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Episode 2: The World of Scarified Rodents

Asteroids may bring pretty bling like gold and platinum, but they also make big dangerous booms! The rat-like creatures on this world have learned to cope in the dankest way with the fewest farts.


1. Noah Guiberson is a getting his PhD in neuroscience at Cornell University. He loves puns and puts them to good use on his podcast Facts Machine! You can follow him on twitter at

2. Ryan Anderson is a planetary scientist at the United States Geological Survey. He literally gets paid to shoot lasers at rocks on Mars! You can follow him on twitter at

3. Rae Richards is an illustrator, graphic designer, and musician based in NYC. You can follow her on twitter at


Moiya 0:08

My name is Moiya McTier, and this is Exolore. the show about facts space world building that tries to transport you to a different alien planet. You're in for a treat today because I have an awesome lineup of guests. We have neuroscientists who studies neurotransmitters. We have a planetary scientist who studies rocks on Mars. And we have an artist/design guru. And together, we're going to imagine the life and culture on a planet that gets hit by a lot of asteroids. So let's go. First, I'd like all of my guests to introduce themselves. So Noah, you're at the top of my screen. Do you want to go first?

Noah 0:42

Hi, I'm Noah Guiberson. I am a PhD in neuroscience at Weill Cornell in New York City. Anything else I should say?

Moiya 0:51

What do you do? Like what specifically do you study?

Noah 0:54

So, what I study basically is the biochemistry of the synapse. So you know, neurons connect to each other across this tiny little gap called synapses. And they release neurotransmitters so that the other neurons can like, know what they're trying to communicate to them. And I study basically the little tiny protein machines that are actually doing that release neurotransmitter, as well as what goes wrong, incredibly wrong when they are mutated.

Moiya 1:20

Right, we'll talk about that later. Rae do you want to go next?

Rae 1:24

Sure, I am Rae Richards. I'm the creative director at a science communications agency. I do illustration, animation, motion graphics. I write music. And my big passion on the side is stargazing, astronomy and anything that has to do with the universe at large cuz that's really cool.

Moiya 1:55

I'm so excited to have you here. You also had this amazing series of skateboard designs, based on work by women in science. That's awesome.

Rae 2:08

Yeah, yeah, so you know, amplifying women in science is also something I feel really passionately about; so I to weave interesting stories into my artwork ... whenever an opportunity arises like skateboards, nothing like a bunch of prose riding on lots of good women's science.

Moiya 2:34

And Ryan, want to tell us about you?

Ryan 2:38

Sure, I'm Ryan Anderson. I am a planetary scientist at the USGS Astrogeology Science Center. And I work on the Mars rovers, Curiosity and the upcoming Perseverance rover. I'm on the Chem-Cam and Super Cam teams respectively, which means I get to shoot rocks on Mars with a laser to figure out what they're made of. The main thing I work on is taking the data from that sort of instrument, and turning it from a squiggly line on your screen into a measurement of the chemistry. But I also do geomorphology of Mars. And I do education outreach. And I'm a big sci-fi, and fantasy fan. So I'm really excited to build a world.

Moiya 3:25

All right. Speaking of Mars, which is a different planet, let's get into the planet of the episode. So like I said before, this planet is exactly like Earth, so it's the same size, it orbits the same type of sun. It has a moon, same atmosphere, it has water and everything, but this planet gets hit by a lot of asteroids. The asteroids, you can think of as "space rock", or "space junk", if you are less inclined. So these asteroids hit the surface of the planet, and some direct consequences of that are that they bring with them precious metals. On earth, [we] get hit by asteroids all the time too, but not nearly as much as this planet that we're going to discuss. And so we are pretty limited to the resources that we have here on Earth. If you're looking for gold, or iron or other resources that you're interested in, we're stuck with what we have. But this other planet gets constantly replenished by new stuff all the time. And of course, being hit by asteroids so frequently, will do stuff to the surface and probably the interior of the planet. So my first question, probably for Ryan, although the two of you can weigh in as well. What would this kind of constant bombardment due to the surface and interior of this planet?

Ryan 4:52

Okay, so we're getting lots of little impact all the time, so basically we're saying that the solar system that this is in, this has a lot more junk than ours does.

Moiya 5:04

Yeah, or maybe this planet orbits in the asteroid belt for some reason.

