An astrogeologic experience with Kirby Runyon

Sarah Al-Ahmed: We are going on an astrogeology adventure. This week on Planetary Radio. I'm Sarah Al-Ahmed of The Planetary Society, with more of the human adventure across our Solar System and beyond. Sometimes when you want to learn more about other worlds, all you have to do is step outside your door. Planetary Radio's creator and former host Mat Kaplan, takes us on an adventure today with Planetary Geologist Kirby Runyon. They'll take us through the terrain of New Mexico, USA as they tour locations that can teach us more about the world's beyond our own. Then, Bruce Betts, the Chief Scientist of The Planetary Society will pop in for WhatsApp, in a discussion of the most otherworldly places we've been. He'll also share a new random space fact. If you love Planetary Radio and want to stay informed about the latest space discoveries, make sure you hit that subscribe button on your favorite podcasting platform. By subscribing, you'll never miss an episode filled with new and awe-inspiring ways to know the cosmos and our place within it. Next week I'll be talking with the team behind NASA's upcoming Dragonfly mission to Saturn's moon Titan. It's a world that's so similar to our own and yet very alien. It's the only other place in our Solar System with a thick nitrogen atmosphere, but it also has rain and lakes and rivers. But instead of flowing liquid water, that world is shaped by liquid methane. There's something really comforting knowing that no matter how distant and strange the other worlds may be, there's often a hint of the familiar. I've been fortunate to travel to numerous places on our beautiful planet. My journeys have taken me through cities and forests, vast oceans and vibrant coral reefs. I've gone to mountains and rivers, and even gone on adventures to marvel at the grand feats of human architecture. Each of these moments is thrilling, but it's the stillness of the desolate regions where harsh winds and endless sands and icy expanses dominate. That's where my imagination goes to other worlds. In these stark landscapes that are far removed from the roar of machinery and the hustle of life, I often find myself mentally transported elsewhere. You and I may never personally stroll the rippled sand of the Martian craters or the cooled volcanic planes on the moon, but earth offers landscapes that are pretty close. Exploring these earthly analogs not only helps us prepare for space missions and develop new technologies, it also brings us tangibly closer to the mysterious worlds that are beyond our human experience. Anyone can have these kinds of adventures by taking a road trip to your local caldera or a desert, but there are also expert tours that you can go on to help you learn more about what earth can teach us about other worlds. Today, we're going to go on a very special adventure with Mat Kaplan, Planetary Radio's previous host, as he joins Kirby Runyon and a band of explorers in the very geology of New Mexico, USA. They'll explore the dunes of White Sands National Park, the Mars-like geology of Kilbourne Hole and the rocks in the Carrizozo Lava Flow. Dr. Kirby Runyon is a planetary geologist, a zero gravity coach, and a space tour guide. He's been on Planetary Radio numerous times. He's a research scientist at the Planetary Science Institute, but prior to that, he had over a decade of experience at the Johns Hopkins University Applied Physics lab. It takes a keen eye and a brain for mysteries to learn how the varied bits of terrain on earth formed, and what they can tell us about other worlds. Here's Kirby Runyon to explain.

Kirby Runyon: Geology is a forensic science. Something happened in the past, some natural processes, and just like a detective at a crime scene, reconstructs events that happened in the past based on the clues in front of them. Geology is the same thing. Some natural processes happened in the past. We read the rock record and we can reconstruct past history, past natural history events, and figure out what happened to make the beautiful landscapes that geologists study.

Sarah Al-Ahmed: As is tradition, Mat Kaplan made some new friends during his journey. Anyone who enjoys rock hunting and thinking about other worlds is definitely our kind of people. Let's meet Shirley Mullen and Paul Mills.

Shirley Mullen: I'm Shirley Mullen.

Paul Mills: I'm Paul Mills.

Mat Kaplan: You are a couple in spite of the different last names.

Shirley Mullen: Yes.

Paul Mills: We are married, yes.

Mat Kaplan: For a long time?

Paul Mills: No, we've only been married 13 and a half years.

Mat Kaplan: That's long enough, I would say. Listen, what got the two of you out on this trip? Are you space people, space geeks the way I am?

Shirley Mullen: No, Paul is a space geek. I am more a humanities person, a historian, philosopher, but when I married Paul, one of his intro comments to me was that he was from outer space, and he didn't smile when he said it. I've just known that he always loved the space, and so this is his birthday present, to be on this trip.

Mat Kaplan: Happy birthday, Paul.

Paul Mills: Thank you very much.

Mat Kaplan: I know I said it before, but so what does this trip mean to you?

Paul Mills: Oh, this is so much more information, and I would say knowledge because of the people we're traveling with, than I ever imagined because we're not only looking at volcanoes, but we're comparing volcanoes here on earth with volcanoes on the moon, and Mars, and other places. That sort of thing is of great interest to me because I'm interested in going to outer space. Now, of course, I know I'm too old for that now, but still I'm interested in it.

Mat Kaplan: John Glen made it. He was about your age. Now, I'm going to give you the opportunity you can refuse, because I know you've said how old you are. Do you want to mention it?

Paul Mills: Well, I'm presently 84. I'll be 85 in February.

Mat Kaplan: You both, I think, especially you, Shirley, have a connection that goes back with our host Kirby, even farther than my connection does.

Shirley Mullen: I don't know, Mat, how long your connection is. Paul and I are both alumni of the same institution that Kirby is, and the institution honored Kirby in 2018 as being the outstanding young alumnus of the year.

Mat Kaplan: You can say its name by the way.

Shirley Mullen: Oh, Houghton College, Houghton College. That's how we got to know Kirby. We were so impressed with his enthusiasm as a teacher and his desire just to have this large vision of the world, and that invitational spirit to live ever larger. I'll just say one other thing, Mat. As I mentioned earlier, I am more a humanities person and there are so many things in the world right now that are troubling. One of the things that this trip has done for me is give me that much longer perspective on time. I think that's one thing all of us need right now, in the midst of the complexity and chaos of the world, this perspective on things. I'm just really grateful for that. Plus, I've really enjoyed the diversity of people on the trip.

Mat Kaplan: Well, I'm glad I can say the same thing.

