Science Friday - Ancient Tools, Life On Mars, An Aurora Named Steve. March 16, 2018, Part 2.

Episode Date: March 16, 2018

Scientists have been trying for a long time to piece together a question: When did traits of modern humans—like complex thinking and behaviors—first develop? Anthropologists have uncovered tools in Kenya that date to 280,000 years ago that contained non-local materials, indicating that early humans developed social networks and advanced technology tens of thousands of years earlier than previously thought. What would daily life be like on the Red Planet? We called a couple experts from NASA, MIT, and Georgia Tech to find out. From meals to transportation, we imagine life on Mars.  Finally, how do you solve a puzzle like Steve? That was the name given to a mysterious southerly pink streak in the aurora borealis, after aurora enthusiasts using the citizen science platform Aurorasaurus began to notice the streak appearing again and again in the images they were sharing.  Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

This is Science Friday. I'm Flora Lichten. Ira Flito is away. This week at South by Southwest, Elon Musk said his BFR, his big rocket capable of reaching Mars, might be ready for testing early next year. Later in the hour, we'll imagine what a Martian civilization might be like with some space futurists. But first, we're talking about another technological revolution. It was a period when new ways of social networking were developing, and innovation was totally changing how folks lived. And no, I'm not talking about Silicon Valley. I'm talking about the Middle Stone Age around 280,000 years ago. This week, researchers report in the journal Science

that our early human ancestors were making advanced tools far earlier than we thought. Forget about that clunky hand axe. We are talking about tiny, intricate spearheads. And these ancient humans may also have been trading with each other. This would push back the first evidence of trading by 100,000 years. So what do these findings tell us about how we became the complicated humans that we are today? Here to talk about that is my next guest. Alison Brooks is the author on these studies.

She's also a professor of anthropology at George Washington University. Welcome to the show. Thank you. Allison, tell me about these tools. Well, they are very carefully made. They required a lot of planning to make them because you had to prepare the block of stone to get off a flake that was just the right thinness and the right shape so that you could then make that flake into a point or a scraper or whatever you wanted to make it into. Yeah, what did they look like? The tools, the points are triangular and sometimes the tip is so sharp that we think.

I think maybe it was designed to make holes rather than slice into animals. And they are made preferentially on a black stone that comes out of a volcano and cools. It's a volcanic material that cools so quickly it doesn't have time to form big crystals, and it is more like a glass. So if you've ever broken a glass, you know how sharp the bits are. And this is the sharpest material that we know of, actually, and sometimes gets used in surgery today because it's so sharp. And how did this change our picture of the Middle Stone Age? Well, the thing is that we knew that at 100,000 they were making points out of this material, and they were importing it from many directions and many sources.

but this is 300 to 320,000, so it's much older than that. We had a publication last year that showed that obsidian was this black glass is called obsidian, that it was being imported from a distance in central Kenya, sorry, that was even greater, but this is 100,000 years before our finding. So the fact that we have these small points, the fact that the bases are trimmed so that they can be easily inserted into a haft, and the fact that they're made of this material, which doesn't occur in the vicinity of the site where we found them, and the fact that we were able to trace the sources of the material in the site, in each level of the site, to a lot of different sources in the surrounding region.

So they weren't just going to one source. They were going to a whole range of sources. So in terms of the types of tools, can you give me an analogy for the kind of technology upgrade we're talking about when we're talking about going from hand axes to these kind of pointy or smaller tools? Well, the technology, it's much smaller, much more specific. The hand axe was a big tool that was more like a Swiss Army knife, that you could use in multiple ways, except it didn't have a lot of different blades, obviously.

You could use the long side of it for cutting up animals. You could use the tip for gouging or picking at things. You could use the broad base of it for pounding things. And so it wasn't a very delicate tool. It couldn't do anything very specific, and you probably couldn't stab it into an animal. You might be able to throw it at something, This sounds like flip phone to iPhone to me.

Yeah. Is that fair? I would say it isn't even a flip phone. It's more like a princess phone or something from the stone age of telephones. So this obsidian, it wasn't nearby. It didn't exist nearby. Where did it come from? Well, we have sources in the surrounding region.

One of them is almost 100 kilometers, which is about 60 miles away. others and there are sources to the north. Most of them are, let's say, 20 to 30 miles away. But the important thing is that these are straight-line distances. This is a landscape like someplace in the Western United States that's full of mountains and mesas and canyons. You can't walk anywhere in a straight line. So, in fact, these are minimum distances if you could actually fly. These were long tracks for people that probably represent moving into places that were occupied by other people.