Ryan 5:10

Okay, so it's closer to a belt or something. So, yeah, you're gonna get a lot more of all sizes of impact, right? So not just going to be a lot more little ones, the big ones will be more common to. All distributions will be amplified, I guess. So the little ones are not going to matter. Right? They, you know, they don't do much compared to the amount of energy you're getting from the sun. A few more little impacts are not going to really change, like the temperature a lot. You might get more particles in the atmosphere, so it might be a little hazier. But, you know, I have no idea how much you would have to increase the impact rate to make that happen. So I think the little stuff is not going to matter, but the fact that you're going to have big impacts a lot more often, that's going to ... do some damage. Your ... life on your planet is going to have to constantly be reset; if you're getting a bunch of big impacts, you know. They're not necessarily going to wipe everything out all the time, every time there's a big impact, but it's going to be a challenge, it's going to be a stress on the life on that planet. The other thing that it can do is if you are getting big impacts, more, really big ones, at least they'll punch a hole in the crust. So you'll have thin spots in the crust. And so you may have more volcanoes there you may have just in general, more activity, you know, geologic activity in those areas, and big impacts they dump so much heat into one spot, you can get lots of hot springs and all sorts of stuff. So like on Mars, we talk about big impacts as a place where life can originate because they blast the crust, they heat it up, they melt all the water and everything just kind of mixes around in these hot areas. And the heat there can last for thousands, tens of thousands of years, depend on the impact. So those are some things to think about. And you're right, if you're getting lots more impacts, you're going to have more precious metals at the surface because when a planet forms, most of that stuff sinks to the middle. But if you're being hit by the former cores of other planets, then you get that stuff sprinkled all over the surface to, so that could be interesting to play with.

Moiya 7:35

Awesome. So we're not thinking about humans going to this planet and figuring out what we would have to do to adapt. We're imagining the life that would form natively on this planet. What types of behaviors would they have to have to survive these impacts?

Rae 7:53

Underground, [they] probably would live better underground, especially if there's a lot of debris and ... yeah, warm blooded underground animals.

Moiya 8:06


Noah 8:08

This all reminded me of ... there's this kind of beetle that it basically can sense that a fire is happening, from up to like 50 miles away. And you would think it's because they want to escape these forest fires, but it's actually they want to run as fast as possible straight towards the forest fire. I think they can only lay their eggs or mate or something in like, freshly burnt wood. And I think that's an interesting fact because it's so like counterintuitive from our perspective, like run away from fire. And we probably would think, "oh, we got to get away from these asteroid impacts". But what if they had some sort of biological reason or then maybe even a reason in their culture where they wouldn't want to, like, you know, get to it as soon as possible. I'm thinking like the storm chasers of twisters, but for asteroids.

Moiya 8:55

Yeah, I really love the idea of having people who live underground so they don't get smushed by the impact, but they need to get to the impact very quickly. And so they have some biological way of finding them.

Noah 9:10

Right. Could be vibration, maybe? Like a smell barrier, maybe it doesn't work the same way, but they, you know?

Moiya 9:19

Yeah, animals who don't see very well and depend a lot on detecting vibrations and pressure waves going through the air. How do they do it?

Noah 9:30

I mean, much the same way that you or I or you or you do, where there's vibration, that basically change the structure of, you know, proteins in sensory neurons usually like in your skin but elsewhere as well. And that basically like disruption of their structure opens little pores, and that's an electric current and electric current allows you to signal back to your brain if you have one. So it's literally the vibration, vibrates you; and your cells respond to that.

Ryan 10:04

I have a bunch of thoughts bouncing around my head after that conversation. So it sounds like what we're talking about really a lot of impact, right? Like, if it's going to be like a constant occurrence that life has to deal with on this planet. So I'm keeping that in mind, and I'm thinking like, "okay, these beetles need fire or need something to reproduce". Impacts, at least big ones, they cause regional or global wildfires, because the big impact happens, and then the stuff shoots out, and then that stuff rains down all over the world. So the amount of energy that's deposited is huge, and so it'll ignite the forests in continent or the world. So we could play into that, and I'm wondering if we have an actual civilization there, and they have something similar to these beatles, I wonder if there's religious significance to these events? You know ... are they part of their culture? Do they celebrate these events? Do they have a big festival? When there's a big impact like this, and the whole world burns down, and they're like, "alll right". So those are a few initial thoughts. As far as you know, sensing impacts, if they're an advanced civilization, obviously, they can have telescopes and they can see this coming, at least the big ones. For smaller impacts, you get, obviously the really bright shooting star, and you get the shockwave from that going through the atmosphere, then you get the earthquake when it hits. And so there's a few different things that you can use to detect the different stages of the impact. And so, just to keep that in people's mind if we're going to be playing on this idea of reacting to the impact. and what that means?

