Our Celestial Bodies, Ourselves

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S1: I’m Katie Coleman, I’m Andrew Maynard. Welcome to Mission Interplanetary.

S2: And this is our first episode,

S1: the very first.

S2: So Cady, how excited are you about Richard for you on a scale of

S1: one to 10? Definitely around a 13

S2: or so I was going to say there’s at least 15 for me. I think this is going to be awesome.

S1: I think about Cruz and our crew is really wonderful to be with. I mean, there’s Lance Garvey, who is the person who had this idea and said, OK, let’s have this podcast, it’s going to be about, well, Andrew, you’re better at saying exactly what it’s about.

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S2: Yeah, we talk about the big questions around humanity and space. But really, it’s about people. It’s about that human side of space and space exploration and where we might actually go. And I hope actually we bring a little bit to these discussions that goes beyond just the science and tech. Let’s talk about the people to talk about the aspirations, to talk about the hopes and maybe some of the pitfalls about us becoming interplanetary species.

S1: When Lance thought about, you know, we’ve got these big questions, you know, and it’s not just about what what’s the newest hardware? What’s the hardest thing about building a rocket that’ll take us to Mars? It’s not about the hardware. It’s not about, you know, those kinds of challenges. It’s really about the opportunities and them and the mysteries that people, real people want to investigate. And he said, Well, you know, we’re in we’re in the 21st century. What would we do? We’d have a podcast. And then he said, You and I are up on a podcast blind date, right? And and it was really clear to me that we are both really curious about the future, but in different ways.

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S2: Yeah. And you said this a number of times, but I love the fact that we come to this from different perspectives. So I’ve never been up to space. So to me, you are the expert here, but I can ask questions.

S1: Well, coming from physics, but also your philosophical background of, you know, trying to understand what this means in the larger scheme of things and what does it mean for people? And why do people make all the difference? So pushing it

S2: back to AACTA? So today on mission into planetary, we are asking what can an asteroid tell us about the history of our solar system?

S1: And I know like a tiny bit about that. I mean, just having been part of as my astronaut training the Antarctic search for meteorites, right where meteorites are like little tiny, tiny asteroids and pieces from that asteroid belt, you know, kind of all made up by the same thing. But then there are special objects. There’s a lot to know, and it’s important in terms of understanding what our origins really are.

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S2: Right, right. And of course, in this episode, we’re going to be talking about a really large, glittery special object. But before we get there, I want to talk about obsessions. So every week we’re going to be talking about what we’re being obsessive about. Cady What’s been your obsession this week? Secrets mm. Tell me more. Well, and I’m sorry, you can’t have secrets.

S1: You know you don’t actually have any but other people do. So, you know, the Perseverance rover is on Mars, and it’s designed by this like wild and wonderful group of people. In fact, I love when they were, you know, coming, you know, getting ready to actually land on Mars. It would put out, you know, the people who made perseverance and they’re there. They all are very multidimensional in terms of their scientific background. But then collectively, they have this sense of fun and and of wanting to make sure that people know that people left this little trail. And so they’re I mean, this week I discovered the bumper sticker. Mm hmm. And that’s what I’ve been obsessed, and it’s kind of like the bumper sticker you would see on the back of somebody’s car might have like a dog and a cat. And you know, or I see ones with little astronauts on them. Of course I love them, right? Right. But this Perseverance’s bumper sticker has like a little tiny rover, one of the first ones, Sojourner, and then the next one and the next one. And then there’s curiosity. And now there’s perseverance. So cool. So Perseverance has a bumper sticker of rovers on its bumper.

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S2: The most far out bumper sticker, literally.

S1: And you Andrew. So I’ve actually been thinking about

S2: space hotels because there is this big thing about space hotel 2027. This company, the claims that are actually going to build this space hotel where you can go up and stay in the space rooms, I guess. I can’t believe that this is really going to happen. Is it? Are people really going to be staying in a space hotel in 2027?

S1: Cady 27. I think it’s possible, but I think the fine print in this case is going to be really important. Yeah, OK. Let’s just say that the accommodations were sparse, the rooms were not big, and I think you’d better check how big your room is going to be in this space hotel. Right, right. But you know, I would go I would go in a minute.

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S2: You, you would. You would go even if the rooms had no bigger than the International Space Station sort of accommodations?

