S2E08: M Dwarf Planet Environment
This week, we're focusing on the physical environment of a planet orbiting an M dwarf star. We talk plate tectonics, atmospheric loss, compact multi-planet systems, and how uranium makes things HOT!
HOSTED by Dr. Moiya McTier (@GoAstroMo), astrophysicist and folklorist
GUESTS
Dr. Wendy Bohon is an earthquake geologist, science communicator, and AAAS If/Then Ambassador. You can follow Wendy on twitter at @DrWendyRocks and learn about all of her amazing work on her website, drwendybohon.com!
Will Waalkes is a PhD candidate in astronomy at UC Boulder who specializes in characterizing planets around M dwarf stars. You can check out his work on his website will-waalkes.github.io
MIDROLL
- Listen to HORSE wherever you get your podcasts, or at horsehoops.com
TRANSCRIPT
Moiya 0:08
Hello there friends. Welcome to Exolore, the show that helps you imagine other worlds with facts and science. I am your host, Dr. Moiya McTier. I'm an astrophysicist who studied pretty much everything in space from planetary orbits to the radiation leftover from the Big Bang to star formation and black holes and galaxy evolution. But I am especially interested in the motion of stars and how that affects the habitability of exoplanets, which are planets outside of our solar system. I am also a folklorist who specializes in building and analyzing fictional worlds. And this podcast is my way of sharing those worlds and that knowledge with you. So let's get started.
Moiya 0:53
This episode is the first in a three part series and every episode in the series will focus on building out the same world. The first episode, this one will focus on building out the environment. The second episode will focus on biology and the third will focus on culture. And the world characteristic for this series was inspired by my first ever exoplanet research project that I did the summer before my senior year of college. And that summer, I was studying a system called Kepler 186, I was really interested in learning the eccentricity of the fifth planet in the solar system, Kepler 186 F. If you want to know more about eccentricity, which is a measure of how elliptical or not round or circular a planet's orbit is, then I would recommend going back and listening to season one, Episode Four, "The World of Dancing Seals", where we imagine[d] what life might be like on a planet that has a very eccentric orbit. But in today's episode and the two others in the series, we're focusing on a different element of that planetary system, we're focusing on its star, because the cool thing about that system was that all of the planets orbited what's called an M dwarf star. And so in this three part series, we're going to be imagining a world that orbits an M dwarf star. And we're going to get into the details of how that really will affect the environment, the biology and the culture. And so without further ado, here are my guests for this environment episode. Thanks, friends for joining me, it's very exciting to have you here. The first thing I'll ask you to do is introduce yourself and Wendy, your left most on my screen. And I typically read from left to right. So do you want to tell me and the listeners who you are and what you do?
Wendy 2:38
Absolutely. My name is Wendy Bohon. And I'm an earthquake geologist at the incorporated research institutions for seismology. I also do science communication. So I work a lot on trying to make sure that we are communicating well about earthquakes and other rapid onset geologic hazards to all of the different stakeholders. So politicians and the public and educators, everybody needs to know more about earthquakes.
Moiya 3:02
That's awesome. How do you communicate that differently to those different groups?
Wendy 3:07
Well, there's a lot of different kind of recommended practices, depending on your audience. But clear, consistent messaging is really important. And also empathetic messaging, the things we study actually affect people's lives. And they can cause a lot of fear and anxiety. And so we love our science. We think it's really interesting and fascinating, but we recognize that it really does impact people's lives and mental health and well-being. So that's really important to keep at the forefront when we're talking about any of these hazards.
Moiya 3:36
It's a really great message. I think it'd be nice if more scientists approach[ed] communication and their work with more empathy.
Will 3:43
I agree.
Moiya 3:43
Yeah, absolutely. Will, what about you?
Will 3:47
Well, I am your friend.
Moiya 3:52
I've known Will, for what is it now? 5-6 years.
Will 3:55
[It's] going on six year[s]. But aside from that, I'm a fourth year PhD candidate at the University of Colorado Boulder, where I work on detecting and characterizing small exoplanets that orbit small stars. So typically, that means M dwarf stars, these sort of very low mass, typically active nearby stars that are very numerous in the galaxy. Without getting [too into it], I try to find these smaller, closer to terrestrial sized planets surrounding stars and ideally study their atmospheres. I'm working on different projects right now about that.