Moiya 12:04

Yeah, let's start thinking about what they might look like. So we have the underground creature, who will develop some sort of adaptation to detect, and maybe quickly get to these impact sites. What do we think they look like?

Noah 12:22

I mean, just using the the asteroid impact, I can't actually speak for the space scientists, but the asteroid impact that I think most people are most familiar with is the, you know, the one that finally killed off all but non-avian dinosaurs. And I think sort of the general story about how mammals sort of rose up in the pecking order, literally, from that was that they were a lot smaller, and they were able to just kind of like, run through the underbrush and didn't need the same amount of food because there was less available, that sort of thing. And so I would imagine just in general, we're talking about kind of smaller creatures. I'm very happy for you guys to say that they're huge. That would be awesome.

Moiya 12:25

They can start off small, and get bigger as time passes and they're able to accrue more resources and adapt more to the environment. So what types of features, physical characteristics do you need to get around underground and create a home there?

Rae 13:24

You need to be compact. I mean big or small, you've got to be compact. So no tremendous plants.

Moiya 13:31

Like, not wings

Rae 13:33

Yeah, no wings.

Moiya 13:35

No capes.

Rae 13:36

No enormous limbs either. I would imagine small limbs or ground

Moiya 13:42

There are some, like mole type things that like burrow really quickly.

Ryan 13:48

Or have real claws.

Moiya 13:50


Rae 13:51

Yeah, we got diggers, real diggers.

Moiya 13:56

All right, I am. I'm picturing like little mole people with giant claws.

Ryan 14:03

That's what's in my head.

Rae 14:06

Yeah. You don't need terribly good eyesight down there, especially if you're going on vibrations.

Moiya 14:13


Rae 14:13

You don't have to have... eyes.

Moiya 14:15

So eyeless, maybe or like, small-eyed mole people ... love it. Let's run with that. What type of things would they value? What types of like behaviors or characteristics or objects would they value? Are they a materialistic society? Are they group-oriented or individualistic? What do you think?

Ryan 14:43

So I would say, my vote would be for more group-oriented because this is a society that constantly has to deal with disasters. And it would be a strong evolutionary benefit to work together, and keep each other alive rather than, "you're on your own, forget you", you know, "you can die in the forest fire and I'll be fine". You know.

Rae 15:09

I'm with this, I'm with this.

Moiya 15:17

Anyone else want to weigh in?

Noah 15:20

Just to bring in another random animal from Earth. I've been thinking of that there may be other better examples than this. For anyone watching, feel free to write in the comments. But I was thinking about naked mole rats recently and how if you see like the pictures of their colonies, there's like, hundreds of them, like all in little piles and keeping each other warm, and basically like maintaining these really elaborate funnel systems cooperatively, and this isn't particularly relevant, but I find it amazing that apparently they don't really get cancer, but that would probably be very useful.

Moiya 15:58

I love the sentence, "I've been thinking a lot about naked mole rats".

Noah 16:01

Well you said like, "I'm just imagining mole people that go like this," I was like, "oh my god you see them too!" Other than just sort of like radiation that could cause DNA damage is that we've already said that these asteroids, like, have a lot of metals in them. And so like, I don't know how to say this, but you know, when you have this big impact of bunch of metal, it's going to sort of disperse or I don't know, "vaporize" is the right term, but like maybe be breathed in. They might, you know, ingest it or otherwise, you know, get it inside their systems. And I know that a lot of chemicals like, I just pulled it up, I'm not doing this off the top of my head, arsenic, cadmium, chromium, nickel, and a lot of compounds that contain those can cause DNA damage.

Ryan 16:46

Yeah, so like ash and dust and stuff, both from the thing that hit and from the target that it hit on the planet. You're going to get that all up in the atmosphere and be breathing that in. So definitely want our species to be resistant to like miner's lung.

Moiya 17:05

Naked mole rat people, that's what we're working with.

Rae 17:10

That's cool that they have to stay together for body warmth. They have no hair, I like the idea of them all together on the ground like that.