S1: Yeah. Well, first of all, you don’t need as much room in in in floating around.

S2: I guess you’ve got three dimensions to float around.

S1: You really don’t. And I would go in a minute. I mean, it’s just going to be the place you close your eyes until you can wake up and go explore the rest of the place.

S2: I guess we’ll just stick the guests to the walls.

S1: Why not sleep in space?

S2: Okay, well, let’s get to our guest and. Today on Interplanetary, we’re asking the question, why should we visit asteroids? Our guest is Lindy Elkins-Tanton, the leader of NASA’s Psyche mission, a journey to explore the asteroid 16 psyche and going to have to ask what that means. One of the 10 largest known asteroids in the Solar System, Lindy, is the vice president of Arizona State University’s Interplanetary Initiative, a fellow at the American Geophysical Union. And in 2018, she was appointed as a member of the American Academy of Arts and Sciences. Lindy Elkins-Tanton. Welcome to Interplanetary

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S3: Andrew. Thank you so much. I’m really excited to be here and talk with you and Cady today.

S2: And it’s doubly exciting because I think you are the persona that really captures into planetary being embedded and in this leadership role in the Interplanetary Initiative. So this is exciting for us,

S1: and I feel like this mission is literally right around the corner. I mean, it came up so fast and it’s just moving faster and faster. And so we wanted to get you before it was already gone on its way.

S3: Cady. I can’t tell you how right you are about that, and it’s kind of silly to say, because what are we? We’re still twenty one months out from launch, but that really is right around the corner and we’ve got no time. We’ve got no margin left like our schedule is tight. Everything is scheduled to the minute. Our assembly test and launch operations starts in one hundred and three days.

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S2: I was just about to ask you whether you actually know the number of days, and the answer is obviously yes. Oh yeah,

S3: yeah, all the different numbers of days. Yes, right?

S1: Yes. OK, planets are the stars of our Solar System, but I suppose technically our Sun is the star of our Solar System. But planets are in a way the celebrities, schoolchildren learn their names, their order. Maybe something about their properties. But asteroids aren’t celebrities. They’re like us, just these comparatively small, anonymous rocks floating in an endless void. So why is Nasser and specifically you sending a spaceship to visit one?

S3: Yeah, you’re right. The planets are the celebrities, but I feel like times are changing. I feel like the days when planets were just the celebrities our past days. It’s a leftover from when that’s all we could really see with our telescopes. And now is our technology and our missions get better and better. We realized that the planets are so vastly outnumbered. It’s not even funny. We’re probably at least two million small worlds in our solar system. And right now, we’re down to eight planets. And so, you know, we got a lot more exploring to do so. Why would we go see these small objects? A lot of it has to do with our fundamental interest in understanding how we came to be. I think that’s a pretty big enough question to motivate a science investigation. What how did our Solar System grow? What was it made of? Why is the Earth habitable? All these questions can be addressed by looking at the raw ingredients, which are the small worlds in our solar system because they’re all different from each other. A different regions of the Solar System have different kinds of small worlds. They have different compositions. Some of them are just really raw materials like straight from the nebula that formed our sun, and others of them have been heated up and and more or less assume the structure of a tiny planet themselves. There is so much to learn.

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S2: So just say a little bit more about that, and I know we want to get to talking about Psyche, but this to me is so important. How how do these lumps of rock? Tell us something about the Earth and the Solar System? Where do they come from? What is the background of these things?

S3: Where do they come from? Yeah. So so imagine imagine the very, very beginning of a solar system. Any solar system, where do they come from? They come from giant molecular clouds. There are these vast clouds of gas and dust, and by dust, I mean, really tiny molecules, maybe organic ones that have a bit of carbon, maybe tiny bits of diamonds, actually little tiny, tiny fragments of little bits of minerals, but mostly gas and nearby nearby, universally speaking, in other words, very, very far away, a star explodes, it goes supernova, and it makes a gigantic explosion. And it sends out this huge shockwave out into the giant molecular cloud, which then presses the gases together and they start to collapse under their own gravitation. They start to collapse and they start to spin. And what happens then, is the middle of them begins to form stars of these collapsing regions. And so first of all, how can we possibly know this? We actually see snapshots of this happening through telescopes. And the other thing is something from that shock wave gets embedded into the giant molecular cloud, the little part of it that became our solar system and we could track it.

