YouSaid · the spoken record

David Kipping

lines on the record: 252
first: 2023-01-28
most recent: 2023-01-28
sittings or episodes: 1
sources: podcast

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“You may be forced to live there forever. There may be no escape unless you invent a space elevator or something. But then how do you even build the infrastructure in space to do something like that in the absence of a successful rocket program? And so the more and more we look at our Earth and think about the sorts of problems we're facing. The more you see things about the earth which make it ideally suited in so many regards, it's almost spooky, right? That we not only”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“Yeah, I mean, they're so close to each other, that helps. And I think the most critical factor would be how massive is the planet. That's always, I mean, one of the challenges with escaping planets, there was a fun paper one of my colleagues wrote that suggested that super Earth planets may be inescapable. If you're a civilization that were born on a super-Earth, the surface gravity is so high that the chemical potential energy of hydrogen or methane, whatever fuel you're using simply is at odds with the gravity of the planet itself. And so you would, you know, our current rockets, I'm not sure with a fraction, but maybe like 90% of the rocket is fuel or something by mass, these things would have to be like the size of the Guy's pyramids of fuel with just a tiny tip on the top in order just to escape their patchetary atmosphere. And so it has been argued that if you live on a super earth,”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“I would think that the force would be fairly similar because the shape of the object would deform to a flat geopotential, essentially, uniform geopotential, but it would lead to a distorted shape for the two objects. I think they would become ellipsoids facing one another. So it would be pretty wild when you, you know, people like flat earth or spherical earth, you fly from space and you see a football-shaped earth as your own planet.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“Was our focus how do you get around this merging problem? So whether they're out there or not, we don't know. We're planning to do a search for them. But it remains an open question. And I think just one of those fun astrophysics curiosities questions where the binary planets exist in the universe. Because then you have binary Earths, you could have binary Neptune, all sorts of wild stuff that would float the sci-fi imagination.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“And so that seems at odds with naively the exoplanet catalogue for which we know so far no binoplanets. And we propose one of the resolutions to this might be that the binary planets are just incredibly difficult to detect, which is also counterintuitive because remember how they form us through this tidal mechanism. And so they form extremely close to each other, sort of the distance that Io is away from Jupiter just a few planetary radii. They're almost touching one another and they're just tidally locked facing each other for eternity. And so in that configuration, as it transits across the star, it kind of looks like you can't really resolve this two planets. It just looks like one planet to you that's going across the star. The temporal resolution of the data is rarely good enough to distinguish that. And so you'd see one transit, but in fact it's two planets very close together, which are transiting at once. And so, yeah, we wrote a paper just recently where we developed some techniques to try and get around this problem.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“So, the formation mechanism proposed here, because it is very difficult to form two protoplanets close to each other like this. They were generally merged within the disk, and so that's why you normally get single planets. But you could have something like Jupiter and Saturn form at separate distances. They could dynamically be scattered in towards one another and basically not quite collide, but have a very close-on encounter. Now, because tidal forces increase dramatically as the distance decreases between two objects, the tides can actually dissipate the kinetic energy and bring them bound into one another. So that seemed when we first hear that, you think, well, that seems fairly contrived that you'd have the conditions just right to get these tides to cause a capture. But numerical simulations have shown that about 10% of planet, planet encounters are shown to produce something like binaries, which is a startling prediction.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“Whereas maybe they form there, but they don't last. They are dynamically unstable in that zone. But once you get out to about the distance that the Earth orbits the Sun or even a little bit closer in, you start to find planets emerging. And so that's the right distance for liquid water, so a distance for potentially life on those plants. And so there may very well be plenty of habitual plants around the binary stars. Binary plants is a little bit different. Binary plants, I don't think we have any serious connection of plant binarity to habitability. Certainly when we investigated it, that wasn't our drive, that this is somehow the solution to life in the universe or anything. It was really just, like all good science questions, curiosity driven question.