Cosmic Queries – Space Volcanoes: Fire and Ice with Natalie Starkey

26:01Really, you think? But people have to live in these places. Location, location, location. Yeah, exactly. And they're beautiful, so, you know, I would quite like to live in a volcano. It has good schools, it's got good roads, but you're on the side of a volcano. As much vessels as you need. We went on a trip to Italy and visited Vesuvius, famous for Pompeii. And no, there's no lava there that I saw, but it was hot. We went near the caldera. It's like, oh, my gosh. Yeah. I was like, whoa. And that obviously is very famous for Pompeii. Very famous. Did you visit the ruins? Yeah. Yeah, yeah, of course, of course.

26:39And there are vineyards on this side of Vesuvius that are thusly identified on the label. So if you want to get it. So it tastes a bit of ash. I think, I don't know. That's the thing about ash. It's really, really good for soil. So, you know, whilst a huge amount of it coming down the mountain, like at Pompeii, you know, is rather devastating, small scatterings of ash quite often are really great for soil. And it has this great ability that it can absorb water into the soil. So it acts as like a fertilizer in the soil and helps to create these amazing crops. Fertilized and irrigated. Very interesting.

27:11Yeah, cool. Matt, give me some more. Yeah, well, so this is Nicholas Godlove. And along these lines, Nicholas is asking, should we be worried or afraid of the super volcanoes of Earth? And what is the most menacing volcano to you in our solar system? Oh, good one. OK, so yeah, super volcanoes, that's a great subject because we hear about, I think Yellowstone is probably the most famous one we hear about. Because it's always, you know, in the media, oh, it's going to erupt, you know, it's going to erupt next year and it's going to devastate everything. But the reality is that... Right, and that thing of like, it's due is how it's always described.

27:43Like, we do an eruption. And it is always due, you know, because we don't have a huge amount of data of how often it's erupted. But the thing is with these supervolcanoes is if they do go, it would be massively devastating. And they create caldera eruptions. So you don't really see anything on the surface initially. You don't see a volcano like Mount Fuji. What will happen is that the ground will literally just explode and you'll end up with this massive caldera left behind. And that has happened throughout history. But the thing is with these... But that area still has good schools, right? We can still...

28:13Yeah. It's quite close to visit. It could blow up completely, but before that happens, you've got... The thing is with supervolcanoes, whilst they have the potential to do that, and we think there's a massive magma chamber sort of under the surface that could be bubbling away, let's say, and, you know, potentially going to erupt... You're a geologist. Why don't you know this? Well, we do, but there's smaller eruptions. We can thump the ground and find oil. Why can't you thump the ground and find where the magma chamber is that might bust? So we know that. We can do the seismic surveys. We know sort of where the ground is hotter and where there's molten material, but it doesn't mean it's all going to erupt in one go.

28:50It could be that it has small eruptions and lets off a bit of steam and then has another one. And so they wouldn't be devastating. And therefore, it lets off that steam and then it's not going to erupt for another million years. So they're almost never as bad as we think they're going to be. And if one is really going to erupt, then we're going to know about it because we're studying them in detail and we'd have a good idea if it was going to do something okay that's encouraging because otherwise to say oh it might erupt in the next 4 000 years that's not helpful yeah and how about the other half of that question what was that i've already forgotten oh that was what is the most menacing volcano yeah to you in our solar system menacing oh but i don't like to give the menacing titles because they're all lovely, but now I don't.

29:33Oh, stop. I guess it's going to be Io. You're not supposed to feel for the volcano. They don't have feelings for you. They will melt you in an instant. Vaporize you. I guess I wouldn't want to be sitting on Io because I think on Io you're almost certainly going to be captured by an eruption somewhere and even if not you'll have probably lava spattered on you from one of its erupting volcanoes. And, you know, its surface is just incredibly hot. So what about, I know it's not active, but Olympus Mons on Mars, isn't that the biggest volcanic mountain in the whole solar system? Yeah, it's massive.

30:12You know, it's like three times higher than Mount Everest. It's absolutely enormous. But the thing is, it's not much different to Hawaii. So the volcanoes that we see, you know, on Mount Elora and Manicaea, it's a very similar type of volcano. And actually, they're not particularly scary when it erupts. I think, you know, the most recent big eruption was kind of 2018. People were able to outwalk the lava most of the time. You know, yes, it was devastating. It kind of, you know, covered houses and land, but you could outwalk it. So it's not too scary. I never heard that sentence before. Matt, let's outwalk the lava.