Paul Mills: Well, I think the diversity of information, because this is a world that I'm not familiar with and the information on that side, the way it's presented, and then the visuals that he's taken us to the craters, now we're standing right here looking at a lava flow that's guarded by two mountain ranges on each side. It's just a magnificent opportunity for an old man to learn something.

Shirley Mullen: The other thing, Mat, I would not have known is clearly interest in space is one of those great mediators between academic astronomers, academic geologists, and what you might call regular people. I'm saying that as an academic, because academics we're a strange group, although not all academics would appreciate that comment. But I just think space brings all kinds of people together, and we need more of those things in our time.

Mat Kaplan: That's one of my boss's favorite sayings. Space brings us together.

Shirley Mullen: Okay. I didn't even know that, Mat, but I really agree with that.

Mat Kaplan: Thank you folks.

Paul Mills: Thank you.

Mat Kaplan: We've got a little bit more to do today. I think we're going out to visit White Sands.

Paul Mills: White Sands.

Shirley Mullen: White Sands, yes. Yes, looking forward to it.

Paul Mills: We'll do some speed runs.

Mat Kaplan: I'm going to slide.

Sarah Al-Ahmed: Mat also encountered a traveler named Brenda Trinidad. I love what she had to say about the inspiration she takes from these kinds of astrogeology tours.

Brenda Trinidad: Thanks. I'm Brenda Trinidad and I'm currently the experienced curator for Insights Science Discovery in El Paso, Texas.

Mat Kaplan: How did you connect with Kirby?

Brenda Trinidad: That's a great story. The overview round table is this beautiful group of space enthusiasts, movers, shakers, catalyst changers that meets every Wednesday and Frank White, thankfully, is the architect of that with the human-

Mat Kaplan: Frank White of The Overview Effect, right?

Brenda Trinidad: Of The Overview Effect.

Mat Kaplan: I tried to make it, I don't make it as often as I should.

Brenda Trinidad: I'm so glad that I found it. I found so many just amazing people that I didn't know I needed to connect with, and Kirby was one of those. This one time where he actually introduced or announced that he was doing these astrogeology tours, and he said he was going to be in El Paso, Texas. Wait a minute, I'm in El Paso, let me send this private chat to him and say we need to talk. He goes, "Oh my gosh. Yes." That's how we met.

Mat Kaplan: That's a great connection.

Brenda Trinidad: Yes.

Mat Kaplan: Tell me more about your title that you just gave us and what that means.

Brenda Trinidad: This is what I'm trying to figure out. Experiences. I am in the space exploration field more to help people understand what it means to experience space, and I'm still trying to figure that out. With The Overview Effect round table, and we're thinking about how do we bring that transformative experience down for people on earth to figure, as I think about it, it's like all on wonder is around us everywhere, if we stop and figure out what that means for us. It could be as simple as we are right now here in White Sands National Monument. Just thinking about our place here among these dunes and the history that's here, it makes me feel amazingly small compared to the environment that I'm in. This is a dark sky place, not officially, but I'm looking at the moon right now. In a week it's going to be the full moon and the public is invited to come out and watch this full moon rise. They celebrate it with story and music and then quiet, where we can just experience. That's what I want to understand, how we create those stories that connect people to each other through this thing we call exploring space.

Mat Kaplan: It's easy to see why you enjoy places like this, but it goes beyond this, right? You've been an analog astronaut.

Brenda Trinidad: I have been an analog astronaut in Poland at Lunares, I think there's more to that, Lunares Habitat. That happened in 2021 and it was very serendipitous because of the research that I was doing in the space tourism, in this idea of how do we give access and participation options to people in space exploration in ways that they probably don't even think they know as an option? Through that, I found the analog astronaut community. Joined the analog astronaut community. Then, a message came out that says, "Hey, there's an opening in two weeks, who's available?" I just happened to be in the right place at the right time with the right resources, and I said, "I can go." They said, "Come on." It was an amazing two-week experience with four other people I never met before, doing what I was... I was the communications officer for that one. At that mission that meant more trying to report out what we were doing, not so much the communication on EVAs. It was a different role, but I got to play everything. I got to meet amazing people doing amazing biological research, psychological research, figuring out why suits don't fit women the same way. Because I couldn't go out on EVAs as much because I couldn't fit into the space suits. But they gave me an opportunity to be on the mission support side and learn how we take care of our people when they're out on EVAs. Monitoring health metrics and talking to them and all that stuff. While it was initially a deficit, it turned out to be a positive, and I'm ready to go back to another one.

Mat Kaplan: How about for real?

Brenda Trinidad: For real? Absolutely. Absolutely would go in a heartbeat.

Mat Kaplan: Good luck.

Brenda Trinidad: Thank you so much.

Mat Kaplan: It's been a great couple of days with you, too.

Brenda Trinidad: Oh, I'm so glad that you came along. I've been learning so much from you and from everybody else on this just wonderful adventure.

Sarah Al-Ahmed: One of the most stunning natural wonders in the United States are the dunes of the White Sands National Park in New Mexico. The park is located in the Tularosa Basin and is home to our planet's largest gypsum dune field. It stretches for over 700 square kilometers. That's about 275 square miles. These gleaming dune fields were the first stop on Kirby Runyon's tour.

Kirby Runyon: The main type of dune that we're encountering here are called barchan dunes, and they have this crescent shape where that's sort of this streamlined, upwind, almost ship-like bow that's facing into the wind. Then, on the downwind side, the lee side, the wind separates, there's actually what's called a flow separation where the wind separates from over the dune. The sand settles out onto a steeply sloping what's called a slip face, and that is always around an angle of 30 degrees or so. If it gets up to about 34 degrees, it will avalanche. This is the shape of a typical barchan sand dune, barchan spelled B-A-R-C-H-A-N, and that's how the dune moves downwind. It moves in a series of avalanches from the slip face, but the whole slip face doesn't avalanche at once. You get individual tongues coming down at different times and it adds up. In fact, when I was doing my PhD, I was measuring Martian barchan dunes images taken from NASA's high-rise camera, and in images of barchan dunes taken above in subsequent years. You could clearly see where the slip face had advanced downwind. Where barchan dunes tend to link up the arms or the horns tend to link up, they get referred to as barchanoid dunes. Here in White Sands, the further downwind you go, so the further to the northeast you go, the wind slows down because it's losing its momentum to all the sand grains. That means that vegetation can start taking hold and the roots' cemented in place even more. Then, you get what looks like superficially, like a reverse barchan, where the horns start pointing upwind because the vegetation roots are holding them in place. We don't have that problem on Mars. Again, it's a pesky vegetation getting in the way of the rocks and sand is just very tiny rocks.