Moiya 4:32
That's gonna be real relevant. I noticed that you were very intentional about using quotes around "small planets" and "small stars." Who are you talking to that 's saying M dwarfs aren't small?
Will 4:45
Okay, so it's not so much that there's disagreement about M dwarfs being small. What a small planet is and what a small star is just means different things to different scientists. So specifically, I'm interested in planets with long periods and in the era of exoplanets that we've discovered, a long period is anything greater than 5 days, so long period planets that are less than 4 Earth radii. This is the sub-Neptune, super Earth, and Earth-like exoplanet regime.
Moiya 5:14
So that means there's lots of range for the size of our planet today. We're not necessarily limiting ourselves to earth-like.
Will 5:21
Right. It doesn't have to be one Earth radius to be a terrestrial planet with an atmosphere.
Moiya 5:26
Awesome. One thing I always ask my guests is what fictional worlds they've been inhabiting lately. So Will, movies, TV shows, books -- what do you got?
Will 5:39
Mostly, I've been in World of Warcraft. I've been I've been playing lots of World of Warcraft lately. I mean, that's where my sense of community comes from right now. It's an online game. So it's not like different in a quarantine, you know, so, it's actually been a really nice environment to hang out in. And I have friends, I have a community. I've just been spending lots of time in there. I started reading Assata: An Autobiography by Assata Shakur. Jesus, I'm two chapters in and I would already die for her. I mean, you know, I would have before. It's a very emotional [and] really difficult read. And it was a very interesting place to put my energy while I was kind of processing this shooting that happened.
Moiya 6:18
Wow, that's a lot.
Will 6:20
Sorry. Well, you asked what I was reading.
Moiya 6:21
No, you don't have to apologize. I admire your ability to choose to take on that sort of emotional toll when we're already dealing with everything else going on. Wendy, what about you? Are you also inhabiting some emotionally fraught fictional worlds?
Wendy 6:40
I am too emotionally fraught, to seek that out in my escapist realities. So I've been reading, Uprooted [by Naomi Novak].
Moiya 6:48
Yes.
Wendy 6:49
Have you read that book? It's so interesting. And I don't really know where it's supposed to be. It's an earth-like planet with trees and whatnot, but they're malevolent and it's very much wizards and escapists in the Nth degree, and then I've been playing Lego Indiana Jones with my six year old twins. So they're having a great time.
Moiya 7:08
So are you like acting out the the Indiana Jones movies? Have your kids seen Indiana Jones?
Wendy 7:13
They have. I mean, we have some questionable parenting during the pandemic.
Moiya 7:18
I'm not here to judge anyone. Also, I definitely watched those when I was little.
Wendy 7:21
You know, it's fine. We cover their eyes, you know, during the face melting scenes and all those kinds of things. And it's a little bit more violent than, say, SpongeBob, which is our normal go-to, but you know, it's fun. And it's Indiana Jones. It's sort of like Star Wars. Like there's guns and they're fighting, but it's kind of a classic. So we're playing the Lego version of that on Xbox and having a good time.
Moiya 7:44
Okay, this is going to show how out of touch I am. I didn't even know you could play Lego on the Xbox. Is it still building?
Wendy 7:51
Basically, you're in a Lego world that's made out of Legos. And so you're interacting just like any other video game, but it's more intended for kids. It's kind of like Minecraft where everything's square, and it's scenes from the movie. So they have hints on what they're supposed to do based on what they remember from the movies.
Will 8:07
Yes, they're very entertaining.
Moiya 8:08
I have a huge weak spot in in video gaming, because I have just never been into it. I didn't have any consoles growing up. And now so much good worldbuilding happens in video games, and I just I want to learn more about it. And today I learned about Lego video games. So thanks.
Will 8:28
If it makes you feel better, a lot of bad worldbuilding happens in video games, too.
Moiya 8:32
Oh, bad worldbuilding happens everywhere. Yeah, but hopefully not bad worldbuilding here today.
Wendy 8:37
No, we're gonna be great. We're gonna build a much better world than the one we have inherited.
Moiya 8:41
Oh, absolutely. I think the bar is set pretty damn low. Let's clear it with flying colors. In today's fictional world, we're doing something a little bit different from the way we did things in Season One. Instead of building out an entire world, in one episode - in one hour long sitting, we're going to split it up into three different sections: environment, biology, and culture. And in today's episode, we're really going to focus on building out the environment of this world, the physical setting. So today, we're going to be building out a world that orbits an M dwarf star, which is why Will is here, and one really cool thing about M dwarfs -- actually a couple really cool things about M dwarfs because I can't limit myself to just one: they are the longest lived and most abundant stars in definitely our galaxy, probably the universe. We think that those things are constant throughout the universe. They can live for like a trillion years.
