0
SPEAKER_01
The following is a conversation with Catherine DeCleer, a professor of planetary science and astronomy at Caltech.
0
SPEAKER_01
Her research is on the surface environments, atmospheres, and thermochemical histories of the planets and moons in our solar system.
0
SPEAKER_01
Quick mention of our sponsors, Fundrise, Blinkist, ExpressVPN, and Magic Spoon.
0
SPEAKER_01
Check them out in the description to support this podcast.
0
SPEAKER_01
As a side note, let me say that this conversation and a few others, quite big ones actually, that are coming up were filmed in a studio where I was trying to outsource some of the work.
0
SPEAKER_01
Like all experiments, it was a learning experience for me.
0
SPEAKER_01
It had some positives and negatives.
0
SPEAKER_01
Ultimately, I decided to return back to doing it the way I was doing before, but hopefully with a team who can help me out and work with me long term.
0
SPEAKER_01
The point is, I will always keep challenging myself, trying stuff out, learning, growing, and hopefully improving over time.
0
SPEAKER_01
My goal is to surround myself with people who love what they do, are amazing at it, and are obsessed with doing the best work of their lives.
0
SPEAKER_01
To me, there s nothing more energizing and fun than that.
0
SPEAKER_01
In fact, I m currently hiring a few folks to work with me on very small projects.
0
SPEAKER_01
If this is something of interest to you, go to lexfriedman.com slash hiring.
0
SPEAKER_01
That s where I will always post opportunities for working with me.
0
SPEAKER_01
As usual, I ll do a few minutes of ads now.
0
SPEAKER_01
I try to make these interesting, but I give you timestamps, so if you skip, please still check out the sponsors by clicking the links in the description.
0
SPEAKER_01
It s the best way to support this podcast.
0
SPEAKER_01
I am very picky about the sponsors we take on, so hopefully if you buy their stuff, as you should, you ll find value in it just as I have.
0
SPEAKER_01
This episode is sponsored by Fundrise, spelled F-U-N-D-R-I-S-E.
0
SPEAKER_01
It sounds like fun, but there s an extra D at the end.
0
SPEAKER_01
Fundrise.
0
SPEAKER_01
It s a platform that allows you to invest in private real estate.
0
SPEAKER_01
If you re at all paying attention to the internet or twitter specially the crypto world is just going bananas there s a lot of chaos is really interesting i ve been paying attention to all the different technologies involved certainly specially bitcoin but also aetherium and yes dogecoin all that kind of stuff.
0
SPEAKER_01
But from my kind of big picture outsider s perspective, I still do think there should be a lot of diversification in your investment portfolio outside of the world of crypto, even if you re playing with crypto.
0
SPEAKER_01
And Fundrise, that s private real estate, seems like a really great place to diversify into.
0
SPEAKER_01
or at least to explore it as an opportunity.
0
SPEAKER_01
Check them out at Fundrise.
0
SPEAKER_01
That s F-U-N-D-R-I-S-E.com slash Lex.
0
SPEAKER_01
150,000 investors use it.
0
SPEAKER_01
It takes just a few minutes to get started at Fundrise.com slash Lex.
0
SPEAKER_01
That s Fundrise.com slash Lex.
0
SPEAKER_01
This episode is also sponsored by Blinkist, my favorite app for learning new things.
0
SPEAKER_01
Blinkist takes the key ideas from thousands of nonfiction books and condenses them down into just 15 minutes that you can read or listen to.
0
SPEAKER_01
I ve actually been looking into speed reading, as I ve tried many times in the past to increase my reading speed, but what I always run into is that comprehension suffers.
0
SPEAKER_01
I think the idea is with speed reading is you can sacrifice some of the comprehension while still getting a lot of the gist of the content of the text, and thereby it s almost like you get to trade off between skimming and understanding the text deeply.
0
SPEAKER_01
And for certain kinds of text, skimming is enough.
0
SPEAKER_01
I really don t think these methods can work at scale for the kind of reading I m doing, but I ll keep trying.
0
SPEAKER_01
The point is, when somebody does the summarization work for you already, like Blinkist does, that s a huge plus.
0
SPEAKER_01
So you should definitely try them out for the kind of the ultra-skimming that they do through the summarization process, but you should also be doing the full-scale deep reading as well.
0
SPEAKER_01
Reading slow, reading carefully, and thinking deeply.
0
SPEAKER_01
Anyway, go to Blinkist.com slash Lex to start your free seven day trial and get 25% off a Blinkist premium membership.
0
SPEAKER_01
That s Blinkist.com slash Lex.
0
SPEAKER_01
This show is also sponsored by ExpressVPN.
0
SPEAKER_01
This time they actually sent me a copy that s pretty upset with Netflix raising their rates and their pitch here is that you should be getting a lot more for your money if you re going to pay that much.
0
SPEAKER_01
And the way to get a lot more for your money is to use ExpressVPN because it opens up the whole
0
SPEAKER_01
different set of locations you can be watching Netflix from because every Netflix is different.
0
SPEAKER_01
Like Netflix UK has a bunch of shows that Netflix US does not.
0
SPEAKER_01
In fact, the same applies across all kinds of platforms where you can watch stuff.
0
SPEAKER_01
This was true for YouTube.
0
SPEAKER_01
For example, for the SNL appearance of Elon, there s a live stream on YouTube for the first time, I think, internationally for SNL that you can watch, but you could not do so in the US.
0
SPEAKER_01
So thanks to services like ExpressVPN, you can essentially travel virtually all over the globe in an instant with a big red button.
0
SPEAKER_01
To do so, you have to go to expressvpn.com slash LexPod to get an extra three months free.
0
SPEAKER_01
That s expressvpn.com slash LexPod.
0
SPEAKER_01
This episode is also sponsored by Magic Spoon, low-carb, keto-friendly cereal.
0
SPEAKER_01
I m currently doing the 72-hour fast, so this is an especially exciting read.
0
SPEAKER_01
Magic Spoon has 0 grams of sugar, 13-14 grams of protein, only 4 net grams of carbs, 140 calories in each serving.
0
SPEAKER_01
They are releasing a new limited time flavor birthday cake.
0
SPEAKER_01
Man, that sounds delicious.
0
SPEAKER_01
My favorite flavor is still cocoa, but birthday cake is pretty good too.
0
SPEAKER_01
Good news for our Canadian friends, they now ship to Canada as well.
0
SPEAKER_01
Like I said, I m doing the 72 hour fast, which is a great opportunity to reflect on life and how much I love food, how much I love all the basic things of life, and how grateful I am to have those things.
0
SPEAKER_01
And I guess the sad but the very human thing is that the best way to appreciate the things that make life so amazing is to take them away.
0
SPEAKER_01
So fasting is a kind of shortcut, maybe a catalyst for self-reflection and gratitude.
0
SPEAKER_01
Anyway, go to magic spoon comm slash Lex and use code Lex at checkout to save $5 off your order That s magic spoon comm slash Lex and use code Lex This is the Lex Friedman podcast and here is my conversation with Catherine DeClear
0
SPEAKER_01
Why is Pluto not a planet anymore?
0
SPEAKER_01
Does this upset you or has justice finally been served?
0
SPEAKER_00
So I get asked this all the time.
0
SPEAKER_00
I think all planetary scientists get asked about Pluto, especially by kids who would just love for Pluto to still be a planet.
0
SPEAKER_00
But the reality is when we first discovered Pluto, it was a unique object in the outer solar system.
0
SPEAKER_00
And we thought we were adding a planet to the inventory of planets that we had.
0
SPEAKER_00
And then over time, it became clear that Pluto was not
0
SPEAKER_00
a unique large object in the outer solar system, that there were actually many of these.
0
SPEAKER_00
And as we started discovering more and more of them, we realized that the concept of Pluto being a planet didn t make sense, unless maybe we added all the rest of them as planets.
0
SPEAKER_00
So, you know, you could have imagined actually a different direction that this could have gone, where all the other objects that were discovered in that belt, or at least all the ones, let s say, above a certain size, became planets instead of Pluto being declassified.
0
SPEAKER_00
But we were now aware of many objects out there in the outer solar system and what s called the Kuiper belt that are of the same size or in some cases even larger than Pluto.
0
SPEAKER_00
So the declassification was really just a realization that it was not
0
SPEAKER_00
in the same category as the other planets in the solar system and we basically needed to refine our definition in such a way that took into account that there s this belt of debris out there in the outer solar system of things with a range of sizes.
0
SPEAKER_01
Is there a hope for clear categorization of what is a planet and not?
0
SPEAKER_01
Or is it all just gray area?
0
SPEAKER_01
When you study planets, when you study moons, satellites of those planets, is there lines that could be cleanly drawn or is it just a giant mess?
0
SPEAKER_01
Is this all like a fluid, not a mess, but it s like fluid of what is a planet, what is a moon of a planet, what is debris, what is asteroids, all that kind of?
0
SPEAKER_00
So there are technically clear definitions that were set down by the IAU, the International Astronomy Union.
0
SPEAKER_02
Is it size-related?
0
SPEAKER_02
Like, what are the parameters based on what?
0
SPEAKER_00
So, the parameters are that it has to orbit the Sun, which was essentially to rule out satellites.
0
SPEAKER_00
Of course, this was a not-very-forward-thinking definition, because it technically means that all extrasolar planets, according to that definition, are not planets.
0
SPEAKER_00
So, it has to orbit the Sun.
0
SPEAKER_00
It has to be large enough that its gravity has caused it to become spherical in shape.
0
SPEAKER_00
which also applies to satellites and also applies to Pluto.
0
SPEAKER_00
The third part of the definition is the thing that really rules out everything else, which is that it has to have cleared out its orbital path.
0
SPEAKER_00
And because Pluto orbits in a belt of material, it doesn t satisfy that stipulation.
0
SPEAKER_01
Why didn t it clear out the path?
0
SPEAKER_01
It s not big enough to knock everybody out of the way?
0
SPEAKER_00
And this actually is not the first time it has happened.
0
SPEAKER_00
So Ceres, when it was discovered, Ceres is the largest asteroid in the Asteroid Belt, and it was originally considered a planet when it was first discovered, and it went through exactly the same
0
SPEAKER_00
story history where people actually realized that it was just one of many asteroids in the asteroid belt region and then it got declassified to an asteroid and now it s back to a dwarf planet.
0
SPEAKER_00
So there is a lot of reclassification.
0
SPEAKER_00
So to me, as somebody who studies solar system objects, I
0
SPEAKER_00
just personally don t care my level of interest in something has nothing to do with what it s classified as.
0
SPEAKER_00
So my favorite objects in the solar system are all moons.
0
SPEAKER_00
And frequently when I talk about them, I refer to them as planets because to me they are planets.
0
SPEAKER_00
They have volcanoes, they have geology, they have atmospheres, they re planet-like worlds.
0
SPEAKER_00
And so the distinction is not super meaningful to me, but it is important just for having a general framework for
0
SPEAKER_00
for understanding and talking about things to have a precise definition.
0
SPEAKER_01
So you don t have a special romantic appreciation of a moon versus a planet versus an asteroid.
0
SPEAKER_01
It s just an object that flies out there and it doesn t really matter what the categorization is.
0
SPEAKER_01
Because there s movies about asteroids and stuff.
0
SPEAKER_01
And then there s movies about the moon, whatever, it s a really good movie.
0
SPEAKER_01
There s something about moons that,
0
SPEAKER_01
that s almost like an outlier.
0
SPEAKER_01
Like you think of a moon as a thing that s the secret part.
0
SPEAKER_01
And the planet is like, the more like vanilla regular part.
0
SPEAKER_01
None of that.
0
SPEAKER_01
You don t have any of that?
0
SPEAKER_00
No, I actually do.
0
SPEAKER_00
I really satellites are the moons are my favorite things in the solar system.
0
SPEAKER_00
And I think part of what you re saying I
0
SPEAKER_00
agree from maybe a slightly different perspective, which is from the perspective of exploration.
0
SPEAKER_00
We ve spent a lot of time sending spacecraft missions to planets.
0
SPEAKER_00
We had a mission to Jupiter, we had a mission to Saturn, we have plenty of missions to Mars and missions to Venus.
0
SPEAKER_00
I think that exploration of the moons in the outer solar system is the next frontier of solar system exploration.
0
SPEAKER_01
The Belt of Debris, just real quick, that s out there, is there something incredible to be discovered there?
0
SPEAKER_01
Again, we tend to focus on the planets and the moons, but it feels like there s probably a lot of stuff out there.
0
SPEAKER_01
And it probably, what is it?
0
SPEAKER_01
It s like a garbage collector from outside of the solar system, isn t it?
0
SPEAKER_01
Like, doesn t it protect from other objects that kind of fly in?
0
SPEAKER_01
It just feels like it s a cool,
0
SPEAKER_01
You know when you like walk along the beach and look for stuff and like look for, it feels like that s that kind of place where you can find cool weird things.
0
SPEAKER_01
I guess in our conversation today when we think about tools and what science is studying, is there something to be studied out there?
0
SPEAKER_01
Or we just don t have maybe the tools yet or there s nothing to be found?
0
SPEAKER_00
There s absolutely a lot to be found.
0
SPEAKER_00
So the material that s out there is remnant material from the formation of our solar system.
0
SPEAKER_00
We don t think it comes from outside the solar system, at least not most of it.
0
SPEAKER_00
But there are so many fascinating objects out there, and I think what you ve hit on is exactly right, that we just don t have the tools to study them in detail.
0
SPEAKER_00
But we can look out there and we can see there are different species of ice on their surface that tells us about the chemical composition of the disk that formed our solar system.
0
SPEAKER_00
Some of these objects are way brighter than they should be, meaning they have
0
SPEAKER_00
some kind of geological activity.
0
SPEAKER_00
People have hypothesized that some of these objects have subsurface oceans.
0
SPEAKER_00
You could even stretch your imagination and say some of those oceans could be habitable.
0
SPEAKER_00
But we can t get very detailed information about them because they re so far away.
0
SPEAKER_00
And so I think if any of those objects were in the inner solar system, it would be studied intently and would be very interesting.
0
SPEAKER_01
So would you be able to design a probe in that like very dense debris field, be able to like hop from one place to another?
0
SPEAKER_01
Is that just outside of the realm of, like how would you even design devices or sensors that go out there and take pictures and land?
0
SPEAKER_01
Do you have to land to truly understand a little piece of rock?
0
SPEAKER_01
Or can you understand it from remotely, like fly up close and remotely observe?
0
SPEAKER_00
You can learn quite a lot from just a flyby and that s all we re currently capable of doing in the outer solar system.
0
SPEAKER_00
The New Horizons mission is a recent example which flew by Pluto and then they had searched for another object that was out there in the Kuiper Belt, any object that was basically
0
SPEAKER_00
somewhere that they could deflect their trajectory to actually fly by.
0
SPEAKER_00
And so they did fly by another object out there in the Kuiper belt and they take pictures and they do what they can do.