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S2: Wow. So it’s so it’s like it’s sort of almost frozen in time, so we can actually. Back to what happened.

S3: It’s like a fingerprint. So get this because this still blows my mind. I love telling the story. So in our solar system at least, and we don’t really know if this is true for all solar systems. It’s kind of an important point, though. What we end up with is a spinning disk of dust and gas with the proto sun in the middle, all the gravity pulling that giant mass into the the middle. Just like the giant mass the same as it is today, the sun overwhelms the mass of the rest of the Solar System, and then the materials in that dust and gas just begin to condense into little pebbles and little rocks. And then they accrete together. They clump together into planetesimals, their tiny planets, planetesimals maybe just tens to hundreds or a thousand kilometers in diameter the size of a state. Maybe a big one is the size of Australia. And so here’s where the fingerprint comes in. It turns out that certain kinds of supernovas produce a very specific radio gennych element aluminum 26. The aluminum with it with the molecular weight of 26 is is radioactive. And as a very short half life, it’s only about I forget it’s less than a million years and it’s short and it’s really cut

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S2: that I love these timescales.

S3: It’s super embarrassing for me not to remember the exact number of aluminum. 26. This radio Jenek isotope is created by the supernova explosion, and it becomes a part of our Solar System. And there’s so much of it, and it’s so radio Janick that when it gets incorporated into this growing planetesimals, they melt from the heat of the radio gennych element. And so there’s no aluminum 26 left. It’s all burned up. But we see its remnants in the fact that the meteorites that fall to Earth now from the asteroid belt, some of them come from small worlds that completely melted in the first few hundred thousand years of the Solar System.

S2: So these rocks that sort of we have in our solar system, they’re actually the fragments of these sort of protoplanets. Exactly. Were that OK? So then this is really interesting. So you mentioned we have these meetings that that lands on Earth that tell us something about this. So why then go out to the asteroids if we’re already having this stuff raining down on us? Yes.

S3: Yeah, it is true that we think that almost all the meteorites that fall to Earth in the present day come from the asteroid belt relatively recently. But we certainly don’t sample everything in the asteroid belt, and we don’t know where the samples come from, and we don’t know what they’re like on a big scale. Imagine if someone handed you a rock the size of your fist and then told you to imagine what the Earth was from that rock?

S2: Yeah, it’s a pretty big stretch.

S3: You can’t. You cannot actually do it. And so to really understand the bigger structure and then also, I’m not that I do absolutely only want to talk about my mission, but there are other missions to small worlds and we try not to talk about them very much. But there are small worlds outside of the Solar System. I mean, outside of the asteroid belt, there are small worlds out orbiting with with Jupiter. That’s what our sister mission Lucy’s going to go look at. There are near-Earth asteroids that cross the orbit of the Earth and threaten us. Psyche is not one of those. And then there’s New Horizons out in the Kuiper Belt looking at these icy worlds for the first time ever. And the information that’s coming in is incredible. And if you would just bear with me one second, I want to tell you the most amazing thing that small worlds have ever told us and will ever tell us until Psyche gets until we get to our Psyche. So this is going to stand for a few years until we discover something astonishing. There are a couple of teams. One of them is is Scott Sheppard at the Carnegie Institution for Science and Chad Trujillo at Northern Arizona University. And another one is is that of Caltech. And they spend a lot of their time looking for small worlds that orbit way past Pluto and outside of other known parts of the Kuiper Belt. They’re really looking for the innermost bodies from the Oort Cloud, which is the farthest population of small bodies. So we really can’t see them yet. They’re too small, too far away. But here’s the thing they found I don’t know a dozen something like that. I don’t know the quite the number right now of these very distant bodies and all of their orbits are lined up in a certain way that almost beyond the shadow of a doubt, statistically they are being influenced by a larger body that orbits out past them. The only way they could be lined up that way is if there was another big planet way out past Pluto that we have not yet discovered. That is perturbing the orbits of these bodies, and they say that it’s something like five to 20 times the size of the Earth. They call it Planet Nine or Planet X, and they’re searching for it right now. So if that is not a great small body story, I don’t know why

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S1: Pluto, we shove it aside, but now we need it again, like we want to know, right?

