lester Nare?

  What is a biosignature?

• 1:17:59Krishna Choudhary?

  Not that hard to understand.

• 1:18:01Lester Nare?

  No, it's not.

• 1:18:01Krishna Choudhary?

  It's like, if if you like, go through it and, you know, like, just go through step by step. It's like, okay, this is the data that we collected. This is why we think that data says what we think it says.

• 1:18:14Lester Nare?

  Right.

• 1:18:14Krishna Choudhary?

  Right? And these are the limitations. These are what we can do next. It's like, no, it's not that crazy difficult to understand the logical steps required to conclude.

• 1:18:24Lester Nare?

  To conclude, to get to get to the conclusion.

• 1:18:26Krishna Choudhary?

  Yeah.

• 1:18:26Lester Nare?

  Um, we're looking for five sigma significance plus.

• 1:18:30Krishna Choudhary?

  Yeah.

• 1:18:31Lester Nare?

  Um, and I'll just do a quick. Uh, housekeeping, uh, the just response has been unbelievable to the show. Yeah. We really appreciate everyone. If you've watched all the way to this part of the show, that means you're a true fan. We really appreciate you. We have, we are literally one of the fastest growing science podcasts on the planet. Yeah, it's unbelievable. It's unbelievable. It's, it's gone global. Um, just continue to add your comments, add your questions, add your clarifications. You can always find all of our episodes anywhere you like to listen to your podcasts on YouTube, Spotify, Apple. We post clips all over our socials on Instagram and Tik Tok and Facebook and X. So you can find us where you want to.

• 1:19:14Lester Nare?

  I, as always, am your host, Lester Nare, joined as always by one of the smartest people I know, our co-host and resident PhD, Krishna Choudhary. This is from First Principles, an amazing emergency pod. Uh, we'll be back next week for regularly scheduled programming. Appreciate you guys. Peace.