Transcript
00:00:00 The following is a conversation with Catherine Duclir, a professor of Planetary Science and
00:00:04 Astronomy at Caltech.
00:00:06 Her research is on the surface environments, atmospheres, and thermochemical histories
00:00:12 of the planets and moons in our solar system.
00:00:16 Quick mention of our sponsors, Fundrise, Blinkist, ExpressVPN, and Magic Spoon.
00:00:22 Check them out in the description to support this podcast.
00:00:25 As a side note, let me say that this conversation and a few others, quite big ones actually,
00:00:30 that are coming up were filmed in a studio where I was trying to outsource some of the
00:00:35 work.
00:00:36 Like all experiments, it was a learning experience for me.
00:00:38 It had some positives and negatives.
00:00:40 Ultimately, I decided to return back to doing it the way I was doing before, but hopefully
00:00:44 with a team who can help me out and work with me long term.
00:00:49 The point is, I will always keep challenging myself, trying stuff out, learning, growing,
00:00:54 and hopefully improving over time.
00:00:56 My goal is to surround myself with people who love what they do, are amazing at it,
00:01:01 and are obsessed with doing the best work of their lives.
00:01:04 To me, there’s nothing more energizing and fun than that.
00:01:08 In fact, I’m currently hiring a few folks to work with me on various small projects.
00:01:12 If this is something of interest to you, go to lexfreedman.com slash hiring.
00:01:17 That’s where I will always post opportunities for working with me.
00:01:21 This is the Lex Friedman Podcast, and here is my conversation with Catherine DeClear.
00:01:28 Why is Pluto not a planet anymore?
00:01:30 Does this upset you or has justice finally been served?
00:01:36 So I get asked this all the time.
00:01:38 I think all planetary scientists get asked about Pluto, especially by kids who, we just
00:01:43 love for Pluto to still be a planet.
00:01:46 But the reality is, when we first discovered Pluto, it was a unique object in the outer
00:01:53 solar system.
00:01:54 And we thought we were adding a planet to the inventory of planets that we had.
00:01:59 And then over time, it became clear that Pluto was not a unique, large object in the outer
00:02:04 solar system, that there were actually many of these.
00:02:08 And as we started discovering more and more of them, we realized that the concept of Pluto
00:02:12 being a planet didn’t make sense unless maybe we added all the rest of them as planets.
00:02:18 So you could have imagined actually a different direction that this could have gone where
00:02:22 all the other objects that were discovered in that belt, or at least all the ones, let’s
00:02:26 say, above a certain size, became planets instead of Pluto being declassified.
00:02:33 But we’re now aware of many objects out there in the outer solar system and what’s called
00:02:37 the Kuiper Belt that are of the same size or in some cases even larger than Pluto.
00:02:44 So the declassification was really just a realization that it was not in the same category
00:02:50 as the other planets in the solar system.
00:02:52 And we basically needed to refine our definition in such a way that took into account that
00:02:57 there’s this belt of debris out there in the outer solar system of things with a range
00:03:03 of sizes.
00:03:05 Is there a hope for clear categorization of what is a planet and not, or is it all just
00:03:10 gray area?
00:03:11 When you study planets, when you study moons, satellites of those planets, is there lines
00:03:18 that could be cleanly drawn or is it just a giant mess?
00:03:20 Is it all like a fluid, let’s say not mess, but it’s like fluid of what is a planet, what
00:03:27 is a moon of a planet, what is debris, what is asteroids, all that kind of…
00:03:32 So there are technically clear definitions that were set down by the IAU, the International
00:03:38 Astronomy Union.
00:03:41 Is it size related?
00:03:42 Like what are the parameters based on?
00:03:44 So the parameters are that it has to orbit the sun, which was essentially to rule out
00:03:49 satellites.
00:03:50 Of course, this was a not very forward thinking definition because it technically means that
00:03:53 all extrasolar planets according to that definition are not planets.
00:03:58 So it has to orbit the sun.
00:04:00 It has to be large enough that its gravity has caused it to become spherical in shape,
00:04:05 which also applies to satellites and also applies to Pluto.
00:04:08 The third part of the definition is the thing that really rules out everything else, which
00:04:11 is that it has to have cleared out its orbital path.
00:04:15 And because Pluto orbits in a belt of material, it doesn’t satisfy that stipulation.
00:04:21 Why didn’t you clear out the path?
00:04:22 It’s not big enough to knock everybody out of the way.
00:04:26 And this actually is not the first time it has happened.
00:04:29 So Ceres, when it was discovered, Ceres is the largest asteroid in the asteroid belt,
00:04:33 and it was originally considered a planet when it was first discovered.
00:04:36 And it went through exactly the same story, history, where people actually realized that
00:04:42 it was just one of many asteroids in the asteroid belt region, and then it got declassified
00:04:47 to an asteroid, and now it’s back to a dwarf planet.
00:04:50 So there is a lot of reclassification.
00:04:52 So to me, as somebody who studies solar system objects, I just personally don’t care.
00:04:59 My level of interest in something has nothing to do with what it’s classified as.
00:05:04 So my favorite objects in the solar system are all moons, and frequently when I talk
00:05:08 about them, I refer to them as planets because to me they are planets.
00:05:12 They have volcanoes, they have geology, they have atmospheres, they’re planet like worlds.
00:05:17 And so the distinction is not super meaningful to me, but it is important just for having
00:05:22 a general framework for understanding and talking about things to have a precise definition.
00:05:28 So you don’t have a special romantic appreciation of a moon versus a planet versus an asteroid.
00:05:34 It’s just an object that flies out there and it doesn’t really matter what the categorization
00:05:38 is.
00:05:39 Because there’s movies about asteroids and stuff, and then there’s movies about the moon,
00:05:45 whatever, it’s a really good movie.
00:05:48 There’s something about moons that’s almost like an outlier.
00:05:55 You think of a moon as a thing that’s the secret part, and the planet is the more vanilla
00:06:03 regular part.
00:06:04 None of that?
00:06:05 You don’t have any of that?
00:06:06 No, I actually do.
00:06:07 I really, satellites are, the moons are my favorite things in the solar system.
00:06:11 I think part of what you’re saying, I agree from maybe a slightly different perspective,
00:06:17 which is from the perspective of exploration, we’ve spent a lot of time sending spacecraft
00:06:22 missions to planets.
00:06:23 We had a mission to Jupiter, we had a mission to Saturn, we have plenty of missions to Mars
00:06:27 and missions to Venus.
00:06:28 I think the exploration of the moons in the outer solar system is the next frontier of
00:06:33 solar system exploration.
00:06:35 The belt of debris, just real quick, that’s out there.
00:06:39 Is there something incredible to be discovered there?
00:06:42 Again, we tend to focus on the planets and the moons, but it feels like there’s probably
00:06:47 a lot of stuff out there and it probably, what is it?
00:06:51 It’s like a garbage collector from outside of the solar system, isn’t it?
00:06:56 Like, doesn’t it protect from other objects that kind of fly in and what, it just feels
00:07:02 like it’s a cool, you know when you like walk along the beach and look for stuff and like
00:07:08 look for, it feels like that’s that kind of place where you can find cool weird things.
00:07:13 Or I guess in our conversation today, when we think about tools and what science is studying,
00:07:20 is there something to be studied out there or we just don’t have maybe the tools yet
00:07:24 or there’s nothing to be found?
00:07:26 There’s absolutely a lot to be found.
00:07:28 So the material that’s out there is remnant material from the formation of our solar system.
00:07:32 We don’t think it comes from outside the solar system, at least not most of it.
00:07:38 But there are so many fascinating objects out there and I think what you fit on is exactly
00:07:44 right that we just don’t have the tools to study them in detail.
00:07:48 But we can look out there and we can see there are different species of ice on their surface
00:07:53 that tells us about, you know, the chemical composition of the disk that formed our solar
00:07:58 system.
00:07:59 Some of these objects are way brighter than they should be, meaning they have some kind
00:08:03 of geological activity.
00:08:04 People have hypothesized that some of these objects have subsurface oceans.
00:08:08 You could even stretch your imagination and say some of those oceans could be habitable.
00:08:12 But we can’t get very detailed information about them because they’re so far away.
00:08:16 And so I think if any of those objects were in the inner solar system, it would be studied
00:08:21 intently and would be very interesting.
00:08:24 So would you be able to design a probe in that like very dense debris field, be able
00:08:30 to like hop from one place to another?
00:08:32 Is that just outside of the realm of like how would you even design devices or sensors
00:08:37 that go out there and take pictures and land?
00:08:42 Do you have to land to truly understand a little piece of rock or can you understand
00:08:47 it from remotely, like fly up close and remotely observe?
00:08:52 You can learn quite a lot from just a flyby and that’s all we’re currently capable of
00:08:56 doing in the outer solar system.
00:08:58 The New Horizons mission is a recent example which flew by Pluto and then they had searched
00:09:05 for another object that was out there in the Kuiper Belt, any object that was basically
00:09:10 somewhere that they could deflect their trajectory to actually fly by.
00:09:13 And so they did fly by another object out there in the Kuiper Belt and they take pictures
00:09:18 and they do what they can do.
00:09:19 And if you’ve seen the images from that mission of Pluto, you can see just how much detail
00:09:25 we have compared to just the sort of reddish dot that we knew of before.
00:09:29 So you do get an amazing amount of information actually from just essentially a high speed
00:09:33 flyby.
00:09:34 It always makes me sad to think about flybys that we might be able to, we might fly by
00:09:41 a piece of rock, take a picture and think, oh, that looks pretty and cool and whatever.
00:09:46 And that you could study certain like composition of the surface and so on.
00:09:49 But it’s actually teeming with life and we won’t be able to see it at first.
00:09:55 And it’s sad.
00:09:56 Cause you know, like when you’re on a deserted island and you wave your hands and the thing
00:10:00 flies by and you’re trying to get their attention and they probably do the same, well in their
00:10:05 own way, bacteria probably, right?
00:10:07 But and we miss it.
00:10:10 I don’t know, some reason it makes me, it’s the FOMO, it’s fear of missing out.
00:10:16 It makes me sad that there might be life out there and we don’t, we’re not in touch with
00:10:23 it.
00:10:24 We’re not talking.
00:10:25 Yeah.
00:10:26 Well, okay.
00:10:27 A sad pause, a Russian philosophical pause.
00:10:32 Okay.
00:10:33 What are the tools available to us to study planets and their moons?
00:10:36 Oh my goodness.
00:10:38 That is such a big question.
00:10:41 So among the field of astronomy, so planetary science broadly speaking, well, it falls kind
00:10:47 of at the border of astronomy, geology, climate science, chemistry, and even biology.
00:10:53 So it’s kind of on the border of many things, but part of it falls under the heading of
00:10:57 astronomy.
00:10:58 And among the things that you can study with telescopes, like solar system moons and planets,
00:11:04 the solar system is really unique in that we can actually send spacecraft missions to
00:11:09 the objects and study them in detail.
00:11:11 And so I think that’s, that’s the kind of type of tool that is, that people are most
00:11:15 aware of, that’s most popularized, these amazing NASA missions that either you fly by the object,
00:11:22 you orbit the object, you land on the object, potentially you can talk about digging into
00:11:27 it, drilling, trying to detect tectonic tremors on its surface.
00:11:35 The types of tools that I use are primarily telescopes and so I, my background is in astrophysics
00:11:42 and so I actually got into solar system science from astronomy, not from, you know, a childhood
00:11:47 fascination with spacecraft missions, which is actually what a lot of planetary scientists
00:11:52 became planetary scientists because of childhood fascination with spacecraft missions, which
00:11:56 is kind of interesting for me to talk to people and see that trajectory.
00:12:00 I kind of came at it from the fascination with telescopes angle.
00:12:03 So you like telescopes, not rockets, or at least when I was a kid it was looking at the
00:12:08 stars and playing with telescopes that really fascinated me and that’s how I got into this.
00:12:14 But telescopes, it’s amazing how much detail and how much information you can get from
00:12:21 telescopes today.
00:12:22 You can resolve individual cloud features and watch them kind of sheer out in the atmosphere
00:12:29 of Titan.
00:12:30 You can literally watch volcanoes on Io change from day to day as the lava flows expand.
00:12:38 So and then, you know, spectroscopy, you get compositional information on all these things
00:12:43 and it’s, when I started doing solar system astronomy, I was surprised by how much detail
00:12:51 and how much information you can get even from Earth and then as well as from orbit
00:12:55 like the Hubble Space Telescope or the James Webb.
00:12:59 So with the telescope, you can, I mean, how much information can you get about volcanoes,
00:13:06 about storms, about sort of weather, just so we kind of get a sense, like what a resolution
00:13:13 we’re talking about?
00:13:15 Well, in terms of resolution, so at a, you know, on a given night, if I go and take a
00:13:20 picture of Io and its volcanoes, you can sometimes see at least a dozen different volcanoes.
00:13:26 You can see the infrared emission coming off of them and resolve them, separate them from
00:13:30 one another on the surface and actually watch how the heat coming off of them changes with
00:13:36 time.
00:13:37 And I think this time variability aspect is one of the big advantages we get from telescopes.
00:13:41 So you send a spacecraft mission there and you get an incredible amount of information
00:13:45 over a very short time period.
00:13:47 But for some science questions, you need to observe something for 30 years, 40 years.
00:13:53 Like let’s say you want to look at the moon Titan, which has one of the most interesting
00:13:57 atmospheres in the solar system.
00:14:00 Its orbital period is 29, 30 years.
00:14:04 And so if you want to look at how its atmospheric seasons work, you have to observe it over
00:14:09 that long of a time period.