Will 9:39
Yeah, some of them longer than that.
Moiya 9:41
That's not me exaggerating. I think when people mean "really big number" they say "like a trillion." I literally mean 1 trillion, like 10 to the 12[th power].
Will 9:49
Not a single M dwarf that was ever born since the beginning of the universe has aged off of its main sequence.
Moiya 9:55
Yeah, we've never seen an M dwarf die.
Will 9:58
Yeah, I'm sorry. You're just bringing up now, but I want to add something about why this is such an important characteristic of building worlds, which is that if you have a planet around a star that more or less the star, I mean, we'll talk about sort of like stellar activity and stuff, I'm sure, but in the sense of the number of stars on the main sequence for a really, really long time, means that you can have planets around them that have evolved in really interesting ways, and that have potentially more opportunities to create and also to lose atmospheres compared with planets and much shorter lived systems.
Moiya 10:32
Yeah, absolutely. And I am so excited to get deeper into the details of what might happen to our planet as it's evolving, both outside with the atmospheres and inside with all of the potential tectonic plates. And Wendy is here to help us decide, you know, what's going on in there. But I do want to say just a couple more things about m dwarfs to really contextualize this. Wendy, I don't know how familiar you are [with M dwarfs].
Wendy 10:56
Not very. So this is great.
Moiya 10:58
Awesome, so here's some extra info. M dwarfs are smaller than our sun, our sun is actually a pretty average star. M dwarfs have masses between 10 and about 60%, the mass of our sun. They have temperatures that are much lower than our sun's temperature between about 2,000-4,000 Kelvin. That's 3,500 to about 7,000 degrees Fahrenheit, which is still very hot, that's still something that would like burn you to a crisp, immediately. Another cool thing about M dwarfs is that they're really magnetically active, they have lots of flares, they give off high amounts of X ray and ultraviolet radiation. And the astronomy community is actually kind of split on whether or not planets around these stars would be habitable. There are lots of papers debating this, so many on both sides. And so today, we're just going to start with the assumption that life is going to happen on this world. And our job here in this episode is to set up the environment for that life to exist on, which we'll get to in the next episode. Will, anything you want to add about M dwarfs?
Will 12:09
Oh, geez. Yeah, I mean, they're really cool in every sense of the word. And, there's a lot of them. This isn't a stellar type that you hear about very much, because we can't see any M dwarfs with the naked eye. So when you're looking at the night sky, you know, none of those dots are endorsed, because even the closest endorse are just so dim, compared to every other type of star.
Wendy 12:33
Hold up, so you're telling me that all of the stars that I see none of them are this type of star? And yet this type of star is the most plentiful star in the universe?
Will 12:43
Yes.
Wendy 12:44
And we can't see them?
Will 12:46
Not with our naked eyes.
Wendy 12:47
That is blowing my mind.
Moiya 12:49
Right? Isn't it so cool?
Wendy 12:51
So many stars.
Will 12:53
And so when I'm trying to find or characterize planets that orbit these stars, even M dwarf stars that are fairly close to us, in our stellar neighborhood are too far away. So they're too dim for us to be able to study.
Moiya 13:05
Yeah, and I want to clarify just a couple of things here. We're talking about these stars being cool and dim, but they're dim for a couple of different reasons. They're dim inherently, like in an absolute sense. If an M dwarf were sitting right next to our sun, it would literally be dimmer, because an object's brightness and its temperature are linked in that way, these stars are cooler, and therefore they give off less light. But they also can appear dimmer because they're far away. Right? So there are two reasons for astronomical objects to to appear dim.
Will 13:35
So what I was trying to say is, if an M dwarf is the same distance as another star, a planet around that M dwarf might be impossible to study its atmosphere, whereas a planet with atmosphere around a brighter star at the same distance, maybe we could do that because of how much brighter it is.
Moiya 13:50
Any questions about M dwarfs, Wendy, before we get into building out this world and thinking about the planet around it?
Wendy 13:57
I'm trying to think about reasons that planets would be habitable, and I'm assuming if it's more dim, our planet would have to be closer to the star than say, maybe Earth is from our Sun.