0
SPEAKER_00
And if you ve seen the images from that mission of Pluto, you can see just how much detail we have compared to just the sort of reddish dot that we knew of before.
0
SPEAKER_00
So you do get an amazing amount of information actually from just essentially a high-speed flyby.
0
SPEAKER_01
It always makes me sad to think about flybys, that we might fly by a piece of rock, take a picture, and think, oh, that looks pretty and cool and whatever, and that you could study certain composition of the surface and so on, but it s actually teeming with life, and we won t be able to see it at first.
0
SPEAKER_01
And it s sad because, you know, like when you re on a deserted island, you wave your hands and the thing flies by and you re trying to get their attention.
0
SPEAKER_01
And they probably do the same.
0
SPEAKER_01
Well, in their own way.
0
SPEAKER_01
Bacteria, probably.
0
SPEAKER_01
Right.
0
SPEAKER_01
But and we miss it.
0
SPEAKER_01
I don t know.
0
SPEAKER_01
Some reason it makes me it s a it s the FOMO.
0
SPEAKER_01
It s fear of missing out.
0
SPEAKER_01
It makes me sad that there might be life out there.
0
SPEAKER_01
And we don t.
0
SPEAKER_01
We re not in touch with it.
0
SPEAKER_01
We re not talking.
0
SPEAKER_02
Yeah, well, okay.
0
SPEAKER_01
A sad pause, a Russian philosophical pause.
0
SPEAKER_01
Okay, what are the tools available to us to study planets and their moons?
0
SPEAKER_00
Oh my goodness, that is such a big question.
0
SPEAKER_00
So among the fields of astronomy, so planetary science, broadly speaking, well, it falls kind of at the border of astronomy, geology, climate science, chemistry, and even biology.
0
SPEAKER_00
So it s kind of on the border of many things, but part of it falls under the heading of astronomy.
0
SPEAKER_00
And among the things that you can study with telescopes, like solar system moons and planets,
0
SPEAKER_00
The solar system is really unique in that we can actually send spacecraft missions to the objects and study them in detail.
0
SPEAKER_00
And so I think that s the kind of type of tool that people are most aware of, that s most popularized, these amazing NASA missions that either you fly by the object, you orbit the object, you land on the object, potentially you can
0
SPEAKER_00
talk about digging into it, drilling, trying to detect tectonic tremors on its surface.
0
SPEAKER_00
The types of tools that I use are primarily telescopes.
0
SPEAKER_00
And so my background is in astrophysics.
0
SPEAKER_00
And so I actually got into solar system science from astronomy, not from, you know, a childhood fascination with spacecraft missions, which is actually what
0
SPEAKER_00
a lot of planetary scientists became planetary scientists because of childhood fascination with spacecraft missions, which is kind of interesting for me to talk to people and see that trajectory.
0
SPEAKER_00
I kind of came at it from the fascination with telescopes angle.
0
SPEAKER_01
She likes telescopes, not rockets, or at least you.
0
SPEAKER_00
When I was a kid, it was looking at the stars and playing with telescopes that really fascinated me.
0
SPEAKER_00
And that s how I got into this.
0
SPEAKER_00
But telescopes, it s
0
SPEAKER_00
amazing how much detail and how much information you can get from telescopes today.
0
SPEAKER_00
You can resolve individual cloud features and watch them kind of sheer out in the atmosphere of Titan.
0
SPEAKER_00
You can literally watch volcanoes on Io change from day to day as the lava flows expand.
0
SPEAKER_00
So, and then, you know, with spectroscopy, you get compositional information on all these things.
0
SPEAKER_00
And it s,
0
SPEAKER_00
when I started doing solar system astronomy, I was surprised by how much detail and how much information you can get even from Earth, and then as well as from orbit, like the Hubble Space Telescope or the James Webb.
0
SPEAKER_01
So with the telescope, you can, I mean, how much information can you get about volcanoes, about storms, about sort of weather, just so we kind of get a sense, like what a resolution we re talking about,
1
SPEAKER_00
Well, in terms of resolution, so on a given night, if I go and take a picture of Io and its volcanoes, you can sometimes see at least a dozen different volcanoes.
1
SPEAKER_00
You can see the infrared emission coming off of them and resolve them, separate them from one another on the surface, and actually watch how the heat coming off of them changes with time.
1
SPEAKER_00
And I think this time variability aspect is one of the big advantages we get from telescopes.
1
SPEAKER_00
So you send a spacecraft mission there and you get an incredible amount of information over a very short time period.
1
SPEAKER_00
But for some science questions, you need to observe something for 30 years, 40 years.
1
SPEAKER_00
Like let s say you want to look at the moon Titan, which has one of the most interesting atmospheres in the solar system.
1
SPEAKER_00
orbital period is 29, 30 years.
1
SPEAKER_00
And so if you want to look at how its atmospheric seasons work, you have to observe it over that long of a time period.
1
SPEAKER_00
And you re not going to do that with a spacecraft, but you can do it with telescopes.
1
SPEAKER_01
Can we just zoom in on certain things like, let s talk about Io, which is the moon of Jupiter.
1
SPEAKER_01
Okay, it s like epic.
1
SPEAKER_01
There s like volcanoes all over the place.
1
SPEAKER_01
From a distance, it s awesome.
1
SPEAKER_01
So can you tell me about this moon?
1
SPEAKER_01
And you re sort of a scholar of many planets and moons, but that one kind of stood out to me.
1
SPEAKER_01
So why is that an interesting one?
1
SPEAKER_00
for so many reasons, but Io is the most volcanically active object in the solar system.
1
SPEAKER_00
It has hundreds of active volcanoes on it.
1
SPEAKER_00
It has volcanic plumes that go hundreds of kilometers up above its surface.
1
SPEAKER_00
It puts out more volume of magma per volcano than volcanoes on Earth today.
1
SPEAKER_00
I think, to me, the reason that it s most interesting is as a laboratory for understanding planetary processes.
1
SPEAKER_00
So one of the broad goals of planetary science is to put together a sort of more general and coherent
1
SPEAKER_00
framework for how planets work in general, our current framework, you know, it started out very Earth centric, we start to understand how Earth volcanoes work.
1
SPEAKER_00
But then when you try to transport that to somewhere like Io that doesn t have an atmosphere, which makes it has a very tenuous atmosphere, which makes a big difference for how the magma degasses.
1
SPEAKER_00
for something that s really small, for something that has a different heat source, for something that s embedded in another object s magnetic field, the kind of intuition we have from Earth doesn t apply.
1
SPEAKER_00
And so broadly, planetary sciences is trying to broaden that framework so that you have a kind of narrative that all you can understand how each planet became different from every other planet.
1
SPEAKER_00
And I m already making a mistake.
1
SPEAKER_00
When I say planet, I mean planets and moons.
1
SPEAKER_00
Like I said, I see the moons as planets.
1
SPEAKER_01
Yeah, I actually already noticed that you didn t introduce Io as the moon of Jupiter.
1
SPEAKER_01
You completely, you kind of ignored the fact that Jupiter exists.
1
SPEAKER_01
It s like, let s focus on the, yeah.
1
SPEAKER_01
Okay, so, and you also didn t mention Europa, which I think is the, is that the most famous moon of Jupiter?
1
SPEAKER_01
Is that the one that gets attention, because it might have life?
1
SPEAKER_00
Exactly, yeah.
1
SPEAKER_01
But to you, Io is also beautiful.
1
SPEAKER_01
What s the difference between volcanoes on Io versus Earth?
1
SPEAKER_01
You said atmosphere makes a difference.
1
SPEAKER_00
Yeah, the heat source plays a big role.
1
SPEAKER_00
So many of the moons in the outer solar system are heated from gravitationally by tidal heating.
1
SPEAKER_00
And I m happy to describe what that is.
1
SPEAKER_00
Well, yeah, please, what s tidal?
1
SPEAKER_00
Yes.
1
SPEAKER_00
So tile heating is...
1
SPEAKER_00
If you want to understand and contextualize planets and moons, you have to understand their heat sources.
1
SPEAKER_00
So for Earth, we have radioactive decay in our interior, as well as residual heat of formation.
1
SPEAKER_00
But for satellites, tidal heating plays a really significant role, and in particular, in driving geological activity on satellites, and potentially making those subsurface oceans in places like Europa and Enceladus habitable.
1
SPEAKER_00
And so the way that that works is if you have multiple moons, and their orbital periods are integer multiples of one another, that means that they re always encountering each other at the same point in the orbit.
1
SPEAKER_00
So, if they were on just random orbits, they d be encountering each other at random places, and the gravitational effect between the two moons would be canceling out over time.
1
SPEAKER_00
But because they re always meeting each other at the same point in the orbit, those gravitational interactions add up coherently, and so that tweaks them into eccentric orbits.
1
SPEAKER_00
So, eccentric orbit or elliptical orbit, it just means non-circular, so a deviation from a circular orbit.
1
SPEAKER_00
And that means that, you know, for Io or Europa, at some points in their orbit, they re closer to Jupiter, and at some points in their orbit, they re farther away.
1
SPEAKER_00
And so, when they re closer, they re stretched out.
1
SPEAKER_00
in a sense, but literally, just not very stretched out, like a couple hundred meters, something like that.
1
SPEAKER_00
And then when they re farthest away, they re less stretched out.
1
SPEAKER_00
And so you actually have the shape of the object deforming over the course of the orbit.
1
SPEAKER_00
And these orbits are like just a couple of days.
1
SPEAKER_00
And so that, in the case of Io, that is literally sufficient friction in its mantle to melt the rock of its mantle.
1
SPEAKER_00
And that s what generates the magma.
1
SPEAKER_01
That s the source of the magma.
1
SPEAKER_01
Okay, so Europa is, I thought there was like ice and oceans underneath kind of thing.
1
SPEAKER_01
So why is Europa not getting the friction?
1
SPEAKER_00
It is, it s just a little bit farther away from Jupiter.
1
SPEAKER_00
And then Ganymede is also in the orbital resonance.
1
SPEAKER_00
So it s a three object orbital resonance in the Jupiter system.
1
SPEAKER_00
But we have these sorts of orbital resonances all over the solar system and also in exoplanets.
1
SPEAKER_00
So for Europa, basically because it s farther from Jupiter, the effect is not as extreme, but you do still have heat generated in its interior in this way, and that may be driving, could be driving hydrothermal activity at the base of its ocean, which obviously would be a really valuable thing for life.
1
SPEAKER_01
Cool.
1
SPEAKER_01
So it s like heating up the ocean a little bit.
1
SPEAKER_00
heating up the ocean a little bit, and specifically in these like hydrothermal vents where we see really interesting life evolve in the bottom of Earth s oceans.
1
SPEAKER_01
That s cool.
1
SPEAKER_01
Okay, so what s Io?
1
SPEAKER_01
What else?
1
SPEAKER_01
So we know the source is this friction, but there s no atmosphere.
1
SPEAKER_01
I m trying to get a sense of what it s like if you and I were to visit Io.
1
SPEAKER_01
Like, what would that look like?
1
SPEAKER_01
What would it feel like?
1
SPEAKER_01
Is the entire thing covered in basically volcanoes?
1
SPEAKER_00
So it s interesting because there s very little atmosphere.
1
SPEAKER_00
The surface is actually really cold, very far below freezing on the surface when you re away from a volcano.
1
SPEAKER_00
But the volcanoes themselves are over a thousand degrees or the magma when it comes out is over a thousand degrees.
1
SPEAKER_01
But it does come to the surface, the magma?
1
SPEAKER_00
It does, yeah.
1
SPEAKER_01
in particular places, whoa, that probably looks beautiful.
1
SPEAKER_01
So it s frozen, not ice.
1
SPEAKER_01
What is rock?
1
SPEAKER_01
It s really cold rock.
1
SPEAKER_01
And then you just have this, what would that look like with no atmosphere?
1
SPEAKER_01
Would it be smoke?
1
SPEAKER_01
What does it look like?
1
SPEAKER_01
Is it just magma, like just red, yellow, like liquidy things?
1
SPEAKER_00
It s black.
1
SPEAKER_00
It s black and red, I guess.
1
SPEAKER_00
Like think of the type of magma that you see in Hawaii.
1
SPEAKER_00
So different types of magma flow in different ways, for example.
1
SPEAKER_00
So in somewhere like Io, the magma is really hot.
1
SPEAKER_00
And so it will flow out in sheets because it has really low viscosity.
1
SPEAKER_00
And I think the lava flows that we ve been having in Hawaii over the past couple of years are probably a decent analogy, although Io s magmas, lavas, are even more fluid and faster moving.
1
SPEAKER_00
How fast?
1
SPEAKER_01
Like what, how fast, like if you, oh, by the way, sorry, through the telescope, are you tracking at what time scale?
1
SPEAKER_01
Like every frame is how far apart?
1
SPEAKER_01
If you re looking through a telescope, are we talking about seconds, are we talking about days, months?
1
SPEAKER_01
When you kind of track, try to get a picture of what the surface might look like, what s the frequency?
1
SPEAKER_00
So it depends a little bit on what you want to do.
1
SPEAKER_00
Ideally every night, but you could take a frame every second and see how things are changing.
1
SPEAKER_00
The problem with that is that for things to change on a one second time scale, to actually see something change that fast, you have to have super high resolution.
1
SPEAKER_00
The spatial resolution we have is a couple hundred kilometers.
1
SPEAKER_00
And so things are not changing on those scales over one second, unless you have something really crazy happening.
1
SPEAKER_01
So if you get a telescope closer to Io, or a camera closer to Io, would you be able to understand something, is that something of interest to you?
1
SPEAKER_01
Would you be able to understand something deeper about these volcanic eruptions and how magma flows and just the rate of the magma, or is it basically enough to have the kilometer resolution?
1
SPEAKER_01
Do you get a sense?
1
SPEAKER_00
No way, we wanna go there.
1
SPEAKER_01
You wanna go to Io?
1
SPEAKER_00
I mean, I don t wanna go there personally, but I wanna send a spacecraft mission there, absolutely.
1
SPEAKER_01
Why, why are you scared?
1
SPEAKER_00
Why am I scared?
1
SPEAKER_01
Oh, you mean you don t?
1
SPEAKER_00
I don t wanna go there as a human.
1
SPEAKER_01
As a human.
1
SPEAKER_00
I wanna send a robot there to look at it though.
1
SPEAKER_01
This is again, everybody s discriminating against robots.
1
SPEAKER_01
This is not, but it s fine.
1
SPEAKER_01
But it s not hospitable to humans in any way, right?
1
SPEAKER_01
So it s very cold and very hot.
1
SPEAKER_00
It s very cold.
1
SPEAKER_00
The atmosphere is composed of sulfur dioxide, so you can t breathe it.
1
SPEAKER_00
There s no pressure.
1
SPEAKER_00
I mean, it s kind of all the same things you talk about.