00:14:11 And you’re not going to do that with a spacecraft, but you can do it with telescopes.
00:14:15 Can we just zoom in on certain things like, let’s talk about Io, which is the moon of
00:14:20 Jupiter.
00:14:21 Right.
00:14:22 Okay.
00:14:23 It’s so big.
00:14:24 There’s like volcanoes all over the place.
00:14:27 It’s from a distance.
00:14:30 It’s awesome.
00:14:31 So can you tell me about this moon and you’re sort of a scholar of many planets and moons,
00:14:37 but that one kind of stood out to me.
00:14:40 So why is that an interesting one?
00:14:42 For so many reasons, but Io is the most volcanically active object in the solar system.
00:14:47 It has hundreds of active volcanoes on it.
00:14:50 It has volcanic plumes that go hundreds of kilometers up above its surface.
00:14:56 It puts out more volume of magma per volcano than volcanoes on Earth today.
00:15:03 But I think to me, the reason that it’s most interesting is as a laboratory for understanding
00:15:10 planetary processes.
00:15:12 So one of the broad goals of planetary science is to put together a sort of more general
00:15:18 and coherent framework for how planets work in general.
00:15:24 Our current framework, you know, it started out very Earth centric.
00:15:27 We start to understand how Earth volcanoes work.
00:15:30 But then when you try to transport that to somewhere like Io that doesn’t have an atmosphere,
00:15:35 which has a very tenuous atmosphere, which makes a big difference for how the magma degasses,
00:15:41 for something that’s really small, for something that has a different heat source, for something
00:15:44 that’s embedded in another object’s magnetic field, the kind of intuition we have from
00:15:49 Earth doesn’t apply.
00:15:50 And so broadly, planetary science is trying to broaden that framework so that you have
00:15:56 a kind of narrative that you can understand how each planet became different from every
00:16:01 other planet.
00:16:02 And I’m already making a mistake.
00:16:04 When I say planet, I mean planets and moons.
00:16:06 Like I said, I see the moons as planets.
00:16:08 As planets.
00:16:09 Yeah.
00:16:10 I actually already noticed that you didn’t introduce Io as the moon of Jupiter.
00:16:14 You completely, you kind of ignored the fact that Jupiter exists.
00:16:19 It’s like, let’s focus on this.
00:16:21 Yeah.
00:16:22 Okay.
00:16:23 So, and you also didn’t mention Europa, which I think is the, is that the most famous moon
00:16:28 of Jupiter?
00:16:29 Is that the one gets attention because it might have life?
00:16:33 Exactly.
00:16:34 Yeah.
00:16:35 But to you, Io is also beautiful.
00:16:37 What’s the difference between volcanoes on Io versus Earth?
00:16:41 You said atmosphere makes a difference.
00:16:44 What the heat source plays a big role.
00:16:48 So many of the moons in the outer solar system are heated from gravitationally by tidal heating.
00:16:55 And I’m happy to describe what that is or, yeah, please, what’s tidal?
00:17:00 Yes.
00:17:01 So tidal heating is, it’s, if you want to understand and contextualize planets and moons,
00:17:07 you have to understand their heat sources.
00:17:10 So for Earth, we have radioactive decay in our interior as well as residual heat of formation.
00:17:16 But for satellites, tidal heating plays a really significant role and in particular
00:17:21 in driving geological activity on satellites and potentially making those subsurface oceans
00:17:27 in places like Europa and Enceladus habitable.
00:17:31 And so the way that that works is if you have multiple moons and their orbital periods are
00:17:37 integer multiples of one another, that means that they’re always encountering each other
00:17:42 at the same point in the orbit.
00:17:46 So if they were on just random orbits, they’d be encountering each other at random places
00:17:50 and the gravitational effect between the two moons would be canceling out over time.
00:17:55 But because they’re always meeting each other at the same point in the orbit, those gravitational
00:18:00 interactions add up coherently.
00:18:02 And so that tweaks them into eccentric orbits.
00:18:06 What’s an eccentric orbit?
00:18:08 So eccentric orbit or elliptical orbit, it just means noncircular, so a deviation from
00:18:12 a circular orbit.
00:18:13 And that means that for Io or Europa, at some points in their orbit, they’re closer to Jupiter
00:18:19 and at some points in their orbit, they’re farther away.
00:18:22 And so when they’re closer, they’re stretched out in a sense, but literally just not very
00:18:29 stretched out, like a couple hundred meters, something like that.
00:18:32 And then when they’re farthest away, they’re less stretched out.
00:18:35 And so you actually have the shape of the object deforming over the course of the orbit.
00:18:40 And these orbits are like just a couple of days.
00:18:42 And so that, in the case of Io, that is literally sufficient friction in its mantle to melt
00:18:49 the rock of its mantle.
00:18:50 And that’s what generates the magma.
00:18:52 That’s the source of the magma.
00:18:54 Yeah.
00:18:55 Okay.
00:18:56 So why is, so Europa is, I thought there was like ice and oceans underneath kind of thing.
00:19:03 So why is Europa not getting the friction?
00:19:05 It is, it’s just a little bit farther away from Jupiter.
00:19:07 And then Ganymede is also in the orbital resonance.
00:19:10 So it’s a three object orbital resonance in the Jupiter system.
00:19:14 But we have these sorts of orbital resonances all over the solar system and also in exoplanets.
00:19:20 So for Europa, basically because it’s farther from Jupiter, the effect is not as extreme,
00:19:25 but you do still have heat generated in its interior in this way.
00:19:29 And that may be driving, could be driving hydrothermal activity at the base of its ocean,
00:19:34 which obviously would be a really valuable thing for life.
00:19:38 Cool.
00:19:39 So it’s like heating up the ocean a little bit.
00:19:42 Heating up the ocean a little bit.
00:19:43 And specifically in these like hydrothermal vents where we see really interesting life
00:19:48 evolve in the bottom of Earth’s oceans.
00:19:51 That’s cool.
00:19:52 Okay.
00:19:53 So what’s Io, what else?
00:19:55 So we know the source is this friction, but there’s no atmosphere.
00:19:59 I’m trying to get a sense of what it’s like if you and I were to visit Io, like what would
00:20:05 that look like?
00:20:06 What would it feel like?
00:20:08 Is this the entire thing covered in basically volcanoes?
00:20:15 So it’s interesting because there’s very little atmosphere.
00:20:18 The surface is actually really cold, very far below freezing on the surface when you’re
00:20:23 away from a volcano, but the volcanoes themselves are over a thousand degrees or the magma when
00:20:28 it comes out is over a thousand degrees.
00:20:30 And so.
00:20:31 But it does come to the surface, the magma?
00:20:33 It does.
00:20:34 Yeah.
00:20:35 In particular places.
00:20:36 Whoa, that probably looks beautiful.
00:20:39 So like, so it’s frozen, not ice.
00:20:42 Like what is, is rock, it’s really cold rock.
00:20:46 And then you just have this like, what is, what does that look, what would that look
00:20:51 like with no atmosphere?
00:20:53 Would that, uh, would it be smoke?
00:20:55 What does it look like?
00:20:58 It’s just magma, like just red, yellow, like liquidy things?
00:21:03 It’s black, it’s black and red, I guess.
00:21:06 Like think of the type of magma that you see in Hawaii.
00:21:10 So different types of magma flow in different ways, for example.
00:21:13 So in somewhere like Io, the magma is really hot and so it will flow out in sheets because
00:21:19 it has really low viscosity.
00:21:23 And I think the lava flows that we’ve been having in Hawaii over the past couple of years
00:21:27 are probably a decent analogy, although Io’s magma’s lavas are even more fluid and faster
00:21:35 moving.
00:21:36 How faster?
00:21:37 Like what, uh, how fat, like if you, uh, by the way, sorry, through the telescope, are
00:21:41 you tracking at what timescale?
00:21:43 Like every frame is how far apart?
00:21:47 If you’re looking through a telescope, are we talking about seconds or we’re talking
00:21:50 about days, months, when you kind of track, try to get a picture of what the surface might
00:21:56 look like, what’s the frequency?
00:21:59 So it depends a little bit on what you want to do.
00:22:03 I, ideally every night, um, but you could take a frame every second and see how things
00:22:09 are changing.
00:22:10 The, the problem with that is that for things to change on a one second timescale, you to
00:22:16 actually see something change that fast, you have to have super high resolution.
00:22:19 The spatial resolution we have is a couple of hundred kilometers.
00:22:22 And so things are not changing on those scales over one second, unless you have something
00:22:28 really crazy happening.
00:22:29 So if you get, if you get a telescope closer to Io, if you get a, or a camera closer to
00:22:36 Io, would you be able to understand something?
00:22:39 Is that something of interest to you?
00:22:41 Would you be able to understand something deeper about these volcanic eruptions and
00:22:46 how magma flows and just the, like the rate of the magma is, or is it basically enough
00:22:52 to have the kilometer resolution?
00:22:55 Do you get it?
00:22:56 No way.
00:22:57 We want to go there.
00:22:58 Absolutely.
00:22:59 You want to go, you want to go to Io?
00:23:00 I mean, I don’t want to go there personally, but I want to send a spacecraft mission there.
00:23:02 Absolutely.
00:23:03 Why?
00:23:04 Why are you scared?
00:23:05 Why am I scared?
00:23:06 Oh, you mean you don’t like, I don’t want to go there as a human as a human.
00:23:11 I want to send a robot there to look at it though.
00:23:13 This is again, everybody’s discriminating against robots.
00:23:16 This is not, but it’s fine.
00:23:18 But it’s not hospitable to humans in any way, right?
00:23:22 Just very cold and very hot.
00:23:24 It’s very cold.
00:23:27 The atmosphere is composed of sulfur dioxide, so you can breathe it.
00:23:31 There’s no pressure.
00:23:32 I mean, it’s kind of all the same things you talk about.
00:23:34 One talks about, about Mars only worse, the atmosphere is still a thousand times less
00:23:39 dense than Mars is.
00:23:42 And the radiation environment is terrible because you’re embedded deep within Jupiter’s
00:23:47 magnetic field and Jupiter’s magnetic field is full of charged particles that have all
00:23:53 come out of Io’s volcanoes actually.
00:23:56 So Jupiter’s magnetic field strips all this material out of Io’s atmosphere and that populates
00:24:03 its entire magnetosphere and then that material comes back around and hits Io and spreads
00:24:07 throughout the system actually.
00:24:08 It’s just, it’s like Io is the massive polluter of the Jupiter system.
00:24:13 Okay, cool.
00:24:15 So what does studying Io teach you about volcanoes on earth or vice versa?
00:24:23 Is in the difference of the two, what insights can you mine out?
00:24:30 That might be interesting in some way.
00:24:34 Yeah.
00:24:35 Well, we try to port the tools that we use to study earth volcanism to Io and it works
00:24:41 to some extent, but it is challenging because the situations are so different and the compositions
00:24:49 are really different.
00:24:50 When you talk about outgassing, you know, earth volcanoes outgassed primarily water
00:24:55 and carbon dioxide, and then sulfur dioxide is the third most abundant gas.
00:25:00 And on Io, the water and carbon dioxide are not there, either it didn’t form with them
00:25:07 or it lost them, we don’t know.
00:25:09 And so the chemistry of how the magma outgassed this is completely different.
00:25:14 But the kind of one to me most interesting analogy to earth is that, so Io, as I’ve said,
00:25:24 it has these really low viscosity magmas, the lava spreads really quickly across its
00:25:29 surface, it can put out massive volumes of magma in relatively short periods of time.
00:25:34 And that sort of volcanism is not happening anywhere else in the solar system today.
00:25:39 But literally every terrestrial planet and the moon had this, what we call very effusive
00:25:46 volcanism early in their history.
00:25:48 Okay, so this is almost like a little glimpse into the early history of earth.
00:25:52 Yeah.
00:25:53 Okay, cool.
00:25:54 So what are the chances that a volcano on earth destroys all of human civilization?
00:26:00 Maybe I wanted to sneak in that question.
00:26:01 Yeah, a volcano on earth.
00:26:06 Do you think about that kind of stuff when you just study volcanoes elsewhere?
00:26:09 Because isn’t it kind of humbling to see something so powerful and so hot, like so unpleasant
00:26:15 for humans, and then you realize we’re sitting on many of them here?
00:26:18 Right.
00:26:19 Yeah, Yellowstone is a classic example.
00:26:22 I don’t know what the chances are of that happening.
00:26:26 My intuition would be that the chances of that are lower than the chances of us getting
00:26:31 wiped out by some other means, that maybe it’ll happen eventually, that there’ll be
00:26:37 one of these massive volcanoes on earth, but we’ll probably be gone by then by some other
00:26:41 means.
00:26:42 Not to sound bleak.
00:26:43 That’s very comforting.
00:26:44 Okay, so can we talk about Europa?
00:26:51 Is there, so maybe can you talk about the intuition, the hope that people have about
00:26:57 life being in Europa?
00:27:00 Maybe also, what are the things we know about it?
00:27:03 What are the things to you that are interesting about that particular moon of Jupiter?
00:27:08 Sure.
00:27:09 Yeah, Europa is, from many perspectives, one of the really interesting places in the solar
00:27:15 system among the solar system moons.
00:27:16 So there are a few, there’s a lot of interest in looking for or understanding the potential
00:27:25 for life to evolve in the subsurface oceans.
00:27:27 I think it’s fairly widely accepted that the chances of life evolving on the surfaces of
00:27:33 really anything in the solar system is very low.