So how do you, so the idea is that maybe these human ancestors traded these materials? Well, I think the idea of trade, this is, I lived with farage. in the Kalahari Desert for many, many months over about 17 years. And the system, the problem with foragers is that they experience times when the environment doesn't provide enough food. There's been a flood. There's been a lack of rainfall. And what do they do?

They don't have a bank where they can put money. They don't have a silo full of grain. They don't have a barn with cows in it. They don't have any way to say for a rainy day except by building up obligations among their neighbors. So people who live in this sort of situation tend to create these relationships. The most valuable thing you might get on a trip like this isn't necessarily the obsidian. It might be the relationship with the people who live with the obsidian. and they consider it a value to meet you

because then if things go bad, you can't move your whole group into that particular person's territory because very soon they wouldn't have anything to eat, but you can move yourself and your children and your wife and so on into that, to go and stay with that person because they'll have some food that you could, that you could survive on. So it's a way of, almost a way of saving for the future.

So does this, one thing that struck me as I was reading these studies was, does this change our sense of the evolution of language? Like, how do you trade with other groups or exchange goods with other groups without language? Well, the point is that we are, or the thing that I find interesting is at the same time, we have some very early evidence of the use of pigment. And you think, how am I going to signal or show who I am before I can be close enough to actually take some of the subsidian? And we can imagine that people might be hostile to somebody

just walking into their territory and taking some of their stone. So it's very interesting to me that we also have pigments in this time range at two of the sites we excavated. One had brown pigments, one had bright red pigments, and the bright red in this brown, often dry landscape really shows up. You can see it very far away. Somebody coming with a red hat on or a red shirt, you really notice it. But this seems like a huge change from,

how we have envisioned human evolution. I mean, I feel like we hear about these things happening much later, like 100,000 years ago, rather than 300,000 years ago. We do. And I have thought for a long time that the roots of the things we see at 100,000 years ago were very ancient. And I've been trying to excavate sites. in that time range that would shed light on exactly what was going on.

So we were really quite amazed to find not only the points, but also all the subsidian that doesn't come from the local area. And I might mention that the pigments don't come from the site either. Wow. So is this changing the narrative in a pretty significant way then? I think that it goes along. I mean, we've been pushing it back for a while. I wrote a paper with a colleague about 18 years ago that said we should push the idea that major aspects of our modern behavior.

We should push that back to before 200,000, but this is now before 300,000. Wow. Why are people resistant to that idea? Well, what people are struggling with is why did we then take over the world? And it looks as if the people who emerged out of Africa and took over the world may have taken it over that the genetics are telling us that they took it over 50,000 or 60,000 years ago. So there's a search for some tremendous change that took place 50 or 60,000 years ago. But we would argue that what happened is actually that maybe there were several excursions out of Africa that didn't leave. any descendants in us, which is given how long ago it was, is certainly possible.

And the one that was successful may be successful because they had used the basic elements of what we're now seeing at 320,000 years to develop even more complicated weaponry, excuse me, or, sorry, even more complicated social relationships or something like that. It's so fascinating. I can't wait to see what you find next. Alison Brooks is a professor of anthropology at George Washington University. Thanks for joining us today. Thank you for having me. After the break, we're going to Mars. Imagine how we live, imagining how we live in what we would do, and most importantly, to me, what we'd eat. Stay tuned. This is Science Friday, and I'm Flor Lichten.

Elon Musk made a surprise cameo at South by Southwest on Sunday, talking with screenwriter Jonathan Nolan, and one of the things they talked about was Elon's interplanetary ambitions. We got an update and a progress report on his big rocket, nicknamed BFR. We are building the first Mars or interplanetary ship right now, and I think we'll be able to do short flights, short sort of up and down flights, probably sometime in the first half of next year. The first half of next year,

Musk says we will be testing a rocket capable of flying to Mars. This got us thinking, what would a Martian town be like? Like, let's think about all that day-to-day stuff that we take for granted here on Earth. Fresh water coming out of the tap, abundant sunshine for growing food, that special flick of the wrist that you have perfected for flipping pancakes. How would all that change in a world with limited water and sunlight and much lower gravity? We called a couple experts to find out. Let me introduce them. Stan Love is a NASA astronaut and planetary scientist at NASA's Johnson Space Center in Houston, Texas.