Sarah Al-Ahmed: Next up, they traveled to Kilbourne Hole, a volcanic crater in southern New Mexico. It's just a short drive southwest of White Sands National Park. Despite their proximity though, Kilbourne Hole is a stark contrast to the gypsum dune fields nearby. Kilbourne Hole is a maar, a type of volcanic crater formed by explosive eruptions when magma comes in contact with groundwater.

Kirby Runyon: Where we're going first is Kilbourne Hole. Now, this is a picture that I took out of an airplane window. I was flying home from Tucson and we were skirting the US-Mexico border, and we flew just south of Kilbourne Hole. Now, this crater was blown in the ground about 47,000 years ago over the period of about one to 10 years. Not sure exactly how long it took to form. I've been looking at this on Google Maps for a long time. When I finally saw it with my own eyes, it was like a veil had been lifted. Seeing something with your own eyes versus only seeing it in pictures is huge. A magma body deep underground intruded beneath this groundwater aquifer and flashed it to steam. It is literally a steam explosion, and it just blew holes in the ground, just from magma seeping up into groundwater, exploding that into steam. It's not just steam. There was bits of rock in there too. The magma would get mixed in with the water and it blew out chunks of rock. You'll see that. There's this hole volcanic ash deposit that you'll see. It looks like it's been blown by the wind, but it's not. It was blown by its own steam. Some of the wall rock, which is currently slumping into the crater, forms things that look like, I think they look like french fries standing up, but they're hexagonal columns. Sometimes when lava is in ideal conditions, it cools and it cracks into hexagonal noodles. The angles on a hexagon are 120 degrees. That is the angle that the rock can use to minimize the stress as it fractures.

Mat Kaplan: Devils Postpile in California as well.

Kirby Runyon: Is that right?

Mat Kaplan: Yeah.

Kirby Runyon: There's a ton of these around. There's a few places on Mars where we think we've seen this columnar jointing. It's called columnar basalt, the rock type is basalt. That's the most common volcanic rock in the Solar System really, not just on earth. But in this wall of a crater on Mars, if you look really closely, there's actually that columnar fracturing and jointing in there as well. If you walk east around the crater about a mile, so budget about 20 minutes, there's a type of rock there called a mantle xenolith. Xenolith literally means alien rock, the prefix xeno. Now, it didn't come from space. It came from deep underground where there's a green mineral called olivine, a gem variety peridot, if you're familiar with that. What happened was a lot of the lava, or excuse me, the magma from deep underground, as it passed through the mantle and trained, got a lot of that rock type caught up with it and erupted it to the surface. That's the only way we have samples of earth's deep interior in the mantle. We can't drill that deep. We rely on volcanic eruptions and explosions like this to bring up rocks from the mantle. You'll see, it's this beautiful green coating on the rock. You can't miss it. Astronauts have trained here for over 50 years. This is on more people's radar. Also, this type of crater, I guess I haven't used the name. It's a maar crater, M-A-A-R, and that just refers to the magma steam explosions. This is one of the prime examples in the Solar System. We're standing at it right now.

Mat Kaplan: You were saying earlier in the car this kind of formation, we should expect to see more of them on Mars, but we don't?

Kirby Runyon: That's right. Yeah. We think that Mars, because of the ground ice and Mar's long history with water and lava and magmatic processes, should have lots of maar craters, and nothing conclusive has been found. The closest thing we found are called rootless cones. It's the reverse of a maar crater, where a maar crater has a hot magma body coming up into a water aquifer, flashing that into steam. A rootless cone has water saturated ground that then a lava flow from above come and flows over, and then steam erupts through that lava. We find those in numerous places around Mars, especially Athabasca Valles. I did my master's degree there, and a few other places, especially around Cerberus Palus, but yeah, nowhere else. It's a mystery why we don't see these. Either they don't form on Mars or they're not preserved, and jury's still out on that. We'll probably need more ground truth.

Mat Kaplan: Is this related to, there was for many years the thought that Mars might be completely dead geologically. We've learned with the evidence coming from InSight still sitting on Mars, that's not really true.

Kirby Runyon: You're right. With InSight, we found that there have continued to be Mars quakes, earthquakes in Mars up to the present. We think the Cerberus Fossae, this region near the Elysium volcanic province, is still under growing, growing pains, it's still groaning and creaking. There could still be lava eruptions in the future that haven't happened yet. We think the lava eruptions at this really young site, around the Cerberus Fossae could be only 2 million years old, which is basically now geologically speaking. Mars could still have some little ekes of volcanic activity left, and it's not too late to form a maar crater on Mars, so get busy Mars. This might be riot light. How did this get here? What? Oh, this is a welded tough.

Brenda Trinidad: Are you getting all this?

Kirby Runyon: Okay. This is welded volcanic ash. It's really pink with a lot of white mineral and black mineral flex in there. This is probably welded volcanic ash that came from the phreatomagmatic, the steam magma explosion. I haven't seen that here, but it's out of place. It's out of context. Interesting.

Mat Kaplan: The fact that you are finding things that are surprising you, that are not in the literature about these places like this, we still have a lot to learn. Don't we?

Kirby Runyon: We have a lot to learn about our own planet, but it's all synergistic learning with our planet and other planets in the Solar System. Yeah, also it speaks to, you got to get your boots on the ground if you want to do geology to the max.

Brenda Trinidad: Yeah, because those don't look like they should be here.

Kirby Runyon: Oh, wait, wait, right here, right here. This is more in place, same kind of rock, but it's embedded in this wind deposited lusts, which is basically just windblown dust that's gotten into the nooks and crannies of all the rocks. Oh, wow.