00:27:37 The radiation environment is too harsh and there’s just not liquids on the surface of
00:27:45 most of these things and it’s canonically accepted that liquids are required for life.
00:27:51 And so the subsurface oceans, in addition to maybe Titan’s atmosphere, the subsurface
00:27:55 oceans of the icy satellites are one of the most plausible places in the solar system
00:28:01 for life to evolve.
00:28:03 Europa and Cellitus are interesting because for many of the big satellites, so Ganymede
00:28:08 and Callisto, also satellites of Jupiter, also are thought to have subsurface oceans.
00:28:13 But they have these ice shells and then there’s an ocean underneath the ice shell.
00:28:19 But on those moons around Ganymede, we think that there’s another ice shell underneath
00:28:23 and then there’s rock.
00:28:25 And the reason that that is a problem for life is that your ocean is probably just pure
00:28:30 water because it’s trapped between two big shells of ice.
00:28:34 So Europa doesn’t have this ice shell at the bottom of the ocean, we think.
00:28:39 And so the water and rock are in direct interaction and so that means that you can basically dissolve
00:28:45 a lot of material out of the rock.
00:28:47 You potentially have this hydrothermal activity that’s injecting energy and nutrients for
00:28:52 life to survive.
00:28:53 And so this rock water interface is considered really important for the potential habitability.
00:29:02 As a small aside, you kind of said that it’s canonically assumed that water is required
00:29:08 for life.
00:29:09 Is it possible to have life like in a volcano?
00:29:13 I remember people were like in that National Geographic program or something kind of hypothesizing
00:29:21 that you can really have life anywhere.
00:29:23 So as long as there’s a source of heat, a source of energy, do you think it’s possible
00:29:27 to have life in a volcano, like no water?
00:29:34 I think anything’s possible.
00:29:37 I think so.
00:29:39 It doesn’t have to be water.
00:29:42 You can tell, as you identified, I phrased that really carefully.
00:29:46 It’s canonically accepted that because scientists recognize that we have no idea what broad
00:29:53 range of life could be out there and all we really have is our biases of life as we know
00:29:57 it.
00:29:58 But for life as we know it, it’s very helpful to have or even necessary to have some kind
00:30:02 of liquid and preferably a polar solvent that can actually dissolve molecules, something
00:30:09 like water.
00:30:10 So the case of liquid methane on Titan is less ideal from that perspective.
00:30:14 But liquid magma, if it stays liquid long enough for life to evolve, you have a heat
00:30:20 source, you have a liquid, you have nutrients.
00:30:22 In theory, that checks your three classic astrobiology boxes.
00:30:28 That’d be fascinating.
00:30:29 I mean, it’d be fascinating if it’s possible to detect it easily.
00:30:32 How would we detect if there is life on Europa?
00:30:38 Is it possible to do in a noncontact way from a distance through telescopes and so on?
00:30:45 Or do we need to send robots and do some drilling?
00:30:51 I think realistically you need to do the drilling.
00:30:56 So Europa also has these long tectonic features on its surface where it’s thought that there’s
00:31:02 potential for water from the ocean to be somehow making its way up onto the surface.
00:31:08 And you could imagine some out there scenario where there’s bacteria in the ocean.
00:31:12 It’s somehow working its way up through the ice shell.
00:31:14 It’s spilling out on the surface.
00:31:16 It’s being killed by the radiation.
00:31:18 But your instrument could detect some spectroscopic signature of that dead bacterium.
00:31:24 But that’s many ifs and assumptions.
00:31:26 That’s a hope because then you don’t have to do that much drilling.
00:31:29 You can collect from the surface.
00:31:32 Skeletons of bacteria.
00:31:33 Right.
00:31:34 I’m thinking even remotely.
00:31:35 Oh, remotely.
00:31:36 Yeah.
00:31:37 That’s sad that there’s a single cell civilization living underneath all that ice trying to get
00:31:45 up.
00:31:46 Trying to get out.
00:31:47 Enceladus gives you a slightly better chance of that because Enceladus is a moon of Saturn
00:31:55 and it’s broadly similar to Europa in some ways.
00:31:59 It’s an icy satellite.
00:32:00 It has a subsurface ocean that’s probably in touch with the rocky interior.
00:32:05 But it has these massive geysers at its south pole where it’s spewing out material that
00:32:09 appears to be originating all the way from the ocean.
00:32:12 And so in that case, you could potentially fly through that plume and scoop up that material
00:32:20 and hope that at the velocities you’d be scooping it up.
00:32:22 You’re not destroying any signature of the life you’re looking for.
00:32:27 But let’s say that you have some ingenuity and can come up with a way to do that.
00:32:31 It potentially gives you a more direct opportunity at least to try to measure those bacteria
00:32:38 directly.
00:32:39 Can you tell me a little more on, how do you pronounce it, Salas?
00:32:45 Enceladus.
00:32:46 Enceladus.
00:32:47 Can you tell me a little bit more about Enceladus?
00:32:49 Like we’ve been talking about way too much about Jupiter, Saturn doesn’t get enough love.
00:32:58 Saturn doesn’t get as much love.
00:32:59 So what’s Enceladus?
00:33:02 Is that the most exciting moon of Saturn?
00:33:05 Depends on your perspective.
00:33:07 It’s very exciting from a astrobiology perspective.
00:33:11 I think Enceladus and Titan are the two most unique and interesting moons of Saturn that
00:33:16 definitely both get the most attention also from the life perspective.
00:33:22 So what’s the more likely Titan or Enceladus for life?
00:33:28 If you were to bet all your money in terms of like investing, which to investigate, what
00:33:33 are the differences between the two that are interesting to you?
00:33:37 Yeah.
00:33:38 So the potential for life in each of those two places is very different.
00:33:43 So Titan is the one place in the solar system where you might imagine, again, all of this
00:33:48 is so speculative, but you might imagine life evolving in the atmosphere.
00:33:53 So from a biology perspective, Titan is interesting because it forms complex organic molecules
00:33:59 in its atmosphere.
00:34:01 It has a dense atmosphere.
00:34:02 It’s actually denser than Earth’s.
00:34:04 It’s the only moon that has an atmosphere denser than Earth’s and it’s got tons of methane
00:34:09 in it.
00:34:10 What happens is that methane gets irradiated, it breaks up and it reforms with other things
00:34:13 in the atmosphere.
00:34:15 It makes these complex organic molecules and it’s effectively doing prebiotic chemistry
00:34:21 in the atmosphere.
00:34:23 While still being freezing cold?
00:34:25 Yes.
00:34:26 Okay.
00:34:27 What would that be like?
00:34:29 Would that be pleasant for humans to hang out there?
00:34:32 It’s just really cold?
00:34:34 There’s nowhere in the solar system that would be pleasant for humans.
00:34:37 It would be cold.
00:34:38 You couldn’t breathe the air.
00:34:40 But colonization wise, if there’s an atmosphere, isn’t that a big plus?
00:34:44 Or still a ton of radiation?
00:34:47 Sure.
00:34:48 Okay.
00:34:49 So Titan, that’s a really nice feature that life could be in the atmosphere because then
00:34:55 it might be remotely observable or certainly is more accessible if you visit.
00:35:01 Okay.
00:35:02 So what about Enceladus?
00:35:05 So that would be still in the ocean.
00:35:07 Right.
00:35:08 And Enceladus has the advantage, like I said, of spewing material out of its south pole
00:35:13 so you could collect it.
00:35:14 But it has the disadvantage of the fact that we don’t actually really understand how its
00:35:21 ocean could stay globally liquid over the age of the solar system.
00:35:28 And so there are some models that say that it’s going through this cyclical evolution
00:35:34 where the ocean freezes completely and thaws completely and the orbit sort of oscillates
00:35:40 in and out of these eccentricities.
00:35:45 And in that case, the potential for life ever occurring there in the first place is a lot
00:35:49 lower because if you only have an ocean for 100 million years, is that enough time?
00:35:55 It also means there might be mass extinction events if it does occur and then it just freezes.
00:36:00 Again, very sad, man.
00:36:01 This is very depressing, all the slaughter of life elsewhere.
00:36:07 How unlikely do you think life is on Earth?
00:36:11 So when you study other planets and you study the contents of other planets, does that give
00:36:18 you a perspective on the origin of life on Earth, which again is full of mystery in itself,
00:36:26 not the evolution, but the origin, the first springing to life, like from nothing to life,
00:36:33 from the basic ingredients to life?
00:36:37 I guess another way of asking it is how unique are we?
00:36:40 Yeah, it’s a great question and it’s one that just scientifically we don’t have an answer
00:36:46 to.
00:36:47 We don’t even know how many times life evolved on Earth, if it was only once or if it happened
00:36:53 independently a thousand times in different places.
00:36:56 We don’t know whether it’s happened anywhere else in the universe, although it feels absurd
00:37:01 to believe that we are the only life that evolved in the entire universe, but it’s conceivable.
00:37:07 We just have just no real information.
00:37:12 We don’t understand really how life came about in the first place on Earth.
00:37:15 I mean, so if you look at the Drake equation that tries to estimate how many alien civilizations
00:37:23 are out there, planets have a big part to play in that equation.
00:37:29 If you were to bet money in terms of the odds of origins of life on Earth, I mean, this
00:37:36 all has to do with how special and unique is Earth.
00:37:40 What you land in terms of the number of civilizations has to do with how unique their rare Earth
00:37:45 hypothesis is.
00:37:47 How rare and special is Earth?
00:37:49 How rare and special is the solar system?
00:37:52 Like if you had to bet all your money on a completely unscientific question, well, no,
00:37:58 it’s actually a rigorously scientific, we just don’t know a lot of things in that equation.
00:38:03 There’s a lot of mysteries about that and it’s slowly becoming better and better understood
00:38:08 in terms of exoplanets, in terms of how many solar systems are out there where there’s
00:38:13 planets that are Earth like planets, it’s getting better and better understood.
00:38:16 What’s your sense from that perspective, how many alien civilizations out there, zero or
00:38:24 one plus?
00:38:25 You’re right that the equation is being better understood, but you’re really only talking
00:38:30 about the first three parameters in the equation or something.
00:38:33 How many stars are there, how many planets per star, and then we’re just barely scratching
00:38:38 the surface of what fraction of those planets might be habitable.
00:38:41 The rest of the terms in the equation are like how likely is life to evolve given habitable
00:38:46 conditions, how likely is it to survive, all these things.
00:38:51 There are all these huge unknowns.
00:38:53 Actually I remember when I first saw that equation, I think it was my first year of
00:38:58 college and I thought this is ridiculous.
00:39:01 This is A, common sense that didn’t need to give a name, you know, and B, just a bunch
00:39:08 of unknowns, it’s like putting our ignorance together in one equation.
00:39:12 But now I understand this equation, you know, it’s not something we’ll ever necessarily
00:39:17 have the answer to, it just gives us a framework for having the exact conversation we’re having
00:39:22 right now.
00:39:23 And I think that’s how it was intended in the first place when it was put into writing
00:39:27 was to give people a language to communicate about the factors that go into the potential
00:39:33 for aliens to be out there and for us to find them.
00:39:38 I would put money on there being aliens, I would not put money on us having definitive
00:39:46 evidence of them in my lifetime.
00:39:49 Well, definitive is a funny, is a funny word.
00:39:54 My sense is, this is the saddest part for me, is my sense in terms of intelligent alien
00:40:01 civilizations, I feel like we’re so, we’re so self obsessed that we literally would not
00:40:11 be able to detect them.
00:40:13 Even when they’re like in front of us, like trees could be aliens, but just their intelligence
00:40:20 could be realized on a scale, on a time scale or physical scale that we’re not appreciating.
00:40:28 Like trees could be way more intelligent than us.
00:40:31 I don’t know.
00:40:32 It’s just a dumb example.
00:40:33 It could be rocks or it could be things like, this, I love this, this is a Dawkins memes.
00:40:41 It could be that ideas are the, like ideas we have, like where do ideas come from?
00:40:46 Where do thoughts come from?
00:40:48 Maybe thoughts are the aliens or maybe thoughts is the actual mechanisms of communication
00:40:55 in physics, right?
00:40:57 This is like, we think of thoughts as something that springs up from neurons firing or where
00:41:03 the hell they come from.
00:41:05 And now what about consciousness?
00:41:08 Maybe consciousness is the communication.
00:41:10 It sounds like ridiculous, but like we’re so self centered on this space, time, communication
00:41:18 and physical space using like written language, like spoken with audio on a time scale that’s
00:41:26 very specific on a physical scale, it’s very specific.
00:41:30 So I tend to think that, but bacteria will probably recognize like moving organisms will
00:41:37 probably recognize, but when that forms itself into intelligence, most likely it’ll be robots
00:41:42 of some kind because we won’t be meeting the origins.
00:41:45 We’ll be meeting the creations of those intelligences.
00:41:49 We just would not be able to appreciate it.
00:41:51 And that’s the saddest thing to me that we, yeah, we’re too dumb to see aliens.
00:42:02 Like we’re too, we kind of think like, look at the progress of science, we’ve accomplished
00:42:07 so much.
00:42:08 The sad thing it could be that we’re just like in the first 0.0001% of understanding
00:42:13 anything is humbling.
00:42:15 I hope that’s true because I feel like we’re very ignorant as a species.
00:42:20 And I hope that our current level of knowledge only represents the 0.001% of what we will
00:42:25 someday achieve.
00:42:26 That actually feels optimistic to me.