30:48Let's go for a nice stroll. Morning constitutional away from the burning rocks. Very cool. Very cool. So Matt, let's slip in one more question before we take our second break. All right. Well, I'm going to, given that we're talking about Olympus Mons, there are two questions, two different people have written in questions that include that. So Cameron Bishop asks, what properties determine the size of a volcano and how did these properties allow Olympus Mons to get so big? Could such a volcano form here on Earth? And Jared Sorba says, if Olympus Mons was able to grow so large due to Mars's weak gravity, why don't we see even larger volcanoes on other active bodies, such as some of the larger moons?

31:26Yeah, brilliant. So, yeah, and that second question's got it exactly right. So Mars is about half the size of Earth, so it has less gravity. So it means that things can simply just grow bigger. So if we took an Olympus Mons-sized volcano or mountain and put it on Earth, it would basically collapse under its own weight because it would just be too heavy. And so it just couldn't form here. It would literally just wouldn't be able to get that big. The other way that Mars has been able to grow such a large volcano is because it doesn't have plate tectonics. Now, I'm hoping most of the listeners are going to know what plate tectonics is.

32:01It's a thing that's very unique to Earth, we think. And it's where the outside of our crust of our planet is basically broken into pieces which move around in relation to each other. And they can kind of knock into each other or they create earthquakes when they slide past one another. And they are what creates many of our volcanoes. And by the way, just to be clear, y 'all only fully embraced that within the last 60 years, right? Yeah, completely. That's not a forever ago thing. Yeah, it was literally, I think it's the 1960s, wasn't it? Yeah, yeah, so 60 years ago. When it first suggested that it was a thing, and people were like, no, the man's crazy.

32:37Yeah, no, I think the suggestion predates that, but before the evidence really gathered to start. I didn't know that, and I also really didn't know that Earth was the only body that we know of that has this. I thought it was a fairly universal thing. No. So that's how we get lots of our volcanoes. But the other type of our volcanoes, luckily, come from mantle plumes. And this is the type, again, Hawaii is the classic example. This is a big chimney of hot rock that rises from the interior of the earth, possibly as deep as the core. And it comes all the way up through the planet and then erupts molten lava at the surface.

33:10And these are very long-lived features on our planet. Now, if you just imagine this chimney of rock in the planet and these plates are moving over the top of that. So what happens at Hawaii is we get this chain of volcanoes. This, you know, chimney of rock keeps erupting and the plate moves over it and we get volcanoes, you know, going along in a linear chain. So the most recent ones are Lower and Malnakeia. Now, in Mars, we've got exactly the same thing happening. Yeah, so this is an archipelago, right? Isn't that what an archipelago is? Yeah, exactly. And many of the Caribbean islands are...

33:39So what you're saying is it's not a continuous busting through of the plate. It busts through and then it stays calm for a while. And over that period, this place shift and it's okay time to bust through again up there you go and so that completely but that's that's fascinating to me because i in my head i these sort of chains of volcanoes i assume they were like all along a fault line or something like that yeah you're saying it's it's almost more like a sort of like a factory line where this they're moving on like the earth is moving along on a conveyor belt and every so often it punches a hole through it and it moves on a bit more and punches another hole precisely and so if you go to honolulu and people like oh it's volcanic, could it erupt?

34:16You're like, no, you can't, because it's nowhere near that plume now. So that is almost certainly not going to happen. But that other island, that's the one. Yeah, that's the one we need to worry about with the molten lava crater at the top. And also, I think I'm right in that the big island in Hawaii would not be sustainable were that fully on land, that the buoyancy of rock and water allows that to build as high as it did from the bottom of the ocean through the ocean surface and then above the ocean surface because it doesn't weigh as much simply because half of it is sitting in water. Is that correct?

34:51Yeah, exactly. Yeah, because I think people forget with those islands that what we see above is not even half of it. And in the middle of the freaking Pacific Ocean. Right. Yeah, where it's very deep. We've got to take another quick break. Another quick break. And when we get back, Matt, you've got more questions for Natalie Starkey, our geologist-turned-astroperson, the keeper on StarTalk.