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“It depends what we're talking about the stars of the planet. Certainly, if stars couple up, that has a big influence on the habitability. Of course, this is very famous from Star Wars Tatooine in Star Wars as a binary star system, and you have Luke Skywalker looking at the sunset and seeing two stars come down. And for years, we thought that was purely a product of George Lucas's incredibly creative mind. And we didn't think that planets would exist around binary star systems. It seems like too tumultuous an environment for a quiescent planetary disk circumstellar disk to form planets from. And yet one of the astounding discoveries from Kepler was that these appear to be quite common. In fact, as far as we can tell, they're just as common around binary stars as single stars. The only caveat to that is that you don't get plants close into binary stars. They have like a clearance region on the inside.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“It's not a complete freak of the universe to be alone, but it is more common for some like stars if you catch up all the sunlight stars in the universe, about half of the Sonic star systems are in binary or trinary systems, and the other half are single. But because those binaries are two or three stars, then cumulatively maybe like a third of all Sonic stars are single.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“The thing that's interesting about binary objects is that they're very common in the universe. Binary stars are everywhere. But the majority of stars seem to live in binary systems. When we look at the outer edges of the solar system, we see binary Kuiper belt objects all the time, asteroids basically bound to one another. Pluto-Sharon is It almost is by many definitions a binary planet, but now it's a dwarf planet. We can call that now, but we know that the universe likes to make things in pairs.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“Which without a plate tectonics may not have been possible, would have had a stagnant lid because it was just too much lithosphere stuck on the top of the planet. And so there are speculative reasons, but intriguing reasons as to why a large moon may be not just important, but central to the question of having the conditions necessary for life. So moons can be habitable in their own right, but they can also play a significant influence on the habitability of the planets they orbit and further they will surely interfere with our attempts to detect life remotely from afar.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“All along you were tricked. It was just a moon that was deceiving you. And so we are never going to, I would claim, really understand or complete this quest of looking for life biosignatures in the universe unless we have a deep knowledge of the prevalence and role that moons have. They may even affect the habitability of the planets themselves. Of course, I reign moon freakishly large by mass ratio, it's the largest moon in the solar system. It's a 1% mass moon. If you look at Jupiter's moons, they're like 10 to the power minus 4, much smaller. And so I wrote moon seems to stabilize the obliquity of our planet. It gives rise to tides, especially early on when the moon was closer, those tides would have covered entire continents. And those rock pools that would have been scattered across the entire plateau may have been the origin of life on our planet. The moon-forming impact may have stripped a significant fraction of lithosphere off the earth.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“So you see two molecules that just shouldn't be there. They normally react with each other. Or even one molecule that's just too reactive to be hanging around the atmosphere by itself. So if you had oxygen and methane hanging out together, those would normally react fairly easily. And so if you detected those two molecules in your pale blue dot spectra, you'd be like, okay, we have evidence for life. Some things metabolizing on this planet. However, the challenge is what if that moon was Titan? Titan has a methane-rich atmosphere and what if the pale blue dot was in fact a plant devoid of life, but it had oxygen because of water undergoing this photolysis reaction splitting into oxygen, hydrogen separately. So then you have all of the hallmarks of what we would claim to be life.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“Just know where to look. I mean, we would like to know where should we listen for technosignatures, where should we be looking for biosignatures? And not only that, but what role does the moon have in terms of its influence on the planet? We talked about these directly imaged telescopes earlier, these missions that want to take a photo, to quote Carl Sagan, the pale blue dart of our planet, but the pale blue dot of an exoplanet. And that's the dream to one day capture that. But as impressive as the resolution is that we are planning and conspiring to design for the future generation telescopes to achieve that, even those telescopes will not have the capability of resolving the Earth and the Moon within that. It'll be a pale blue dot pixel, but the moon's gray grayness will be intermixed with that pixel. And so this is a big problem because one of the ways that we are claiming to look for life in the universe is a chemical desequilibrium.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“To 10% outcome. So it's not particularly inevitable that that happens. But we do often see about half of all sunlight stars have either a mini-Neptune, a Neptune or a Jupiter inhabitone of their stars. That's a very, very common occurrence that we see. Yet we have no idea how often they have moons around them, which could also be habitable. And so there may very well be if even one in five of them has an earth-like moon or even a Mars-like moon around them, then there would be more habitable real estate in terms of exomoons than exoplanets in the universe.