Brenda Trinidad: What do you mean? It's welded?

Kirby Runyon: Yeah, that's what happens sometimes when volcanic ash, it's really hot, it's got a lot of gas in it, and it welds and fuses itself together after it's been deposited as a fluffy but hot deposit.

Mat Kaplan: This is all wonderful. But what makes this the place that NASA chose to train astronauts to be geologists?

Kirby Runyon: I think Kilbourne, well, Kilbourne Hole is one of many places that astronauts train and NASA and also private astronauts too. It's very otherworldly. Yeah, it's not an impact crater, but impact craters and volcanic craters are all big holes in the ground with uplifted rims. It's a rugged terrain. You get to test your powers of observation here. I just rediscovered volcanic tough, and Brenda found some olivine basalt, where we weren't supposed to find it. It really tests an astronaut's ability to make real time observations, real time serendipitous discoveries. NASA astronauts use a philosophy called flexecution, flexible execution, where you have a detailed plan, a geologic field traverse plan, but you're flexible in how you execute that plan, because you make serendipitous discoveries like this. I like to call it serendipity. It's the ability to answer scientific questions you're not smart enough to ask.

Mat Kaplan: Do you remember the story? I think it was Apollo 17, the last Apollo mission, the only one that had a geologist on the trip, Harrison Schmitt. They went off the track and it was not, at that point, NASA didn't really want people to deviate from the plan, but they picked up one particular rock. Do you know the one I'm talking about?

Kirby Runyon: I think I know what you're talking about. I think it might've been Apollo 15 where the crew was, they were not professional geologists, but Dave Scott and Jim Irwin were very-

Mat Kaplan: You're right, you're right.

Kirby Runyon: They were very well-trained in geology, maybe close to the equivalent of a master's or at least an advanced bachelor's degree in geology. They were on the rover heading back to the lunar module. Mission control wanted them to get back, but they found a rock. In fact, it was a vesicular basalt in a sea of non-vesicular basalt, that is rock without any little holes in it. They found a bubbly rock, in other words. Dave really wanted to stop and pick it up, but didn't want to say anything to Jim because Houston would hear and then tell them no. They made up some excuse about needing to check their seat belts and like, "Stand by, Houston, for a seatbelt check." You'd have to go look at the actual transcript, but my understanding is they made hand motions to each other and Dave reached down off the rover and picked up that rock. You can go, if you go Google images for seatbelt basalt, you can see pictures of it. It's geologically interesting because it's, like I said, it's this bubbly rock in a sea of non-bubbly volcanic rocks on the moon. The little story that it tells contributes to the bigger story of understanding the moon's history and therefore earth's history. You got to love serendipitous science.

Mat Kaplan: You were telling us you grew up in this geologically not quite as interesting part of Michigan. Then, you started coming to places like this?

Kirby Runyon: Yeah, I hope I don't offend any of fellow Michiganders, that I grew up in a geologically boring area. But yeah, I started coming out west. I started seeing the planet poking through the undercover and the open expanses of the southwest deserts and the incredible varied volcanoes and explosion craters like Kilbourne Hole here really got me hooked. Brenda, where did you find that?

Mat Kaplan: Where did you find that?

Brenda Trinidad: Right there. We were just walking-

Kirby Runyon: Where? Oh, my goodness. Where?

Brenda Trinidad: Okay, you could backtrack us.

Mat Kaplan: What are we looking at?

Kirby Runyon: Okay, so Brenda, do you want to describe this?

Brenda Trinidad: It's that green you were telling us about, but I don't remember the whole scientific biggie, but this is the peridot. But the backside of it looks like that volcanic, but then the front side is just, at first I thought it was moss, but I was like, "There's no water." Then I saw this little baby.

Kirby Runyon: Oh, wow.

Mat Kaplan: That is gorgeous.

Kirby Runyon: What we're looking at here is the outside of the rock is basalt, but we would call this an olivine basalt or also it's a mantle xenolith. There's this gorgeous almost Wizard of Oz green color here.

Brenda Trinidad: This guy, this is the most-

Kirby Runyon: This is the mineral olivine and it's really common in volcanics, and it's what the mantle of rocky planets like Earth and Mars and the moon are made out of.

Mat Kaplan: Yeah, a xenolith?

Kirby Runyon: Yes, alien rock, a xenolith, alien rock, meaning that it didn't come from space, but it did come from deep underground brought up by a magma or a volcanic eruption. As magma went through the mantle of earth, it entrained a lot of these rocks with it and then erupted them onto the surface. Because we can't drill deep enough into earth's mantle, or at all, we have to rely on these volcanic processes to show us what the inside of our own planet looks like.

Brenda Trinidad: This came from way deep down-

Kirby Runyon: Below the cross, below the lithosphere in the mantle, and it's this gorgeous green that coats outside of this rock.

Brenda Trinidad: There's a couple of them back there.

Kirby Runyon: Okay.

Mat Kaplan: We're headed down toward the floor of the crater now, and it's not that steep, but it's quite slippery.

Kirby Runyon: We're actually not on the rim. The actual rim is right up there. You see like a cliff face?

Mat Kaplan: Yeah, I do.

Kirby Runyon: We're headed to that. We're headed down the wall of the crater, the scarp, and once we get to the scarp... Oh, if you look back behind you, there are some really beautiful cross bedding.

Mat Kaplan: Oh, that is beautiful. Now, I remember seeing things that look like that from, I don't know if it was Curiosity or, but yeah, just very much like that, what we're looking at now.

Kirby Runyon: You're right. Curiosity on Mars has imaged a lot of that cross-bedded sandstone. Gale and Jezero crater, we do see a lot of this stuff, but in those cases, in the case of Gale Crater, it was formed from windblown sediment, sand dune, sand ripples. In the case of Jezero Crater, deltas, river deltas can make similar kinds of sedimentary cross bedding. This looks superficially the same except that it was formed almost instantaneously in a volcanic blast.

Mat Kaplan: This is the kind of stuff now that in those deltas Perseverance is picking up samples. because it's the delta where hopefully that stuff's going to come back here someday.