1
SPEAKER_00
One talks about Mars only worse.
1
SPEAKER_00
The atmosphere is still a thousand times less dense than Mars is.
1
SPEAKER_00
And the radiation environment is terrible because you re embedded deep within Jupiter s magnetic field.
1
SPEAKER_00
And Jupiter s magnetic field is full of charged particles that have all come out of Io s volcanoes, actually.
1
SPEAKER_00
So Jupiter s magnetic field strips all this material out of Io s atmosphere.
1
SPEAKER_00
And that populates its entire magnetosphere, and then that material comes back around and hits Io and spreads throughout the system, actually.
1
SPEAKER_00
It s like Io is the massive polluter of the Jupiter system.
1
SPEAKER_01
Okay, cool.
1
SPEAKER_01
So what does studying Io teach you about volcanoes on Earth, or vice versa?
1
SPEAKER_01
In the difference of the two, what insights can you mine out?
1
SPEAKER_01
that might be interesting in some way.
1
SPEAKER_00
Yeah, it s, we try to port the tools that we use to study Earth volcanism to IO, and it works to some extent, but it is challenging, because the situations are so different.
1
SPEAKER_00
And the compositions are really different.
1
SPEAKER_00
When you talk about outgassing, you know, Earth volcanoes outgas primarily water and carbon dioxide, and then sulfur dioxide is the third most abundant gas.
1
SPEAKER_00
And, and on IO, the water and carbon dioxide are not there.
1
SPEAKER_00
Either it didn t form with them or it lost them, we don t know.
1
SPEAKER_00
And so the chemistry of how the magma outgasses is completely different.
1
SPEAKER_00
But the kind of one, to me, most interesting analogy to Earth is that
1
SPEAKER_00
So Io, as I ve said, it has these really low-viscosity magmas.
1
SPEAKER_00
The lava spreads really quickly across its surface.
1
SPEAKER_00
It can put out massive volumes of magma in relatively short periods of time.
1
SPEAKER_00
And that sort of volcanism is not happening anywhere else in the solar system today, but literally every terrestrial planet and the moon had this, what we call, very effusive volcanism early in their history.
1
SPEAKER_01
Okay, so this is almost like a little glimpse into the early history of Earth.
1
SPEAKER_00
Yeah.
1
SPEAKER_01
Okay, cool, so what are the chances that a volcano on Earth destroys all of human civilization?
1
SPEAKER_01
Maybe I wanted to sneak in that question.
1
SPEAKER_00
Yeah, a volcano on Earth.
1
SPEAKER_01
Do you think about that kind of stuff when you just study volcanoes elsewhere?
1
SPEAKER_01
because isn t it kind of humbling to see something so powerful and so hot, so unpleasant for humans, and then you realize we re sitting on many of them here?
1
SPEAKER_00
Right, yeah, Yellowstone as a classic example.
1
SPEAKER_00
I don t know what the chances are of that happening.
1
SPEAKER_00
My intuition would be that the chances of that are lower than the chances of us getting wiped out by some other means, that in the time,
1
SPEAKER_00
you know, that maybe it ll happen eventually, that there ll be one of these massive volcanoes on Earth, but we ll probably be gone by then by some other means.
1
SPEAKER_00
Not to sound bleak, but... It s very comforting.
1
SPEAKER_01
Okay, so can we talk about Europa?
1
SPEAKER_01
Is there...
1
SPEAKER_01
So maybe can you talk about the intuition, the hope that people have about life being in Europa?
1
SPEAKER_01
Maybe also, what are the things we know about it?
1
SPEAKER_01
What are the things to you that are interesting about that particular moon of Jupiter?
1
SPEAKER_00
Sure.
1
SPEAKER_00
Yeah, Europa is, from many perspectives, one of the really interesting places in the solar system, among the solar system moons.
1
SPEAKER_00
So there are a few
1
SPEAKER_00
There s a lot of interest in looking for or understanding the potential for life to evolve in the subsurface oceans.
1
SPEAKER_00
I think it s fairly widely accepted that the chances of life evolving on the surfaces of really anything in the solar system is very low.
1
SPEAKER_00
The radiation environment is too harsh and there s just not liquids on the surface of most of these things.
1
SPEAKER_00
canonically accepted that liquids are required for life.
1
SPEAKER_00
And so the subsurface oceans, in addition to maybe Titan s atmosphere, the subsurface oceans of the icy satellites are one of the most plausible places in the solar system for life to evolve.
1
SPEAKER_00
Europa and Enceladus are interesting because for many of the big satellites, so Ganymede and Callisto, also satellites of Jupiter, also are thought to have subsurface oceans.
1
SPEAKER_00
So they have these ice shells, and then there s an ocean underneath the ice shell.
1
SPEAKER_00
But on those moons around Ganymede, we think that there s another ice shell underneath, and then there s rock.
1
SPEAKER_00
And the reason that that is a problem for life is that your ocean is probably just pure water because it s trapped between two big shells of ice.
1
SPEAKER_00
So Europa doesn t have this ice shell at the bottom of the ocean, we think.
1
SPEAKER_00
And so the water and rock are in direct interaction.
1
SPEAKER_00
And so that means that you can basically dissolve a lot of material out of the rock.
1
SPEAKER_00
You potentially have this hydrothermal activity that s injecting
1
SPEAKER_00
energy and nutrients for life to survive, and so this rock-water interface is considered really important for the potential habitability.
1
SPEAKER_01
As a small aside, you kind of said that it s canonically assumed that water is required for life.
1
SPEAKER_01
Is it possible to have life in a volcano?
1
SPEAKER_01
I remember people, like in that National Geographic program or something, kind of hypothesizing that you can really have life anywhere, so as long as there s a source of heat, a source of energy.
1
SPEAKER_01
Do you think it s possible to have life in a volcano, like no water?
1
SPEAKER_00
I think anything s possible.
1
SPEAKER_00
I think it s so, water, it doesn t have to be water, that s sort of, you can tell, as you identified, I phrased that really carefully, it s canonically accepted that, because we recognize that, you know, scientists recognize that we have no idea what broad range of life could be out there, and all we really have is our biases of life as we know it.
1
SPEAKER_00
But for life as we know it, it s very helpful to have or even necessary to have some kind of liquid and preferably a polar solvent that can actually dissolve molecules, something like water.
1
SPEAKER_00
So the case of liquid methane on Titan is less ideal from that perspective.
1
SPEAKER_00
But you know, liquid magma,
1
SPEAKER_00
If it stays liquid long enough for life to evolve, you have a heat source, you have a liquid, you have nutrients.
1
SPEAKER_00
In theory, that checks your three classic astrobiology boxes.
1
SPEAKER_01
That d be fascinating.
1
SPEAKER_01
I mean, it d be fascinating if it s possible to detect it easily.
1
SPEAKER_01
How would we detect if there is life on Europa?
1
SPEAKER_01
Is it possible to do in a non-contact way from a distance through telescopes and so on?
1
SPEAKER_01
Or do we need to send robots and do some drilling?
1
SPEAKER_00
I think realistically you need to do the drilling.
1
SPEAKER_00
So Europa also has these long tectonic features on its surface where it s thought that there s potential for water from the ocean to be somehow making its way up onto the surface.
1
SPEAKER_00
And you could imagine some out there scenario where there s bacteria in the ocean, it s somehow working its way up through the ice shell, it s spilling out on the surface, it s being killed by the radiation, but your instrument could detect some spectroscopic signature of that.
1
SPEAKER_00
dead bacterium, but that s, you know, that s many ifs and assumptions.
1
SPEAKER_01
That s a hope, because then you don t have to do that much drilling, you can collect from the surface.
1
SPEAKER_00
Right, or I m thinking even remotely.
1
SPEAKER_00
Oh, remotely.
1
SPEAKER_01
Yeah.
1
SPEAKER_01
That s sad that there s a single cell civilization living underneath all that ice, trying, trying, trying to get up, trying to get out.
1
SPEAKER_00
So Enceladus gives you a slightly better chance of that because Enceladus is a moon of Saturn, and it s broadly similar to Europa in some ways.
1
SPEAKER_00
It s an icy satellite, it has a subsurface ocean that s probably in touch with the rocky interior, but it has these massive geysers at its south pole where it s
2
SPEAKER_01
out material that appears to be originating all the way from the ocean.
2
SPEAKER_01
And so in that case, you could potentially fly through that plume and scoop up that material and hope that at the velocities you d be scooping it up, you re not destroying any signature of the life you re looking for.
2
SPEAKER_01
But let s say that you have some ingenuity and can come up with a way to do that, you know, it potentially gives you
2
SPEAKER_01
a more direct opportunity at least to try to measure those bacteria directly.
2
SPEAKER_00
Can you tell me a little more on, how do you pronounce it?
2
SPEAKER_00
Salas?
2
SPEAKER_01
Enceladus.
2
SPEAKER_00
Enceladus?
2
SPEAKER_00
Can you tell me a little bit more about Enceladus?
2
SPEAKER_00
Like we ve been talking about way too much about Jupiter.
2
SPEAKER_00
Saturn doesn t get enough love.
2
SPEAKER_00
Not enough really.
2
SPEAKER_00
Saturn doesn t get as much love, so what s Enceladus?
2
SPEAKER_00
Is that the most exciting moon of Saturn?
2
SPEAKER_01
Depends on your perspective.
2
SPEAKER_01
It s very exciting from an astrobiology perspective.
2
SPEAKER_01
I think Enceladus and Titan are the two most unique and interesting moons of Saturn.
2
SPEAKER_01
They definitely both get the most attention also from the life perspective.
2
SPEAKER_00
So what s more likely, Titan or Enceladus for life?
2
SPEAKER_00
If you were to bet all your money in terms of like investing, which to investigate, what are the difference between the two that are interesting to you?
2
SPEAKER_01
Yeah, so the potential for life in each of those two places is very different.
2
SPEAKER_01
So Titan is the one place in the solar system where you might imagine, again, all of this is so speculative, but you might imagine life evolving in the atmosphere.
2
SPEAKER_01
So from a biology perspective, Titan is interesting because it forms complex organic molecules in its atmosphere.
2
SPEAKER_01
It has a dense atmosphere.
2
SPEAKER_01
It s actually denser than Earth s.
2
SPEAKER_01
It s the only moon that has an atmosphere denser than Earth s.
2
SPEAKER_01
And it s got tons of methane in it.
2
SPEAKER_01
What happens is that methane gets irradiated, it breaks up and it reforms with other things in the atmosphere.
2
SPEAKER_01
It makes these complex organic molecules and it s effectively doing prebiotic chemistry in the atmosphere.
2
SPEAKER_00
While still being freezing cold.
2
SPEAKER_01
Yes.
2
SPEAKER_00
Okay.
2
SPEAKER_00
What would that be like?
2
SPEAKER_00
Would that be pleasant for humans to hang out there?
2
SPEAKER_00
Is it just really cold?
2
SPEAKER_01
There s nowhere in the solar system that would be pleasant for humans.
2
SPEAKER_01
It would be cold.
2
SPEAKER_01
You couldn t breathe the air.
2
SPEAKER_00
Colonization-wise, if there s an atmosphere, isn t that a big plus?
2
SPEAKER_00
Or still a ton of radiation?
2
SPEAKER_00
Okay, so, okay, so Titan, that s a really nice feature that the life could be in the atmosphere, because then it might be remotely observable, or certainly is more accessible if you visit.
2
SPEAKER_00
Okay, so what about Enceladus?
2
SPEAKER_00
So that would be still in the ocean.
2
SPEAKER_01
Right.
2
SPEAKER_01
And Enceladus has the advantage, like I said, of spewing material out of its south pole so you could collect it.
2
SPEAKER_01
But it has the disadvantage of the fact that we don t actually really understand how its ocean could stay frozen, or sorry, could stay globally liquid over the age of the solar system.
2
SPEAKER_01
And so there are some models that say that it s going through this
2
SPEAKER_01
cyclical evolution where the ocean freezes completely and thaws completely and the orbit sort of oscillates in and out of these eccentricities.
2
SPEAKER_01
And in that case, the potential for life ever occurring there in the first place is a lot lower because if you only have an ocean for 100 million years, is that enough time?
2
SPEAKER_00
And it also means there might be mass extinction events if it does occur.
2
SPEAKER_00
Then it just freezes.
2
SPEAKER_00
Again, very sad, man.
2
SPEAKER_00
This is very depressing.
2
SPEAKER_00
All that slaughter of life elsewhere.
2
SPEAKER_00
How unlikely do you think life is on Earth?
2
SPEAKER_00
So when you look, when you study other planets, and you study the contents of other planets,
2
SPEAKER_00
Does that give you a perspective on the origin of life on Earth?
2
SPEAKER_00
Which again is full of mystery in itself.
2
SPEAKER_00
Not the evolution, but the origin.
2
SPEAKER_00
The first springing to life.
2
SPEAKER_00
Like from nothing to life.
2
SPEAKER_00
From the basic ingredients to life.
2
SPEAKER_00
I guess another way of asking it is how unique are we?
2
SPEAKER_01
Yeah, it s a great question and it s one that just scientifically we don t have an answer to.
2
SPEAKER_01
We don t even know how many times life evolved on Earth, if it was only once or if it happened independently a thousand times in different places.
2
SPEAKER_01
We don t know whether it s happened anywhere else in the universe, although it feels absurd to believe that we are the only life that evolved in the entire universe, but it s conceivable.
2
SPEAKER_01
We just have just no real information.
2
SPEAKER_01
We don t understand really how life came about in the first place on Earth.
2
SPEAKER_00
I mean, so if you look at the Drake equation, that tries to estimate how many alien civilizations are out there.
2
SPEAKER_00
Planets have a big part to play in that equation.
2
SPEAKER_00
If you were to bet money,
2
SPEAKER_00
in terms of the odds of origins of life on Earth.
2
SPEAKER_00
I mean, this all has to do with how special and unique is Earth.
2
SPEAKER_00
What you land in terms of the number of civilizations has to do with how unique the rare Earth hypothesis is.
2
SPEAKER_00
How rare, special is Earth?
2
SPEAKER_00
How rare and special is the solar system?
2
SPEAKER_00
Like if you had to bet all your money on a completely unscientific question.
2
SPEAKER_00
Well no, it s actually rigorously scientific, we just don t know a lot of things in that equation.
2
SPEAKER_00
There s a lot of mysteries about that.
2
SPEAKER_00
And it s slowly becoming better and better understood in terms of exoplanets, in terms of how many solar systems are out there, where there s planets that are Earth-like planets.
2
SPEAKER_00
It s getting better and better understood.
2
SPEAKER_00
What s your sense?
2
SPEAKER_00
From that perspective, how many alien civilizations out there?
2
SPEAKER_01
so zero or one you re right that the equation is is being better understood but you re really only talking about the first three parameters in the equation or something you know how many stars are there how many planets per star and then we re just barely scratching the surface of what fraction of those planets might be habitable the rest of the terms in the equation are like how likely is life to evolve given habitable conditions how likely is it to survive all these things uh...