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“Agree You'd have to convince me. I NASA has been on this quest for a long time, and it's sometimes called EaterEarth. It's the frequency of Earth-like, usually they say planets in the universe. How common are planets similar to our Earth in terms of, ultimately we'd like to know everything about these plants in terms of the amount of water they have, how much atmosphere they have. But for now, it's kind of focused just on the size and the distance from the star, essentially. How often do you get similar conditions to that? That was Kepler's primary mission. really just kind of flirted with the answer, didn't quite get to a definitive answer. But I always say, look, if we're looking, if that's our primary goal to look for earth-like, I would say worlds, then moons has to be a part of that because we know that Earth-like from the Kepler data, the preliminary result is that Earth-like planets around sun-like stars is not an inevitable outcome. It seems to be something like a one.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“You know, most of the time the plant has an atmosphere already. And so there's almost a guaranteed success that you're going to learn something about the atmosphere by pointing Joduist T at it. Whereas in our case, there's a harder cell. We are looking for something that we do not know for sure exists yet or not. And so we are pushing the telescope to do something which is inherently more risky.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“The temperature of those atmospheres. So that's very exciting. But we are competing with that. And I think that's. We have a completely different objective, which is, in our case, to try and look for the first evidence of these small moons around these planets, potentially even moons which could be habitable, of course. So I think it's a very exciting goal. But attack has to make a human judgment essentially about which science are they most excited by which one has the highest promise of return, the most highest chance of return. And so that's hard because if you look at a planetary atmosphere,”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“Attacks are not machines, they're not a piece of computer code. They will make their selections based off human judgment. And a lot of the telescope, certainly within the field of exoplanets, because there's different fields of astronomy, but within the field of exoplanets, I think a good expectation is that most of the telescope time that JPC have will go towards atmospheric retrieval, which is sort of alluded to earlier, you know, like detecting molecules in the atmospheres, not by a signatures because as I said, it's really not designed to do that. It's pushing jiduis T probably too far to expect it to do that. But it could detect, for example, a carbon dioxide-rich atmosphere on TRAPIS 1E. That's not a biosignature, but you could prove it's like a Venus in that case, or maybe like a Mars in that case. Both those have carbon dioxide-rich atmospheres doesn't prove or disprove the existence of life either way, but it is our first characterization of the nature of those atmospheres. Maybe we can even tell the pressure level.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“Lots of moons are fairly similar size, sort of 30% the size of the Earth. And this telescope is the first one that can find them. And so we're very excited about the profound implications of ultimately solving this journey we're on in astronomy, which is to understand our uniqueness. We want to understand how common is the solar system. Are we the architecture that frequently emerges naturally? Or is there something special about what happened here?”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“Because they transit so frequently, there's maybe a hundred opportunities. And so then the tat can say, okay, they want 10 transits, there's 100 opportunities here. It's easier for us to give them time. We're almost in the worst case scenario. We're proposing to look for examines around two cool planets. And so we really only have one bite of the cherry for each one. And so our sales pitch has been that these are extremely precious events. And more importantly, JWST is the only telescope, the only machine humanity has ever constructed, which is capable of finding moons akin to the moons in our solar system. Kepler can't do it, even Hubble can't do it. Judiciary is the first one. And so there is a new window to the universe because we know these moons exist. They're all over the place in the solar system. You have the moon, you have Io, Callisto, Europa, Ganymede, Titan.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“Yeah, it's hard. And there were certain programs like doing a deep field study where you just more or less point the telescope. And that's pretty open. I mean, you're just accumulating photons. You can just point at that patch of the sky whenever the telescope is not doing anything else and just get to your month, let's say a month of integration time is your goal over the lifetime at JWST. So that's maybe a little bit easier to schedule. It's harder, especially for us looking at cool worlds because as I said earlier, these plants transit very infrequently. So we have to wait if you're looking at the earth transiting the sun, an alien watching us, they would only get one opportunity per year to do that observation. The transit lasts for about 12 hours. And so if they don't get that time, it's hard. That's it. If it conflicted with another proposal that wants to use another time critical element, it's much easier for planets like these hot plants or these close implants.