00:42:29 Well, I feel like that’s easier for us to comprehend in the space of biology and not
00:42:35 as easy to comprehend in the space of physics, for example, because we have a sense that
00:42:39 like we have it, like if you, if you talk to theoretical physicists, they have a sense
00:42:45 that we understand the basic laws that form the nature of reality of our universe.
00:42:54 But so there’s much more, like physicists are much more confident.
00:42:58 Biologists are like, uh, this is a squishy mess, we’re doing our best, physicists, but
00:43:06 I would be, it’d be fascinating to see if physicists themselves would also be humbled
00:43:10 by their being like, what the hell is dark matter and dark energy?
00:43:15 What the hell is the, not just the origin of the, not just the big bang, but everything
00:43:21 that happened since the big bang.
00:43:24 A lot of things that happened since the big bang, we have no ideas about except basic
00:43:27 models of physics.
00:43:28 Right.
00:43:29 What happened before the big bang?
00:43:30 Yeah.
00:43:31 Yeah.
00:43:32 What happened before?
00:43:33 Or what’s happening inside the black hole?
00:43:34 Why is there a black hole at the center of our galaxy?
00:43:36 Can somebody answer this?
00:43:37 A supermassive black hole.
00:43:39 Nobody knows how it started.
00:43:41 And they seem to be like in the middle of all galaxies.
00:43:44 Um, so that could be a portal for aliens to communicate through consciousness.
00:43:48 Okay.
00:43:49 Um, all right, back to planets.
00:43:51 How, um, what’s your favorite outside of earth?
00:43:55 What’s your favorite planet or moon?
00:43:57 Maybe outside of the ones we, well, first, have we talked about it already or, and then
00:44:03 if we did mention it, what’s the one outside of that?
00:44:05 Oh gosh.
00:44:06 I have to come up with another favorite that’s not IO.
00:44:08 Oh, IO is the favorite.
00:44:09 Oh, absolutely.
00:44:10 Why is IO the favorite?
00:44:12 I mean, basically everything I’ve, I’ve already said, it’s just such a, an amazing and unique
00:44:17 object.
00:44:18 Um, but on, I guess a personal note, it’s probably the object that made me become a
00:44:26 planetary scientist.
00:44:28 It’s the first thing in the solar system that really deeply captured my interest.
00:44:34 Um, and when I started my PhD, I wanted to be an astrophysicist working on things like
00:44:42 galaxy evolution, um, and sort of slowly, I had done some projects in the solar system,
00:44:48 but IO was the thing that like really caught me in to doing solar system science.
00:44:53 Okay.
00:44:54 Let’s, let’s leave, uh, moons aside.
00:44:56 What’s your favorite planet?
00:44:58 It sounds like you like moons better than planets.
00:45:01 So it’s, uh, that’s accurate.
00:45:02 Um, but the planets are, are fascinating.
00:45:05 I think, you know, I find that the planets in the solar system really fascinating.
00:45:10 What I like about the moons is that they, there’s so much less that is known.
00:45:17 There’s still a lot more discovery space and the questions that we can ask are still the,
00:45:21 the bigger questions.
00:45:22 Gotcha.
00:45:23 Um, which, you know, I, and maybe I’m being unfair to the planets because we’re still
00:45:27 trying to understand things like, was there ever life on Mars?
00:45:31 And that is a huge question and one that we’ve sent numerous robots to Mars to try to answer.
00:45:37 So maybe I’m being unfair to the planets, but, but there is certainly quite a bit more
00:45:41 information, uh, that we have about the planets than the moons.
00:45:44 But I mean, Venus is, is a fascinating object.
00:45:48 So I like the objects that lie at the extremes.
00:45:53 I think that if we can make a sort of theory or, or like I’ve been saying, framework for
00:45:59 understanding planets and moons that can incorporate even the most extreme ones, then, you know,
00:46:04 those are the things that really test your theory and test your understanding.
00:46:08 And so they’ve always really fascinated me.
00:46:10 Not so much the nice habitable places like Earth, but these extreme places like Venus
00:46:15 that have, um, sulfuric acid clouds and just incredibly hot and dense surfaces.
00:46:23 And Venus, of course, I love volcanism for some reason, and, and Venus has, probably
00:46:30 has volcanic activity, definitely has in their recent past, maybe has ongoing today.
00:46:37 What do you make of the news and maybe you can update it in terms of life being discovered
00:46:41 in the atmosphere of Venus?
00:46:44 Is that, sorry.
00:46:45 Okay.
00:46:46 You have opinion.
00:46:47 I can already tell you have opinions.
00:46:49 Was that fake news?
00:46:50 I got excited when I saw that.
00:46:52 What’s the, what’s the final, uh, is there a life on Venus?
00:46:56 So the detection that was reported was the detection of the molecule phosphine.
00:47:01 Um, and they said that they tried every other mechanism they could think of to produce phosphine
00:47:10 and they, none of, no mechanism worked.
00:47:13 And then they said, well, we know that life produces phosphine.
00:47:16 And so that was sort of the train of logic.
00:47:19 And, um, I don’t personally believe that phosphine was detected in the first place.
00:47:25 Okay.
00:47:26 So then, I mean, this is just one study, but I, as a layman, I’m skeptical a little bit
00:47:35 about tools that sense the contents of an atmosphere, like contents of an atmosphere
00:47:41 from remotely and making conclusive statements about life.
00:47:46 Oh yeah.
00:47:48 Well that connection that you just made, the contents of the atmosphere to the life is,
00:47:53 is a tricky one.
00:47:54 And yeah, I know that that claim received a lot of criticism for the lines of logic
00:48:00 that went from detection to, uh, to claim of life.
00:48:05 Even the detection itself though, did, doesn’t, doesn’t meet the sort of historical scientific
00:48:11 standards of, of a detection.
00:48:14 Um, the, it was a very tenuous detection and only one line of the species was detected.
00:48:20 And a lot of really complicated data analysis methods had to be applied to even make that
00:48:26 weak detection.
00:48:27 Yeah.
00:48:28 Um.
00:48:29 So it could be, it could be noise, it could be polluted data, it could be all the, all
00:48:32 those things.
00:48:33 And so it doesn’t have, it doesn’t meet the, the level of rigor that you would hope.
00:48:38 But of course, I mean, we’re doing our best and it’s clear that, uh, the human species
00:48:44 are hopeful to find life.
00:48:46 Clearly.
00:48:47 Yes.
00:48:48 Everyone is so excited about that possibility.
00:48:50 All right.
00:48:51 Let’s, uh, let me ask you about Mars.
00:48:56 So, um, there’s a guy named Elon Musk and, uh, he seems to want to take something called
00:49:05 Dogecoin there.
00:49:07 First of the month.
00:49:08 I’m just, I’m just kidding about the Dogecoin.
00:49:11 I don’t even know what the heck is up with that whole, um, I think, uh, I think humor
00:49:20 has power in the 21st century in a way to spread ideas in the most positive way.
00:49:28 So I love that kind of humor because it makes people smile, but it also kind of sneaks.
00:49:37 It’s like a Trojan horse for cool ideas.
00:49:40 You you open with humor and you, uh, like the humor is the appetizer.
00:49:45 And then the main meal is the science and the engineering anyway, uh, do you think it’s
00:49:52 possible to colonize Mars or other planets in the solar system, but we’re especially
00:50:02 looking to Mars.
00:50:04 Is there something about planets that make them very harsh to humans?
00:50:09 Is there something in particular you think about and maybe in a high like big picture
00:50:14 perspective, do you have a hope we, we do in fact become a multi planetary species?
00:50:19 I do think that if our species survives long enough and we don’t wipe ourselves out or
00:50:26 get wiped out by some other means that we will eventually be able to colonize other
00:50:32 planets.
00:50:33 I do not expect that to happen in my lifetime.
00:50:36 I mean, tourists may go to Mars, tourists, people who commit years of their life to go
00:50:41 into Mars as a tourist may go to Mars.
00:50:43 Um, I don’t think that we will colonize it.
00:50:46 Um, is there a sense why it’s just too harsh on the environment to, uh, to, to, like it’s
00:50:53 too costly to build something habitable there for a large population.
00:51:00 I think that we need to do a lot of work and learning how to use the resources that are
00:51:06 are on the planet already to do the things we need.
00:51:09 So if you’re talking about someone going there for a few months, um, so we’ll back up a little
00:51:16 bit.
00:51:17 There are many things that make Mars not hospitable, temperature, you can’t breathe the air, you
00:51:22 need a pressure suit, even if you’re on the surface, the radiation environment is, you
00:51:27 know, even in all of those things, the radiation environment is too harsh for the human body.
00:51:31 Um, all of those things seem like they could eventually have technological solutions.
00:51:37 Um, the challenge, the, the real significant challenge to me seems to be the, the creation
00:51:46 of a self sustaining civilization there.
00:51:49 You know, you can bring pressure suits, you can bring oxygen to breathe, but those are
00:51:53 all in limited supply.
00:51:55 And if we’re going to colonize it, we need to find ways to make use of the resources
00:51:59 that are there to do things like produce food, produce the air, the humans need to keep breathing
00:52:05 just in order to make it self sustaining.
00:52:07 There’s a tremendous amount of work that has to be done.
00:52:09 And people are working on these problems, but I think that’s going to be a major obstacle
00:52:15 in going from visiting where we can bring everything we need to survive in the short
00:52:19 term to actually colonizing.
00:52:21 Yeah.
00:52:22 I find that whole project of the human species quite inspiring these like huge moonshot projects.
00:52:33 Somebody I was reading something, um, in terms of the source of food that’s that may be the
00:52:38 most effective on Mars is you could farm insects.
00:52:42 That’s the easiest thing to farm.
00:52:44 So we’d be eating like cockroaches before living on Mars because that’s the easiest
00:52:50 thing to actually, um, as a source of protein.
00:52:54 So growing a source of protein is the easiest thing as insects.
00:52:57 I just imagine this giant for people who are afraid of insects.
00:53:03 This is not a pleasant, maybe you’re not supposed to even think of it that way.
00:53:07 It’d be like a cockroach milkshake or something like that.
00:53:09 Right.
00:53:10 I wonder if, have people been working on the genetic engineering of, of insects to make
00:53:15 them radiation friendly, right.
00:53:19 Or pressure resistant or whatever.
00:53:22 What can possibly go wrong with making radiation resistant, they’re already like survived everything.
00:53:29 Plus I, um, I took an allergy test, um, in Austin.
00:53:32 So there’s everybody’s alert is like the allergy levels are super high there.
00:53:36 Uh, and, uh, one of the things, apparently I’m not allergic to any insects except cockroaches.
00:53:43 It’s hilarious.
00:53:44 So maybe, uh, um, well, I’m going to use that as a, you know, people use, uh, an excuse
00:53:50 that I’m allergic to cats to not have cats.
00:53:52 I’m going to use that as an excuse to, uh, not go to Mars as one of the first batch of
00:53:56 people.
00:53:57 I was going to ask if you had the opportunity, would you go?
00:54:00 Yeah, I’m joking about the cockroach thing.
00:54:03 I would definitely go.
00:54:04 I love challenges.
00:54:05 I love, I love things.
00:54:08 I love doing things where the possibility of death is, is, uh, not insignificant because
00:54:17 it makes me appreciate it more.
00:54:22 Meditating on death makes me appreciate life.
00:54:27 And uh, when the meditation on death is forced on you because of how difficult the task is,
00:54:35 I enjoy those kinds of things.
00:54:37 Most people don’t, it seems like, but I love the idea of difficult journeys, um, for no
00:54:44 purpose whatsoever, except exploration, going into the unknown, seeing what the limits of
00:54:50 the human mind and the human body are is like, what the hell else is this whole journey that
00:54:55 we’re on for?
00:54:56 I, I, uh, but it could be because I grew up in the Soviet Union.
00:55:00 There’s a kind of love for space, like the, the space race, the cold war created.
00:55:07 I don’t know if still it permeates American culture as much, but especially with the dad
00:55:13 as a scientist, I think I’ve, I’ve loved the idea of humans striving out towards the stars
00:55:20 always, like from the engineering perspective has been really exciting.
00:55:24 I don’t know if people love that as much in America anymore.
00:55:27 I think, uh, Elon is bringing that back a little bit, that excitement about rockets
00:55:31 and going out there.
00:55:33 But, uh, so that’s, that’s hopeful, but for me, I always loved that idea.
00:55:38 From a alien scientist perspective, if you were to look back on earth, is there something
00:55:47 interesting you could say about earth?
00:55:49 Like, how would you summarize earth?
00:55:51 Like in a report, you know, like, uh, Hitchhiker’s Guide to the Galaxy, like if you had to report,
00:55:57 like write a paper on earth or like a letter, like a, like a one pager, um, summarizing
00:56:03 the contents of the surface and the atmosphere, is there, is there something interesting?
00:56:06 Like, do you ever take that kind of perspective on it?
00:56:11 I know you like volcanism, so volcanoes that will probably be in the report.
00:56:14 I was going to say that’s where I was going to go first.
00:56:17 Uh, there are a few things to say about the atmosphere, but in terms of the volcanoes,
00:56:20 so one of the really interesting puzzles to me in planetary science is so we can, we can
00:56:28 look out there and we’ve been talking about surfaces and volcanoes and atmospheres and
00:56:32 things like that.
00:56:33 But that is just, you know, this tiny little veneer on the outside of the planet and most
00:56:38 of the planet is completely sort of inaccessible to telescopes or to spacecraft missions.
00:56:43 You can drill a meter into the surface, but you know, that’s still really the veneer.
00:56:47 Um, and one of the cool puzzles is looking at what’s going on on the surface and trying
00:56:53 to figure out what’s happening underneath or just any kind of indirect means that you
00:56:59 have to study the interior because you can’t dig into it directly, even on Earth.