He's been up in the shuttle and on spacewalks too. Welcome to Science Friday, Stan. Thanks very much. My pleasure to be here. Ariel Ekbla is founder and lead of the MIT Media Space Exploration Initiative in Cambridge, Massachusetts. She joins us via Skype. Welcome to Cy Frey. Great to be on.

Thanks for having me, Flora. Okay, and if you have a question about life on the red planet, please give us a call. Our number is 844-724-8255. That's 844-Sai Talk or tweet us at SciFri. Stan, Elon Musk made a corny dad joke about opening a Mars bar during the South by Southwest panel. But in all seriousness, what would it be like to have a cocktail in low gravity? Well, refreshing, I'm sure, especially since our current reduced gravity crew members don't get to taste any alcohol while they're on a mission. People never drink on the ISS?

That's what I was told, and I didn't see any alcohol when I was there. And U.S. policy is we don't have alcohol on station. Other partner nations may have their own rules. I'm thinking of those tiny airplane bottles. You could just sneak it into a space suit. I think they might be tiny little airplane bags in this case. Ariel, you wrote a group at MIT, the space exploration initiatives, which isn't so much about building the rockets, but thinking about the tech will need when we get to Mars and

how to create positive space culture. So what kind of innovations, what do we need to be thinking about to have a high quality of life on Mars? Well, that's a great question, and that is something that the space. exploration initiative is thinking about in MIT Media Lab. We're looking at the technologies and the tools of engagement that will not just help humans survive once they get there, but also delight them, keep them engaged. Some of this is thinking about space food and yes, even space cocktails, like you mentioned with Stan. And then some of it is technical, rigorous literature reviews

about what are the current state-of-the-art technologies for, say, water reclamation, agriculture, future of architecture, what will we actually be living in when we are on the surface, that then inform some of the prototypes that we're actually building here in the lab on a day-to-day basis. One of the main goals of the initiative is not just to be designers, but we're designers, builders, and deployers, and actually trying to think about creating these technologies that previously had just been sci-fi. But now, if Elon is correct, and in just a number of a few years, we might be there, that we'll need to have those technologies ready to actually use.

use on the surface. I think we should get right to the very important issue of food. Stan, what would we eat on Mars? Whatever we can get. At first, it's probably going to be stuff that we ship from Earth. We have no possibility of producing food on Mars right now. The closest analog we have to that would be the very small, brightly lit greenhouse room they have at the South Pole Station in Antarctica for the long winter. There's no... flights in and out and all the food that the folks eat has to be either frozen, thermally stabilized, or occasionally you get a little bit of lettuce or a tomato out of that greenhouse, and it's

the highlight of your day. Thermally stabilized does not sound delicious. It is not delicious. And it's a very important, I'm glad you asking the question. It's something we should all be thinking about. If you read the journals of the Arctic explorers from around 1900, it is all about the food. On Mars, you know, you can't go outside without putting on a 300-pound space suit. The scenery is rarely going to change.

The people are rarely going to change. You have to live in a sealed habitat. It can only be limited in size. And when your surroundings are that monotonous, food becomes immensely important. So what could we expect? I mean, I have this picture from the Martian of, you know, vast fields being grown inside. Do I need to erase that image? It would be great if we could do it, but if you look at what we get with an acre of farmland on Earth, without thinking about it, every square yard of that field receives about a kilowatt of light energy from the sun all day.

That's a lot of grow lights, and it takes many acres to feed a colony. So we'd need the volume to put all those plants in. We'd need all the light to make the plants grow. And then, of course, every watt of artificial light, once it's been projected out, becomes a watt of artificial heat that you have to get rid of. And in space, getting rid of waste heat is really hard. If you imagine going to your bathroom. Yeah. Well, go in your bathroom, turn on eight hair dryers and leave them there for an hour or so and then go back in your bathroom.