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“Because that's already super than the first cycle. So the first cycle of James Webb was about six to And this will probably be more like 20 to 1, I would expect”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“It's a really difficult process. I don't envy the tech that are going to have to make this decision. We call it the tack the time allocation committee that make this decision. And I've served on these before, and it's very difficult. I mean, typically for Hubble, we were seeing at least 10, sometimes 20 times the number of proposals for telescope time versus available telescope time. Virginuist, there has been one call already that has gone out. We call it cycle one, and that was oversubscribed by, I think something like six to one, seven to one. And the cycle two, which is just been announced fairly recently, and the deadline is actually the end of this month. So my team totally laser focused on running our proposals right now. That is expected to be much more competitive, probably more comparable to what Hubble saw. And so it's hard.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“About sort of four years of staring at the same star with one telescope, there'd be some breaks, but it'd be hard to schedule much else because you'll have to continuously catch each one of these transits to build up your signal to noise. And so TRC is never going to do that. In principle, technically, JWST could technically have the capability of just about detecting a biosignature on an earth-like planet around a non-sun-like star, but still, impressively, have basically the technology to do that, but we simply cannot dedicate all of its time practically to that one resource. And so Starship opens up opportunities like that of mass producing these kinds of telescopes, which will allow us to survey for life in the universe, which of course is one of the grand goals of astronomy.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“Star formation astronomers, those of us studying exoplanets, those of us wanting to study the ultra-deep fields and the origin of the first galaxies, the expansionary of the universe, everyone has to share this resource, but we could potentially each have one JWST each that is maybe just studying a handful of the brightest exoplanet stars and measuring their atmospheres. This is important because if you talked about this planet Trapez 1E earlier, that planet, if GDPC stared at it and tried to look for biosignatures, by which I mean oxygen, nitrous oxide, methane, it would take it of order of 200 transits to get even a very marginal, what we'd call two and a half sigma detection of those, which basically nobody would believe with that. And 100 transits, I mean, this thing transits once every six days.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“At least comparatively compared to JBST. And very large mirrors into space, you can more or less repurpose ground-based mirrors. The Hubble Space Telescope mirror and the JBST mirrors are designed to be extremely lightweight, and that increase their costs significantly. They have these kind of honeycomb design on the back to try and minimize the weight. If you don't really care about weight because it's so cheap, then you could just literally grab many of the existing ground-based mirrors across tusks across the world, four meter, five meter mirrors, and just pretty much attach them to a chassis and have your own space-based telescope. I think the breakthrough foundation, for instance, is an entity that has been interested in doing this sort of thing. And so that raises the prospects of having not just one JWST that just, you know, JBST is a fantastic resource, but it's split between all of us. Cosmology.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“There's two things. I mean, it's the launch cast itself, which is hopefully going to mean per kilogram it's going to dramatically reduce the cost of the level, even if it's a factor of 10 higher than what Elon originally promised, this is going to be a revolution for the cost to launch. That means you could do all sorts of things. You could launch large telescopes which could be basically like JWST, but you don't even have to fold them up. JWST had this whole issue with its design that it's six and a half meters across. And so you have to, there's no fuselage which is that large at the time Aries 4 wasn't large enough for that. And so they had to fold it up into this kind of complicated origami. And so a large part of the cost was figuring out how to fold it up, testing that it unfolded correctly, repeated testing. And, you know, there was something like 130 fail points or something during this unfolding mechanism. And so all of us were holding our breath during that process. But if you have the ability to just launch arbitrarily large mass.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“Human controlling that descent. And so you have to put all of your faith and your trust in the computer code or the AI or whatever it is that you've put on board that thing to make the correct descent. And so there's this famous period course seven minutes of hell where you're basically waiting for that light travel time to come back to know whether your vehicle successfully landed on the surface or not. And during that period you know in your mind simultaneously that it is doing these multi-stages of deploying its parachute, deploying the crane, activating its jets to come down and controlling its descent to the surface. And then the crane has to fly away so it doesn't accidentally hit the rover. And so there's a series of multi-stage points where any of them go wrong, the whole mission could go awry. And so the fact that we are fairly consistently able to build these.