00:57:03 You can’t dig deep into Earth.
00:57:06 Uh, so from that perspective, looking at Earth, um, one thing that you would be able to tell
00:57:13 from orbit, given enough time, is that Earth has tectonic plates.
00:57:18 So you would see that volcanoes follow the edges.
00:57:22 If you trace where all the volcanoes are on Earth, they follow these lines that trace
00:57:27 the edges of the plates.
00:57:28 And similarly, you would see things like the, uh, Hawaiian string of volcanoes that you
00:57:34 could infer just like, you know, we did as people actually living on Earth, that the
00:57:39 plates are moving over some plume that’s coming up through the mantle.
00:57:43 And so you could use that to say, if the aliens could look at where the volcanoes are, are
00:57:48 happening on Earth and say something about the fact that Earth has plate tectonics, which
00:57:51 makes it really unique in the solar system.
00:57:54 Um…
00:57:55 Oh, really?
00:57:56 So the other planets don’t have plate tectonics?
00:57:57 It’s the only one that has plate tectonics.
00:57:58 Yeah.
00:57:59 What about Io and the friction and all that, that’s not plate tectonics?
00:58:03 What’s the difference between…
00:58:04 Oh, it’s plate tectonics, like another layer of like solid rock that moves around and there’s
00:58:11 cracks.
00:58:12 Exactly.
00:58:13 Yeah.
00:58:14 So, so Earth has plates of solid rock sitting on top of a partially molten layer, and those
00:58:19 plates are kind of shifting around.
00:58:22 Um, on Io, it doesn’t have that.
00:58:26 And the volcanism is what we call heat pipe volcanism.
00:58:28 It’s the magma just punches a hole through the crust and comes out on the surface.
00:58:32 I mean, that’s a simplification, but that’s effectively what’s happening.
00:58:35 Through the freezing cold crust?
00:58:38 Yes.
00:58:39 Very cold, very rigid crust.
00:58:41 Yeah.
00:58:42 How do you, how does that look like, by the way?
00:58:44 I don’t think we’ve mentioned, so the gas that’s expelled, like if we were to look at
00:58:49 it, is it beautiful or is it like boring?
00:58:51 The gas?
00:58:52 I mean, the whole thing, like the magma punching through, the icy…
00:58:56 Oh my gosh.
00:58:57 Yes, I’m sure it would be beautiful, and the pictures we’ve seen of it are beautiful.
00:59:00 You have, so the magma will come out of the lava, will come out of these fissures, and
00:59:07 you have these curtains of lava that are maybe even a kilometer high.
00:59:13 So if you looked at videos, I don’t know how many volcano videos you’ve looked at on Earth,
00:59:17 but you sometimes see a tiny, tiny version of this in Iceland.
00:59:20 You see just these sheets of magma coming out of a fissure when you have this really
00:59:24 low viscosity magma, sort of water like, coming out of these sheets.
00:59:29 And the plumes that come out, because there’s no atmosphere, all the plume molecules are
00:59:35 just plume particles, where they end up is just a function of the direction that they
00:59:42 left the vent, so they’re all following ballistic trajectories, and you end up with these umbrella
00:59:47 plumes.
00:59:48 You don’t get these sort of complicated plumes that you have on Earth that are occurring
00:59:53 because of how that material is interacting with the atmosphere that’s there.
00:59:56 You just have these huge umbrellas, and it’s been hypothesized, actually, that the atmosphere
01:00:01 is made of sulfur dioxide, and that you could have these kind of ash particles from the
01:00:07 volcano and the sulfur dioxide would condense onto these particles, and you’d have sulfur
01:00:13 dioxide snow coming out of these volcanic plumes.
01:00:18 And there’s not much light, though, right?
01:00:21 So you wouldn’t be able to, like, it would not make a good Instagram photo, because you
01:00:25 have to, would you see the snow?
01:00:28 Sure.
01:00:29 There’s light.
01:00:30 It depends.
01:00:31 Oh, okay.
01:00:32 So you could, okay.
01:00:33 It depends what angle you’re looking at it, where the sun is, all the things like that.
01:00:36 You know, the sunlight is much weaker, but it’s still there.
01:00:38 It’s still there.
01:00:41 And how big is Io in terms of gravity?
01:00:44 Is it smaller?
01:00:45 Is it a pretty small moon?
01:00:47 It’s quite a bit smaller than Earth anyway.
01:00:49 It’s smaller than Earth.
01:00:50 Okay.
01:00:51 Okay.
01:00:52 Cool.
01:00:53 So they float up for a little bit.
01:00:54 So it floats.
01:00:55 Wow.
01:00:56 Yeah.
01:00:57 No, you’re right.
01:00:58 That would be gorgeous.
01:01:00 What else about Earth is interesting besides volcanoes?
01:01:03 So plate tectonics.
01:01:04 I didn’t realize that that was a unique element of a planet in the solar system, because that,
01:01:13 I wonder what, I mean, we experienced as human beings, it’s quite painful because of earthquakes
01:01:17 and all those kinds of things, but I wonder if there’s nice features to it.
01:01:22 Yeah.
01:01:23 So coming back to habitability again, things like tectonics and plate tectonics are thought
01:01:30 to play an important role in the surface being habitable.
01:01:33 And that’s because you have a way of recycling materials.
01:01:36 So if you have a stagnant surface, everything, you know, you use up all the free oxygen,
01:01:41 everything reacts until you no longer have reactants that life can extract energy from.
01:01:48 And so if nothing’s changing on your surface, you kind of reach this stagnation point.
01:01:53 But something like plate tectonics recycles material, you bring up new fresh material
01:01:58 from the interior, you bring down material that’s up on the surface, and that can kind
01:02:04 of refresh your nutrient supply, in a sense, or the sort of raw materials that the surface
01:02:10 has to work with.
01:02:11 So from a kind of astrobiologist perspective, looking at Earth, you would see that recycling
01:02:19 of material because the plate tectonics, you would also see how much oxygen is in Earth’s
01:02:24 atmosphere.
01:02:25 And between those two things, you would identify Earth as a reasonable candidate for a habitable
01:02:30 environment in addition to, of course, the, you know, pleasant temperature and liquid
01:02:35 water.
01:02:37 But the abundance of oxygen and the plate tectonics both play a role as well.
01:02:41 And also see like tiny dot satellites flying around and rockets.
01:02:45 Well, sure, yes.
01:02:46 I wonder if they would be able to, I really think about that, like, if aliens were to
01:02:50 visit, and would they really see humans as the thing they should be focusing on?
01:02:58 I think it would take a while, right?
01:03:00 Because it’s so obvious that that should, because there’s like so much incredible,
01:03:06 in terms of biomass, humans are a tiny, tiny, tiny fraction.
01:03:10 There’s like ants, they would probably detect ants, right?
01:03:15 Or they probably would focus on the water and the fish because there’s like a lot of
01:03:19 water.
01:03:20 I was surprised to learn that there’s more species on land than there is in the sea.
01:03:25 Like there’s 90, I think 90 to 95% of the species are on land.
01:03:29 Or on land?
01:03:30 On land.
01:03:31 Not in the sea?
01:03:32 No.
01:03:33 Not in the sea.
01:03:34 Not in the sea, but no, the variety that like the branches created by evolution, apparently
01:03:40 it’s probably a good answer from evolutionary biology perspective, why land created so much
01:03:45 diversity, but it did.
01:03:46 So like the sea, there’s so much not known about the sea, about the oceans, but it’s
01:03:53 not, it’s not diversity friendly.
01:03:57 What can I say?
01:03:58 It needs to improve its diversity.
01:04:01 Do you think the aliens would come, I mean, the first thing they would see is I suppose
01:04:04 our cities, assuming that they had some idea of what a natural world looked like, they
01:04:10 would see cities and say, these don’t belong.
01:04:13 Which of these many species created these?
01:04:15 Yeah.
01:04:16 I mean, there’s, if I were to guess, it would, it’s a good question.
01:04:21 I don’t know if you do this when you look at the telescope, whether you look at geometric
01:04:27 shapes.
01:04:28 Like if it’s, cause to me like hard corners, like what do we think is engineered?
01:04:38 Things that are like, have kind of straight lines and corners and so on, they would probably
01:04:42 detect those in terms of buildings would stand out to them because that’s, that goes against
01:04:47 the basic natural physics of the world.
01:04:52 But I don’t know if the electricity and lights and so on, it could be, I honestly, it could
01:04:58 be the plate tectonics.
01:05:01 It could be like, that they’re like the volcanoes that’d be okay.
01:05:04 That’s a source of heat.
01:05:05 And then they would focus.
01:05:07 They might literally, I mean, depending on how alien life forms are, they might notice
01:05:12 the microorganisms before they notice the big, like notice the ant before the elephant.
01:05:20 Cause like there’s a lot more of them depending what they’re measuring.
01:05:24 We think like size matters, but maybe with their tools of measurement, they would look
01:05:29 for quantity versus size.
01:05:32 Like why focus on the big thing, focus on the thing that there’s a lot of.
01:05:36 And when they see humans, depending on their measurement devices, they might see we’re
01:05:40 made up of billions of organisms.
01:05:43 Like the fact that we have, we’re very human.
01:05:46 We think we’re one organism, but that may not be the case.
01:05:49 They might see, in fact, they may also see like a human city as one organism.
01:05:56 Like what is this thing that like, clearly this organism gets aroused at night because
01:06:03 the lights go on and then, and then it like, it sleeps during the day.
01:06:11 I don’t know how, like the, what perspective you take on the city.
01:06:16 Is there something interesting about earth or other planets in terms of weather patterns?
01:06:20 So we talked a lot about volcanic patterns.
01:06:26 Is there something else about weather that’s interesting, like storms or variations in
01:06:32 temperature, all those kinds of things?
01:06:36 Yeah.
01:06:38 So there’s sort of every planet and moon has a kind of interesting and unique weather pattern.
01:06:45 And those weather patterns are really, we don’t have a good understanding of them.
01:06:50 We don’t even have a good understanding of the global circulation patterns of many of
01:06:56 these atmospheres, why the storm systems occur.
01:07:00 So the composition and occurrence of storms and clouds and these objects is another one
01:07:08 of these kind of windows into the interior that I was talking about with surfaces.
01:07:13 One of these ways that we can get perspective and what the composition is at the interior
01:07:18 and how the circulation is working.
01:07:20 So circulation will bring some species up from deeper in the atmosphere of the planet
01:07:26 to some altitude that’s a little bit colder and that species will condense out and form
01:07:30 a cloud at that altitude.
01:07:32 And we can detect in some cases what those clouds are composed of.
01:07:39 But looking at where those occur can tell you how the circulation cells are, whether
01:07:46 the atmospheric circulation is, say, coming up at the equator and going down at the poles
01:07:50 or whether you have multiple cells in the atmosphere.
01:07:53 And I mean, Jupiter’s atmosphere is just insane.
01:07:57 There’s so much going on.
01:07:58 You look at these pictures and there’s all these vortices and antivortices and you have
01:08:02 these different bands that are moving in opposite directions that may be giving you information
01:08:09 about the deep, like deep in the atmosphere, physically deep properties of Jupiter’s interior
01:08:20 and circulation.
01:08:22 What are these vortices?
01:08:24 What’s the basic material of the storms?
01:08:27 It’s condensed molecules from the atmosphere.
01:08:30 So ammonia ice particles in the case of Jupiter, it’s methane ice in the case of let’s say
01:08:36 Uranus and Neptune and other species, you can kind of construct a chemical model for
01:08:40 which species can condense where.
01:08:42 And so you see a cloud at a certain altitude within the atmosphere and you can make a guess
01:08:47 at what that cloud is made of and sometimes measure it directly and different species
01:08:51 make different colors as well.
01:08:53 Oh, cool.
01:08:55 Ice storms.
01:08:56 Okay.
01:08:57 I mean, the climate of Uranus has always been fascinating to me because it orbits on its
01:09:02 side and it has a 42 year orbital period.
01:09:07 And so, you know, with Earth, our seasons are because our equator is tipped just a little
01:09:11 bit to the plane that we orbit in.
01:09:13 So sometimes the sunlight’s a little bit above the equator and sometimes it’s a little bit
01:09:16 below the equator.
01:09:17 But on Uranus, it’s like for 10 years, the sunlight is directly on the North Pole and
01:09:22 then it’s directly on the equator and then it’s directly on the South Pole.
01:09:26 And it’s actually kind of amazing that the atmosphere doesn’t look crazier than it does.
01:09:33 But understanding how, taking again, like one of these extreme examples, if we can understand
01:09:38 why that atmosphere behaves in the way it does, it’s kind of a test of our understanding
01:09:43 of how atmosphere is.
01:09:45 So like heats up one side of the planet for 10 years and then freezes it the next, like,
01:09:55 and that you’re saying should probably lead to some chaos.
01:10:00 And it doesn’t.
01:10:01 The fact that it doesn’t tells you something about the atmosphere.
01:10:04 So atmospheres have a property that surfaces don’t have, which is that they can redistribute
01:10:08 heat a lot more effectively.
01:10:09 Right.
01:10:10 So they have a stabilizing, like self regulating aspect to them that they’re able to deal with
01:10:15 extreme conditions.
01:10:19 But predicting how that complex system unrolls is very difficult, as we know, about predicting
01:10:27 the weather on Earth even.
01:10:28 Oh, my goodness.
01:10:29 Yeah.
01:10:30 Even with the little variation we have on Earth.