That's what it's going to be like being in a room with grow lights on Mars. And on Earth, you can open a window and the heat goes outside or turn on your air conditioner and pump. that heat outside in space with Mars's thin atmosphere. It's cold, but it's thin. It's hard to put heat into that. It's going to be a challenge. Interesting. Ariel, are you thinking about this, food in space? We are indeed. And Stan brings up a really great point about the light requirements and thinking about the power budget for how much power and electricity do you really have available and how much natural light or full-spectrum artificial light could you bring to bear on an agricultural project, likely indoors because, of course, we know that the perchlorates and marsh and soil are going to make it

very difficult to do any agriculture outdoors in addition to the limited atmosphere. Two specific technologies that we're looking at right now around space food. One is radiotropic fungi, so fungi that really can survive well in the presence of some radiation. And also because they're low light, the ability to potentially grow some of these fungi as a dual-purpose crop. There's really innovative research coming out of Red House studios from Chris Mowers Group. They're a group that just came to the Media Lab over the weekend for our Beyond the Cradle Conference, which brought together about 60 leading thinkers, visionaries, and builders for the future of space exploration. The idea is to grow fungal mycelium, which are the roots of fungi, use those as binding material with some other organic matter.

This can be a primitive for, say, something like a building brick for a colony for architecture, and then use the flowering part of the mushroom, the part that we would actually eat, to be an early example of grown on Mars space food. So that's thought number one is really relying heavily on mushrooms. Like your stir fry would be growing out of your walls? There you go. Yes, you're looking for that tasty mushroom to add to your stir fry

and you go plug it off the bricks that are enclosing you on the Martian habitat. Yes, we could envision such a future. I think realistically we'd be a little bit worried about containment, And so you're most likely going to see those fungi grown in something like a food computer, which actually brings me to the second example, which is fantastic work being done at the MIT Media Lab from the Open Agriculture Initiative, with whom we're collaborating for our space food research theme, looking at how can you have very energy efficient, small, contained, controlled environments, little food computers, where you could be able to start growing and thinking about not sustainable

agriculture for an entire colony, but at least the start of agriculture for a few Martian. astronauts. We have a tweet from Flap. There's water on Mars, but is it safe to drink? Stan? I'd want to filter and purify that first. We know you mentioned the perchlorates in the soil. Water on Mars is all frozen or in the vapor form. Liquid water can only exist in certain low-lying areas on certain very warm days. So we're going to probably mine it out of the soil in the form of ice, you'd have to melt it, make sure that you get all the grid out of it. And then, yeah, with the chemistry going on in the Martian soil, you'd want to make sure you ran that through some filtration before you chugged it down. Let's go to the phones. Let's go to Andrew in Houston, Texas.

Hey, Andrew. Hi. Tell me your question. I'm curious what would happen to our bone density in a lower gravity environment and what kind of Exercise we might want to do to take care of ourselves on Mars? Stan? Oh, excellent question. So first of all, we have astronauts in a zero-gravity environment on the space station all the time now and have them had them up there continuously since the year 2000. And without exercising two and a half hours a day, and an hour or an hour and a half of that each day is on a resistive exercise machine that mimics weightlifting.

Of course, you can lift a lot of weight in zero-g and it doesn't really help your body much. The machine we have, you're fighting against air, compressed air in a cylinder. So it's the equivalent of weightlifting. And those folks are coming back with pretty good bone density. Of course, we know that just daily life on Earth keeps your bone density healthy. We have no idea whether Mars's gravity is enough to keep your bone density healthy because we don't have any data between zero and one G. So that's one of the things we're going to learn when we go to Mars is whether you have to exercise that much extra to keep your bones healthy

or whether the gravity there is enough to keep your bones healthy. What's the gravity like on Mars? It's three-eighths of Earth's gravity. So you'd weigh a little less than half of what you do on Earth. You'd bounce with every step. Your gate would be quite different than it is on Earth. You would take your steps more slowly, and you'd want to build high ceilings,

or people are going to bump their heads. Ariel, have you thought about, there seems like there's some sports potential, new sports potential on Mars. Have you thought about this? sports or games? Ooh, I love this idea of sports. I will admit that we have been thinking about zero-g games

and some of them and how they might be applicable to a reduced gravity environment like Mars. This was actually another workshop just held it beyond the cradle over the weekend by one of our masterminds at the lab and the instructor of the sci-fi class, sci-fi-fab class. The idea is to look at how astronauts

can engage in really meaningful leisure time. So we know that mental health and equanimity is key and being able to, To do just fun, energetic things is a great way to be able to keep astronauts healthy and engage when they're either in orbit or potentially one of the first lone astronaut explorers on Mars. A lot of the unique things that we might think about for zero gravity, flying Tetris blocks, like what Chris Hadfield has done, Canadian astronaut with Velcro on scrabble pieces to be able to bring up his favorite pastime, are things that we could consider on Mars if you're thinking not so much of a floating, you know, zero gravity chamber, but more of just the distance. that you could bound, like Stan said, the ability to do maybe a little bit more acrobatic activity. If you want to get in on this conversation, ask a question about life on Mars. Our phone number is 844-8255-844-Sy-Talk.