2
SPEAKER_01
There are all these huge unknowns.
2
SPEAKER_01
Actually, I remember when I first saw that equation, I think it was my first year of college, and I thought, this is ridiculous.
2
SPEAKER_01
This is a common sense that didn t need to give a name, you know?
2
SPEAKER_01
and B, just a bunch of unknowns.
2
SPEAKER_01
It s like putting our ignorance together in one equation.
2
SPEAKER_01
But I ve actually, now I understand this equation, you know, it s not something we ever necessarily have the answer to.
2
SPEAKER_01
It just gives us a framework for having the exact conversation we re having right now.
2
SPEAKER_01
And I think that s how it was intended in the first place when it was put into writing, was to give people a language to communicate about the factors that go into the potential for aliens to
2
SPEAKER_01
be out there and for us to find them.
2
SPEAKER_01
I would put money on there being aliens.
2
SPEAKER_01
I would not put money on us having definitive evidence of them in my lifetime.
2
SPEAKER_00
Well, definitive is a funny word.
2
SPEAKER_00
My sense is, this is the saddest part for me, is my sense in terms of intelligent alien civilizations,
2
SPEAKER_00
I feel like we re so self-obsessed that we literally would not be able to detect them, even when they re like in front of us.
2
SPEAKER_00
Like trees could be aliens, but just their intelligence could be realized on a scale, on a time scale or physical scale that we re not appreciating.
2
SPEAKER_00
Trees could be way more intelligent than us.
2
SPEAKER_00
I don t know.
2
SPEAKER_00
It s just a dumb example.
2
SPEAKER_00
It could be rocks.
2
SPEAKER_00
Or it could be things like, I love this, this is Dawkins memes.
2
SPEAKER_00
It could be the ideas we have.
2
SPEAKER_00
Where do ideas come from?
2
SPEAKER_00
Where do thoughts come from?
2
SPEAKER_00
Maybe thoughts are the aliens.
2
SPEAKER_00
Or maybe thoughts is the actual mechanisms of communication.
2
SPEAKER_00
in physics, right?
2
SPEAKER_00
This is like, we think of thoughts as something that springs up from neurons firing.
2
SPEAKER_00
Where the hell did they come from?
2
SPEAKER_00
And now, what about consciousness?
2
SPEAKER_00
Maybe consciousness is the communication.
2
SPEAKER_00
It sounds like ridiculous, but like, we re so self-centered on this space-time communication in physical space, using like written language, like spoken with audio,
2
SPEAKER_00
on a time scale that s very specific, on a physical scale that s very specific.
2
SPEAKER_00
So I tend to think that bacteria will probably recognize, like moving organisms will probably recognize, but when that forms itself into intelligence, most likely it ll be robots of some kind, because we won t be meeting the origins, we ll be meeting the creations of those intelligences.
2
SPEAKER_00
We just would not be able to appreciate it, and that s the saddest thing to me, that,
2
SPEAKER_00
We, yeah, we re too dumb.
2
SPEAKER_00
to see aliens.
2
SPEAKER_00
Like we re too, we kind of think like, look at the progress of science.
2
SPEAKER_00
We ve accomplished so much.
2
SPEAKER_00
The sad thing, it could be that we re just like in the first 0.0001% of understanding anything.
2
SPEAKER_00
It s humbling.
2
SPEAKER_01
I hope that s true.
2
SPEAKER_01
Because I feel like we re very ignorant as a species.
2
SPEAKER_01
And I hope that our current level of knowledge only represents the 0.001% of what we will someday achieve.
2
SPEAKER_01
That actually feels optimistic to me.
2
SPEAKER_00
Well, I feel like that s easier for us to comprehend in the space of biology and not as easy to comprehend in the space of physics, for example, because we have a sense that like, if you talk to theoretical physicists, they have a sense that we understand the basic laws that form the nature of reality of our universe.
2
SPEAKER_00
But so there s much more, like physicists are much more confident.
2
SPEAKER_00
Biologists are like, this is a squishy mess, we re doing our best.
2
SPEAKER_00
But I would be, it d be fascinating to see if physicists themselves would also be humbled by their being, like what the hell is dark matter and dark energy?
2
SPEAKER_00
What the hell is the, not just the origin, not just the Big Bang, but everything that happened since the Big Bang.
2
SPEAKER_00
A lot of things that happened since the Big Bang we have no ideas about except basic models of physics.
2
SPEAKER_01
Or what happened before the Big Bang.
2
SPEAKER_00
Yeah, what happened before.
2
SPEAKER_00
Or what s happening inside a black hole.
2
SPEAKER_00
Why is there a black hole at the center of our galaxy?
2
SPEAKER_00
Can somebody answer this?
2
SPEAKER_00
A supermassive black hole?
2
SPEAKER_00
Nobody knows how it started.
2
SPEAKER_00
And they seem to be in the middle of all galaxies.
2
SPEAKER_00
So that could be a portal for aliens to communicate through consciousness.
2
SPEAKER_00
All right, back to planets.
2
SPEAKER_00
What s your favorite outside of Earth?
2
SPEAKER_00
What s your favorite planet or moon?
2
SPEAKER_00
Maybe outside of the ones.
2
SPEAKER_00
Well, first, have we talked about it already?
2
SPEAKER_00
And then if we did mention it, what s the one outside of that?
2
SPEAKER_01
Oh gosh, I have to come up with another favorite that s not Ayo.
2
SPEAKER_00
Oh, Ayo is the favorite.
2
SPEAKER_00
Oh, absolutely.
2
SPEAKER_00
Why is Ayo the favorite?
2
SPEAKER_01
I mean, basically everything I ve already said.
2
SPEAKER_01
It s just such an amazing and unique object.
2
SPEAKER_01
But on, I guess, a personal note, it s probably the object that made me become a planetary scientist.
2
SPEAKER_01
It s the first thing in the solar system that really deeply captured my interest.
2
SPEAKER_01
When I started my PhD, I wanted to be an astrophysicist working on things like galaxy evolution.
2
SPEAKER_01
And sort of slowly, I had done some projects in the solar system, but I was the thing that like really caught me in to doing solar system science.
2
SPEAKER_00
Okay, let s let s leave moons aside.
2
SPEAKER_00
What s your favorite planet?
2
SPEAKER_00
It sounds like you like moons better than planets.
2
SPEAKER_00
So it s, that s accurate.
2
SPEAKER_01
But the planets are, are fascinating.
2
SPEAKER_01
I think
2
SPEAKER_01
You know, I find the planets in the solar system really fascinating.
2
SPEAKER_01
What I like about the moons is that there s so much less that is known.
2
SPEAKER_01
There s still a lot more discovery space and the questions that we can ask are still the bigger questions.
2
SPEAKER_00
Gotcha.
2
SPEAKER_01
Which, you know, maybe I m being unfair to the planets because we re still trying to understand things like, was there ever life on Mars?
2
SPEAKER_01
And that is a huge question and one that we ve sent numerous robots to Mars to try to answer.
2
SPEAKER_01
So maybe I m being unfair to the planets.
2
SPEAKER_01
But there is certainly quite a bit more information that we have about the planets than the moons.
2
SPEAKER_01
But, I mean, Venus is a fascinating object.
2
SPEAKER_01
I like the objects that lie at the extremes.
2
SPEAKER_01
I think that if we can make a sort of theory or like I ve been saying framework for understanding planets and moons that can incorporate even the most extreme ones, then you know, those are the things that really test your theory and test your understanding.
2
SPEAKER_01
And so they ve always really fascinated me, not so much the nice habitable places like Earth, but these extreme places like Venus that have
2
SPEAKER_01
sulfuric acid clouds and just incredibly hot and dense surfaces.
2
SPEAKER_01
And Venus, of course, I love volcanism for some reason, and Venus has, probably has volcanic activity, definitely has in their recent past, maybe has ongoing today.
2
SPEAKER_00
But what do you make of the news?
2
SPEAKER_00
Maybe you can update it in terms of life being discovered in the atmosphere of Venus.
2
SPEAKER_00
Is that, sorry, okay.
2
SPEAKER_00
You have an opinion, I can already tell you have opinions.
2
SPEAKER_00
Was that fake news?
2
SPEAKER_00
I got excited when I saw that.
2
SPEAKER_00
What s the final, is there a life on Venus?
2
SPEAKER_01
So the detection that was reported was the detection of the molecule phosphine.
2
SPEAKER_01
And they said,
2
SPEAKER_01
they tried every other mechanism they could think of to produce phosphine, and no mechanism worked.
2
SPEAKER_01
And then they said, well, we know that life produces phosphine.
2
SPEAKER_01
And so that was sort of the train of logic.
2
SPEAKER_01
And I don t personally believe that phosphine was detected in the first place.
2
SPEAKER_00
Okay, so I mean, this is just one study.
2
SPEAKER_00
But I, as a layman, am skeptical a little bit
2
SPEAKER_00
about tools that sense the contents of an atmosphere, like contents of an atmosphere from remotely, and making conclusive statements about life.
2
SPEAKER_01
Oh, yeah, well, that connection that you just made, the contents of the atmosphere to the life is...
2
SPEAKER_01
is a tricky one.
2
SPEAKER_01
And yeah, I know that that claim received a lot of criticism for the lines of logic that went from detection to claim of life.
2
SPEAKER_01
Even the detection itself, though, doesn t
2
SPEAKER_01
doesn t meet the sort of historical scientific standards of detection.
2
SPEAKER_01
It was very tenuous detection and only one line of the species was detected and a lot of really complicated data analysis methods had to be applied to even make that weak detection.
2
SPEAKER_00
So it could be noise, it could be polluted data, it could be all those things, and so it doesn t meet the level of rigor that you would hope.
2
SPEAKER_00
But of course, I mean, we re doing our best.
2
SPEAKER_00
And it s clear that the human species are hopeful to find life.
2
SPEAKER_01
Clearly, yes.
2
SPEAKER_01
Everyone is so excited about that possibility.
2
SPEAKER_00
All right, let me ask you about Mars.
2
SPEAKER_00
So,
2
SPEAKER_00
There s a guy named Elon Musk, and he seems to wanna take something called Dogecoin there, first of the moon.
2
SPEAKER_00
I m just kidding about the Dogecoin.
2
SPEAKER_00
I don t even know what the heck is up with that whole.
2
SPEAKER_00
I think humor has power in the 21st century in a way to spread ideas in the most positive way.
2
SPEAKER_00
I love that kind of humor, because it makes people smile, but it also kind of, it s like a Trojan horse for cool ideas.
2
SPEAKER_00
You open with humor and you, like the humor is the appetizer and then the main meal is the science and the engineering.
2
SPEAKER_00
Anyway, do you think it s possible to colonize Mars?
2
SPEAKER_00
or other planets in the solar system, but we re especially looking to Mars.
2
SPEAKER_00
Is there something about planets that make them very harsh to humans?
2
SPEAKER_00
Is there something in particular you think about?
2
SPEAKER_00
And maybe in a high, like big picture perspective, do you have a hope we do, in fact, become a multi-planetary species?
2
SPEAKER_01
I do think that if our species survives long enough, and we don t wipe ourselves out or get wiped out by some other means, that we will
2
SPEAKER_01
eventually be able to colonize other planets.
2
SPEAKER_01
I do not expect that to happen in my lifetime.
2
SPEAKER_01
I mean, tourists may go to Mars, tourists, people who commit years of their life to going to Mars as a tourist may go to Mars.
2
SPEAKER_01
I don t think that we will colonize it.
2
SPEAKER_00
Is there a sense why it s just too harsh of an environment to, I guess, too costly to build something habitable there for a large population?
2
SPEAKER_01
I think that we need to do a lot
3
SPEAKER_02
of work and learning how to use the resources that are on the planet already to do the things we need.
3
SPEAKER_02
So if you re talking about someone going there for a few months,
3
SPEAKER_02
So I ll back up a little bit.
3
SPEAKER_02
There are many things that make Mars not hospitable.
3
SPEAKER_02
Temperature, you can t breathe the air, you need a pressure suit.
3
SPEAKER_02
Even if you re on the surface, the radiation environment is, you know, even in all of those things, the radiation environment is too harsh for the human body.
3
SPEAKER_02
All of those things seem like they could eventually have technological solutions.
3
SPEAKER_02
The challenge, the real significant challenge to me seems to be the creation of a self-sustaining civilization there.
3
SPEAKER_02
You know, you can bring pressure suits, you can bring oxygen to breathe, but those are all in limited supply, and if we re going to colonize it, we need to find
3
SPEAKER_02
ways to make use of the resources that are there to do things like produce food, produce the air that humans need to keep breathing, just in order to make it self-sustaining, there s a tremendous amount of work that has to be done.
3
SPEAKER_02
And people are working on these problems, but I think that s going to be a major obstacle in going from visiting where we can bring everything we need to survive in the short term to actually colonizing.
3
SPEAKER_01
Yeah, I find that whole project of the human species quite inspiring, these huge moonshot projects.
3
SPEAKER_01
Somebody, I was reading something in terms of the source of food that may be the most effective on Mars, is you could farm insects.
3
SPEAKER_01
That s the easiest thing to farm.
3
SPEAKER_01
So we ll be eating cockroaches if we re living on Mars.
3
SPEAKER_01
because that s the easiest thing to actually, as a source of protein.
3
SPEAKER_01
So growing a source of protein is the easiest thing as insects.
3
SPEAKER_01
I just imagine this giant, for people who are afraid of insects, this is not a pleasant, maybe you re not supposed to even think of it that way.
3
SPEAKER_01
It ll be like a cockroach milkshake or something like that.
3
SPEAKER_02
Right, I wonder, have people been working on the genetic engineering of insects to make them
3
SPEAKER_01
more radiation-friendly.
3
SPEAKER_02
Or pressure-resistant or whatever.
3
SPEAKER_01
What can possibly go wrong?
3
SPEAKER_01
Cockroaches become radiation-resistant.
3
SPEAKER_01
They re already like survived everything.
3
SPEAKER_01
Plus I took an allergy test in Austin, so everybody s like the allergy levels are super high there.
3
SPEAKER_01
And one of the things apparently, I m not allergic to any insects except cockroaches, which is hilarious.
3
SPEAKER_01
So maybe,
3
SPEAKER_01
Well, I m gonna use that as, you know how people use an excuse that I m allergic to cats to not have cats?
3
SPEAKER_01
I m gonna use that as an excuse to not go to Mars as one of the first batch of people.
3
SPEAKER_02
I was gonna ask, if you had the opportunity, would you go?
3
SPEAKER_01
Yeah, I m joking about the cockroach thing.
3
SPEAKER_01
I would definitely go.
3
SPEAKER_01
I love challenges.
3
SPEAKER_01
I love doing things where the possibility of death is not insignificant.
3
SPEAKER_01
because it makes me appreciate it more.