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“Yeah, I mean, Kursty has been leaving these little pods on the surface quite recently. There's some neat photos you can find online. And they kind of look like lightsaber hilts. So to me, I think I tweeted something like, you know, this weapon is your life. Like, don't lose a curiosity because it's just dumping these little vials everywhere. And it is scooping up these things. And the intention is that in the future, there will be a sample return mission that will come and pick these up. But it's, I mean, the engineer behind those things is so impressive. The thing that blows me away the most has been the landings, especially I'm trying to be a pilot at the moment. So that's the sort of, you know, watching landings has become like my pet hobby on YouTube at the moment and how not to do it, how to do it with different levels of conditions and things. But with the, you know, when you think about landing on Mars, just the light travel time effect means that there's no possibility of...”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“Possibly. I mean, I'm sure that some people would be concerned about that. I think we would hopefully have some containment procedures if we did sample return. Or you mean you don't even really need a sample return. These days you can pretty much send it like a little micro laboratory to the planet to do all the experiments in situ and then just send them back to your planet, the data. And so I don't think it's necessary, especially for a case like that where you might have contamination concerns that you have to bring samples back. Although probably if you brought back Europen sushi, it would probably sell for quite a bit with the billionaires in New York City.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“I mean, we always worry about a space virus coming here or some kind of external source. And we would be the source of that potential contamination.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“As well, and now we're sort of accelerating that process to some degree. And so if you dig into Europa's surface, which probably is completely pristine, it's very unlikely there has been much exchange with the outside world for its subsurface ocean. You are for the first time potentially introducing bacterial spores into that environment that may compete or may introduce spurious signatures for the life you're looking for. And so it's almost an ethical question as to how to proceed with looking for life on this subsurface oceans. And I don't think we've really have a good resolution for at this point.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“Feasible ish with you know, especially with something like Starship that could launch a huge digger basically to the surface and you could just excavate away at the surface. But for something like Europa, we really are still unclear about how thick the ice layer is, how you would melt through that huge thick layer to get to the ocean. And then potentially also discussions about contamination. The problem with looking for life in the solar system, which is different from looking for life with exoplanets, is that you always run the risk of, especially if you visit there, of introducing the life yourself. It's very difficult to completely exterminate every single microbe and spore on the surface of your rover or the surface of your lander. And so there's always a risk of introducing something. I mean, to some extent, there is continuous exchange of material between these plants. Naturally, on top of that,”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“Dead or a living. Right. And so, yeah, maybe it's easier than Venus because certainly you can imagine just a balloon floating through the atmosphere or a drone or something that would have the capability of just scooping up and sampling. To dig into the surface of Mars is maybe...”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“Reinvigorated about the prospects of going back to Venus and doing another mission there. In fact, there's now two NASA missions, Veritas and Da Vinci, which are going to be going back and before 2030 or the 2030s. And then we have a European mission, I think, that's slated now and even a Chinese mission might be coming along the way as well. So it might have multiple missions going to Venus, which has long been overlooked. I mean, apart from the Soviets, there really has been very little in the way of exploration of Venus, certainly as compared to Mars. Mars has enjoyed most of the activity from NASA's rovers and surveys. And Mars is certainly fascinating. There's this signature of methane that has been seen there before. Again, the discussion is whether that methane is a product of biology, which is possible, certainly that happens on the Earth, or whether it's some geological process that we are yet to fully understand could be”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“Yeah, I mean, how much do we believe the detection in the first place? If you do believe it, does that necessarily mean there's life there? And what gives, how can you have life in the Venus' atmosphere in the first place? Because it's been seen as like a hellhole place for imagining life. But I guess the counter to that has been that, okay, yes, the surface is a horrendous place to imagine life thriving. But as you go up in altitude, the very dense atmosphere means that there is a cloud layer where the temperature and the pressure become actually fairly similar to the surface of the earth. And so it may be there are microbes stirring around in the clouds which are producing phosphine. At the moment, this is fascinating. It's got a lot of us”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“The judge and jury are still out on that. There was a very provocative claim and signature of a phosphine-like spectral absorption. But it could have also have been some of the molecule in particular, sulfur dioxide, which is not a biosignature.