What about Mars apparel? It seems like it would have to be bulky. If you're going outside, absolutely. If you saw the movie The Martian, our hero was going out in a fair, lightweight suit, and that may be a little bit optimistic, at least with current technology. Mars's atmosphere, as far as your body concern, is a vacuum. You are just as dead on Mars if you take your helmet off as you would be if you did it on the moon or out in deep space. It is not close to enough to support life or even get one breath in before you lose consciousness.

So it's going to look like a full-blown space suit, the big white suit that our station astronauts use to conduct spacewalks, except it's going to need a lot more mobility in the hips. To do a spacewalk, you basically never use your legs. Walking around on a planet, especially with 3.8s G, which if your suit weighs 350 pounds, is still a pretty heavy suit. You're going to need hip mobility and the ability to bend your knees and bend your ankles, which our current spacesuit doesn't have, but our Apollo moon suits had to a limited extent. So it's going to be a big, heavy, bulky space suit until we can do something.

something about Mars's atmosphere to make it better. I'm Flora Lichten, and this is Science Friday from PRI, Public Radio International. In the book, Dune, the Desert Dwellers on that dry, sandy planet, Aracas, wear so-called still suits. They capture sweat and breath and everything and turn it back into drinking water. Is that going to be something we need to develop? I don't think so. First of all, most of your time you're going to be in a habitat. Water will be precious.

You'll either have to mine it out of the soil, hopefully not bring it from Earth because that's going to be even harder. And so we'll want to recapture all the water that we can. But the water that you sweat when you exercise, on Iraqis, it goes out in the atmosphere and it's very hard to claw it back. In a sealed habitat, it's going to end up in your humidity removal system, which you have to have. Otherwise, it's going to be unbearably muggy in the place all the time.

So we can reclaim it that way. the water that you exhale with each breath, you would want to capture that on a desert planet, but on Mars, again, it's going into the cabin atmosphere, and we'll pick it up in the dehumidifier. We have a tweet from Damien, how hard would it be to sunbathe on Mars? And could you? Ariel? Very interesting question from Damien about the potential impact of the sun's rays. So we know that at that distance, Mars is much further out than the Earth. The sun's rays will be weaker than what we would typically experience on Earth.

And yet I would still not recommend it. I think it's an issue of a radiation dosage. And when you're on the surface of Mars, you're dealing with Mars's significant lack of an atmosphere that's comparable to what Earthlings are used to experience. So no, I would not recommend a sunbatting experience on Mars in the near future. To riff on Stan's comment about the sweat and the suits, we do have a couple of researchers here looking at innovative textiles that can kick. capture sweat along the lines and seams of an internal suit. So this is less for, say, those bulky EVA suits, the external vehicular activity suits, and more for something you might wear on the inside. Yes, Stan is absolutely right that the humidity in a capture system, saying something

like a HAB module on a Martian colony, would be able to capture most of the moisture, not just that you're losing from your body, but that you're also perspiring through your breath and your respiration, but we're interested still in having a unique new textile fabric for these suits, for hygiene, actually. When you think about hygiene on a Martian colony, it's something that's not going to come as easily as it would even in the International Space Station, just due to resource constraints. And so being able to correctly and efficiently wicks sweat and the minerals that are also exuded in sweat away from your body might be a really helpful thing for hygiene. Are you talking about a self-showering, self-showering clothes?

That is a great tagline. I shall suggest that in the future. Something along those lines, yes. And I think a source of really fantastic inspiration for us for that project is the biosuit coming out of David Newman's Manned Vehicle Laboratory at MIT Arrow Astro. And looking at a close form bodysuit, it's form fitting. It looks also very fashionable, very space forward thinking. And has these fantastic seam lines that are isopressure lines. So if you can combine the flexibility that comes with a suit dynamically designed,

for you to be moving freely with something like a self-cleaning, self-showering functionality, that's something that we're really excited and are looking into. Stay with us, everybody. We're going to be talking lots more about life on Mars. And after the break, we'll also talk about an old idea that's being reinvented for travel across the red planet, the airship. There's one big difference, though, from the ones here on Earth. Stay with us.