3
SPEAKER_01
Meditating on death makes me appreciate life.
3
SPEAKER_01
And when the meditation on death is forced on you because of how difficult the task is, I enjoy those kinds of things.
3
SPEAKER_01
Most people don t, it seems like.
3
SPEAKER_01
But I love the idea of difficult journeys.
3
SPEAKER_01
for no purpose whatsoever except exploration, going into the unknown, seeing what the limits of the human mind and the human body are.
3
SPEAKER_01
It s like, what the hell else is this whole journey that we re on for?
3
SPEAKER_01
But it could be because I grew up in the Soviet Union, there s a kind of love,
3
SPEAKER_01
for space, like the space race, the Cold War created, I don t know if still it permeates American culture as much, but especially with the dad as a scientist, I think I ve,
3
SPEAKER_01
I ve loved the idea of humans striving out towards the stars, always, like from the engineering perspective.
3
SPEAKER_01
It s been really exciting.
3
SPEAKER_01
I don t know if people love that as much in America anymore.
3
SPEAKER_01
I think Elon is bringing that back a little bit, that excitement about rockets and going out there.
3
SPEAKER_01
So that s hopeful, but for me, I always loved that idea.
3
SPEAKER_01
From an alien scientist perspective, if you were to look back on Earth,
3
SPEAKER_01
is there something interesting you could say about Earth?
3
SPEAKER_01
Like how would you summarize Earth?
3
SPEAKER_01
Like in a report, you know, like Hitchhiker s Guide to the Galaxy, like if you had to report, like write a paper on Earth, or like a letter, like a one pager, summarizing the contents of the surface and the atmosphere, is there something interesting?
3
SPEAKER_01
Like do you ever take that kind of perspective on it?
3
SPEAKER_01
I know you like volcanism, so volcanoes, that ll probably be in the report.
3
SPEAKER_02
I was going to say that s where I was going to go first.
3
SPEAKER_02
There are a few things to say about the atmosphere, but in terms of the volcanoes, so one of the
3
SPEAKER_02
really interesting puzzles to me in planetary sciences.
3
SPEAKER_02
So we can look out there, and we ve been talking about surfaces and volcanoes and atmospheres and things like that.
3
SPEAKER_02
But that is just this tiny little veneer on the outside of the planet.
3
SPEAKER_02
And most of the planet is completely sort of inaccessible to telescopes or to spacecraft missions.
3
SPEAKER_02
You can drill a meter into the surface, but that s still really the veneer.
3
SPEAKER_02
And one of the cool puzzles is looking at what s going on on the surface and trying to figure out what s happening underneath, or just any kind of indirect means that you have to study the interior because you can t dig into it directly.
3
SPEAKER_02
Even on Earth, you can t dig deep into Earth.
3
SPEAKER_02
So from that perspective, looking at Earth,
3
SPEAKER_02
One thing that you would be able to tell from orbit, given enough time, is that Earth has tectonic plates.
3
SPEAKER_02
So you would see that volcanoes follow the edges.
3
SPEAKER_02
If you trace where all the volcanoes are on Earth, they follow these
3
SPEAKER_02
lines that trace the edges of the plates.
3
SPEAKER_02
And similarly, you would see things like the Hawaiian string of volcanoes that you could infer, just like, you know, we did, as people actually living on Earth, that the plates are moving over some plume that s coming up through the mantle.
3
SPEAKER_02
And so you could use that to say, if the aliens could look at where the volcanoes are happening on Earth and say something about the fact that Earth has plate tectonics, which makes it really unique in the solar system.
3
SPEAKER_01
Oh, really?
3
SPEAKER_01
So the other plants don t have plate tectonics?
3
SPEAKER_02
It s the only one that has plate tectonics, yeah.
3
SPEAKER_01
What about Io and the friction and all that, that s not plate tectonics?
3
SPEAKER_01
What s the difference between... Oh, it s plate tectonics, like another layer of solid rock that moves around and there s cracks?
3
SPEAKER_01
Exactly.
3
SPEAKER_02
Yeah, so Earth has plates of solid rock sitting on top of a partially molten layer and those plates are kind of shifting around.
3
SPEAKER_02
On Io,
3
SPEAKER_02
It doesn t have that, and the volcanism is what we call heat pipe volcanism.
3
SPEAKER_02
It s the magma just punches a hole through the crust and comes out on the surface.
3
SPEAKER_02
I mean, that s a simplification, but that s effectively what s happening.
3
SPEAKER_01
Through the freezing cold crust.
3
SPEAKER_02
Yes.
3
SPEAKER_02
Very cold, very rigid crust.
3
SPEAKER_02
Yeah.
3
SPEAKER_01
How does that look like, by the way?
3
SPEAKER_01
I don t think we ve mentioned, so the gas that s expelled, if we were to look at it, does it look beautiful, or does it look boring?
3
SPEAKER_02
The gas?
3
SPEAKER_01
Like the whole thing, like the magma punching through.
3
SPEAKER_01
Oh my gosh.
3
SPEAKER_01
The icy.
3
SPEAKER_02
Yes, I m sure it would be beautiful, and the pictures we ve seen of it are beautiful.
3
SPEAKER_02
So the magma will come out of the lava, will come out of these fissures, and you have these curtains of lava that are,
3
SPEAKER_02
maybe even a kilometer high.
3
SPEAKER_02
So if you looked at videos, I don t know how many volcano videos you ve looked at on Earth, but you sometimes see a tiny, tiny version of this in Iceland.
3
SPEAKER_02
You see just these sheets of magma coming out of a fissure when you have this really low viscosity magma, sort of water-like coming out at these sheets.
3
SPEAKER_02
And the plumes that come out, because there s no atmosphere, all the plume molecules are just
3
SPEAKER_02
or plume particles, where they end up is just a function of the direction that they left the vent.
3
SPEAKER_02
So they re all following ballistic trajectories.
3
SPEAKER_02
And you end up with these umbrella plumes, you don t get these sort of complicated plumes that you have on Earth, that are occurring because of how that material is interacting with the atmosphere that s there, you just have these huge umbrellas.
3
SPEAKER_02
And it s been hypothesized, actually, that the atmosphere is made of sulfur dioxide.
3
SPEAKER_02
And
3
SPEAKER_02
that you could have these kind of ash particles from the volcano and the sulfur dioxide would condense onto these particles and you d have sulfur dioxide snow coming out of these volcanic plumes.
3
SPEAKER_01
And there s not much light though, right?
3
SPEAKER_01
So you wouldn t be able to like it would make a good it would not make a good Instagram photo because you have to.
3
SPEAKER_01
Would you see the snow?
3
SPEAKER_02
Sure.
3
SPEAKER_02
There s light.
3
SPEAKER_02
It depends.
3
SPEAKER_01
Okay, so you could, okay.
3
SPEAKER_02
Depends what angle you re looking at it, where the sun is, all the things like that.
3
SPEAKER_02
You know, the sunlight is much weaker, but it s still there.
3
SPEAKER_01
It s still there.
3
SPEAKER_01
And how big is Io in terms of gravity?
3
SPEAKER_01
Is it smaller?
3
SPEAKER_01
Is it a pretty small moon?
3
SPEAKER_02
It s quite a bit smaller than Earth anyway.
3
SPEAKER_01
It s smaller than Earth, okay.
3
SPEAKER_01
Okay, cool, so they float up for a little bit.
3
SPEAKER_01
So it floats, yeah, no, you re right, that would be gorgeous.
3
SPEAKER_01
What else about Earth is interesting besides volcanoes?
3
SPEAKER_01
So plate tectonics, I didn t realize that that was a unique element of a planet in the solar system.
3
SPEAKER_01
Because that, I wonder what, I mean, we experience it as human beings, it s quite painful because of earthquakes and all those kinds of things, but I wonder if there s nice features to it.
3
SPEAKER_02
Yeah, so coming back to habitability again, things like tectonics and plate tectonics are thought to play an important role in the surface being habitable.
3
SPEAKER_02
And that s because you have a way of recycling materials.
3
SPEAKER_02
So if you have a stagnant surface, everything, you know, you use up all the free oxygen, everything reacts until you no longer have reactants that life can extract energy from.
3
SPEAKER_02
And so if nothing s changing on your surface, you kind of reach this stagnation point.
3
SPEAKER_02
But something like plate tectonics recycles material.
3
SPEAKER_02
You bring up new fresh material from the interior, you bring down material that s up on the surface, and that can kind of refresh your nutrient supply, in a sense, or the sort of raw materials that the surface has to work with.
3
SPEAKER_02
So from a kind of astrobiologist perspective, looking at Earth, you would see that recycling of material because the plate tectonics, you would also see how much oxygen is in Earth s atmosphere.
3
SPEAKER_02
And between those two things, you would identify Earth as a reasonable candidate for a habitable environment, in addition to, of course, the, you know, pleasant temperature and liquid water.
3
SPEAKER_02
But the abundance of oxygen and the plate tectonics both play a role as well.
3
SPEAKER_01
And also see like tiny dot satellites flying around and rockets.
3
SPEAKER_01
I wonder if they would be able to, I really think about that, like if aliens were to visit, I mean, would they really see humans as the thing they should be focusing on?
3
SPEAKER_01
I think it would take a while, right?
3
SPEAKER_01
Because it s so obvious that that should, because there s like so much incredible, in terms of biomass, humans are a tiny, tiny, tiny fraction.
3
SPEAKER_01
There s like ants.
3
SPEAKER_01
they would probably detect ants, right?
3
SPEAKER_01
Or they probably would focus on the water and the fish, because there s like a lot of water.
3
SPEAKER_01
I was surprised to learn that there s more species on land than there is in the sea.
3
SPEAKER_01
Like there s 90, I think 90 to 95% of the species are on land.
3
SPEAKER_02
Or on land, not in the sea.
3
SPEAKER_01
Not in the sea.
3
SPEAKER_01
I thought like there s so much going on in the sea, but no, the variety that like the branches created by evolution, apparently, it s probably a good answer from evolutionary biology perspective, why land created so much diversity, but it did.
3
SPEAKER_01
So like the sea, there s so much not known about the sea, about the oceans,
3
SPEAKER_01
It s not diversity friendly.
3
SPEAKER_01
What can I say?
3
SPEAKER_01
It needs to improve its diversity.
3
SPEAKER_01
What can you say?
3
SPEAKER_02
Do you think the aliens would come?
3
SPEAKER_02
I mean, the first thing they would see is, I suppose, our cities.
3
SPEAKER_02
Assuming that they had some idea of what a natural world looked like, they would see cities and say, these don t belong.
3
SPEAKER_02
Which of these many species created these?
3
SPEAKER_01
Yeah, I mean, there s, if I were to guess, it would, it s a good question.
3
SPEAKER_01
I don t know if you do this when you look at the telescope, whether you look at geometric shapes, like if it s, because to me, like hard corners, like what do we think is engineered?
3
SPEAKER_01
things that are like have kind of straight lines and corners and so on.
3
SPEAKER_01
They will probably detect those in terms of buildings would stand out to them.
3
SPEAKER_01
Because that s that goes against the basic natural physics of the world.
3
SPEAKER_01
But
3
SPEAKER_01
I don t know if the electricity and lights and so on, it could be, honestly, it could be the plate tectonics.
3
SPEAKER_01
It could be like, hmm, like the volcanoes, that d be, okay, that s a source of heat, and then they would focus.
3
SPEAKER_01
They might literally, I mean, depending on how alien life forms are, they might notice the microorganisms before they notice the big, like notice the ant before the elephant.
3
SPEAKER_01
Cause like there s a lot more of them, depending what their measuring device.
3
SPEAKER_01
We think like size matters, but maybe with their tools of measurement, they would look for quantity versus size.
3
SPEAKER_01
Like why focus on the big thing, focus on the thing that there s a lot of.
3
SPEAKER_01
And when they see humans, depending on their measurement devices, they might see we re made up of billions of organisms.
3
SPEAKER_01
Like, the fact that we re very human, we think we re one organism, but that may not be the case.
3
SPEAKER_01
They might see, in fact, they might also see like a human city as one organism.
3
SPEAKER_01
Like, what is this thing that like, clearly this organism gets aroused at night, because the lights go on, and then it sleeps during the day.
3
SPEAKER_01
I don t know, like what perspective you take on the city.
3
SPEAKER_01
Is there something interesting about Earth or other planets in terms of weather patterns?
3
SPEAKER_01
So we talked a lot about volcanic patterns.
3
SPEAKER_01
Is there something else about weather that s interesting, like storms or variations in temperature, all those kinds of things?
3
SPEAKER_02
Yeah, so there s sort of every planet and moon has a kind of interesting and unique weather pattern.
3
SPEAKER_02
And those weather patterns are really, we don t have a good understanding of them.
3
SPEAKER_02
We don t even have a good understanding of the the global circulation patterns of many of these atmospheres, why the storm systems occur.
3
SPEAKER_02
So
3
SPEAKER_02
The composition and occurrence of storms and clouds and these objects is another one of these kind of windows into the interior that I was talking about with surfaces, one of these ways that we can get perspective and what the composition is of the interior and how the circulation is working.
3
SPEAKER_02
So circulation will bring some species up from deeper in the atmosphere of the planet to some altitude that s a little bit colder and that species will condense out and form a cloud at that altitude.
3
SPEAKER_02
and we can detect, in some cases, what those clouds are composed of.
3
SPEAKER_02
And looking at where those occur can tell you how the circulation cells are, whether the atmospheric circulation is, say, coming up at the equator and going down at the poles, or whether you have multiple cells in the atmosphere.
3
SPEAKER_02
And I mean, Jupiter s atmosphere
3
SPEAKER_02
is just insane.
3
SPEAKER_02
There s so much going on.
3
SPEAKER_02
You look at these pictures, and there s all these vortices and anti-vortices, and you have these different bands that are moving in opposite directions that may be giving you information about the deep in the atmosphere, physically deep properties of Jupiter s interior and circulation.
3
SPEAKER_01
What are these vortices?
3
SPEAKER_01
What s the basic material of the storms?
3
SPEAKER_02
It s condensed molecules from the atmosphere, so ammonia ice particles.
3
SPEAKER_02
In the case of Jupiter, it s methane ice.
3
SPEAKER_02
In the case of, let s say, Uranus and Neptune and other species, you can kind of construct a chemical model for which species can condense where, and so you see a cloud at a certain altitude within the atmosphere, and you can make a guess at what that cloud is made of, and sometimes measure it directly, and different species make different colors as well.
3
SPEAKER_01
Oh, cool.
3
SPEAKER_01
Ice storms, okay.
3
SPEAKER_02
I mean, the climate of Uranus has always been fascinating to me because it orbits on its side, and it has a 42-year orbital period.
3
SPEAKER_02
And so with Earth, our seasons are because our equator is tipped just a little bit to the plane that we orbit in.