Kirby Runyon: Hopefully someday. Yeah. What we're looking at formed 47,000 years ago in a series of volcanic eruptions, but the story starts about 255 million years ago during the breakup of the Supercontinent Pangaea. If we fast-forward that 255 million years ago, the continents are pulling apart. Oceanic crust is making way for these continents to move by getting buried underground, and actually descending to the core mantle boundary beneath earth. Going back to 66 million years ago, the dinosaurs were on their way out. Two things were happening 66 million years ago. One, there were enormous volcanic eruptions in what is now Siberia, and that was causing catastrophic climate change. These are volcanic eruptions that would've coated all of Northern Russia, like seas of lava that we can't comprehend. At the same time that was happening and the planet was undergoing catastrophic climate change from all that volcanic degassing, an errant asteroid slammed into what is now the Yucatan Peninsula blasting so much debris into the sky, it blocked out the sun. Also, starting forest fires for thousands of miles around there, as the hot rock that was ejected from that crater reentered the atmosphere and landed starting forest fires. We had mass forest fires, massive climate change from the volcanoes, then punctuated with an exclamation mark of an asteroid impact, and the dinosaurs died off. Now, mammal life had already started and that continued through that mass extinction. Fast-forward from 66 million years ago to only 35 million years ago, the dinosaurs had already been extinct for 31 million years. At 35 million years ago, early North America, the continents had started to move to their present locations, but early North America was starting to rift apart. Deep beneath our feet, there's a plume of hot rock coming up from near the core mantle boundary deep underground, and it's pushing up on this part of North America causing this uplift in the Colorado Plateau. Just like baked cookies in the oven, it will start to rise and then crack at the surface. That exact same rising and stretching and cracking is what's happening right here in what's called the Basin and Range Province, basically west in this part of New Mexico, all the way to California. You see it most in Nevada and Utah, but the Basin and Range refers to a series, it's like this washboard terrain. You get these series of mountain ranges and then down dropped basins in between there. We're in a section controlled by what's called the Rio Grande Rift, and this started rifting apart about 35 million years ago. It really started accelerating rifting apart between 10 and 25 million years ago. As it's pulling apart, that's making way for underground magma to come up through all these newly formed cracks, this plumbing in the ground. The pressure's getting taken off. When you take pressure off hot rocket, it melts, it forms magma, and we started getting volcanic eruptions happening all around here. From 1.2 million to a few tens of thousands of years ago, there were volcanic eruptions going off everywhere. Tomorrow, we're going to one of the youngest volcanic flows that's only 5,000 years old. This is 47,000 years old, and we're standing right here in front of this piece of rock here. This is a type of rock called basalt. It's the most common type of volcanic rock on the surfaces of rocky planets in our Solar System. All the holes in here, anyone have an idea of what caused all the little holes? You'll see this everywhere around here, they're called vesicles. We call this a vesicular basalt, and all the little holes are from outgassing. Magma has a lot of dissolved gases in it just like soda does. When you take the pressure off the magma and it erupts as lava, it fizzes, it bubbles just like opening champagne or pop, I'm from Michigan, we say pop, or beer. This is probably a volcanic bomb. This was probably part of a volcanic eruption. This was ejected out of the crater and then landed here, or not too far from here. These are all over the place.

Paul Mills: Would that be a heavier type of rock than another kind of rock, the same size?

Kirby Runyon: It's a little denser. This would be a little bit heavier than a chunk of granite the same size, probably.

Paul Mills: Correct.

Kirby Runyon: The minerals in here have a lot of iron and magnesium in them, whereas granite doesn't have so much. Granite's more aluminum. The things that make granite granite and not basalt are more aluminum, calcium, and sodium as opposed to iron and magnesium in this rock right here. Let's see. The closest we have, like I said, the closest we have to these sorts of rocks on Mars, they're called rootless cones. That's what I was mentioning in the car. They look like a cone shaped volcano. Again, there's an outstanding mystery why we don't see stuff like this on Mars. There's no other place in the Solar System we would really expect this, where we have this combination of groundwater and lava. Mercury is out. Too close to the sun, too hot, no water. Venus is out, although probably not early Venus. We think Venus had oceans up until about a billion years ago. For its first three and a half billion years, Venus could have had these, although they would've been erased from subsequent volcanic and tectonic activity. Moon doesn't, there's maybe a chance, just in the last few months we're getting surprising results from asteroid, sample return missions that have returned samples from the asteroids Bennu and Ryugu that show that water has played a huge role in altering some of those minerals. That's a huge surprise for me especially in the last few months. We never expected or I never expected water alteration on asteroids. Looking out at the crater, at the walls of the crater, exposing the geologic record, the bottommost layers are from ancient stream beds, the ancestral Rio Grande River as we move up. That's the pinky rocks. You can see the pink orange over here to the left. Above that is a basalt flow called the Afton Basalt. Then, above that, if we walk on down here, we get to the ash layers. As you examine the ash layers, you really begin to see where it looks like it was windblown. But of course, that wasn't from the wind, that was just from the eruptive force from the blast and the steam explosion as the magma vaporized the groundwater.

Sarah Al-Ahmed: We'll be right back with the rest of Mat Kaplan's astrogeology adventure with Kirby Runyon after this short break.

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Sarah Al-Ahmed: About a hundred kilometers or 60 miles northeast of Kilbourne Hole is a place called Carrizozo Lava Flow. It's a vast field of volcanic rock that stretches 70 kilometers or 44 miles. It's one of the youngest and best preserved flows in the continental United States. Carrizozo Lava Flow was created by an eruption about 5,000 years ago and left behind this other worldly field of black rugged terrain.

Mat Kaplan: Day two Kirby, and much better weather today. We got chased off the side of a volcano yesterday by wind and lightning and hail.

Kirby Runyon: And hail, oh yeah, and rain. We were trying to explore Aden Crater, which is not an impact crater, it's a volcanic crater in the Potrillo volcanic field of Southern California. It's this beautiful 1,700 foot or so diameter volcanic crater that just has this extensive lava flow surrounding it. It is a bugger of a place to get to. You remember the roads we were driving over?