This is Science Friday, and I'm Flora Lichten, sitting in for Ira Flato. So we're talking about what life might be like in space or on the surface of Mars with my guests. Stan Love is a NASA astronaut and planetary scientist at NASA's Johnson Space Center. Ariel Ekplah is founder and lead of the MIT Space Exploration Initiative. And if you've seen the Martian, you know that getting from point A to point B can be quite an ordeal on Mars. It is slow, dangerous. You have to ration your battery power and avoid all of those sharp brown. rocks that seem to just want to puncture your wheels.

So I'd like to bring on another guest now to talk about transportation. He's done some thinking about other ways we might get around the red planet. John Paul Clark is a professor of aerospace and industrial and systems engineering at Georgia Tech in Atlanta. Welcome to Science Friday. Hi, happy to be here. John Paul, tell me about this Martian blimp idea. A couple of us at Georgia Tech were thinking about whether a vacuum air should, was viable. And basically, for those who don't know, a vacuum airship is same principle as a balloon

or a divisible, but instead of filling the inside with a lower density, lighter gas, you basically have an inside purely evacuated. So you're using the same principle, you're displacing a gas or an atmosphere, but instead of filling it with a lighter gas, you're filling with nothing. The big challenge, of course, is that that structure has to resist all the compression that you would naturally want to occur. And so we've done a fair bunch of analysis and we found that with the materials that we have now, and luckily for us, the atmosphere in Mars is just like perfect amongst all the planets in our solar system for actually deploying a vacuum ownership. So what is the structure that actually prevents this pressure from the Mars atmosphere from

popping that balloon? Yeah. Well, it turns out that it's kind of like a sphere. but it's really an euthraeotahedron, basically eight-sided figure. And what happens that we actually build a truss, and then we have a very thin, basically membrane layer outside of that trust. So if you look at it, it kind of looks like a slightly defy up the soccer ball or something like that in terms of the flat side. I'm thinking of like a geodesic dome. Yes, exactly.

It started like that. And the key thing, though, is that those geodesic domes usually have all the structure on the outside. This one actually has a trustwork inside. And the key thing for our trust work is that they're made up what we call 10-seguty beams, which are very light, and basically you have the actual beams themselves in compression, and they have wires and tension. So they have some really cool properties, and one of them is that they don't buckle, even though they're very thin. What would you use this for? What kind of transportation? Is it for long distances? Is it more of the Amtrak of Mars?

Is it, you know, like the subway? What's it for? You can use it for pretty much any of those purposes. We've actually sketched out concepts for doing surveillance and scientific research for moving entire habitats if you build a big enough one. Like you have a habitat you want to go explore another part of the planet. Or if you just basically want to get from point A to point B, the cool thing is just basically, you know, you can never achieve a perfect vacuum.

And so you just need to determine how close you get to perfect vacuum to determine the altitude you want to crew that. And then you have to have some obvious system system provided horizontal propulsion. The best thing of all is that unlike a balloon or a derigible where if you have a puncture, you basically have to refill it with gas. This time, if you have a puncture in the membrane, you just patch it and just re-evaluate it. And it's good to go. Let's go to the phones. Let's go to Matt in Pittsburgh. Hi, Matt. Hi, how are you? Great. What's your question? Yeah, I was just curious if there were any theories or anticipated impact to genetics as, you know, the small population of human beings colonize Mars, what would subsequent generations look like? Would there be an effect of physicality? Has there been kind of any thought around that?

I was wondering about that, too, if in low gravity, humans would get stretched out. and they would get taller. Exactly. Stan? Oh, good question. My understanding is that predictive genetics has not been a successful field of study for our species, so nobody knows.

I think the second order thought would be if there were tigers that ate people who didn't get stretched out, then people would get taller. But we're probably not going to take tigers with us. So it's tough to know how genetic drift would result in a change in the population without some sort of selective pressure to go with it.