S3: Right. Plus, Pluto is still alive, isn’t it? Because it still has heat coming from its interior? It still has. It has glaciers and mountains and ice fields. It’s amazing.

S1: Something this confused me, Lindy is so this is the metal asteroid or mostly metal asteroid that we’re going to. And yet we also talk about these meteorites that we find on the Earth being metal. And so why is it unusual that it’s metal, right? I’m missing that,

S3: missing the metal story. So here’s the metal story,

S1: the heavy metal story, the heavy

S3: metal, the part that makes us really cool like rock idols, because that’s a heavy metal mission, you know, as middle aged people suddenly metal rock idols. So this aluminum 26 story, right melts these planetesimals just in the first tiny instance of the Solar System, really, if you look at it on a grand scale. And what happens is the primary. Those primitive materials are partly iron, nickel metal, and they’re partly rock, and the iron nickel metal sinks to the middle and becomes an iron core. That’s the same structure that the Earth has that the Moon has. The Moon has a metal core Mars, Venus, Mercury all have metal cores, which we can never, ever visit. Some of these planetesimals obviously had metal cores, and some of them got broken up and some of their little bits of their metal cores land on Earth and we find them there iron meteorites. But when you look out into the asteroid belt with a telescope and you’re looking at the reflected light and you’re trying to figure out what all these objects are out of, maybe to one point something million asteroids in the asteroid belt, we’ve only found nine that seem to be made of metal. It’s really, really rare. And there’s only one of them that’s big, and that’s Psyche. So it’s an absolute unique object in our solar system. As far as we know, there’s no other like it.

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S2: So, so then as far as you know, it sounds like this is the core of one of these these protoplanets. I mean, is it just a sort of fraction of the core, do you think? How does it fit in with these early planets?

S3: Andrew I wish I could answer the question of what Psyche is and how it fits in.

S1: So, so couple of couple of really important

S3: things I tell people whenever I give a talk about Psyche and I tell all the data that we now have and the reasons why we think we know what it is or we have an idea, I’m really just about certain that everything I tell you now is going to be proven to be wrong when we get there, because our imagination is never sufficient for what you actually find in space. Plus, the data that we’ve taken from Earth, it’s actually self-contradictory. Psyche really, from its density, the best we can measure has to be largely made of metal. We don’t really know what the rest of it is. Mm hmm. And we don’t really know where the metal came from. So the very simplest guess is that it’s it’s a part of the core of a planetesimal that was melted and formed a core like I was describing with some of the rock from the outside still attached. Sounds like a kind of a simple, plausible story the way I’ve been telling it. But there are a whole bunch of caveats. Here’s one caveat in order to create Psyche that has the core exposed in only a little bit of rock, still attached takes between four and eight destructive impacts with other objects and no constructive impacts nothing that clumped it back together, which means that it’s a very unusual circumstance. People run models of the Solar System, and sometimes they don’t make any Psyche at all. And sometimes they make one. So it’s a it’s a highly unlikely circumstance. And yet that is the most likely hypothesis we have right now for what Psyche is, which makes me think we really don’t know what it is.

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S2: Yeah, but isn’t this the beauty of science? Not only that, you’re discovering stuff that you don’t know, but you could be wrong. I mean, I this I’m sure this sounds counter to what so many people understand about science, but we love to be wrong because that’s when you learn something new.

S3: Yes. And it’s also, I think, a test. It’s a test of our fidelity to our science to say very willingly, this is our best guess. We really think this to be true, and probably it’s going to be wrong. And then when it’s wrong to stand up and say it was wrong, and here’s our next best guess that’s kind of how knowledge rolls forward.

S1: Yeah. And one thing that I love is when you’re trying to explain to people why we should go and what and what, what you think is the is the the best story, the right story. Now I want you to listen to the sound Lindy. Do you hear that out of a book? It’s the sound of a sound of a flip flop. It’s our flipbook Lindy. You gave this to me and they’re still on my windowsill, and I love the fact that the proposal had to involve. I mean, you were just, you know, you know, you can’t be carting all sorts of giant models into the room. Everything has to be on paper or computer and that your, well, you taught your team came up with this one.