Mat Kaplan: Oh yeah, I do. I was in the third seat, so I was bouncing. It was a thrill ride.

Kirby Runyon: You didn't hit your head on the ceiling, did you?

Mat Kaplan: Not too many times.

Kirby Runyon: Oh, good. Yeah. But it was a rough road and we were walking up to the crater as we started getting pelted with rain. We got in the suburban and then the hail started and we peeled out of there because we didn't want to get stuck back there. It is hard to get to, but the lava flow, the crater itself is a perfect microcosm for so many summit volcanic calderas on Mars. If you think of the summit caldera on Olympus Mons or the smaller Tharsis volcanoes like Arsia Mons, Pavonis Mons, and Ascraeus Mons, the summits of these volcanoes basically look exactly like Aden Crater. They're just way bigger. In fact, some of my planetary geology colleagues use Aden Crater as this perfect terrestrial analog for these Martian calderas.

Mat Kaplan: We will get in a couple of minutes to where we are now as we continue to walk along this beautiful trail. Oh, my God, that is a gorgeous formation right there. I better stop now and say, what are we looking at?

Kirby Runyon: Right now we're looking at a piece of uplifted basaltic tumulus. What is that? We're looking at part of a lava flow from 5,200 years ago, the Carrizozo Lava Flow. We're looking at this portion of the lava flow that literally inflated from the lava being pressurized in the tube beneath it and pushing up and cracking opened the crust, like the way a muffin or a cookie cracks when you bake it. It's towering above us. I don't know, what is that, 20 feet up maybe?

Mat Kaplan: Yeah, I would say, yeah.

Kirby Runyon: We're just looking at this almost, not quite vertical, but it's like maybe 60, 70 degrees tilted. These beautiful ropes of pahoehoe lava, like what you'd see forming in Hawaii right now, coming down the side of that. It's just this imposing massive, almost black rock in front of us.

Mat Kaplan: When was this formed? When was this molten lava, or magma actually?

Kirby Runyon: Well, it was lava on the surface, so 5,200 years ago. This is the second youngest lava flow in the continental United States. Over the span of about 30 years, 5,000 years ago or so, this 75 kilometer long, 45 kilometer long lava flow got in place through a tube fed vulcanism, where a lava river literally creates the tube that it insulates and allows it to flow for so many tens of miles or kilometers.

Mat Kaplan: Lava tubes. One of the most exciting things that we're beginning to look for are places like the moon and Mars. This is the point of this trip. What are the parallels between this place and what we see elsewhere around the Solar System?

Kirby Runyon: Yeah. Well, so basaltic lava is really the most common rock type on the surfaces of planets, of rocky planets in the Solar System. From Mercury, to the moon, Venus, Mars, even some large asteroids are covered with basaltic lava flows. Our whole ocean basin, which is most of the surface area of earth underneath the water, that's all basalt. Any basaltic lava flow you get to explore is immediately analogous to basaltic flows around the Solar System. Now, I'm pointing out as we walk along, so we're on a paved trail at the Valley of Fires Recreation area, the Carrizozo flow. Just off to our right here, you can see the domed roof of a small lava tube.

Mat Kaplan: Yeah, it's gorgeous.

Kirby Runyon: Is that something you'd want to be in a space and try to wedge yourself into?

Mat Kaplan: I don't know. I might want to send a robot first.

Kirby Runyon: Sure. Yeah. Well, it's only like two feet tall, so that's most lava tubes right there. But we're looking down into this, a little bit of an inflation pit right here where you can see the roof of this small tumulus has collapsed down into it.

Mat Kaplan: I got to take a picture of this, but I'm going to keep talking for a moment. This is a miniature example of some, you showed us picture of an earthbound lava tube that's big enough to walk in. We expect, right, that we're going to find big ones like that on the moon and Mars.

Kirby Runyon: We'll probably find them on the moon and Mars. We've certainly seen a lot of collapsed pits on the moon. There are some interesting spacecraft concepts for how you'd get robots down in there and then maybe eventually humans, but there's just a lot of unanswered questions. We know from a few sideways looking oblique images from the lunar reconnaissance orbiter narrow angle camera that they do extend underneath the roof a little way. We know that they, at least a few of them, are a limited extent caves and not just pits. If you had some sort of like a cable car system for future astronauts, that might be the ideal way to comfortably get down in there.

Mat Kaplan: As we've seen in some science fiction as well, it might be a good place to live and stay out from under the micro meteorites and a lot of the radiation.

Kirby Runyon: Maybe, I'm going to channel a little bit of our friend Bill Nye here and say, do you really want to live in a cave?

Mat Kaplan: I would not, actually.

Kirby Runyon: Right. A great place to visit, great place to have a scientific research outposts. I like windows and natural light personally.

Mat Kaplan: Yeah. Oh, God, look at this. Got to get a picture of this. Where we are has these, and the various places we're visiting have these parallels to things we are seeing more and more of all over the Solar System.

Kirby Runyon: Yeah. I'm frequently surprised when I talk to people about the moon, that people have no concept that the moon is basically a volcano planet. So many of the landforms we see on the moon are either from impact cratering or from volcanoes, or some form of volcanism. All the dark areas you see on the moon just with your naked eye, those are all cooled lava planes. If you really zoom in using spacecraft images from the lunar reconnaissance orbiter, you can clearly see the jagged outlines of lava flows. We see volcanic vents that are often oval in shape. We see some volcanic cones like you see out in Arizona and New Mexico. The moon is just riddled with signs of volcanic features. Same thing with Mars. We see lava vents in so many places and lava channels and lava flows, many places across the moon and Mars. Even Jupiter's moon Io, we were talking about that earlier. Even some of the spacecraft images, brand new from the Juno orbiter, are showing us brand new pictures of the surface of Io, which is constantly changing. All of those lava flows are also basalt.

Mat Kaplan: I've often said, boy, the worst job in the Solar System would be to be a cartographer, a map maker on Io.

Kirby Runyon: Yes, exactly. No, as soon as you make your map, it's obsolete for Io.