Moiya 14:09
Yes, absolutely. These M dwarf systems have smaller or closer in habitable zones, then brighter and hotter stars like our sun.
Wendy 14:18
That's good to know. Okay.
Moiya 14:20
And you figured it out. That's the best part of this. So I really want to focus first on these flares. A lot of people who say M dwarf planets aren't habitable say that because of the magnetic activity of these stars. So, first, what do these flares do? How can they actually affect the planet?
Will 14:41
Yeah, so the sun has sunspots and the solar activity cycle, and there are occasionally solar flares, you know, it's been 115 years since the last solar flare powerful enough to disrupt our energy grid, but it does happen, you know, stars do stuff. M dwarf stars, like you said, are magnetically active, they are much more active, especially when they're young, and so M dwarfs, don't maintain that same level of activity their whole life. But there is a significant period of time when most types of M dwarfs woud be so active that they likely will have stripped the atmospheres of terrestrial planets around them. So stars can do two things with these flares. They're emitting high energy radiation, and they're emitting particles and ions, what we call "plasma" into interplanetary space. And if all the solar activity interacts with the planet's atmosphere, it has a tendency to excite and destroy molecules in that atmosphere so that those molecules and atoms escape to space. In particular, water, [which] in any kind of volatile state, if you have a water ocean, you might have vapor in your atmosphere, ultraviolet photons interact with that water, they break it up into OH and H and the hydrogen escapes.
Moiya 15:55
That's so rude. I like my hydrogen. I like my hydrogen here on my planet.
Will 15:59
It turns out that all life we know of needs water.
Moiya 16:03
That's kind of important. Yeah.
Will 16:04
Just as an aside, if you have a larger mass planets outside of the context of habitability, you know, Jupiter is not a habitable planet.
Moiya 16:11
At least not for humans.
Will 16:13
Oh, fair, okay, but by all of our current definitions of habitability. But if you have mass, you can hold on to more stuff, especially if you're very massive, you can hold on to single protons, you know, these hydrogen atoms that have been dissociated or something. So this is why larger planets, if you're already past a certain mass limit, somewhere in the vicinity of being a little bit less massive than Neptune. So past the mass limit, you actually can hold on to your atmosphere, even with a star that's very active.
Moiya 16:40
That's why you can have these massive gas giants really close to their stars, these hot Jupiters, as they're called, that don't lose their atmosphere because they have such a strong gravitational field due to lots of mass. They have lots of junk in the trunk, if you will, and magnetic fields. Yes, they have these massive things that can help them hold on to their atmospheres, even if they're much closer to their stars.
Will 17:05
Yeah, we call it a B field, and the B stands for badonkadonk.
Moiya 17:09
Did you just make that up? I've never heard that before that.
Will 17:12
No, you're the one that brought junk in the trunk into it.
Moiya 17:16
Okay, so these flares, they can strip away atmospheres when you eventually get to the point of a civilization that may require electricity. And depend on some sort of electricity grid, these flares can interfere with that. But that's for a future episode in this series. Let's talk about the planet itself. Wendy, you very smartly pointed out that it's going to have to be closer to its star. And Will, you said that if it's bigger, it might have an easier time holding on to its atmosphere. So my question for both of you is how big do we want to make this planet?
Wendy 17:48
Not too small because if it's too small, it's not going to be tectonically active. And we want it to be tectonically active, because that's going to help us to maintain life that will allow volatiles to leave the planetary system and create atmosphere, create liquid water, as long as our you know, Labrador retriever puppy of a sun isn't shooting all of these flares out, which are then causing the volatiles to escape all of the hydrogens running away. So, you know, geologic activity requires heat, either from primordial heat from the formation of the planet, or heat from the decay of radioactive materials inside of the planet. And so if you have a larger planet, then it's going to take longer for that heat to dissipate. And so you have kind of a longer lifespan for tectonic activity. I don't know how big is too big, but we don't want it to be too small, because then it would turn into like the moon, or perhaps even Mars, where it just has one kind of outer shell instead of having, you know, the heat escaping and things moving around the way that we do on earth. And even like you see on Venus.
Moiya 18:47
Yeah, that's a really great point. And we especially want to be able to hold on to heat for a long time, because it's a system that's going to last for a really long time up to a trillion years.