Ariel, have you looked at this? I think I'll echo Stan's answer here in that we're thinking about it and yet the right answers that the data's not in yet. It's very tempting to speculate and say, you know, maybe in the course of a generation, we wouldn't necessarily expect to see major genetic shifts, maybe a little bit of epigenetic shift,

but could just the varying environment for a generation raised on Mars, say, lead them to be taller just because over the course of their singular lifetime, the force of gravity is not pulling down on their muscles and bones while they're in an early childhood development stage. And so then it's fun to speculate and think, well, does that mean if Martians took a tourist trip back to Earth, would they struggle under the weight of Earth gravity? These are all questions that we're asking, but until we do actually have some data coming in from a few Martian colonists, it'll be hard to know for sure. What I would point listeners to is

Chris Mason's work at Cornell. Chris was just here over the weekend talking about the genetics behind the NASA twin study and some of the DNA changes that we are seeing between Scott Kelly and Mark Kelly for their differing times in space. Hmm. How many humans do you need to actually create a self-sustaining population, like a healthy gene pool? Stan? Well, I've taken a look at that recently, and I have seen numbers anywhere from 500,

to 100,000. Oh, that's a tough experiment to do, and I hope we don't guess low. But certainly in the thousands would be a safe guess. So we're talking about a decent-sized town. Yeah, indeed. Let's go to the phones. We have Caden and in Hawthorne, Florida.

Hi, welcome to Science Friday. Hi, this is Caden. And maybe turn down your radio, if you don't mind. Okay. So would Wi-Fi and, like, electronics work on Mars? Would they be affected? Would they be better? Would they be worse? Great question. That is a fantastic question. A lot of the infrastructure that we rely on for things like

Wi-Fi and electronics and GPS here on Earth are actually due to satellites that we have in orbit, so a large infrastructure that we have orbiting the Earth at any one time. We're just starting to plan for what that infrastructure might be like. say we, not just the MIT Media Lab space exploration initiative, but more broadly, the Jet Propulsion Lab at NASA, other groups like SpaceX, trying to think about what is that infrastructure around Mars in orbit that we would need to really support on surface operations? Another class of support, in addition to, say, GPS satellites or internet producing, providing satellites would be a staging base. And when Flora mentioned geodesic domes earlier in the context of Jean-Paul's work,

That reminds me of the Tessori project at the MIT Media Lab, a proposal for self-assembling space architecture that would essentially be flexible, reconfigurable modules for astronauts to live in in orbit around Mars as they're preparing for missions to the surface and coming back. And maybe we can augment those type of Tessori self-assembling structures with technology and capability to give you Wi-Fi access, which is a great question. We can put some Wi-Fi transmitters on below my airships, actually. Put a bunch of them up, and we can create a little network. That sounds great. We're solving the problems right here on this show. And as far as the function of the basic electronics, those work pretty well on Mars.

You know, every time we send a probe out into space, all of our communication satellites, the rovers on Mars, those are all chock full of electronics. They have to be designed to withstand a few extra radiation hits, can flip bits in memories, but they work in general very reliably, and we wouldn't have trouble with basic electronics on Mars. We have a tweet from Christine, which says, did you have to mention pancakes at the carb-craving hour in the afternoon? Please tell me they would not be as fluffy on Mars, or would they be fluffier, discuss?

My vote is fluffier. the carbon dioxide gas and the pancake is going to expand. There's going to be less gravity making the pancake flat. I think you're going to end up with nice fluffy pancakes. I think that's the perfect place to leave this conversation. I want to thank you all for joining me today. Stan Love is a NASA astronaut and planetary scientist at NASA's Johnson Space Center in Houston, Texas. Ariel Ekbaugh is founder and lead of the MIT Media Lab Space Exploration Initiative in Cambridge, Massachusetts,

and John Paul Clark is a professor of aerospace and industrial and systems engineering at Georgia Tech in Atlanta. You might have met Steve. Steve is kind of a loner, yet extremely popular and very weird. Steve does not come out in winter. Steve is pinkish mauve and manifests as a streak in the sky. Steve is a phenomenon in the Aurora, the northern lights, that citizen scientists and Aurora enthusiasts have been looking at for the past couple of years. And Steve has attracted a lot of attention because it just doesn't look like the rest of the aurora.

And it's often much further south than typical aurora colors. But new research, a collaboration between citizen observers and professional scientists, has an answer for what might be causing Steve. It's published in the journal Science Advances this week. I'll let my next guest explain what they learned and explain why Steve is named Steve. Liz McDonald is founder of the Citizen Science Project Auroraosaurus and a space physicist at NASA's Goddard Space Flight Center. Welcome back, Liz.