Mat Kaplan: All right. One thing that is clear from all of us, so here's another wonderful-

Kirby Runyon: There's a little bit of a caved in lava tube right there. Here's a context view from, this is Sir Richard Branson's space flight two years ago, looking out the back of the spaceship Unity. This is the Carrizozo Lava Flow where we're at right here, and this is White Sands. This picture is just from the International Space Station, like we said in the car, it's 75 kilometers long. It was in place 5,200 years ago. Okay, over the course of about 30 years. Now, what makes this flow interesting is that it's confined between the mountains on the west and on the east, and it's a type of lava flow called a tube fed lava flow, where you would have rivers of lava. I took this still from active flows in Hawaii, but what happens, as the lava's flowing along, it'll cool on the top. Then, that cooled top crust acts as insulation for the lava underneath.

Paul Mills: To stay hot.

Kirby Runyon: To stay hot. Exactly. Yeah. Towards the end of that river or tube system, the lava will break out. It's literally called a breakout, and it'll continue flowing. The top will cool and then it'll stay hot and it'll keep flowing. It creates the tube that insulates it, it creates its own tube for it to continue traveling through. That's how you were able to have a lava flow 75 kilometers long from Little Black Peak, way up north there, 40 some miles, 75 kilometers south that way, is because it was a self-insulating flow. Lava also has the property that it's like ketchup in that you can have a pile of ketchup on your plate and when you dip a french fry in it, it flows. It's called a Bingham plastic. Your blood is the same way. It's got a certain, what we call a yield stress, where it acts like a soft solid until you nudge it hard enough and it begins to flow. What that means for lava is that it also creates its own levies that it flows through. The lava on the edge of the flow is in contact and it cools in place.

Mat Kaplan: One of the things that is obvious in hearing you across this trip is your enthusiasm, your excitement about all of this, which is great to hear because you've been at this for a while. But isn't this also what you're hoping to share with others? Those of us on this trip, but also if things go well, with a lot of other people.

Kirby Runyon: Yeah, thanks for asking. I am transitioning in my career from full-time research scientists to part-time research scientists, part-time really tour guide that's a scientific... that I call informed enthusiasm. The scientific type tours that aren't just for scientists. I want everyone to be able to come along maybe on same host trips monthly to the Planetary analog terrains in New Mexico and get to basically let people have their vacations on the moon and Mars without leaving Earth. I've also had the privilege of leading Virgin Galactic ticket holders, people that have paid and they are going to fly in space, of showing them the landscape beneath them that they are going to see from space. I call this perspective from space to in your face. Right now, we're in the in your face part because we're just a few feet away from gorgeous lava flows. But this is the exact lava flow that suborbital private astronauts see from suborbital space, whether that's with Virgin Galactic or with Blue Origin. Frank White is our friend, our space philosopher friend who has coined the term the overview effect, for this mental cognitive shift that people undergo whenever they see Earth from space. I want to help people who experience the overview effect have a more informed overview effect so they can understand the same lava flow or the same sand dune field from a millimeter perspective to a tens or hundreds of kilometers perspective and hopefully blow their minds even more.

Mat Kaplan: Kids or more their teachers?

Kirby Runyon: Oh, man. Well, my answer's always going to be everybody, but I'm really going for teachers right now. Teachers have it rough. They're in classrooms, they're teaching out of textbooks so often. They're oftentimes teaching to the test. It's rare, I think, that they can teach from their firsthand experience and their own excitement and enthusiasm. What I'm really hoping that we get to do is to have sponsored teacher trips out here, where teachers can take a few days of a break, come outside, not sit in front of a computer, get up close and personal with the rocks, get up close and personal with the planet as a stand in for other planets and moons. Be able to learn from their own experience and bring that same informed enthusiasm back to their classroom, whether that's kindergarten through 12th grade or community college. Those are really the target teacher audiences I'm after.

Mat Kaplan: I hope this works. I love your phrase informed enthusiasm, which you are really good at. I have to bring up one other thing because you and I go way back. Planetary Radio playing a part in leading you in this direction.

Kirby Runyon: That's right.

Mat Kaplan: But also, my former colleague, Emily Lakdawalla, what was her role?

Kirby Runyon: I hope Emily is listening. Hi, Emily, if you're listening, because her blogs on The Planetary Society website, Planetary.org, were instrumental for me pursuing a career in planetary geology. In the mid to late 2000s I was a physics major and I would procrastinate from doing my physics homework by reading her planetary geology blog, where she would take a spacecraft image, maybe from the Mars exploration Rover, Spirit, and Opportunity, or a picture of maybe one of the moons of Saturn from the Cassini orbiter. Then, she would walk the reader through the geology of the image. I got hooked on geology because of the space connection with Mars, the moon, the moons of Saturn. I ended up pursuing that for my master's and PhD, and then now my research career. Now, I hope to hopefully inspire people from all walks of life, just from the space curious to the space tourist and everyone in between, about the geology that shapes not only our planet, but moons and asteroids and planets around the Solar System. Emily and The Planetary Society were definitely big parts of that.

Mat Kaplan: You are pretty early yet in this process. The group that is out with us today, a test group, right? We're Guinea pigs?

Kirby Runyon: Yeah, that's right. Some friends have agreed to come along on one of my field trips out here as we go through the field routine and test out logistics and travel options and how interesting things are. I think it's all interesting and I hope everyone thinks it's interesting, but you never know. This is a little bit of a test run. I've been out here several times before, but I'm hoping that this can grow into a regular cadence of events.

Mat Kaplan: I am honored to be in this group as one of your Guinea pigs, and I wish you nothing but success with this. It is absolutely a wonderful experience. We are surrounded by some of the most beautiful territory I've seen on earth. It's great to hear you sharing your passion, the PB&J, right?

Kirby Runyon: That's right.

Mat Kaplan: That passion, beauty and joy for it. Is there a way for people to learn more as you head into hopefully doing more of these?

Kirby Runyon: Yeah, thanks. I hope people can visit my website, Planex.space, that's P-L-A-N-E-X dot S-P-A-C-E. Also, follow me on LinkedIn, Kirby Runyon. I post regularly about planetary geology and also zero gravity flights incidentally. But my website, my business Planex, that stands for planetary experience. I want people to experience the planets.