S3: You can’t have those flip books. It just absolutely gives me chills. So we spent six years working on this proposal and proposing it through the many steps the progressive steps of trying to win a big completed mission from NASA. And it started in 2011 with the science hypothesis that was a real science groupies kind of science hypothesis I could explain. To what it was a year ago. So who cares? But I will tell you that the group little group of scientists who study and cared a lot, and when we stood up to talk about it at the first conference, it was standing room. Only there were hundreds of people in the room to listen to this talk, and they were already lined up at the microphones to tell us we were wrong before I even started speaking. So it’s the kind of thing that really got scientists super excited. And what we realized over the next couple of years, because you get so into your own head that we had in mind this whole storyline that I’ve just explained to you the dust and clumps together, and it heats up from the Radio 10X and it melts and forms a core, and then it’s impacted over and over. And then part of the course is revealed and you can measure you hope it’s magnetic field that still stays. That whole kind of story was in our heads and caused us to design the spacecraft the way we did. That’s the reason we picked the science instruments so we could test these hypotheses exactly what the instruments that we chose with exactly the way that they’re going to measure things. Nobody else understood that nobody else had that filmstrip running in their head day and night. And so we had to be able to explain that filmstrip to engineers and people who were not immediately in our tiny corner of science and the whole review board and all the administrators. And it turns out you also can’t always have a YouTube video in front of people’s faces. And so we made flip books. We worked with this wonderful artist to make flip books so that people could sit there and flip the flip book and go, OK, so that’s what they think they’re measuring then, and that’s what they think they’re measuring them. The flip book was our way to communicate this film filmstrip that had been running in our heads for six years.

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S2: And so you’ve got to extend that story to the broader Psyche mission because arts and creativity seem to be central to what you’re doing, complementing the science.

S3: I love the opportunity to talk about the art that we’re doing, and it’s been a passion of mine actually my whole life to. Well, I guess I haven’t quite put it this way before. But in the broadest sense, to trying to get people to realize that all the things we’re endeavoring to do in our lives, assuming we are endeavouring to do something, the endeavors are very similar. We’re all humans trying to grapple with and interact with and understand what’s around us.

S2: Thank you.

S3: Can I tell you or did I ever tell you the story of the celestial police? No. Fantastic story, which I really think that you need to hear. So, so in right around eighteen hundred, there was a man named Bode who made up a mathematical expression that correctly anticipated the spacing of the planets Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune. But it also predicted one between Mars and Jupiter. So it turns out this expression is totally meaningless. You can write a polynomial that has any number of zeros, any number of predictions, and it just happens to have found one that did everything but had one extra. But everybody thought it was real. And so this huge coalition of astronomers in Europe set out to find the missing planet. And they were they were led by a guy in Germany named France, Xavier von Zuk. He was the lead. And he named them Deimos Poets II, the celestial police, because they were going to set straight the heavens that were disorderly and unruly and incorrect. And so they started searching. And I think in 18 or six, maybe it’s not the right number they found series. That’s why series this one series is the first asteroid that was ever found. And they kept searching and kept searching. 1852. They found 16 Psyche. This was found by Annabel Diasporas in Naples, and they kept finding asteroids and numbering them until finally they realized there was no planet there. And and so then a further realization that came out a little further was that Jupiter’s gravity is so gigantic that no planet could ever have been there. And in fact, Jupiter, through so many smaller objects out of the way that Mars was starved and never got to grow up to be a big planet. Mars is what we call a planetary embryo is just a little baby planet because Jupiter starved it. And so all we have is we have this tiny little Mars and then some shrapnel, which really wouldn’t have added up to even anything the size of Mars. So there never was a planet there. Hmm. I know it’s enough to make you cry.

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S1: It is so awesome. So what are the three things you’d like to get from this mission, like when you get there? And I guess it’s going to be around Psyche for almost two years, right? Mm hmm. What? What is that mean? Actually, we know it might change, which is exciting. But right now, what do you think it might say?