3
SPEAKER_02
So sometimes the sunlight s a little bit above the equator, and sometimes it s a little bit below the equator.
3
SPEAKER_02
But on Uranus, it s like for 10 years, the sunlight is directly on the North Pole, and then it s directly on the equator, and then it s directly on the South Pole.
3
SPEAKER_02
And it s actually kind of amazing that the atmosphere doesn t look crazier than it does.
3
SPEAKER_02
But understanding how, taking again, like one of these extreme examples, if we can understand why that atmosphere behaves in the way it does, it s kind of a test of our understanding of how atmospheres work.
3
SPEAKER_01
So it like heats up one side of the planet for 10 years.
3
SPEAKER_01
and then freezes it the next, like, and that you re saying would be.
4
SPEAKER_01
should probably lead to some chaos, and it doesn t.
4
SPEAKER_00
The fact that it doesn t tells you something about the atmosphere.
4
SPEAKER_00
So atmospheres have a property that surfaces don t have, which is that they can redistribute heat a lot more effectively.
4
SPEAKER_01
So they have a stabilizing, like self-regulating aspect to them, that they re able to deal with extreme conditions.
4
SPEAKER_01
But predicting how that complex system
4
SPEAKER_01
on rolls is very difficult, as we know, about predicting the weather on Earth even.
4
SPEAKER_00
Oh my goodness.
4
SPEAKER_01
Even with the little variation we have on Earth.
4
SPEAKER_00
You know, people have tried to put together global circulation models.
4
SPEAKER_00
You know, we ve done this for Earth.
4
SPEAKER_00
People have tried to do these for other planets as well.
4
SPEAKER_00
And it is a really hard problem.
4
SPEAKER_00
So Titan, for example, like I said, it s one of the best studied atmospheres in the solar system, and people have tried to make these global circulation models and actually predict what s going to happen moving into sort of the next season of Titan, and those predictions have ended up being wrong.
4
SPEAKER_00
And so then, you know, I don t know, it s always exciting when a prediction is wrong, because it means that there s something more to learn, like your theory wasn t sufficient, and then you get to go back and learn something by how you have to modify the theory to make it fit.
4
SPEAKER_01
I m excited by the possibility of one day there ll be, for various moons and planets, there ll be news programs reporting the weather with the fake confidence of, like as if you can predict the weather.
4
SPEAKER_01
We talked quite a bit about planets and moons.
4
SPEAKER_01
Can we talk a little bit about asteroids?
4
SPEAKER_00
For sure.
4
SPEAKER_01
What s an asteroid and what kind of asteroids are there?
4
SPEAKER_00
So the asteroids, let s talk about just the restricted to the main asteroid belt, which is the region, it s a region of debris basically between Mars and Jupiter.
4
SPEAKER_00
And
4
SPEAKER_00
the sort of belts of debris throughout the solar system, the outer solar system, you know, the Kuiper belt that we talked about, the asteroid belt, as well as certain other populations where they accumulate because they re gravitationally more favored, are remnant objects from the origin of the solar system.
4
SPEAKER_00
And so one of the reasons that we are so interested in them, aside from potentially the fact that they could come hit Earth, but scientifically,
4
SPEAKER_00
it s, it gives us a window into understanding the composition of the material from which Earth and the other planets formed, and how that material was kind of redistributed over the history of the solar system.
4
SPEAKER_00
So the asteroids, one could classify them in two different ways.
4
SPEAKER_00
Some of them are ancient objects.
4
SPEAKER_00
So they
4
SPEAKER_00
accreted out of the sort of disk of material that the whole solar system formed out of and have kind of remained ever since more or less the same.
4
SPEAKER_00
They ve probably collided with each other and we see all these collisional fragments.
4
SPEAKER_00
And you can actually look and based on their orbits say, you know, like these 50 objects originated as the same object.
4
SPEAKER_00
you can see them kind of dynamically moving apart after some big collision.
4
SPEAKER_00
And so some of them are these ancient objects, maybe that have undergone collisions.
4
SPEAKER_00
And then there s this other category of object that is the one that I personally find really interesting, which is remnants of objects that could have been planets.
4
SPEAKER_00
So early on, a bunch of potential planets accreted that we call planetesimals, and they formed, and they formed with a lot of energy, and they had enough time to actually differentiate.
4
SPEAKER_00
So some of these objects differentiated into cores and mantles and crusts.
4
SPEAKER_00
And then they were subsequently
4
SPEAKER_00
distracted in these massive collisions.
4
SPEAKER_00
And they now we have these fragments, we think fragments floating around the asteroid belt that are like bits of mantle bits of core bits.
4
SPEAKER_01
Basically, it s like puzzle pieces that you might be able to stitch together.
4
SPEAKER_01
Or I guess it s it s all it s all mixed up.
4
SPEAKER_01
So you can t stitch together the original planet candidates.
4
SPEAKER_01
Or is that possible to try to see if they kind of
4
SPEAKER_00
I mean, there s too many objects in there to... I think that there are cases where people have kind of looked at objects and by looking at their orbits, they say these objects should have originated together, but they have very different compositions.
4
SPEAKER_00
And so then you can hypothesize maybe they were different fragments of a differentiated object.
4
SPEAKER_00
But one of the really cool things about this is, you know, we ve been talking about
4
SPEAKER_00
getting clues into the interiors of planets.
4
SPEAKER_00
We ve never seen a planetary core or deep mantle directly.
4
SPEAKER_00
Some mantle material comes up on our surface and then we can see it, but you know, in sort of in bulk.
4
SPEAKER_00
We haven t seen these things directly and these asteroids potentially give us a chance to like, look at what our own core and mantle is like, or at least would be like if it had been also floating through space for a few billion years and getting irradiated and all that.
4
SPEAKER_00
But it s a cool potential window or like analogy into the interior of our own planet.
4
SPEAKER_01
Well, how do you begin studying some of these asteroids?
4
SPEAKER_01
If you were to put together a study, what are the interesting questions to ask that are a little bit more specific?
4
SPEAKER_01
Do you find a favorite asteroid that could be tracked and try to track it through telescopes?
4
SPEAKER_01
Or do you, is it has to be, you have to land on those things to study it?
4
SPEAKER_00
So when it comes to the asteroids, there s so many of them and the big pictures or the big questions are answered.
4
SPEAKER_00
So some questions can be answered by zooming in in detail on individual object, but mostly you re trying to do a statistical study.
4
SPEAKER_00
So you want to look at
4
SPEAKER_00
thousands of objects, even hundreds of thousands of objects, and figure out what their composition is and look at, you know, how many big asteroids there are of this composition versus how many small asteroids of this other composition and put together these kind of statistical properties of the asteroid belt.
4
SPEAKER_00
And those properties can be directly compared with the results of simulations for the formation of the solar system.
4
SPEAKER_01
What do we know about the surfaces of asteroids or the contents of the insides of asteroids?
4
SPEAKER_01
And what are still open questions?
4
SPEAKER_00
So I would say that we don t know a whole lot about their compositions.
4
SPEAKER_00
Most of them are small, and so you can t study them in such detail with telescopes as you could a planet or moon.
4
SPEAKER_00
And at the same time, because there are so many of them, you could send a spacecraft to a few, but you can t really get a statistical survey with spacecraft.
4
SPEAKER_00
And so a lot of...
4
SPEAKER_00
what we, a lot of what has been done comes down to sort of classification.
4
SPEAKER_00
You look at how bright they are.
4
SPEAKER_00
You look at whether they re red or blue.
4
SPEAKER_00
Simply, you know, whether their spectrum is sloped towards long wavelengths or short wavelengths.
4
SPEAKER_00
There are certain, if you point a spectrograph at their surfaces, there are certain features you can see.
4
SPEAKER_00
So you can tell that some of them have silicates on them.
4
SPEAKER_00
But these are the sort of
4
SPEAKER_00
they re pretty basic questions.
4
SPEAKER_00
We re still trying to classify them based on fairly basic information, in kind of combination with our general understanding of the material the solar system formed from.
4
SPEAKER_00
And so you re sort of, you re coming in with prior knowledge, which is that you more or less know what the materials are the solar system formed from, and then you re trying to classify them into these categories.
4
SPEAKER_00
There s still
4
SPEAKER_00
a huge amount of room for understanding them better and for understanding how their surfaces are changing in the space environment.
4
SPEAKER_01
Is it hard to land on an asteroid?
4
SPEAKER_01
Is this a dumb question?
4
SPEAKER_01
It feels like it would be quite difficult to actually operate a spacecraft in such a dense field of debris.
4
SPEAKER_00
Oh, the asteroid belt, there s a ton of material there, but it s actually not that dense.
4
SPEAKER_00
It is mostly open space.
4
SPEAKER_00
So mentally, do picture mostly open space with some rocks.
4
SPEAKER_00
The problem is some of them are not thought to be solid.
4
SPEAKER_00
So some of these asteroids, especially these core mantle fragments, you can think of as sort of solid like a planet.
4
SPEAKER_00
But some of them are just kind of aggregates of material.
4
SPEAKER_00
We call them rubble piles.
4
SPEAKER_00
And so there s not necessarily
4
SPEAKER_01
might look like a rock, but do a lot of them have kind of clouds around them, like a dust cloud thing?
4
SPEAKER_01
Or do you know what you re stepping on when you try to land on it?
4
SPEAKER_01
What are we supposed to be visualizing here?
4
SPEAKER_01
This is like very few have water, right?
4
SPEAKER_00
There s some water in the outer part of the asteroid belt, but they re not quite like comets.
4
SPEAKER_01
Okay.
4
SPEAKER_00
in the sense of having clouds around them.
4
SPEAKER_00
There are some crazy asteroids that do become active, like comets.
4
SPEAKER_00
That s a whole other category of thing that we don t understand.
4
SPEAKER_00
But their surfaces, I mean, we have visited some.
4
SPEAKER_00
You can, you know, find pictures the spacecraft have taken of them.
4
SPEAKER_00
We ve actually scooped up material off of the surface of some of these objects.
4
SPEAKER_00
We re bringing it back.
4
SPEAKER_00
to analyze it in the lab.
4
SPEAKER_00
And there s a mission that s launching next year to land on one of these supposedly core fragment objects to try to figure out what the heck it is and what s going on with it.
4
SPEAKER_00
But the surfaces, you know, they re, they re
4
SPEAKER_00
You can picture a solid surface with some little grains of sand or pebbles on it and occasional boulders, maybe some fine dusty regions, dust kind of collecting in certain places.
4
SPEAKER_01
Is there, do you worry about this?
4
SPEAKER_01
Is there any chance that one of these fellas destroys all of human civilization by
4
SPEAKER_01
an asteroid kind of colliding with something, changing its trajectory and heading its way towards Earth.
4
SPEAKER_00
That is definitely possible.
4
SPEAKER_00
And it doesn t even have to necessarily collide with something and change its trajectory.
4
SPEAKER_00
We re not tracking all of them.
4
SPEAKER_00
We can t track all of them yet.
4
SPEAKER_00
You know, there s still... A lot of them.
4
SPEAKER_00
People are tracking a lot of them, and we are doing our best to track more of them, but there are a lot of them out there, and it would be potentially catastrophic if one of them impacted Earth.
4
SPEAKER_00
Have you, are you aware of this Apophis object?
4
SPEAKER_00
So there s an asteroid, a near-Earth object called Apophis that people thought had a decent probability of hitting Earth in 2029 and then potentially again in 2036.
4
SPEAKER_00
So they did a lot of studies.
4
SPEAKER_00
It s not actually going to hit Earth, but it is going to come
4
SPEAKER_00
very close.
4
SPEAKER_00
It s going to be visible in the sky in a relatively dark, I mean, not even that dark, probably not visible from Los Angeles, but
4
SPEAKER_00
and it s gonna come a tenth of the way between the Earth and the Moon.
4
SPEAKER_00
It s gonna come closer, apparently, than some geosynchronous communication satellites.
4
SPEAKER_00
Oh, wow.
4
SPEAKER_00
So that is a close call, but people have studied it and apparently are very confident it s not actually going to hit us, but it wasn t.
4
SPEAKER_01
I m gonna have to look into this, because I m very sure, I m very sure what s gonna happen if an asteroid actually hits Earth.
4
SPEAKER_01
that the scientific community and government will confidently say that we have nothing to worry about, it s going to be a close call.
4
SPEAKER_01
And then last minute, they ll be like, there was a miscalculation.
4
SPEAKER_01
They re not lying, it s just like the space of possibilities, because it s very difficult to track these kinds of things, and there s a lot of kind of, there s complexities involved to this, there s a lot of uncertainties.
4
SPEAKER_01
Something tells me that human civilization will end with, we ll see it coming,
4
SPEAKER_01
And then last minute there ll be a oops.
4
SPEAKER_01
We ll see it coming and we ll be like, no, this is threatening, but no problem, no problem.
4
SPEAKER_01
And last minute it ll be like, oops, that was a miscalculation.
4
SPEAKER_01
And then it s all over in a matter of like a week.
4
SPEAKER_01
We re just very positive and optimistic today.
4
SPEAKER_01
Is there any chance that Bruce Willis can save us?
4
SPEAKER_01
In the sense that from what you know about asteroids, is there something that,
4
SPEAKER_01
you can catch them early enough to change volcanic eruptions, right?
4
SPEAKER_01
Sort of drill, put a nuclear weapon inside and break up the asteroid or change its trajectory.
4
SPEAKER_00
There is potential for that if you catch it early enough in advance.
4
SPEAKER_00
I think, in theory, if you knew
4
SPEAKER_00
five years in advance.
4
SPEAKER_00
depending on the objects and how much you would need to deflect it, you could deflect it a little bit.
4
SPEAKER_00
I don t know that it would be sufficient in all cases.
4
SPEAKER_00
And this is definitely not my specific area of expertise, but my understanding is that there is something you could do.
4
SPEAKER_00
But it also, how you would carry that out depends a lot on the properties of the asteroid.
4
SPEAKER_00
If it s a solid object versus a rubble pile.
4
SPEAKER_00
So let s say you planted some,
4
SPEAKER_00
bomb in the middle of it, and it blew up, but it was just kind of a pile of material anyway, and then that material comes back together, and then you kind of just have the same thing.
4
SPEAKER_01
Presumably, its trajectory would be altered, but it s- It s like Terminator 2, when it s like the thing that just like, you shoot it and it splashes, and then it comes back together.
4
SPEAKER_01
It would be very useless.
4
SPEAKER_01
That s fascinating.
4
SPEAKER_01
And what s fascinating, I ve gotten a lot of hope
4
SPEAKER_01
from watching SpaceX rockets that land.
4
SPEAKER_01
There s so much, it s like, oh wow, from an AI perspective, from a robotics perspective, wow, we can do a hell of an amazing job with control.
4
SPEAKER_00
And,
4
SPEAKER_01
But then we have an understanding about surfaces here on Earth, we can map up a lot of things.