01:10:31 You know, people have tried to put together global circulation models.
01:10:35 You know, we’ve done this for Earth.
01:10:36 People have tried to do these for other planets as well.
01:10:38 And it is a really hard problem.
01:10:41 So Titan, for example, like I said, it’s one of the best studied atmospheres in the solar
01:10:45 system, and people have tried to make these global circulation models and actually predict
01:10:50 what’s going to happen moving into sort of the next season of Titan.
01:10:55 And those predictions have ended up being wrong.
01:10:57 And so then, you know, I don’t know, it’s always exciting when a prediction is wrong
01:11:00 because it means that there’s something more to learn, like your theory wasn’t sufficient.
01:11:06 And then you get to go back and learn something by how you have to modify the theory to make
01:11:09 it fit.
01:11:11 I’m excited by the possibility of one day there will be for various moons and planets,
01:11:15 there will be like news programs reporting the weather with the fake confidence of like
01:11:22 as if you can predict the weather.
01:11:25 We talked quite a bit about planets and moons.
01:11:28 Can we talk a little bit about asteroids?
01:11:31 For sure.
01:11:32 What is, what’s an asteroid?
01:11:34 And what kind of asteroids are there?
01:11:36 So the asteroids, let’s talk about just the restricted to the main asteroid belt, which
01:11:41 is the region, it’s a region of debris basically between Mars and Jupiter.
01:11:49 And the, these sort of belts of debris throughout the solar system, the outer solar system,
01:11:57 you know, the Kuiper belt that we talked about, the asteroid belt, as well as certain other
01:12:01 populations where they accumulate because they’re gravitationally more favored, are
01:12:08 remnant objects from the origin of the solar system.
01:12:11 And so one of the reasons that we are so interested in them, aside from potentially the fact that
01:12:17 they could come hit Earth, but scientifically it’s, it gives us a window into understanding
01:12:27 the composition of the material from which Earth and the other planets formed and how
01:12:34 that material was kind of redistributed over the history of the solar system.
01:12:40 So the asteroids, one could classify them in two different ways.
01:12:44 Some of them are ancient objects.
01:12:45 So they accreted out of the sort of disc of material that the whole solar system formed
01:12:54 out of and have kind of remained ever since more or less the same.
01:13:02 They’ve probably collided with each other and we see the, all these collisional fragments
01:13:06 and you can actually look and based on their orbits say, you know, like these 50 objects
01:13:13 originated as the same object.
01:13:16 You can see them kind of dynamically moving apart after some big collision.
01:13:22 And so some of them are these ancient objects maybe that have undergone collisions.
01:13:26 And then there’s this other category of object that is the one that I personally find really
01:13:30 interesting which is remnants of objects that could have been planets.
01:13:38 So early on a bunch of potential planets accreted that we call planetesimals and they formed
01:13:45 and they formed with a lot of energy and they had enough time to actually differentiate.
01:13:49 So some of these objects differentiated into cores and mantles and crests.
01:13:53 And then they were subsequently disrupted in these massive collisions and they, now
01:14:00 we have these fragments, we think fragments floating around the asteroid belt that are
01:14:05 like bits of mantle, bits of core, bits of crest basically.
01:14:08 So it’s like puzzle pieces that you might be able to stitch together or I guess it’s
01:14:14 all mixed up so you can’t stitch together the original planet candidates or is that
01:14:22 possible to try to see if they kind of, I mean, there’s too many objects in there to.
01:14:28 I think that there are cases where people have kind of looked at objects and by looking
01:14:33 at their orbits, they say these objects should have originated together, but they have very
01:14:37 different compositions.
01:14:39 And so then you can hypothesize maybe they were different fragments of a differentiated
01:14:44 object.
01:14:45 But one of the really cool things about this is, you know, we’ve been talking about getting
01:14:49 clues into the interiors of planets.
01:14:52 We’ve never seen a planetary core or deep mantle directly.
01:14:57 Some mantle material comes up on our surface and then we can see it, but, you know, sort
01:15:01 of in bulk.
01:15:03 We haven’t seen these things directly and these asteroids potentially give us a chance
01:15:08 to like look at what our own core and mantle is like, or at least would be like if it had
01:15:14 been also floating through space for a few billion years and getting irradiated and all
01:15:18 that.
01:15:19 But it’s a cool potential window or like analogy into the interior of our own planet.
01:15:26 Well, how do you begin studying some of these asteroids?
01:15:30 What if you were to put together a study, like what are the interesting questions to
01:15:33 ask that are a little bit more specific?
01:15:37 Do you find a favorite asteroid that could be tracked and try to track it through telescopes?
01:15:43 Or do you, is it has to be, do you have to land on those things to study it?
01:15:51 So when it comes to the asteroids, there are so many of them and the big pictures or the
01:15:58 big questions are answered, so some questions can be answered by zooming in in detail on
01:16:08 individual object, but mostly you’re trying to do a statistical study.
01:16:11 So you want to look at thousands of objects, even hundreds of thousands of objects and
01:16:18 figure out what their composition is and look at, you know, how many big asteroids there
01:16:25 are of this composition versus how many small asteroids of this other composition and put
01:16:29 together these kinds of statistical properties of the asteroid belt.
01:16:34 And those properties can be directly compared with the results of simulations for the formation
01:16:40 of the solar system.
01:16:42 What do we know about the surfaces of asteroids or the contents of the insides of asteroids
01:16:50 and what are still open questions?
01:16:52 So I would say that we don’t know a whole lot about their compositions.
01:17:00 Most of them are small and so you can’t study them in such detail with telescopes as you
01:17:07 could, you know, a planet or moon and at the same time, because there are so many of them,
01:17:11 you could send a spacecraft to a few, but you can’t really like get a statistical survey
01:17:17 with spacecraft.
01:17:18 And so a lot of what we, a lot of what has been done comes down to sort of classification.
01:17:24 You look at how bright they are, you look at whether they’re red or blue, simply, you
01:17:31 know, whether their spectrum is sloped towards long wavelengths or short wavelengths.
01:17:35 There are certain, if you point a spectrograph at their surfaces, there are certain features
01:17:41 you can see.
01:17:42 So you can tell that some of them have silicates on them.
01:17:46 But these are the sort of, they’re pretty basic questions.
01:17:50 We’re still trying to classify them based on fairly basic information in kind of combination
01:17:55 with our general understanding of the material the solar system formed from.
01:17:59 And so you’re sort of, you’re coming in with prior knowledge, which is that you more or
01:18:03 less know what the materials are the solar system formed from, and then you’re trying
01:18:06 to classify them into these categories.
01:18:09 There’s still a huge amount of room for understanding them better and for understanding how their
01:18:17 surfaces are changing in the space environment.
01:18:20 Is it hard to land on an asteroid?
01:18:23 Is this a dumb question?
01:18:26 It feels like it would be quite difficult to actually operate a spacecraft in such a
01:18:36 dense field of debris.
01:18:38 Oh, the asteroid belt, there’s a ton of material there, but it’s actually not that dense.
01:18:44 It is mostly open space.
01:18:47 So mentally do picture like mostly open space with some rocks.
01:18:51 The problem is some of them are not thought to be solid.
01:18:54 So some of these asteroids, especially these, these core mantle fragments, you can think
01:18:58 of as sort of solid like a planet, but some of them are just kind of aggregates of material.
01:19:04 We call them rubble piles.
01:19:06 And so there’s not necessarily.
01:19:08 Might look like a rock, but do a lot of them have kind of clouds around them, like a dust
01:19:15 cloud thing, or like, do you know what you’re stepping on when you try to land on it?
01:19:22 Like what are we supposed to be visualizing here?
01:19:26 This is like very few have water, right?
01:19:29 There’s some water in the outer part of the asteroid belt, but they’re not quite like
01:19:32 comets in the sense of having clouds around them.
01:19:37 There are some crazy asteroids that do become active like comets.
01:19:41 That’s the whole other category of thing that we don’t understand.
01:19:45 But their surfaces, I mean, we have visited some, you can find pictures that spacecraft
01:19:50 have taken of them.
01:19:51 We’ve actually scooped up material off of the surface of some of these objects.
01:19:54 We’re bringing it back to analyze it in the lab.
01:19:58 And there’s a mission that’s launching next year to land on one of these supposedly core
01:20:04 fragment objects to try to figure out what the heck it is and what’s going on with it.
01:20:09 But the surfaces, you know, they’re, they’re, you can picture a solid surface with some
01:20:16 little grains of sand or pebbles on it and occasional boulders, maybe some fine dusty
01:20:23 regions, dust kind of collecting in certain places.
01:20:28 Is there this, do you worry about this?
01:20:30 Is there any chance that one of these fellas destroys all of human civilization by an asteroid
01:20:41 kind of colliding with something, changing its trajectory and then heading its way towards
01:20:45 earth?
01:20:47 That is definitely possible.
01:20:49 And it doesn’t even have to necessarily collide with something and change its trajectory.
01:20:54 We’re not tracking all of them.
01:20:56 We can’t track all of them yet.
01:20:57 You know, there’s still a lot of them.
01:21:01 People are, people are tracking a lot of them and we are doing our best to track more of
01:21:05 them.
01:21:06 But there are a lot of them out there and it would be potentially catastrophic if one
01:21:09 of them impacted earth.
01:21:11 Have you, are you aware of this Apophis object?
01:21:16 So there’s an asteroid, a near earth object called Apophis that people thought had a decent
01:21:23 probability of hitting earth in 2029 and then potentially again in 2036.
01:21:28 So they did a lot of studies.
01:21:29 It’s not actually going to hit earth, but it is going to come very close.
01:21:35 It’s going to be visible in the sky in a relatively dark, I mean, not even that dark, probably
01:21:40 not visible from Los Angeles, but, and it’s going to come a 10th of the way between the
01:21:50 earth and the moon.
01:21:51 It’s going to come closer apparently than some geosynchronous communication satellites.
01:21:55 Oh wow.
01:21:56 So that is a close call, but people have studied it and apparently are very confident it’s
01:22:02 not actually going to hit us, but it was.
01:22:04 I’m going to have to look into this because I’m very sure, I’m very sure what’s going
01:22:08 to happen if an asteroid actually hits earth.
01:22:13 That the scientific community and government will confidently say that, uh, we have nothing
01:22:23 to worry about.
01:22:24 It’s going to be a close call.
01:22:26 And then last minute they’ll be like, there was a miscalculation.
01:22:30 They’re not lying.
01:22:31 It’s just like the space of possibilities, because it’s very difficult to track these
01:22:35 kinds of things and there’s a lot of kind of, um, there’s complexities involved in this.
01:22:40 There’s a lot of uncertainties that I just, something tells me that human civilization
01:22:46 will end with, we’ll see it coming.
01:22:49 And then last minute there’ll be a, oops, we’ll like, we’ll see it coming and we’ll,
01:22:54 it’ll be like, no, it’s just, it’s just threatening, but no problem.
01:22:57 No problem.
01:22:58 And last minute it’ll be like, oops, that was a miscalculation.
01:23:01 And it’s all over in a matter of like a week, or just very positive and optimistic today.
01:23:10 Is there any chance that Bruce Willis can save us in the sense that from what you know
01:23:16 about asteroids, is there something that, um, you can catch them early enough to, uh,
01:23:24 change volcanic, uh, eruptions, right, um, sort of drill, put a nuclear weapon inside
01:23:31 and break up the asteroid or change its trajectory?
01:23:37 There is potential for that.
01:23:38 If you catch it early enough in advance, um, I think in theory, if you knew five years
01:23:48 in advance, um, depending on the objects and how close, how much you would need to deflect
01:23:56 it, um, you could deflect it a little bit.
01:24:00 I don’t know that it would be sufficient in all cases.
01:24:04 Um, and this is definitely not my specific area of expertise, but my understanding is
01:24:09 that there is something you could do.
01:24:11 Um, but it also, how you would carry that out depends a lot on the properties of the
01:24:17 asteroid.
01:24:18 If it’s a solid object versus a rubble pile.
01:24:20 So let’s say you planted some bomb in the middle of it and it blew up, but it was just
01:24:26 kind of a pile of material anyway.
01:24:28 And then that material comes back together and then you kind of just have the same thing.
01:24:33 Presumably its trajectory would be altered, but it’s, it’s like a terminator too.
01:24:38 When it’s like the thing that just like you shoot it in splashes and then comes back together
01:24:43 will be very useless.
01:24:44 That’s fascinating.
01:24:45 It was fascinating.
01:24:48 I’ve gotten a lot of hope from watching, uh, uh, SpaceX rockets that land.
01:24:56 There’s so much.
01:24:57 It’s like, Oh wow.
01:24:58 From an AI perspective, from a robotics perspective, wow, we can do a hell of an amazing job with
01:25:06 control.
01:25:09 And but then we have an understanding about surfaces here on earth, we can map up a lot
01:25:15 of things.
01:25:16 I wonder if we can do that.
01:25:17 Some kind of detail of being able to have that same level of precision in landing on
01:25:23 surfaces with as wide of a variety as asteroids have to be able to understand the exact properties
01:25:31 of the surface and be able to encode that into whatever rocket that lands sufficiently
01:25:37 to, I presume humans, unlike the, unlike the movies, humans would likely get in the way.
01:25:44 Like it should all be done by robots and like land drill, place the, the explosive that
01:25:52 should all be done through control, the robots.
01:25:56 And then you should be able to dynamically adjust to, um, to the surface.
01:26:01 The flip side of that for a robotics person, I don’t know if you’ve seen these, it’s been
01:26:05 very heartbreaking.