Will 18:56
And thanks to how spherical objects work, even just making it a little bit larger in size means that it can hold on to its feet a lot longer. I would say lower limit Earth radius, smaller than that tectonics become an issue like Wendy is saying, but there's an upper limit for this based on observational evidence of exoplanet statistics, which is that we probably won't have a terrestrial planet with an atmosphere the way that we're imagining unless that planet is less than 1.6 Earth radii.
Moiya 19:26
I love that paper.
Will 19:27
Yeah.
Moiya 19:29
The title of the paper is literally like "Most Planets bigger than 1.6 Earth radii aren't rocky." It's such a straightforward title. And I love it.
Will 19:37
So I bought a sticker from Erin May who runs the sticker shop and she has the Fulton gap plot sticker. So I'm waiting until I get a new laptop. I'm putting the slot on it.
Moiya 19:49
Do you want to explain what the Fulton gap is?
Will 19:52
Sure. So it's a histogram of how many planets we see of a certain size and essentially what it's saying is around 1.6 Earth radii we see this huge drop in the number of plants we see. And then we see another peak come up after like 1.8 - 2 Earth radii. So an interpretation of this is that once you've reached a certain size, well, then you have enough mass to actually hold on to a much larger atmosphere. And you're no longer this small terrestrial planet trying to hold on to this, you know, paper, thin layer, you've passed some threshold where now you can hold on to significantly more atmosphere.
Moiya 20:24
Okay, well, then, let's zero in on something that's like one and a half times the size of Earth. So it's not too small to limit tectonic activity. It's not too big. That way we can make sure it's still rocky. What do we want it to be made up? Because right now we're talking about size. But that's slightly different from mass, right? If we make this planet out of really dense materials, it can be much more massive. Wendy, if you had to build your like, ideal planet from scratch? What would you make it out of?
Wendy 20:56
That's a good question. And I don't know that I've ever really thought about it coming from quite that way. When I think about planetary composition, I think about the way the planet evolves. And so you start off with kind of a particular primordial oozy magma, that's all basaltic. You know, it's like kind of heavy and dense. And then as you continue through this plate tectonics cycle, you start to differentiate out the minerals, it's almost like a milkshake, you know, the foamy part rises to the top, and then your other stuff sinks to the bottom. And so the foamy stuff, the earth minerals that are silica-rich, the quartz, those sorts of things will come up to the top. And so you get this differentiation of the heavy stuff sinking to the bottom and forming the core, and then the lighter materials rising up and forming the lithosphere. And you continue that differentiation throughout the history of the planet. So what we should start with is not something I've thought a lot about.
Moiya 21:45
Okay, cool. Do you want to start with something that's very similar to Earth? And then we can take away or add as we see fit?
Wendy 21:52
Yeah, that sounds good. What do you think Will?
Will 21:54
Well, we've talked about how old M dwarfs can be, but we also need to star that's not too old because if it formed in the galaxy, before there were sufficient supernovae, then there aren't going to be any heavy elements to make our planets out of. So you know, we also want to make sure that our star is is young enough.
Moiya 22:14
I see that Lineweaver 2004 paper coming up. The Lineweaver paper is a paper that's very relevant to my dissertation research on galactic habitability, which talks about how you need to have a sufficient amount of metals, [and] for astronomers, anything heavier than helium is a metal. And I know that drives a lot of people nuts. But that's our vernacular. And so this paper talks about how you need a lot of metals to make a habitable planet and metals increase in abundance over time, because stars are forming these metals in their cores and supernovae are forming these heavier metals and then pushing them out into space. So yeah, that's a really good point. We don't want a very old star. We want a young M dwarf that has lots of metals in it -
Will 23:02
Young enough.
Moiya 23:03
Yeah. Youngish.
Wendy 23:04
Okay, but we can't have it too young, because then it's sending out too many flares, which will destroy our atmosphere. So we have a sweet spot in dwarf age.
Will 23:12
Exactly. We want it to be pretty juvenile, like 6-8 billion years old.
Wendy 23:18
Basically, it's got its driver's license.
Will 23:20
Yeah.
Wendy 23:21
Okay.
Moiya 23:21
I love that. So our M dwarf has a driver's license, it's about 7 billion years old. So it's older than our sun, which means potentially any civilizations on it could be more advanced. That's an interesting thing that we might pick up later in this world series. Wendy, I'm really interested in what you said about the radioactive material helping to provide heat in this planet. What types of material? What's actually making the heat?