4
SPEAKER_01
I wonder if we can do that some kind of detail of being able to have that same level of precision in landing on surfaces with as wide of a variety as asteroids have.
4
SPEAKER_01
So be able to understand the exact properties of the surface
4
SPEAKER_01
and be able to encode that into whatever rocket that lands sufficiently to i presume humans unlike them unlike the movies he was would likely get in the way i guess you d all be done by robots michael and drill placed uh... the explosive that should all be done to control the robots and then you should be able to dynamically just to uh...
4
SPEAKER_01
to the surface.
4
SPEAKER_01
The flip side of that, for a robotics person, I don t know if you ve seen these, it s been very heartbreaking.
4
SPEAKER_01
Somebody I know well, Russ Tedrick at MIT, led the DARPA Robotics Challenge team for the Humanoid Robot Challenge.
4
SPEAKER_01
For DARPA, I don t know if you ve seen videos of robots on two feet falling.
4
SPEAKER_01
but you re talking about millions, several years of work with some of the most brilliant roboticists in the world, millions of dollars, and the final thing is a highlight video on YouTube of robots falling, but they had a lot of trouble with uneven surfaces.
4
SPEAKER_01
That s basically what you have to do with, the challenge involves, you re mostly autonomous with some partial human communication.
4
SPEAKER_01
but that human communication is broken up, like you don t get a, you get a noisy channel.
4
SPEAKER_01
So you can, humans can, which is very similar to what it would be like in humans remotely operating a thing on an asteroid.
4
SPEAKER_01
And so with that, robots really struggle.
4
SPEAKER_01
There s some hilarious, painful videos of like a robot not able to like open the door.
4
SPEAKER_01
And then it tries to open the door without like, it misses the handle and in doing so like falls.
4
SPEAKER_01
I mean, it s painful to watch.
4
SPEAKER_01
So there s that, and then there s SpaceX.
4
SPEAKER_01
So I have hope from SpaceX, and then I have less hope from Bipedal Robotics.
4
SPEAKER_01
But it s fun to kind of imagine.
4
SPEAKER_01
And I think the planetary side of it comes into play in understanding the surfaces of these asteroids more and more.
4
SPEAKER_01
that forget sort of destruction of human civilization, it d be cool to have like spacecraft just landing on all these asteroids to study them at scale and being able to figure out dynamically whether it s a rubble pile or whether it s a solid objects.
4
SPEAKER_01
Do you see that kind of future of science maybe 100, 200, 300 years from now where there s just robots
4
SPEAKER_01
expanding out through the solar system, like sensors essentially.
4
SPEAKER_01
Some of it taking pictures from a distance, some of them landing, just exploring and giving us data.
4
SPEAKER_01
Cause it feels like we re working with very little data right now.
4
SPEAKER_00
Sure.
4
SPEAKER_00
I, I do see exploration going that way.
4
SPEAKER_00
I think, um,
4
SPEAKER_00
the way that NASA is currently or historically has been doing missions is putting together these these really large missions that do a lot of things that are extremely well tested and have a very low rate of failure.
4
SPEAKER_00
But now that these sort of CubeSat
4
SPEAKER_00
technologies are becoming easier to build, easier to launch.
4
SPEAKER_00
They re very cheap.
4
SPEAKER_00
And you know, NASA is getting involved in this as well.
4
SPEAKER_00
There s a lot of interest in these missions that are relatively small, relatively cheap, and just do one thing.
4
SPEAKER_00
So
5
SPEAKER_00
So you can really optimize it to just do this one thing.
5
SPEAKER_00
And maybe you could build 100 of them and send them to different asteroids.
5
SPEAKER_00
And they would just collect this one piece of information from each asteroid.
5
SPEAKER_00
It s a kind of different, more distributed way of doing science, I guess.
5
SPEAKER_00
And there s a ton of potential there.
5
SPEAKER_00
I agree.
5
SPEAKER_01
Let me ask you about objects or one particular object from outside our solar system.
5
SPEAKER_01
We don t get to study many of these, right?
5
SPEAKER_01
We don t get stuff that just flies in out of nowhere from outside the solar system and flies through.
5
SPEAKER_01
Apparently there s been two recently in the past few years.
5
SPEAKER_01
One of them is a muamua.
5
SPEAKER_01
What are your thoughts about Oumuamua?
5
SPEAKER_01
So fun to say.
5
SPEAKER_01
Could it be space junk from a distant alien civilization or is this just a weird shaped comet?
5
SPEAKER_00
I like the way that s phrased.
5
SPEAKER_00
So a muamua is a fascinating object.
5
SPEAKER_00
Just the fact that we have started discovering things that are coming in from outside our solar system is amazing, and can start to study them.
5
SPEAKER_00
And now that we have seen some, we can
5
SPEAKER_00
design now kind of thinking in advance, the next time we see one, we will be much more ready for it, we will know which telescopes we want to point at it, we will have explored whether we could even launch a fast turnaround mission to actually like, get to it before it leaves the solar system.
5
SPEAKER_00
In terms of a muamua, yeah, it s
5
SPEAKER_00
For an object in our solar system, it s really unusual in two particular ways.
5
SPEAKER_00
One is the dimensions that we don t see natural things in our solar system that are kind of long and skinny.
5
SPEAKER_00
The things we see in our solar system don t deviate from spherical by that much.
5
SPEAKER_00
And then that it showed these strange properties of accelerating as it was leaving the solar system, which was not understood at first.
5
SPEAKER_00
In terms of the alien space junk, you know, as a scientist, I cannot rule out that possibility.
5
SPEAKER_00
I have no evidence to the contrary.
5
SPEAKER_00
However... So you re saying there s a chance.
5
SPEAKER_00
I cannot, as a scientist, honestly say that I can rule out that it s alien space junk.
5
SPEAKER_00
However, I see the kind of alien explanation as following the Sagan s extraordinary claims require extraordinary evidence.
5
SPEAKER_00
If you are going to actually claim that something is aliens,
5
SPEAKER_00
you need to carefully evaluate, one needs to carefully evaluate the other options and see whether it could just be something that we know exists that makes sense.
5
SPEAKER_00
In the case of Oumuamua,
5
SPEAKER_00
there are explanations that fit well within our understanding of how things work.
5
SPEAKER_00
So there are two hypotheses for what it could be made of.
5
SPEAKER_00
They re both basically just ice shards.
5
SPEAKER_00
In one case, it s a nitrogen ice shard that came off of something like Pluto in another solar system.
5
SPEAKER_00
That Pluto got hit with something and broke up into pieces, and one of those pieces came through our solar system.
5
SPEAKER_00
In the other scenario, it s
5
SPEAKER_00
a bit of a failed solar system.
5
SPEAKER_00
So our solar system formed out of a collapsing molecular cloud.
5
SPEAKER_00
Sometimes those molecular clouds are not massive enough, and they sort of collapse into bits, but they don t actually form a solar system, but you end up with these kind of chunks of hydrogen ice, apparently.
5
SPEAKER_00
And so one of those chunks of hydrogen ice could have got ejected and passed through our solar system.
5
SPEAKER_00
So both cases,
5
SPEAKER_00
explain these properties in about the same way.
5
SPEAKER_00
So those ices will sublimate once they ve passed the sun.
5
SPEAKER_00
And so as they re moving away from the sun, you have the hydrogen or nitrogen ice sublimating off the sunward part of it.
5
SPEAKER_00
And so that is responsible for the acceleration.
5
SPEAKER_00
The shape also, because you have all this ice sublimating off the surface, if you take something, the analogy that
5
SPEAKER_00
works pretty well here is for a bar of soap.
5
SPEAKER_00
Your bar of soap starts out sort of close to spherical, at least from a physicist s perspective.
5
SPEAKER_00
And as you use it over time, you eventually end up with this long, thin shard because it s been just by sort of weathering, as we would call it.
5
SPEAKER_00
And so in the same way, if you just sublimate material off of one of these ice shards, it ends up long and thin, and it ends up accelerating out of the solar system.
5
SPEAKER_00
And so given that these properties can be reasonably well explained that way,
5
SPEAKER_00
You know, we should be extremely skeptical about attributing things to aliens.
5
SPEAKER_01
See, the reason I like to think that it s aliens is because it puts a lot of priority on us not being lazy and we need to catch this thing next time it comes around.
5
SPEAKER_01
I like the idea that there s objects, not like, it almost saddens me.
5
SPEAKER_01
They come out of the darkness really fast and just fly by and go and leave.
5
SPEAKER_01
it just seems like a wasted opportunity not to study them.
5
SPEAKER_01
It s the easiest way to do space travel outside of the solar system, is having the things come to us, right?
5
SPEAKER_00
I like that way of putting it.
5
SPEAKER_01
And it would be nice to just land on it.
5
SPEAKER_01
And first of all, really importantly, detect it early.
5
SPEAKER_00
Yes.
5
SPEAKER_01
And then land on it with a really nice spacecraft and study the hell out of it.
5
SPEAKER_01
If there s a chance it s aliens, alien life,
5
SPEAKER_01
It just feels like such a cheap way, inexpensive way to get information about alien life or something interesting that s out there.
5
SPEAKER_01
And I m not sure if an ice shard from another planetary system will be interesting, but it very well could be.
5
SPEAKER_01
It could be totally new sets of materials.
5
SPEAKER_01
It could be, tell us about composition of planets we don t quite understand.
5
SPEAKER_01
And it s just nice when, especially in the case of a momoa, I guess it was pretty close to earth.
5
SPEAKER_01
It would have been nice to, you know, let s say, don t go there, they come to us.
5
SPEAKER_01
I don t know.
5
SPEAKER_01
That s what makes me, that s what makes me quite sad.
5
SPEAKER_01
It s a missed opportunity.
5
SPEAKER_00
Well, yeah, and whether whether you think it s aliens or not, it s it s a missed opportunity.
5
SPEAKER_00
But you know, we weren t prepared and we will be prepared for the next ones.
5
SPEAKER_00
And as so there s been a movement in astronomy more towards what s called time domain astronomy.
5
SPEAKER_00
So kind of monitoring the whole sky all the time at all wavelengths, that s kind of the goal.
5
SPEAKER_00
And so we expect to detect
5
SPEAKER_00
many more of these in the future, even though these were the first two we saw, our potential to detect them is only increasing with time.
5
SPEAKER_00
And so there will be more opportunities.
5
SPEAKER_00
And, you know, based on these two, we now can
5
SPEAKER_00
actually sit and think about what we ll do when the next one shows up.
5
SPEAKER_01
I also, what it made me realize, I know I didn t really think through this, but it made me realize if there is alien civilizations out there, the thing we re most likely to see first would be space junk.
5
SPEAKER_01
My stupid understanding of it.
5
SPEAKER_01
And the second would be really dumb kind of,
5
SPEAKER_01
you could think of maybe like relay nodes or something, objects that you need to have a whole lot of for particular purposes of like space travel and so on, like speed limit signs or something, I don t know, whatever we have on earth a lot of, that s dumb, it s not aliens in themselves, it s like artifacts that are useful to the engineering in the systems that are engineered by alien civilizations.
5
SPEAKER_01
So like,
5
SPEAKER_01
it would, we would see a lot of stuff in terms of setting, in terms of looking for alien life and trying to communicate with it.
5
SPEAKER_01
Maybe we should be looking not for like smart creatures or systems to communicate with.
5
SPEAKER_01
Maybe we should be looking for artifacts or even as dumb as like space junk.
5
SPEAKER_01
It just kind of reframed my perspective of like, what are we looking for as signs?
5
SPEAKER_01
Because there could be a lot of stuff that doesn t have intelligence, but gives us really strong signs that there somewhere is life or intelligent life.
5
SPEAKER_01
And yeah, that made me kind of, I know it might be dumb to say, but it reframed the kind of thing that we should be looking for.
5
SPEAKER_00
Yeah, so the benefit of looking for intelligent life is that we perhaps have a better chance of recognizing it.
5
SPEAKER_00
We couldn t necessarily recognize what an alien stop sign looked like.
5
SPEAKER_00
And maybe, you know, the theorists or the people who sort of model and try to understand solar system objects are pretty good at coming up with models for anything.
5
SPEAKER_00
I mean, maybe a mua mua was a stop sign, but we re clever enough that we could come up with some physical explanations for it.
5
SPEAKER_00
And then, you know, we all want to go with the simplest possible.
5
SPEAKER_00
We all want to believe the sort of most skeptical possible explanation.
5
SPEAKER_00
And so we missed it because we re too good at coming up with alternate explanations for things.
5
SPEAKER_01
And it s such an outlier, such a rare phenomenon that we can t study a hundred or a thousand of these objects.
5
SPEAKER_01
We had just one.
5
SPEAKER_01
And so the science almost destroys the possibility of something special being there.
5
SPEAKER_01
It s like Johnny Ive, this designer of Apple, I don t know if you know who that is.
5
SPEAKER_01
He s the lead designer.
5
SPEAKER_01
He s the person who designed the iPhone and all the major things.
5
SPEAKER_01
And he talked about, he s brilliant, one of my favorite humans on earth and one of the best designers in the history of earth.
5
SPEAKER_01
He talked about like when he had this origins of an idea, like in his baby stages, he would not tell Steve Jobs because Steve would usually like trample all over it.
5
SPEAKER_01
He would say this is a dumb idea.
5
SPEAKER_01
And so I sometimes think of the scientific community in that sense because the weapon of the scientific method is so strong at its best that it sometimes crushes the out of the box outlier
5
SPEAKER_01
evidence.
5
SPEAKER_01
You know, we don t get a lot of that evidence because we don t have, we re not lucky enough to have a lot of evidence, so we have to deal with just special cases.
5
SPEAKER_01
And special cases could present an inkling
5
SPEAKER_01
of something much bigger, but the scientific method user tramples all over it.
5
SPEAKER_01
And it s hard to know what to do with that because the scientific method works.
5
SPEAKER_01
But at the same time, every once in a while, it s like a balance.
5
SPEAKER_01
You have to do 99% of the time, you have to do like scientific rigor, but every once in a while, this is not you saying, me saying, smoke some weed and sit back and think, I wonder, you know, it s the Joe Rogan thing, it s entirely possible.
5
SPEAKER_01
that it s alien space junk.
5
SPEAKER_01
Anyway.
5
SPEAKER_00
Yeah, I think so.
5
SPEAKER_00
I completely agree.
5
SPEAKER_00
And I think that most scientists do speculate about these things.
5
SPEAKER_00
It s just, at what point do you act on those things?
5
SPEAKER_00
So you re right that the scientific method has inherent skepticism.
5
SPEAKER_00
And for the most part, that s a good thing, because it means that we re not just believing crazy things all the time.
5
SPEAKER_00
But
5
SPEAKER_00
It s an interesting point that requiring that high level of rigor occasionally means that you will miss something that is truly interesting because you needed to verify it three times and it wasn t verifiable.