01:26:07 Uh, somebody I know well, Russ Tedrick at MIT led the DARPA robotics challenge team for
01:26:14 the humanoid robot challenge for DARPA.
01:26:15 I don’t know if you’ve seen videos of robots on two feet falling, but you’re talking about
01:26:20 millions, you know, several years of work from with some of the most brilliant roboticists
01:26:24 in the world, millions of dollars.
01:26:27 And the final thing is a highlight video on YouTube of robots falling, but they had a
01:26:31 lot of trouble with uneven surfaces.
01:26:33 That’s basically what you have to do with, uh, the challenge involves you’re mostly autonomous
01:26:38 with some partial human communication, but that human communication is broken up.
01:26:43 Like you don’t get a, you get a noisy channel, so you can, humans can, which is very similar
01:26:48 to what it would be like in humans remotely operating a thing on an asteroid.
01:26:54 And so with that, robots really struggled.
01:26:57 There’s some hilarious painful videos of like a robot, not able to like open the door.
01:27:03 And then it tries to open the door without like, it misses the handle and in doing so
01:27:07 like falls, I mean, it’s, um, it’s painful to watch.
01:27:12 So like that, there’s that, and then there’s SpaceX.
01:27:15 So I have hope from SpaceX and then I have less hope from bipedal robotics, um, but it’s
01:27:21 fun.
01:27:22 It’s fun to kind of imagine.
01:27:23 And I think the planetary side of it comes into play in understanding the surfaces of
01:27:28 these asteroids more and more that, you know, forget sort of destruction of human civilization.
01:27:34 It’d be cool to have like spacecraft just landing on all these asteroids to study them
01:27:39 at scale and being able to figure out dynamically what, you know, whether it’s a rubble pile
01:27:44 or whether it’s, um, a solid objects, like, do you see that kind of future of science?
01:27:51 Maybe a hundred, 200, 300 years from now, where there’s just robots expanding out through
01:27:57 the solar system, like sensors, essentially.
01:28:00 Some of it taking pictures from a distance, some of them landing, just exploring and giving
01:28:04 us data.
01:28:05 Cause it feels like we’re working with very little data right now.
01:28:10 Sure I, I do see exploration going that way.
01:28:14 I think, um, the way that NASA is currently or historically has been doing missions is
01:28:23 putting together these, these really large missions that do a lot of things and are extremely
01:28:28 well tested and have a very low rate of failure.
01:28:30 But now that, um, these sort of CubeSat technologies are, are becoming easier to build, easier
01:28:38 to launch, they’re, they’re very cheap.
01:28:41 And you know, NASA is getting involved in this as well.
01:28:43 There’s, there’s a lot of interest in these missions that are relatively small, relatively
01:28:48 cheap and just do one thing.
01:28:50 So you can really optimize it to just do this one thing.
01:28:54 And maybe you could build a hundred of them and send them to different asteroids.
01:28:57 And they would just collect this one piece of information from each asteroid.
01:29:01 It’s a kind of different, more distributed way of doing science, I guess.
01:29:06 And there’s a ton of potential there, I agree.
01:29:11 Let me ask you about objects or one particular object from outside our solar system.
01:29:17 We don’t get to study many of these, right?
01:29:19 They don’t, we don’t get stuff that just flies in out of nowhere from outside the solar system
01:29:24 and flies through.
01:29:25 Apparently there’s been two recently in the past few years.
01:29:30 One of them is Amuamua.
01:29:34 What are your thoughts about Amuamua?
01:29:37 So fun to say.
01:29:38 Could it, could it be space junk from a distant alien civilization or is it just a weird shaped
01:29:44 comet?
01:29:45 I like the way that’s phrased.
01:29:49 Um, so Amuamua is, is a fascinating object.
01:29:53 Just the fact that we have started discovering things that are coming in from outside our
01:29:57 solar system is amazing and can, can start to study them.
01:30:01 And now that we have seen some, we can design now kind of thinking in advance.
01:30:09 The next time we see one, we will be much more ready for it.
01:30:11 We will know which telescopes we want to point at it.
01:30:14 We will have explored whether we could even launch a fast turnaround mission to actually
01:30:18 like get to it before it leaves the solar system.
01:30:23 In terms of Amuamua, yeah, it’s, for an object in our solar system, it’s really unusual in
01:30:30 two particular ways.
01:30:33 One is the dimensions that we don’t see natural things in our solar system that are kind of
01:30:38 long and skinny.
01:30:39 We see, the things we see in our solar system don’t deviate from spherical by that much.
01:30:45 And then that it showed these strange properties of accelerating as it was leaving the solar
01:30:50 system, which was not understood at first.
01:30:53 So in terms of the alien space junk, you know, as a scientist, I cannot rule out that possibility.
01:31:03 I have no evidence to the contrary.
01:31:05 Um, however,
01:31:06 See, you’re saying there’s a chance.
01:31:10 I cannot, I cannot, as a scientist, honestly say that I can rule out that it’s alien space
01:31:16 junk.
01:31:17 However, I see the kind of alien explanation as following this, the Sagan’s extraordinary
01:31:26 claims require extraordinary evidence.
01:31:29 If you are going to actually claim that something is aliens, you need to carefully evaluate,
01:31:37 everyone needs to carefully evaluate the other options and see whether it could just be something
01:31:43 that we know exists that makes sense.
01:31:45 In the case of Oumuamua, there are explanations that fit well within our understanding of
01:31:53 how things work.
01:31:54 So there are a couple, there are two hypotheses for what it could be made of.
01:31:59 They’re both basically just ice shards.
01:32:02 In one case, it’s a nitrogen ice shard that came off of something like Pluto in another
01:32:05 solar system, that Pluto got hit with something and broke up into pieces, and one of those
01:32:10 pieces came through our solar system.
01:32:13 In the other scenario, it’s a bit of a failed solar system.
01:32:19 So our solar system formed out of a collapsing molecular cloud.
01:32:24 Sometimes those molecular clouds are not massive enough, and they sort of collapse into bits,
01:32:29 but they don’t actually form a solar system, but you end up with these kind of chunks of
01:32:33 hydrogen ice, apparently.
01:32:35 And so one of those chunks of hydrogen ice could have got ejected and passed through
01:32:38 our solar system.
01:32:39 So both cases explain these properties in about the same way.
01:32:45 So those ices will sublimate once they’ve passed the sun, and so as they’re moving away
01:32:50 from the sun, you have the hydrogen or nitrogen ice sublimating off the sunward part of it,
01:32:55 and so that is responsible for the acceleration.
01:32:58 The shape also, because you have all this ice sublimating off the surface, if you take
01:33:04 something, the analogy that works pretty well here is for a bar of soap.
01:33:11 Your bar of soap starts out sort of close to spherical, at least from a physicist perspective,
01:33:17 and as you use it over time, you eventually end up with this long, thin shard because
01:33:21 it’s been just by sort of weathering, as we would call it.
01:33:28 And so in the same way, if you just sublimate material off of one of these ice shards, it
01:33:32 ends up long and thin, and it ends up accelerating out of the solar system.
01:33:37 And so given that these properties can be reasonably well explained that way, we should
01:33:43 be extremely skeptical about attributing things to aliens.
01:33:47 See, the reason I like to think that it’s aliens is because it puts a lot of priority
01:33:54 on us not being lazy and we need to catch this thing next time it comes around.
01:34:00 I like the idea that there’s objects, it almost saddens me, they come out of the darkness
01:34:06 really fast and just fly by and go and leave.
01:34:10 It just seems like a wasted opportunity not to study them.
01:34:16 It’s the easiest way to do space travel outside of the solar system is having the things come
01:34:22 to us.
01:34:23 Right?
01:34:24 I like that way of putting it.
01:34:25 And it would be nice to just land on it.
01:34:28 And first of all, really importantly, detect it early and then land on it with a really
01:34:36 nice spacecraft and study the hell out of it.
01:34:47 If there’s a chance it’s aliens, alien life, it just feels like such a cheap way, inexpensive
01:34:56 way to get information about alien life or something interesting that’s out there.
01:35:03 And I’m not sure if an ice shard from another planetary system will be interesting, but
01:35:08 it very well could be.
01:35:09 It could be totally new sets of materials.
01:35:11 It could be, tell us about composition of planets we don’t quite understand.
01:35:16 And it’s just nice when, especially in the case of a Moa Moa, I guess it was pretty
01:35:19 close to earth.
01:35:20 It would have been nice to, don’t go there, they come to us, I don’t know.
01:35:30 That’s what makes me quite sad.
01:35:31 It’s a missed opportunity.
01:35:32 Well, yeah.
01:35:34 And whether you think it’s aliens or not, it’s a missed opportunity, but we weren’t
01:35:39 prepared and we will be prepared for the next ones.
01:35:44 So there’s been a movement in astronomy more towards what’s called time domain astronomy.
01:35:49 So kind of monitoring the whole sky all the time at all wavelengths.
01:35:53 That’s kind of the goal.
01:35:54 And so we expect to detect many more of these in the future, even though these were the
01:35:58 first two we saw, our potential to detect them is only increasing with time.
01:36:02 And so there will be more opportunities and based on these two, we now can actually sit
01:36:09 and think about what we’ll do when the next one shows up.
01:36:11 I also, what it made me realize, I know I didn’t really think through this, but it made
01:36:16 me realize if there is alien civilizations out there, the thing we’re most likely to
01:36:21 see first would be space junk.
01:36:24 My stupid understanding of it.
01:36:28 And the second would be really dumb kind of, you could think of maybe like relay nodes
01:36:34 or something objects that you need to have a whole lot of for particular purposes of
01:36:41 like space travel and so on.
01:36:44 Like a speed limit signs or something, I don’t know, whatever we have on earth, a lot of
01:36:49 that’s dumb.
01:36:50 It’s not alien aliens in themselves.
01:36:52 It’s like artifacts that are useful to the engineering in the systems that are engineered
01:36:57 by alien civilizations.
01:36:59 So like it would, we would see a lot of stuff in terms of setting, in terms of looking for
01:37:05 alien life and trying to communicate with it.
01:37:08 Maybe we should be looking not for like smart creatures or systems to communicate with.
01:37:17 Maybe we should be looking for artifacts or even as dumb as like space junk.
01:37:23 It just kind of reframed my perspective of like, what are we looking for as signs?
01:37:29 Cause there could be a lot of stuff that doesn’t have intelligence, but gives us really strong
01:37:34 signs that there’s somewhere is life or intelligent life.
01:37:37 And yeah, that made me kind of, I know it might be dumb to say, but reframe the kind
01:37:44 of thing that we should be looking for.
01:37:46 Yeah.
01:37:48 So the benefit of looking for intelligent life is that we perhaps have a better chance
01:37:53 of recognizing it.
01:37:56 We couldn’t necessarily recognize what an alien stop sign look like.
01:38:01 And maybe the theorists are the people who sort of model and try to understand slow system
01:38:07 objects are pretty good at coming up with models for anything.
01:38:10 I mean, maybe a mua mua was a stop sign, but we’re clever enough that we could come up
01:38:15 with some physical explanations for it.
01:38:18 And then we all want to go with the simplest possible, we all want to believe the sort
01:38:22 of most skeptical possible explanation.
01:38:25 And so we missed it because we’re too good at coming up with alternate explanations for
01:38:29 things.
01:38:30 And it’s such an outlier, such a rare phenomenon that we can’t study a hundred or a thousand
01:38:35 of these objects.
01:38:36 We have to, we had just one.
01:38:38 And so the science almost destroys the possibility of something special being there.
01:38:43 It’s like Johnny Ive, this designer of Apple, I don’t know if you know who that is.
01:38:48 He’s the lead designer.
01:38:49 He’s the person who designed the iPhone and all the major things.
01:38:53 And he talked about, he’s brilliant, one of my favorite humans on earth and one of the
01:38:58 best designers in the history of earth.
01:39:02 He talked about like when he had this origins of an idea, like in his baby stages, he would
01:39:07 not tell Steve Jobs because Steve would usually like trample all over it.
01:39:11 He would say, this is a dumb idea.
01:39:14 And so I sometimes think of the scientific community in that sense, because the weapon
01:39:19 of the scientific method is so strong at its best that it sometimes crushes the out of
01:39:26 the box outlier evidence.
01:39:30 We don’t get a lot of that evidence because we don’t have, we’re not lucky enough to have
01:39:35 a lot of evidence.
01:39:36 So we have to deal with just special cases and special cases could present an inkling
01:39:42 of something much bigger, but the scientific method user tramples all over it.
01:39:46 And it’s hard to know what to do with that because the scientific method works, but at
01:39:52 the same time, every once in a while, it’s like a balance.
01:39:54 You have to do 99% of the time, you have to do like scientific rigor, but every once in
01:40:00 a while, this is not you saying, me saying, smoke some weed and sit back and think, I
01:40:06 wonder, you know, it’s the Joe Rogan thing.
01:40:09 It’s entirely possible that it’s alien space junk.
01:40:13 Anyway.
01:40:14 Yeah.
01:40:15 I think so.
01:40:16 I completely agree.
01:40:18 And I think that most scientists do speculate about these things.
01:40:23 It’s just at what point do you act on those things?
01:40:28 So you’re right that the scientific method has inherent skepticism, and for the most
01:40:33 part, that’s a good thing because it means that we’re not just believing crazy things
01:40:39 all the time.
01:40:41 But it’s an interesting point that requiring that high level of rigor occasionally means
01:40:50 that you will miss something that is truly interesting because you needed to verify it
01:40:56 three times and it wasn’t verifiable.