Wendy 23:50
Well, there's lots of different radioactive materials inside of the earth, including things that most people have heard of, like uranium, which decays into thorium. So you have these decay reactions. And when they decay, they produce heat. So we do need radioactive elements to be inside of the earth, or our planet. I said the earth because I always say the earth, I am also a planetary scientist. It's just that the earth is my planet, so we definitely have to have radioactive materials to allow that additional source of heat, uranium for sure. Let's go with uranium. We don't even need the other ones. Let's just say uranium to make it easy.
Moiya 24:25
All right, just uranium Do you want a bunch of uranium in this planet?
Wendy 24:30
That's an interesting thing, right? If we have a lot of heat, and we're going to be diffusing that heat out. And so that means you would have really active tectonics, you would have really active volcanism, so that would definitely impact our societies for habitability, where they would be able to stay on the planet.
Will 24:47
Well, I mean, that tectonic activity can decrease over time like it did on the earth. So I think more in the direction of what you're describing, like having more uranium or outgassing, all the stuff, that's a good source of a secondary atmosphere for a planet.
Wendy 25:01
Yeah, so okay, we've got a bigger planet than Earth, which means it's going to hold heat better. And if we have more radioactive material inside the earth, that's going to be creating additional heat, we would have a more active plate tectonic or more active tectonic regime, which means, in particular, increased volcanism, but also increased hazards from things like earthquakes and the types of gases that we don't want, like sulfur, sulfuric acid, and, and that sort of thing, which can be problematic for crops and society and all those things for life.
Moiya 25:28
For human life.
Wendy 25:29
True.
Moiya 25:31
Yeah. So one thing I want to give you the freedom to do here is not limit yourself to what would be okay for human life. Basically, whatever type of planet we come up with here, the biologist in the next episode is going to have to come up with a lifeform that can survive there.
Wendy 25:45
Ooh.
Will 25:46
Well, I'm glad were first.
Wendy 25:47
Yeah,
Moiya 25:48
So you have all the freedom here.
Wendy 25:50
What are all those extremophile environments, right, like in the hot springs in Yellowstone, and all of that, like, wow, that'd be fun.
Will 25:58
Well, okay. I mean, we solve our questionable gases in the atmosphere problem by just having it be a water civilization.
Moiya 26:05
Okay, haven't done one of those in a while, it'd be nice to revisit that.
Will 26:09
I mean, I guess it's not our job to decide what civilization is. But I'm just thinking ahead.
Wendy 26:12
I know, we're moving on to a different episode and far outside of our area of expertise here, but like, I want them to live symbiotically with those bacteria that live in super hot environments [where they] form this whole ecosystem together.
Moiya 26:28
Noted, I will let the people in the next episode know.
Wendy 26:32
Sorry y'all.
Moiya 26:34
So if there's increased tectonic activity on this world, like if you're a person, not necessarily a human person, but a person standing, or crawling, or whatever existing on the surface of this planet, how do you notice or engage with increased tectonic activity? Like how does it affect your life?
Wendy 26:54
Well, the speed of plate tectonics could be dependent on the amount of heat that's being released. So I wonder if there were plates if they're moving around much faster, which means that your mountain building processes would be faster, you would have more volcanic activity, so you'd have all kinds of different types of volcanoes around they'd be more plentiful. And in more places, the crust would turn over faster,[because] in some places, the crust is created, and in other places, it has to go somewhere. So it would be destroyed faster, but you would also maybe have increased erosion, if you have a different atmosphere, things could be working more quickly to get rid of the rocks. So it could be a changing environment, but I think the things you would notice the most would be the results of the tectonics and day to day life, which would be more volcanic eruptions, more earthquakes and those sorts of things.
Moiya 27:40
Yeah, I love the idea of a world that's more constantly in flux than ours.
Will 27:46
Yeah, this reminds me of N.K. Jemisin's, "The Broken Earth" Trilogies, where in this universe - not getting into the kind of more supernatural elements of it, they live in this place where there's a lot more sort of geological peril, and they sort of just get used to whole cities of people dying every once in a while. So again, this is back to the civilization part, but I think they could get used to it.
Moiya 28:09
Yeah, find ways to adapt.
Wendy 28:12
So I have a question then that has to do maybe with how close our world is to the star. Would it be rotating? Or would it be like the moon always facing one direction? I don't know what that's called.