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“Which then oxidizes the surface. And so there could be a residual oxygen signature just due to this photolysis process. So we've been trying to generalize. And certainly in recent years there's been other suggestions things we could look for in the solar system beyond nitrous oxide, basically laughing gas is a product of microbes. That's something that we're starting to get more interested in looking for. Methane gas in combination with other gases can be an important biosignature. phosphine as well and phosphine is particularly relevant to the solar system because there was a lot of interest for Venus recently. You may have heard that there was a claim of a biosignature in Venus' atmosphere. I think it was like two years ago now.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“Oxidize things and so within about a million years you would probably lose all the oxygen on planet Earth. So that was conventionally how we thought we could look for life. And then we started to realize that it's not so simple because either might be other things that life does apart from photosynthesis. Certainly the vast majority of Earth's history had no oxygen and yet there was living things on it so that doesn't seem like a complete test. And secondly could there be other things that produce oxygen besides from life a growing concern has been these false positives in biosignature work. And so one example of that would be photolysis that happens in the atmosphere when ultraviolet right hits the upper atmosphere. It can break up water vapor. The hydrogen splits off to the oxygen. The hydrogen is much lighter atomic species and so it can actually escape certainly planets like the earth's gravity. That's why we don't have any hydrogen or very little helium. And so that leaves you with the oxygen.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“When we look for life, it's hard to define even what life is, but we can maybe do a better job in defining the sorts of things that life does. And that provides some aspects, some avenue for looking for them. In the classically, conventionally, I think we thought the way to look for life was to look for oxygen. Oxygen is a byproduct of photosynthesis on this planet. We didn't always have it. Certainly if you go back to the Archean period, there was, you know, you have this period called the Great Oxidation Event where the Earth floods with oxygen for the first time and starts to saturate the oceans and then the atmosphere. And so that oxygen, if we detect it on another planet, whether it be Mars, Venus, or an exoplanet, whatever it is, that was long thought to be evidence for something doing photosynthesis. Because if you took away all the plant life on the Earth, the oxygen wouldn't just hang around here as a highly reactive molecule.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“years or more to calm down. And during that period, they're producing huge amounts of x-rays, ultraviolet radiation that could potentially rip off the entire atmosphere. It may desiccate the plants in the system. And so even if water arrived by comets or something, it may have lost all that water due to this prolonged period of high activity. So we have lots of open-ended questions about these M dwarf planets, but they are the most accessible. And so In the near term, if we detect anything in terms of biosignatures, it's going to be for one of these red dwarf stars. It's not going to be a true Earth twin, as we would recognize it as having a”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“And those are quite easily detectable, not with a space-based telescope, but even from the ground. And that's just because the star is so much smaller that the relative increase or decrease in brightness is enhanced significantly because that's smaller size. So Trap is 1E. It's a planet which is in the right distance for liquid water. It has a slightly smaller size than the Earth. It's about 90% the size of the Earth, about 80% the mass. And it's one of the top targets right now for potentially having life. And yet it raises many questions about what would that environment be like. This is a star which is one eighth the mass. It's stars like that take a long time to come off that adolescence. When stars first form like the sun, it takes them maybe 10, 100 million years to sort of settle in to that main sequence lifetime. But for stars like these late M dwarfs as we call them, they can take up to a billion”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“Yeah. I mean, it depends on the type of style we're talking about. If it is a star truly like the sun, the dip that causes is 84 parts per million. I mean, that's just, it's like the same as like a firefly flying in front of like a giant floodlight at a stadium or something. That's the kind of the brightness contrast that you're trying to compare to. So it's extremely difficult detection. In the very, very best cases we can get down to that. But as I said, we don't really have any true Earth analogs that have been in the exoplanet candidate yet. Unless you relax that definition, you say it's not just doesn't have to be a star just like the sun. It could be a star that's smaller than the sun. It could be these orange dwarfs or even the red dwarf stars. And the fact those stars are smaller means that for the same size planet passing in front of it, more light is blocked out. And so a very exciting system, for example, is Trappis 1, which has seven plants, which are smaller than the Earth.