Noah 17:18

I don't know. I think people think they don't have hair because it's easier to move around in their really tight tunnels.

Rae 17:31

There's less friction against your environment inside but still l laying on top of each other hairless is adorable.

Noah 17:40

You did ask about like the cultural significance of these impacts, and like what kind of society they were having. And since we've talked about, they might want to like get to it as soon as possible, I feel like we've talked about a couple things the asteroids bring, and one is like [what] Ryan, you mentioned, I guess like heat that is created by that. So maybe it's a really icy surface. And that's a way for them to get water or, like the metals that are there. And maybe like, you know, they could have like a biological need that makes them really want to get to say that water. But they also might have a cultural desire to get the things that come with like that water impact, which might be like metals that are coming down as well. And they might have a role.

Moiya 18:24


Ryan 18:25

We didn't really decide why they want to go to the impacts?

Moiya 18:29

No, I really like this, this idea of maybe an icy surface because all of these impacts can throw up thick clouds into the air that may be block sun, and so maybe the surface of the planet is incredibly cold except for where these impacts happen. Does that make sense?

Noah 18:46


Ryan 18:46

I could buy that.

Moiya 18:47

Want to check that, Ryan? All right, cool.

Ryan 18:49

I'm good with that.

Moiya 18:54

Rae, you are our resident artists. Are you frozen?

Noah 19:00

Just like the surface of the planet. It's time for Rae to come back.

Moiya 19:07

Oh, you're back. Okay. Awesome. So you are our resident artists. And I think that it'd be really cool to think about how to really picture this world. So if they're advanced enough, and I like to imagine that they are, they'll build a civilization and I don't know, do you have any thoughts on what that civilization might look like? Like what is the mole peoples' aesthetic?

Rae 19:33

I mean, I'm imagining earthy structures. Structures that reflect the underground. A dome, like mud style walls, earthy tones. If it's an ice world, especially, if the surface of the planet is icy, then there's a lot of light on the surface. If they bring structures up from under the ground, they probably want to make the surface look more like the underground, warm tones. They have giant claws, right, we're talking mole people. So what they're able to fashion with those claws is also an interesting thought. Unless they are so advance.

Moiya 20:24

Maybe their art is based a lot on carving instead of like painting?

Rae 20:29

Yeah. Yeah, unless they were so advanced that they could fashion different types of tools like artists, obviously with paint brushes, they don't paint by fingers. So that maybe it's a combination. A lot of relief stuff from earlier days before advanced tools and as they get farther along, maybe more applied paint and different methods of expression. But earthy... I imagine, they would love to bring that feeling of being underground, above the ground. They don't have vision or need for light. So a lot of textured things that can be felt and enjoyed through their senses that might be more advanced for them. Sound I'm assuming they have good ears.

Moiya 21:33

So like the acoustics of all of the buildings are very important.

Rae 21:37

I would imagine acoustics would be important and textures would be important. Smells, earthy smell would be important things that would bring them pleasure. There's a whole world of people who focus on that in art.

Moiya 21:57


Rae 21:59

Yeah, yeah, there are people who specialize in that sort of thing. It's totally not my realm. But I would imagine these creatures would have a lot of emphasis on the smell of things since their eyes aren't very advanced and the feel of things. The feel of each other underground, the feel of tight spaces and textures would be really important to them. So I imagine they would build structures related to those things that give them comfort.

Noah 22:37

You've talked a little bit with the structures in relation to the fact that they like don't have fur, presumably maybe they don't have clothing because it would sort of present the same challenges that burden in tunnels. Um, but I was thinking when you were talking about like, would they have like really interesting, personalized like tattoos? Or maybe if they couldn't like see, they might have that kind of tattoo that like is tactile, like a certification.

Moiya 23:03


Rae 23:05

All right. Yeah. That would be really cool. You know, it'd be deep scarring in different shapes so that it's more tactile and you could enjoy the feeling of it. Definitely. And I guess underground ... things echo so much, that maybe music would probably be more harmonic or focused on multiple harmonies perhaps. The way that different sounds resonate underground or in tight spaces, so I could picture them like chanting in various different harmonies, six part harmony, chanting underground probably sounds really cool. I could imagine the mole people being into that.

Noah 24:01

Maybe all their tunnels like make a big organ.