01:40:58 I also think like when you communicate with the general public, I think there’s power
01:41:03 in that 1% speculation of just demonstrating authenticity as a human being, as a curious
01:41:10 human being.
01:41:12 I think too often, I think this is changing, but I saw, I’ve been quite disappointed in
01:41:18 my colleagues throughout 2020 with the coronavirus.
01:41:23 There’s too much speaking from authority as opposed to speaking from curiosity.
01:41:28 There’s some of the most incredible science has been done in 2020, especially on the virology
01:41:32 biology side.
01:41:34 And the kind of being talked down to by scientists is always really disappointing to me as opposed
01:41:41 to inspiring.
01:41:42 Like the things we, there’s a lot of uncertainty about the coronavirus, but we know a lot of
01:41:47 this stuff and we speak from scientists from various disciplines, speak from data in the
01:41:54 face of that uncertainty.
01:41:56 And we’re curious, we don’t know what the hell is going on.
01:41:58 We don’t know if this virus is going to evolve, mutate.
01:42:02 We don’t know if this virus or the next one might destroy all human civilization.
01:42:07 You can’t speak with certainty.
01:42:08 In fact, I was on a survey paper about masks, something I don’t talk much about because
01:42:16 I don’t like politics, but we don’t know if masks work, but there’s a lot of evidence
01:42:22 to show that they work for this particular virus.
01:42:24 The transmission of the virus is fascinating actually.
01:42:27 The biomechanics of the way viruses spread is fascinating.
01:42:33 If it wasn’t destructive, it would be beautiful.
01:42:36 And we don’t know, but it’s inspiring to apply the scientific method to the best of our ability,
01:42:42 but also to show that you don’t always know everything and to, perhaps not about the virus
01:42:47 as much, but other things speculate.
01:42:51 What if, you know, what if it’s the worst case and the best case?
01:42:57 Because that’s ultimately what we are, descendants of apes that are just curious about the world
01:43:00 around us.
01:43:01 Yeah, I’ll just add to that, not on the topic of masks, but on the topic of curiosity.
01:43:11 I mean, I think that’s, astronomy and planetary sciences, a field are a little, are unique
01:43:19 because for better and for worse, they don’t directly impact humanity.
01:43:26 So you know, we’re not studying virology to prevent transmission of, you know, illness
01:43:34 amongst humans.
01:43:35 We’re not characterizing volcanoes on earth that could destroy cities.
01:43:40 We, it really is a more curious and in my opinion, playful scientific field than many.
01:43:49 So for better and worse, we can kind of afford to pursue some of the speculation more because
01:43:54 human lives are not in danger if we speculate a little bit too freely and get something
01:44:00 wrong.
01:44:01 Yeah, definitely.
01:44:03 In the space of AI, I am worried that we’re sometimes too eager, speaking for myself,
01:44:09 to like flip the switch to on just to see like what happens.
01:44:14 Maybe sometimes we want to be a little bit careful about that because bad things might
01:44:19 happen.
01:44:21 Is there books or movies in your life long ago or recently that were inspiring, had an
01:44:27 impact on you that you would recommend?
01:44:30 Yeah, absolutely.
01:44:31 So many that I just don’t know where to start with it.
01:44:35 So I love reading.
01:44:37 I read obsessively.
01:44:38 I’ve been reading fiction and a little bit of nonfiction, but mostly fiction obsessively
01:44:43 since I was a child and just never stopped.
01:44:47 So I have some favorite books.
01:44:50 None of them are easy readings.
01:44:51 So I definitely, I mean, I recommend them for somebody who likes an intellectual challenge
01:44:56 in the books that they read.
01:44:59 So maybe I should go chronologically.
01:45:02 I have at least three.
01:45:04 I’m not going to go through 50 here.
01:45:07 Yeah, I’d love to also like maybe ideas that you took away from what you mentioned.
01:45:14 Yeah.
01:45:15 Yeah.
01:45:16 Why they were so compelling to me.
01:45:20 One of the first books that really captured my fascination was Nabokov’s book Pale Fire.
01:45:27 Are you familiar with it?
01:45:29 So I read it actually for a class.
01:45:34 It’s one of the few books I’ve ever read for a class that I actually really liked.
01:45:39 And the book is, it’s in some sense a puzzle.
01:45:44 He’s a brilliant writer, of course, but the book is like, it’s formatted like a poem.
01:45:52 So there’s an introduction, a very long poem and footnotes, and you get partway through
01:45:59 it before realizing that the whole thing is actually a novel, unless you sort of read
01:46:04 up on it going in.
01:46:05 But the whole thing is a novel and there’s a story that slowly reveals itself over the
01:46:10 course of all of this and kind of reveals this just fascinating character basically
01:46:21 and how his mind works in this story.
01:46:24 The idea of a novel also being a kind of intellectual puzzle and something that slowly reveals itself
01:46:31 over the course of reading was really fascinating to me and I have since found a lot more writers
01:46:36 like that.
01:46:38 In a contemporary example that comes to mind is Kazuo Ishiguro, who’s pretty much all of
01:46:44 his books are like slow reveals over the course of the book and like nothing much happens
01:46:49 in the books, but you keep reading them because you just want to know like what the reality
01:46:54 is that he’s slowly revealing to you.
01:46:57 The kind of discovery oriented reading maybe.
01:47:02 What’s the second one?
01:47:04 Perhaps my favorite writer is Renier Maria Rilke.
01:47:08 Wow.
01:47:09 Are you familiar with him?
01:47:11 No, also not familiar.
01:47:13 You’re hitting hidden ones.
01:47:14 I mean, I know in the book of Well, but I’ve never read Pale Fire, but Rilke, I’ve never,
01:47:19 I know it’s a very difficult read, I know that much.
01:47:22 Yeah, right.
01:47:23 All of these are difficult reads.
01:47:25 I think I just, I read for in part for an intellectual challenge, but Rilke, so he wrote
01:47:33 one thing that might be characterizable as a novel, but he wrote a lot of poetry.
01:47:38 I mean, he wrote this series of poems called the Duino Elegies that were very impactful
01:47:43 for me personally, just emotionally, which actually it kind of ties in with astronomy
01:47:53 in that there’s a sense in which we’re all going through our lives alone and there’s
01:48:01 just this sense of profound loneliness in the existence of every individual human.
01:48:10 I think I was drawn to astronomy in part because the sort of vast spaces, the kind of loneliness
01:48:18 and desolateness of space made the sort of internal loneliness feel okay.
01:48:24 In a sense, it like gave companionship and that’s how I feel about Rilke’s poetry.
01:48:32 He turns the kind of desolation and loneliness of human existence into something joyful and
01:48:40 almost meaningful.
01:48:42 Yeah, there’s something about melancholy, I don’t know about Rilke in general, but like
01:48:48 contemplating the melancholy nature of the human condition that makes it okay.
01:49:00 I got gentle from an engineering perspective, think that there is so much loneliness we
01:49:05 haven’t explored within ourselves yet and that’s my hope is to build AI systems that
01:49:12 help us explore our own loneliness.
01:49:15 I think that’s kind of what love is and friendship is, is somebody who in a very small way helps
01:49:22 us explore our own loneliness, like they listen, we connect like two lonely creatures connect
01:49:28 for a time and it’s like, oh, like acknowledge that we exist together for a brief time, but
01:49:38 in a somewhat shallow way, I think relative to how much it’s possible to truly connect
01:49:43 as two consciousnesses.
01:49:44 So AI might be able to help on that front.
01:49:48 So what’s the third one?
01:49:49 Actually, you know, I hadn’t realized until this moment, but it’s yet another one of these
01:49:54 kind of slow reveal books.
01:49:57 It’s a contemporary Russian, I think Russian American writer named Olga Grushin and she
01:50:05 wrote this just phenomenal book called The Dream Life of Sukhanov that I read this year.
01:50:12 Maybe it was last year for the first time and it’s just a really beautiful, this one
01:50:18 you could call a character study, I think of a Russian father coming to terms with himself
01:50:26 and his own past as he potentially slowly loses his mind.
01:50:33 Slow reveal.
01:50:36 Slow reveal.
01:50:37 Well, that’s apparent from the beginning.
01:50:39 I hope I don’t think it’s a spoiler.
01:50:43 Decline into madness.
01:50:44 Spoiler alert.
01:50:45 So all of these are really heavy.
01:50:47 I don’t know.
01:50:48 I just, I don’t have anything lighter to recommend.
01:50:50 Ishiguro is the light version of this.
01:50:53 Okay.
01:50:54 Well, heavy has a certain kind of beauty to it in itself.
01:50:58 Is there advice you would give to a young person today that looks up to the stars and
01:51:03 wonders what the heck they want to do with their life?
01:51:05 So career, science, life in general, you’ve for now chosen a certain kind of path of curiosity.
01:51:15 What insights do you draw from that that you can give us advice to others?
01:51:20 I think for somebody, I would not presume to speak to giving people advice on life and
01:51:27 humanity overall, but for somebody thinking of being a scientist.
01:51:33 So there are a couple of things, one sort of practical thing, which is career wise,
01:51:40 I hadn’t appreciated this going into science, but you need to, so the questions you’re working
01:51:47 on and the techniques you use are both of very high importance, maybe equal importance
01:51:55 for being happy in your career.
01:51:58 If there are questions you’re interested in, but the techniques that you need to use to
01:52:01 do them are tedious for you, then your job is going to be miserable even if the questions
01:52:07 are inspiring.
01:52:09 So you have to find, but if the techniques that you use are things that excite you, then
01:52:14 your job is fun every day.
01:52:16 So for me, I’m fascinated by the solar system and I love telescopes and I love doing data
01:52:22 analysis, playing with data from telescopes, coming up with new ways to use telescopes
01:52:25 and so that’s where I have found that mesh.
01:52:28 But if I was interested in, you know, the dynamical evolution of the solar system, how
01:52:32 the orbits of things evolve, then I would need to do a different type of work that I
01:52:36 would just not find as appealing and so it just wouldn’t be a good fit.
01:52:39 And so it sort of seems like an unromantic thing to have to think about the techniques
01:52:44 being the thing you want to work on also, but it really makes a profound difference
01:52:49 for I think your happiness and your scientific career.
01:52:52 I think that’s really profound.
01:52:53 It’s like the thing, the menial tasks.
01:52:56 If you enjoy those, that’s a really good sign that that’s the right path for you.
01:53:00 I think David Foster Wallace said that the key to life is to be unborable.
01:53:06 So basically everything should be exciting.
01:53:09 I don’t think that’s feasible, but you should find an area where everything is exciting.
01:53:15 I mean, depending on the day, but you could find the joy in everything, not just the big
01:53:20 exciting things that everyone thinks is exciting, but the details, the repetitive stuff, the
01:53:28 menial stuff, the stuff that takes years, the stuff that involves a lot of failure and
01:53:32 all those kinds of things that you find that enjoyable.
01:53:35 That’s actually really profound to focus on that because people talk about like dreams
01:53:40 and passion and goals and so on, the big thing, but that’s not actually what takes you there.
01:53:44 What takes you there is every single day, putting in the hours, and that’s what actually
01:53:49 makes up life is the boring bits.
01:53:51 If the boring bits aren’t boring, then that’s an exciting life because when you were talking
01:54:00 so romantically and passionately about IO, I remember the poem by Robert Frost.
01:54:06 So let me ask you, let me read the poem and ask what your opinion is.
01:54:11 That’s called Fire and Ice.
01:54:12 Oh yeah.
01:54:13 I could almost recite this from memory.
01:54:16 Some say the world will end in fire.
01:54:18 Some say in ice.
01:54:19 From what I’ve tasted of desire, I hold with those who favor fire.
01:54:23 But if I had to perish twice, I think I know enough of hate to say that for destruction
01:54:29 ice is also great and would suffice.
01:54:33 So let me ask, if you had to only choose one, would you choose the world to end in fire,
01:54:41 in volcanic eruptions, in heat and magma, or in ice, frozen over?
01:54:51 Fire or ice?
01:54:52 Fire.
01:54:53 Excellent choice.
01:54:54 I’ve always been a fan of chaos and the idea of things just slowly getting cold and stopping
01:55:10 and dying is just so depressing to me.
01:55:14 So much more depressing than things blowing up or burning or getting covered by a lava
01:55:20 flow.
01:55:21 Somehow the activity of it endows it with more meaning to me, maybe.
01:55:27 I’ve just now had this vision of you in action films where you’re walking away without looking
01:55:32 back and this explosion’s behind you and you put on shades and then it goes to credits.
01:55:38 Catherine, this is awesome, I think your work is really inspiring.
01:55:45 The kind of things we’ll discover about planets in the next few decades is super cool and
01:55:50 I hope, I know you said there’s probably not life in one of them, but there might be and
01:55:55 I hope we discover just that.
01:55:58 And perhaps even on Io, within the volcanic eruptions, there’s a little creature hanging
01:56:04 on that we’ll one day discover.
01:56:06 Thank you so much for wasting all your valuable time with me today, it was really awesome.
01:56:10 Yeah, likewise, thank you for having me here.
01:56:14 Thanks for listening to this conversation with Catherine Duclear and thank you to Fundrise,
01:56:19 Blinkist, ExpressVPN and Magic Spoon.
01:56:23 Check them out in the description to support this podcast.
01:56:26 And now let me leave you with some words from Carl Sagan.
01:56:29 On Titan, the molecules that have been raining down like mana from heaven for the last four
01:56:34 billion years might still be there, largely unaltered, deep frozen, awaiting for the chemists
01:56:41 from Earth.
01:56:42 Thank you for listening and hope to see you next time.