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“And so, all you can do is see where that one pixel, which contains potentially dozens of planets and the star, maybe even multiple stars, dims for a short amount of time.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“Very exciting, distinct way of detecting planets. But it, as you can imagine, is going to be far easier to detect planets, which are really far away from their star to do that, because that's going to make that separation really big. And then you also want the star to be really close to us, so the nearest stars. Not only that, but you would prefer that planet to be really hot. Because the hotter it is, the brighter it is. And so that tends to bias direct imaging towards planets which are in the process of forming. So things which have just formed the planet still got all of its primordial heat embedded within it and its glowing, we can see those quite easily. But for the planets, more like the Earth, of course, they've cooled down. And so we can't see that the light is pitiful compared to a newly formed planet. We would like to get there with direct imaging. That's the dream is to have the pale blue dart, an actual photograph of it, maybe even just a one pixel photograph of it. But for now, the entire solar system is one pixel, certainly with the transit method most of the time.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“Writing your description. I think just to build upon that a little bit more, it might be almost like your vision is completely blurry. Like you have an extreme eye prescription. And so you can't resolve anything. Everything's just blurs, but you can tell that something was there because it just got fainter for a short amount of time. Someone passed in front of a light. And so that light in your eyes would just dim for a short moment. Now, the reason we have that problem with blowness or resolution is just because the stars are so far away. I mean, these are the closest stars are four light years away, but most of the stars kept are looked at with thousands of light years away. And so there's absolutely no chance that the telescope can physically resolve the star or even the separation between the planet and the star is too small, especially for a telescope like Kepler. It's only a meter across. In principle, you can make those detections, but you need a different kind of telescope. We call that direct imaging. And direct imaging is a very”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“Transits you see, the easier it is to detect it because you build up signal to noise. If you see the same thing tic tick, tick tit to take, the more ticks you get, the easier is to find it. And so it was really a shame that Kepler was just at the limit of where we were expecting it to start to see Earth-like planets. And in fact, it really found zero. Zero planets that are around stars like the Sun orbits similar to the Earth around the Sun and could potentially be similar to our own planet in terms of its composition. And so it's a great shame, but that's why gives astronomers more to do in the future.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“Not a direct connection, but they're connected via an intermediate parameter, which is their separation from the star. The planet will be cool if it's further away from the star. Which in turn means that the probability of getting that alignment correct is going to be less. On top of that, they also transit their star less frequently. So if you go to the telescope and you want to discover hot Jupiter, you could probably do it in a week or so because the orbital period is of order of one, two, three days. So you can actually get the full orbit two or three times over. Whereas if you want to set an Earth-like planet, you have to observe that star for three, four years. And that's actually one of the problems with Kepler. Kepler was this very successful mission that NASA launched over a decade ago now, I think. And it discovered thousands of planets. It's still the dominant source of exoplanets that we know about. But unfortunately, it didn't last as long as we would have liked it to. It died after about 4.35 years, I think it was. And so for an Earth-like planet, that's just enough to catch four transits. Four transits was kind of seen as the minimum. But of course, the more...”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source
“Much harder, they're harder for several reasons. The method we primarily use is the transit method, so this is really eclipses. As the planet passes in front of the star, it blocks out some starlight. The problem with that is that not all planets pass in front of their star. They have to be aligned correctly from your line of sight. And so the further away the planet is from the star, the cooler it is, the less likely it is that you're going to get that geometric alignment. So whereas a hot Jupiter about 1% of hot Jupiters will transit in front of their star, only about 0.5%, maybe even a quarter of a percent of Earth-like planets will have the right geometry to transit. And so that makes it much, much harder for us.”
2023-01-28 · Lex Fridman Podcast · #355 – David Kipping: Alien Civilizations and Habitable Worlds · IDENTIFIED FROM THE TRANSCRIPT · source