Rae 24:04

Yes, I was just thinking that before when you were saying something about underground, the thought is flashed through my mind oh, like a pipe organ and then flash the other way through.

Ryan 24:17

I'm wondering if, you know, there's something I read a long time ago about, like how elephants communicate with infrasound over very long distances. I wonder if you could have something similar with these underground dwellers if hearing and vibration is so important to them, you know, maybe this colony over here can communicate that 150 miles away, either through their music or through some other, you know, sound wave technology.

Noah 24:49

Like what?

Rae 24:51


Ryan 24:52

Oh, yeah.

Rae 24:53

Well, that would be pretty cool. It's mushroom fungus under the ground. The biggest part of the organism is an underground network of entirely white fibers that communicate with all the plants, trees, everything underground. They call it the "Wood Wide Network" for fun, mushroom geeks. It would be really cool maybe if they interacted with other things under the ground, you grow those in the dark. They're really sustainable food matter. They're great material for building things. You can make anything out of mycelium. They use it to communicate to.

Noah 25:44

You know how like, it feels really good when you're at the beach and like, you put your feet like in the sand? You know, I'm talking about?

Rae 25:51

Yes, I do.

Noah 25:53

Maybe that's like, maybe there are places where they can like, you know, like, get in touch with the mycelium. It's like underground, they just like put their little like claws on and they're just like, "ah, I feel a connection."

Rae 26:03

Yes. I love that. It's almost like a religious experience.

Noah 26:07


Rae 26:07


Noah 26:08


Moiya 26:09

This is so good.

Noah 26:11

Before we move on. Can I make a quick mole related, underground instrument fun? Do you think that one of their instruments would be the "digory do"?

Rae 26:27

No, but honestly that instrument would sound pretty incredible underground. Yeah, yeah. I'm into it. It goes with the chanting.

Moiya 26:38

Right. Thank you. That was the best contribution you've made so far, Noah. I really appreciate it.

Rae 26:47

I can see one carved with like mole people in it. Yeah, it's good work.

Moiya 26:52

Absolutely. What about different roles that might be very common in society, like the jobs that people might have, what does the society need to function?

Rae 27:05

Let's make it matriarchal. Can we?

Moiya 27:07


Ryan 27:11

Sticking with the mole-rat thing.

Noah 27:13


Rae 27:14


Moiya 27:14

Are mole rats matriarchal?

Noah 27:17

Oh, yeah.

Ryan 27:17


Noah 27:17

And they have a queen and everything, yeah.

Moiya 27:20

All right, so there's there's a queen. What else do people do?

Ryan 27:26

Mushroom farmer, apparently.

Noah 27:27


Rae 27:28

Oh yeah farmers great, mushroom farmers. Awesome.

Moiya 27:31


Noah 27:32

Probably like mole manicurist, but like for both practical and ornamental reasons.

Moiya 27:47

Yeah, no, I I'm really glad you brought it up.

Noah 27:49

It's a legitimate theory.

Rae 27:53

I'm thinking about someone getting like stars and moons carved into their claws. Sorry. That's what I would do.

Noah 28:02

You know, you get it.

Moiya 28:04

By the end of this conversation we all have to come up with what our claw designs would be if we lived on this planet. What else?

Ryan 28:14

I think you'd need some people who go above ground?

Moiya 28:17

Yeah. What do they do about above the ground?

Ryan 28:20

You know, whatever resources they need from the surface whether I don't know if their mushrooms grow on wood from the surface or whatever or resources they can't get by digging.

Moiya 28:32

Yeah, yeah, like mining to get all of those metals from asteroids.

Rae 28:37

Mm hmm, and burnt ash is really great fertile soil so maybe if the impact sites they would want to collect blackened earth.

Ryan 28:48

Yeah, I'm picturing like, you know, the the harvester ants they go pick up leaves and carry them back to their their burrow to grow mushrooms on them?

Rae 28:56

Mm hmm. Yeah.

Moiya 28:58

Do you think that there would be a lot of scientists? Do you think that this would be a flexible society? And if so, what science do you think might be like practiced a lot?

Rae 29:19


Noah 29:22


Moiya 29:27


Noah 29:27

Chemistry for sure. They have to know a lot about molarity.

Rae 29:33

Astronomy to detect incoming.

Ryan 29:36

Yeah, yeah, I was going back and forth on astronomy because if they're not a visually oriented species, like you said earlier, and maybe they would first get into astronomy through things lik