Hi, thank you. Why is Steve named Steve? So first, for those of you don't know, the citizen scientists and amateur photographers were photographing the night sky. They saw this different thing. It used to be called a proton arc, but in talking to the scientists from NASA and the University of Calgary,

we didn't think that was an appropriate name. So they said, okay, we'll give it a new name and keep taking observations. And so the name is inspired by the movie Over the Hedge, and it was named by Chris Ratzliff, who's the administrator of the Alberta Aurora Chasers of Facebook group. So Steve was named by the people, but sounds like you're sticking with it. Yeah, so the paper publishes shows a result where all the stars, actually the Steve and the ESA satellite swarm aligned and really allowed us to understand more about the true meaning of Steve. And so what we found was that Steve is associated with a really strong flow of particles in the upper atmosphere. And that is associated with heating of the plasma,

and also that somehow causes the glow of Steve, which is different. And so we're keeping the name. We actually, when we see it from satellites, we do know what it is. It's, a sub-aroral ion drift. And that's something that has been studied for a long time, but never known to have this visible component. So that's what's new and really exciting. And the name, we've given it a backonym, to be strong thermal emission velocity enhancement,

corresponding to what you see in the upper atmosphere, corresponding to what's causing Steve. I'm Flora Lichten, and this is Science Friday from PRI, Public Radio International. Okay, so River of ions, I'm trying to imagine what it is exactly. Can you just sort of break it down for me even further? Yeah, it's a little hard to explain because the aurora is happening farther to the north, and then there's a gap, and then there's this narrow ribbon of light.

And the aurora is driven by processes that happen hundreds of thousands of miles out in the near-Earth space environment, the magnetosphere. But at lower latitudes, Steve is corresponding to something happening still out in the magnetosphere, but closer in, in the inner magnetosphere. So that's where the sub- auroral ion drift is getting set up,

and it's driven by the same phenomena that's driving and enhancing the aurora. So is this just particles from the sun? When you say sub-arora drift, are we talking about charged particles? from the sun that are hitting particles in the magnetosphere? Yeah, so that's what normally drives the aurora, and those particles come in and they bounce off the upper atmosphere

and release light. And in this case, it's actually a different mechanism in the upper atmosphere that we think is producing the light. It's that the drift is so strong that the plasma, the charge particles move, and they heat up the neutral particles in the very upper level of our atmosphere. And so that's a different mechanism causing the light. Why is Steve Pinky Purple?

That also we don't fully know. And it is related to that drift. We think that at these latitudes, the chemistry of the upper atmosphere is getting changed by this strong drift. And so you have some really exotic wavelengths of light being excited that are different, and the wavelengths that are excited in the normal aurora because of the different process.

It's amazing to me that we didn't know Steve existed until now. Yeah, this region is not very well studied, and so there are still some mysteries out there. And so it's really exciting that citizen scientists with their photographs have captured these new aspects. So mostly Steve is purple, but you also get a little bit of green light, that pops up and moves around, and that is some really exotic plasma physics that we don't even understand yet. Where can I see Steve?

So you can see Steve. It's been reported all over Alberta and most of Canada, also Scotland, Tasmania, I just found out today, New Zealand, and slightly less exotic places like Michigan and Montana. Are there other Steve's out there? There could be some more mysteries in the night sky. Our citizen science project is happy to collect observations from people and work with people for deeper understanding of what they may be. And really by working together, it's not just one observation.

It's several observations of Steve, and so we can better characterize these new characteristics. And where should people go if they want to get involved with a aurorasaurus? It's aurorasaurus, like a dinosaur.org. That's great. Thank you so much, Liz McDonald, founder of aurorasaurus and a space physicist at NASA's scattered spaceflight center. Thanks for coming on the show. Thank you.

BJ Leederman composed our theme music, and if you missed any part of this program or you'd like to hear it again, subscribe to our podcasts. And if you have a smart speaker, ask it to play Science Friday whenever you want. Now every day is Science Friday. Say hi to us on Facebook, Twitter, Instagram, or email us, SciFri at ScienceFriday.com. Send feedback. Tell us what you'd like to hear us cover. Ira will be back next week.

And next week, I'll be back at my main gig. I host a podcast called Every Little Thing from Gimlet Media, and it's in all the places that you get your podcasts. In New York, I'm Flora Lichten.