S3: The news story? What do I think the news story might say? Well, I will tell you, the very first thing that I want to get out of it would be a news story with a headline something like people from all over the world look up tonight to see a new kind of world that humans have never seen before. That’s what I want. I want that first close up image to be out on the web and have everyone in the world want to see what that is and think about what this is that there’s a world way out there that we’ve never seen before. And now we’re seeing it and we’re a better species for it and we’re understanding something new. That’s really what I want the most. In fact, we’re setting up the data pipeline so that our images will be on the web available to everyone in the world for free within 30 minutes of receiving them. We’re not holding them back at all. In fact, we just went through this. It’s a quite a process to figure this out. So that’s the first headline. And then and then I would love for us to see shapes on the surface of Psyche that are unlike shapes that anyone has ever seen before so that everyone in the world can look at it and go, What is that? That doesn’t look like anything I’m familiar with. Let’s stretch our brains. Let’s see things we’ve never seen before. And then I hope that it is the core of a planet. And I would love to see that headline, and it was wouldn’t be the first headline and wouldn’t happen right away. It’s going to take a lot of proving right. Our first and only view that humankind will ever have of the metal core of a planet, that that would be a really great one. I’d love that. And this is why I have to think

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S1: there’s another one. One of the

S3: things, there’s one other thing. Here’s the only headline that would be better than that. Psyche proven to not be a metal core and in fact, is a kind of material never foreseen that would be pretty great.

S2: What a wonderful way to wrap up that that idea that you’re wrong, but you’re wrong in such an exciting way that it opens up brand new vistas. I hope so. So, so remind us all when this is all going to happen. When are we going to see these headlines?

S3: Well, we are launching in August of 2020 to proudly launching on a Falcon Heavy in the collaboration between nascent Space X. That’s going to be a really exciting launch, I think. And then we’ll cruise out through space for about three and a half years, and we’ll get there around January of twenty twenty six and we’ll get approached photos. So it’ll be a little speck of light and then a bigger speck of light. And maybe it’ll be a disk and we’re going to get a sneak up on it. As we come closer and closer, we’ll be sharing those photos and seeing it as we come closer and closer and begin to resolve information. And then we’ll really enter into orbit in January of twenty twenty six.

S2: I and I love the fact that you framed this as a unifying experience, not just for the scientific community, not just for America, but for everybody on Earth.

S3: That is the purpose of space exploration. Otherwise, we just shouldn’t even be doing it.

S2: Lindy Elkins-Tanton. This has been fantastic. Thank you so much.

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S1: Lindy Thank you.

S3: I appreciate you all so much. Thank you, Cady. Thank you, Andrew. This is great fun.

S2: So most of us have been to space. I have, yeah, I know you have, but most of us only experience space through the photos and videos we see.

S1: So we’re used to seeing what space looks like second hand. But what does space sound like

S2: on mission interplanetary? We can’t show you pictures, cast audio format. Instead, you’ll hear what space sounds

S1: like in a segment we call sounds of space.

S2: Who Cady, so what do you think that was?

S1: Well, it sounded like something that was very stressed out. OK. Yeah, I’m just going to I mean, it seems it seems like it wants to tell us something, but it’s just, I mean, it’s just it just can’t get through. So I’m going to say it’s about communication. Maybe in a marriage, I don’t know. But maybe it is space communication, a case

S2: in a marriage that was actually the sound of wind on Mars. And it was a recording that was taken on February the 22nd, 2021 by the SuperCam instrument on board NASA’s Perseverance rover. And this is actually different than the first sound of the Martian when you may have had that was recorded on the rover’s first solo Martian day.

S1: Oh, I heard about that because in the beginning, they I mean, it takes a while to take the data and then really figure out what it means. And that included the sound of the rover the first time, right?

S2: And they managed to take that out. But isn’t that incredible that we’re actually hearing for the first time really what it might be like? And of course, you know, people have already pointed out that you would never hear it because you’d have a spacesuit on. But if you had your ear out there on the Martian landscape, this is what you would be listening to.

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S1: I mean, it makes a difference to me to look up at Mars and know that that’s what it sounds like.

S2: So let’s listen to that again. That’s it for this week. Thank you so much for joining us.

S1: Mission Interplanetary is produced by Lance Garvey. Our sound designer and engineer is Steven Christensen, and our music was composed by Mario Énergies.

S2: Remember to subscribe to us on Apple Podcasts, Spotify or wherever you get your podcasts. And please do leave us a review if you have any questions. Email us at Interplanetary Podcast at ASU Dot Edu and please do recommend us to your friends, your family, your colleagues. In fact, anyone you bump into

S1: Mission Interplanetary is a production of Arizona State University’s Interplanetary Initiative, and Slate

S2: will be back next week, asking the big questions about space exploration.

S1: The future is interplanetary.

S2: We’ll see you there.