5
SPEAKER_01
I also think like when you communicate with the general public, I think there s power in that 1% speculation of just demonstrating authenticity as a human being, as a curious human being.
5
SPEAKER_01
I think too often, I think this is changing, but I saw, I ve been quite disappointed in my colleagues throughout 2020 with the coronavirus.
5
SPEAKER_01
There s too much speaking from authority as opposed to speaking from curiosity.
5
SPEAKER_01
There s some of the most incredible science that s been done in 2020, especially on the virology, biology side.
5
SPEAKER_01
And the kind of being talked down to by scientists is always really disappointing to me, as opposed to inspiring.
5
SPEAKER_01
Like the things we, there s a lot of uncertainty about the coronavirus, but we know a lot of stuff.
5
SPEAKER_01
And we speak from, scientists from various disciplines speak from data in the face of that uncertainty.
5
SPEAKER_01
And we re curious, we don t know what the hell is going on.
5
SPEAKER_01
We don t know if this virus is going to evolve, mutate.
5
SPEAKER_01
We don t know if this virus or the next one might destroy all of human civilization.
5
SPEAKER_01
You can t speak with certain, in fact, I was on a survey paper about masks.
5
SPEAKER_01
something I don t talk much about, because I don t like politics, but we don t know if masks work, but there s a lot of evidence to show that they work for this particular virus.
5
SPEAKER_01
The transmission of the virus is fascinating, actually.
5
SPEAKER_01
The biomechanics of the way viruses spread is fascinating.
5
SPEAKER_01
If it wasn t destructive, it would be beautiful.
5
SPEAKER_01
And we don t know, but it s inspiring to apply the scientific method to the best of our ability, but also to show that you don t always know everything, and perhaps not about the virus as much, but other things speculate.
5
SPEAKER_01
What if?
5
SPEAKER_01
What if it s the worst case and the best case?
5
SPEAKER_01
Because that s ultimately what we are, descendants of apes that are just curious about the world around us.
5
SPEAKER_00
Yeah, I ll just add to that, not on the topic of masks, but on the topic of curiosity.
5
SPEAKER_00
I mean, I think that astronomy and planetary science as a field are unique because for better and for worse, they don t directly impact humanity.
5
SPEAKER_00
So, you know, we re not studying virology to prevent transmission of, you know, illness amongst humans.
5
SPEAKER_00
characterizing volcanoes on Earth that could destroy cities.
5
SPEAKER_00
And it really is a more curious and, in my opinion, playful scientific field than many.
5
SPEAKER_00
So for better and worse, we can kind of afford to pursue some of the speculation more because human lives are not in danger if we speculate a little bit too freely and get something wrong.
5
SPEAKER_01
Yeah, definitely.
5
SPEAKER_01
In the space of AI, I am worried that we re sometimes too eager, speaking for myself, to flip the switch to on just to see what happens.
5
SPEAKER_01
Maybe sometimes we wanna be a little bit careful about that, because bad things might happen.
5
SPEAKER_01
Is there books or movies in your life, long ago or recently, that were inspiring, had an impact on you that you would recommend?
5
SPEAKER_00
Yeah, absolutely.
5
SPEAKER_00
So many that I just don t know where to start with it.
5
SPEAKER_00
So I love reading.
5
SPEAKER_00
I read obsessively.
5
SPEAKER_00
I ve been reading fiction and a little bit of nonfiction, but mostly fiction obsessively since I was a child and just never stopped.
5
SPEAKER_00
So I have some favorite books.
5
SPEAKER_00
None of them are easy readings.
5
SPEAKER_00
So I definitely, I mean, I recommend them for somebody who likes an intellectual challenge in the books that they read.
5
SPEAKER_00
So maybe I should go chronologically.
5
SPEAKER_00
I have at least three.
5
SPEAKER_00
I m not going to go through 50 here.
5
SPEAKER_01
But yeah, I d love to also like, maybe ideas that you took away from sure you mentioned.
5
SPEAKER_00
Yeah, yeah.
5
SPEAKER_00
Why they were so compelling to me.
5
SPEAKER_00
One of the first books that really captured my fascination was Nabokov s book Pale Fire.
5
SPEAKER_01
Oh, wow.
5
SPEAKER_00
Are you familiar with it?
5
SPEAKER_00
I read it actually for a class.
5
SPEAKER_00
It s one of the few books I ve ever read for a class that I actually really liked.
5
SPEAKER_00
And the book is, it s in some sense, a puzzle.
5
SPEAKER_00
He s a brilliant writer, of course.
5
SPEAKER_00
But the book is like, it s formatted like a poem.
5
SPEAKER_00
So there s an introduction, a very long poem, and footnotes.
5
SPEAKER_00
And
5
SPEAKER_00
you get partway through it before realizing that the whole thing is actually a novel unless you sort of read up on it going in but but the whole thing is a novel and there s a story that slowly reveals itself over the course of all of this and kind of reveals this
5
SPEAKER_00
just fascinating character basically and how his mind works in this story.
5
SPEAKER_00
The idea of a novel also being a kind of intellectual puzzle and something that slowly reveals itself over the course of reading was really fascinating to me and I have since found a lot more writers like that.
5
SPEAKER_00
contemporary example that comes to mind is Kazuo Ishiguro, who s pretty much all of his books are like slow reveals over the course of the book and like nothing much happens in the books, but you keep reading them because you just want to know like what the reality is that he s slowly revealing to you.
5
SPEAKER_00
The kind of discovery oriented reading maybe.
5
SPEAKER_01
What s the second one?
5
SPEAKER_00
Perhaps my favorite writer is Renier Maria Rilke.
5
SPEAKER_00
Wow.
5
SPEAKER_00
Are you familiar with him?
5
SPEAKER_01
No, also not familiar.
5
SPEAKER_01
You re hitting the hidden ones.
5
SPEAKER_01
I mean, I know in the Book of Well, but I ve never read Pale Fire.
5
SPEAKER_01
But Rilke, I ve never, I know it s a very difficult read.
5
SPEAKER_01
I know that much.
5
SPEAKER_00
Yeah, right.
5
SPEAKER_00
All of these are difficult reads.
5
SPEAKER_00
I think I just,
5
SPEAKER_00
I read for in part for an intellectual challenge.
5
SPEAKER_00
But Rilke, so he wrote one thing that might be characterizable as a novel, but he wrote a lot of poetry.
5
SPEAKER_00
I mean, he wrote this series of poems called the Duino Elegies that were very impactful for me.
6
SPEAKER_00
personally, just emotionally.
6
SPEAKER_00
Which actually, it kind of ties in with astronomy, in that
6
SPEAKER_00
there s there s a sense, you know, in which we re all going through our lives alone.
6
SPEAKER_00
And there s just this sense of kind of profound loneliness in the existence of every individual human.
6
SPEAKER_00
And I think I was drawn to astronomy in part because
6
SPEAKER_00
the sort of vast spaces, the kind of loneliness and desolateness of space made the sort of internal loneliness feel okay, in a sense, it like gave companionship.
6
SPEAKER_00
And that s how I feel about Rilke s poetry.
6
SPEAKER_00
He turns the kind of desolation and loneliness of human existence into something joyful and almost meaningful.
6
SPEAKER_01
Yeah, there s something about melancholy, I don t know about Rilke in general, but contemplating the melancholy nature of the human condition that makes it okay.
6
SPEAKER_01
I tend to, from an engineering perspective, think that there is so much loneliness we haven t explored within ourselves yet.
6
SPEAKER_01
And that s my hope is to build AI systems that help us explore our own loneliness.
6
SPEAKER_01
I think that s kind of what love is and friendship is, is somebody who in a very small way helps us explore our own loneliness.
6
SPEAKER_01
Like they listen.
6
SPEAKER_01
We connect like two lonely creatures connect for a time.
6
SPEAKER_01
And it s like, oh, like acknowledge that we exist together.
6
SPEAKER_01
Like,
6
SPEAKER_01
for a brief time, but in a somewhat shallow way, I think relative to how much it s possible to truly connect those two consciousnesses.
6
SPEAKER_01
So AI might be able to help on that front.
6
SPEAKER_01
So what s the third one?
6
SPEAKER_00
Actually, you know, I hadn t realized until this moment, but it s yet another one of these kind of slow reveal books.
6
SPEAKER_00
It s a contemporary Russian, I think, Russian American writer named Olga Grushin, G-R-U-S-H-I-N.
6
SPEAKER_00
And she wrote this just phenomenal book called The Dream Life of Sukhonov that I read this year.
6
SPEAKER_00
Maybe it was last year for the first time.
6
SPEAKER_00
And it s just a really beautiful
6
SPEAKER_00
This one you could call a character study, I think, of a Russian father coming to terms with himself and his own past as he potentially slowly loses his mind.
6
SPEAKER_00
Slow reveal.
6
SPEAKER_01
Slow reveal.
6
SPEAKER_00
Well, that s apparent from the beginning.
6
SPEAKER_00
I hope I don t think it s a spoiler.
6
SPEAKER_01
declining to madness.
6
SPEAKER_01
Spoiler alert.
6
SPEAKER_00
So all of these are really heavy.
6
SPEAKER_00
I don t know.
6
SPEAKER_00
I just, I don t have anything lighter to recommend.
6
SPEAKER_00
Ishiguro s the light version of this.
6
SPEAKER_00
Okay.
6
SPEAKER_01
Well, heavy has a certain kind of beauty to it in itself.
6
SPEAKER_01
Is there advice you would give to a young person today that looks up to the stars and wonders what the heck they want to do with their life?
6
SPEAKER_01
So career, science, life in general, you ve for now chosen a certain kind of path of curiosity.
6
SPEAKER_01
what insights do you draw from that that you can give as advice to others?
6
SPEAKER_00
I think for somebody, I would not presume to speak to giving people advice on life and humanity overall, but for somebody thinking of being a scientist, so there are a couple of things.
6
SPEAKER_00
One sort of practical thing, which is career-wise, I hadn t appreciated this going into science, but you need to
6
SPEAKER_00
So the questions you re working on and the techniques you use are both of very high importance, maybe equal importance for being happy in your career.
6
SPEAKER_00
If there are questions you re interested in, but the techniques that you need to use to do them
6
SPEAKER_00
are tedious for you, then your job is going to be miserable, even if the questions are inspiring.
6
SPEAKER_00
But if the techniques that you use are things that excite you, then your job is fun every day.
6
SPEAKER_00
So for me, I m fascinated by the solar system, and I love telescopes.
6
SPEAKER_00
And I love doing data analysis, playing with data from telescopes, coming up with new ways to use telescopes.
6
SPEAKER_00
And so that s where I have found that mesh.
6
SPEAKER_00
But if I was interested in, you know, the dynamical evolution of the solar system, how the orbits of things evolve, then I would need to do a different type of work that I would just not find as appealing.
6
SPEAKER_00
And so it just wouldn t be a good fit.
6
SPEAKER_00
And so it sort of is, seems like an unromantic thing to have to think about the techniques being the thing you want to work on also.
6
SPEAKER_00
But it really makes a profound difference for, I think, your happiness.
6
SPEAKER_00
scientific career.
6
SPEAKER_01
I think that s really profound.
6
SPEAKER_01
It s like the thing, the menial tasks.
6
SPEAKER_01
If you enjoy those, that s a really good sign that that s the right path for you.
6
SPEAKER_01
I think David Foster Wallace said that the key to life is to be unboreable.
6
SPEAKER_01
So basically, everything should be exciting.
6
SPEAKER_01
I don t think that s feasible, but you should find an area where everything is exciting.
6
SPEAKER_01
I mean, depending on the day, but you could find the joy in everything, not just the big exciting, quote unquote, things that everyone thinks is exciting, but the details, the...
6
SPEAKER_01
the repetitive stuff, the menial stuff, the stuff that takes years, the stuff that involves a lot of failure and all those kinds of things that you find that enjoyable.
6
SPEAKER_01
That s actually really profound to focus on that.
6
SPEAKER_01
Because people talk about like dreams and passion and goals and so on, the big thing, but that s not actually what takes you there.
6
SPEAKER_01
What takes you there is every single day, putting in the hours, and that s what actually makes up life, is the boring bits.
6
SPEAKER_01
And if the boring bits aren t boring, then that s an exciting life.
6
SPEAKER_01
Let me, because when you were talking so romantically and passionately about Ayo, I remember the poem by Robert Frost.
6
SPEAKER_01
So let me ask you, let me read the poem and ask what your opinion is.
6
SPEAKER_01
It s called Fire and Ice.
6
SPEAKER_00
Oh, yeah, I could almost recite this from memory.
6
SPEAKER_01
Some say the world will end in fire, some say in ice.
6
SPEAKER_01
From what I ve tasted of desire, I hold with those who favor fire.
6
SPEAKER_01
But if I had to perish twice, I think I know enough of hate to say that for destruction, ice is also great and will suffice.
6
SPEAKER_01
So let me ask, if you had to only choose one,
6
SPEAKER_01
Would you choose the world to end in fire, in volcanic eruptions, in heat and magma or in ice frozen over?
6
SPEAKER_01
Fire or ice?
6
SPEAKER_00
Fire.
6
SPEAKER_00
Excellent choice.
6
SPEAKER_00
I ve always been a fan of chaos and the idea of things just
6
SPEAKER_00
slowly getting cold and stopping and dying is just so depressing to me so much more depressing than things blowing up or you know burning and they re getting covered by a lava flow somehow they re like activity of it
6
SPEAKER_00
endows it with more like meaning to me, maybe.
6
SPEAKER_01
I ve just now had this vision of you, you know, in action films where you re walking away without looking back and there s explosions behind you.
6
SPEAKER_01
And you just got, and you put on like shades and then it goes to credits.
6
SPEAKER_01
So, Katherine, this was awesome.
6
SPEAKER_01
I think your work is really inspiring.
6
SPEAKER_01
The kind of things we ll discover about planets in the next few decades is super cool.
6
SPEAKER_01
And I hope, I know you said,
6
SPEAKER_01
There s probably not life in one of them, but there might be, and I hope we discover just that.
6
SPEAKER_01
And perhaps even on Io, within the volcanic eruptions, there s a little creature hanging on that we ll one day discover.
6
SPEAKER_01
Thank you so much for wasting all your valuable time with me today.
6
SPEAKER_01
It was really awesome.
6
SPEAKER_00
Yeah, likewise.
6
SPEAKER_00
Thank you for having me here.
6
SPEAKER_01
Thanks for listening to this conversation with Catherine Declare, and thank you to Fundrise, Blinkist, ExpressVPN, and Magic Spoon.
6
SPEAKER_01
Check them out in the description to support this podcast.
6
SPEAKER_01
And now, let me leave you with some words from Carl Sagan.
6
SPEAKER_01
On Titan, the molecules that have been raining down like mana from heaven for the last four billion years might still be there, largely unaltered, deep frozen, awaiting for the chemists from Earth.
6
SPEAKER_01
Thank you for listening and hope to see you next time.