Mat Kaplan: You've done 16 zero G flights?

Kirby Runyon: I've done 16 zero G flights. I have almost 20 minutes in moon gravity, over an hour in zero gravity, about 10 minutes in Mars gravity. Mars gravity is underrated, by the way. I think Mars gravity is great.

Mat Kaplan: All right, I'm going to stop talking to you now because I'm intensely envious and I got to get on one of those flights. Thank you very much.

Kirby Runyon: My pleasure, Mat. Thank you.

Mat Kaplan: It's the last stop on our two-day adventure in the southwest. I'm standing on top of one of the many dunes in White Sands National Park, New Mexico. It is yet another gorgeous, an entirely unique place, except that it's not really unique because Kirby was just telling us how similar it is to places elsewhere around the Solar System, Mars, Saturn's Moon Titan, perhaps even Venus. It has been an outstanding trip. If you have not been to this part of the Southwest, it's worth your time and trouble. For Planetary Radio and The Planetary Society, I'm Mat Kaplan.

Sarah Al-Ahmed: I've spoken to so many scientists who have started their astrogeology career because of their experiences exploring the wilds near their homes. You never know when one weird rock could change your life. If you'd like to know more about Kirby Runyon's astrogeology tours, I'll leave a link to the website on the show page for this episode of Planetary Radio. I'm also happy to report that we'll be hearing more from Mat Kaplan in our last show of the year. Keep an eye out for that. Now, let's check in with Bruce Betts, the Chief Scientist of The Planetary Society for WhatsApp. Hey, Bruce.

Bruce Betts: Hi, Sarah. How are you doing?

Sarah Al-Ahmed: Doing really well. I don't know if you can tell, I'm a little hoarse. I spent all weekend at LA Comic-Con talking my face off like you do. But I wanted to say, I love that Mat is finally off going on adventures. When he stepped down from the show, I envisioned him sitting on a beach somewhere. But I feel like geology adventure in the middle of nowhere is more his style.

Bruce Betts: Yeah, I'm the one sitting on the beach. Mat's doing that and he did caves a while back when he was doing the show. He's a wild man.

Sarah Al-Ahmed: That's awesome.

Bruce Betts: Yeah, he's an inspiration.

Sarah Al-Ahmed: I wanted to ask though, what are some of the weirdest, most other worldly places you've been to on Earth? Because every once in a while, when I'm in the middle of the nowhere, I always try to imagine to myself, what other world might this be like?

Bruce Betts: Washington, DC, but in terms of interesting geology, it's boring because other people who've been there would say it, but Death Valley, which is huge and has a bunch of weird stuff in different places. From salt flats to alluvial planes and colored rocks and sand dunes and all sorts of weird stuff. Also, making the mistake of going down inside those volcanic center cone the first time I've took that field trip. What about you, Sarah? You already talked about this.

Sarah Al-Ahmed: Yeah, no, I think the sand dunes is what my brain always goes to because I've spent a lot of time camping in the deserts outside of Dubai and Oman. Just dunes as far as the eye can see.

Bruce Betts: Hardcore.

Sarah Al-Ahmed: Yeah, it really makes you feel isolated, but I imagine being on Mars as close to that.

Bruce Betts: You know what life is about?

Sarah Al-Ahmed: Heck, yeah.

Bruce Betts: We just passed recently the 25th anniversary of the beginning of the International Space Station, as it was defined by the first couple big modules coming together. I thought I'd do a little ISS stuff, and I'll start with just the most stunning construction statement, which is it was assembled using 42 assembly flights, 37 on the US space shuttles and five on the Russian proton Soyuz. That's a lot of space flight.

Sarah Al-Ahmed: That's a lot.

Bruce Betts: A lot of assembly. Maybe next week we'll talk a little more about an obscure fact that I've found that you'll hear first from me. Stay tuned.

Sarah Al-Ahmed: I did want to tell you this story because I feel like it would warm your heart the way that it warmed my heart. But I went to LA Comic-Con like you do, and it was my first time being a panelist, and we were on a panel called Ad Astra Per Aspera, classic. It was all about lessons we could take from Star Trek. Afterwards, someone who was a member of The Planetary Society came up to me and was just really excited to meet me there and basically made a statement about how cool it is that there are more women visibly in science, and what that means to her, and inspiring other little girls around the world. I came way with just so much joy. Then, immediately after that got myself marched down to a booth in the back to go meet the people from the fleet, which is like an organization of people that dress up in Star Trek outfits, but they do charity events, so that kind of thing. I went down there and got myself inducted into the fleet. Basically, now I'm just going to have more people to space party with.

Bruce Betts: Wow. Congratulations. Should we end on that note?

Sarah Al-Ahmed: Let's do it.

Bruce Betts: I hesitate to say this, but I'm going to try anyway. All right, everybody, go out there, look up the night sky and think about what initiation ceremony and what secret handshake Sarah must have been involved with when joining the fleet. Thank you, and goodnight.

Sarah Al-Ahmed: We've reached the end of this week's episode of Planetary Radio, but we'll be back next week with an update from the Dragonfly mission team to Saturn's moon Titan. A dual quadcopter the size of a rover flying around one of the weirdest moons in our Solar System is exactly what I want for the future of space exploration. You can help others discover the passion, beauty, and joy of space, science, and exploration by leaving a review and a rating on platforms like Apple Podcasts or Spotify. Your feedback not only brightens our day, but helps other curious minds find their place in space through Planetary Radio. You can also send us your space slots, questions and poetry at our email at [email protected]. Or, if you're a Planetary Society member, leave a comment in the Planetary Radio space in our member community app. I'd love to know what the most otherworldly locations you've been to on Earth are. There's a lot of really beautiful places out there that'll make you feel like you're standing on Mars. Planetary Radio is produced by The Planetary Society in Pasadena, California, and is made possible by our members who love our beautiful blue dot and everything that it can teach us about the world's beyond. You can join our merry band of space bands at planetary.org/join. Mark Hilverda and Rae Paoletta are our associate producers. Andrew Lucas is our audio editor, Josh Doyle composed our theme, which is arranged and performed by Pieter Schlosser. Until next week, ad astra.