35:26we're back star talked neil degrasse tyson here matt where can we find you on social media you can find me uh at matt kershyn on the various things and probably science is my podcast okay And that's on all the podcast platforms. Wherever podcasts are sold near you. Yes. Okay. Yeah. Yeah. Ask at your local bookshop for my podcast. Yeah, there you go. And Natalie, where can we find you on social media? I'm at Starkey Stardust on, yeah, all the platforms. And yeah. Starkey Stardust. S-T-A-R-K-E-Y. E-Y. Yeah. Starkey Stardust. I love it. Yeah. Yeah. So I think we had to take a break before you completed the answer to why Olympus Mons is so big on Mars.

36:09So we learned that the Hawaiian chain of islands, they're all volcanic, and that's just magma punching through in a new spot as the plate tectonics take it by. So Mars, I think, doesn't have plate tectonics. So is that what happened there? Yeah, we don't. We don't think it does. We haven't got any evidence for it there. Now, obviously, it's not an active planet today, so we know it's not happening today. Trying to work out whether it happened in the past, we just don't have any evidence for it, so we don't think it did. So we call it a stagnant lid planet, basically just one big crust and it didn't move.

36:42So what happens there is if you've got one of these mantle plumes coming up from the interior of the planet onto the surface, that plate isn't moving anywhere. It's just going to carry on erupting for millions of years. Through the same hole. Through the same hole. Maybe even a billion years or more. So, yeah, it just grows larger and larger and larger in one place. And that's exactly what happened with Olympus Mons. All right, cool. Cool. Which is the largest volcanic mountain in the solar system? I think it's the largest mountain, isn't it? Yeah, yeah, yeah. Okay, good, good. All right, Matt, keep them coming.

37:15Okay, well, this is a question Chester Lipschitz has sent in that touches on both of your areas of expertise. do today's volcanic activities have much of an uh have much of any impact on the cooling down and gradual solidifying of the core if so how long would it take would we lose our ability to maintain a stable magnetosphere and atmosphere before we even have to worry about the problems the sun is going to give us in a few billion days wow hey what an apocalyptic does he get any sleep at night so i think he's basically then asking like as as heat is coming out through these volcanoes is it cooling down the inside of the Earth?

37:50And is it doing it at such a rate that it's going to start changing how the Earth is? And let me simplify that question to Natalie. Why is Earth still hot? Yeah, no, that's exactly it. So the volcanoes are basically just a manifestation of a planet cooling itself down. So it has all this internal heat, and it needs to go somewhere, and volcanoes let that heat escape into space. Which means we are cooling down. We are cooling down. But luckily, we have plenty of heat. So we've got two, main two types of heat in most of the planets will be the heat that was left over from the formation of the planet so that when the planets formed it was all a bit chaotic and things were colliding with each other and basically kinetic energy of two objects colliding into each other turns into heat energy and so it gets trapped within the cores of most of the planets so all the moons in fact so we've got a lot of heat from four and a half billion years ago and it's been trapped in ever since um outside of the core we've got a mantle which is made up of silicate rocks so these are kind of the basalts and stuff we were talking about that's a really good insulator so it keeps that it's kept that heat inside the planet the larger you are the more heat you can retain now the other way that would create heat is actually continuous process and it's it's nuclear heat so we've actually got radioactive decay going on within our planet basically atoms that are unstable decay to more stable atoms and they release heat during this process because they release little atoms that then collide with other things inside the planet and create heat now it sounds like it wouldn't be very an important process, but actually there's so much decay going on in the planet that we're creating about half our current day heat from that process.

39:23So why isn't Mars also creating heat? So it is, but it's cooled down a lot more now because it started off smaller, so it never had as much heat to start with. And then because its mantle is smaller and its crust where it has all these heat producing elements, it then has just lost that heat. Okay, so we have volcanoes and Venus still has volcanoes. Exactly. And we're sister planets. Yeah, Venus is probably a similar the temperature inside we talk about the surface temperature of the planets it almost doesn't really relate to what's going on inside so mercury being right next to the sun can even had have ice on its surface so i love that another side of that question was if it does cool down we might lose our magnetic field because you the way you drive a magnetic field by the movement of conducting materials yeah and when you move charges you you within a field you generate Within an electric field, you can generate a magnetic field.

40:16And so we rely on a molten inner region of iron, it's self-conducting material, to generate a magnetic field, which shields us from certain forms of solar wind that could then strip our atmosphere of molecules that we care about, Okay. Including the water molecule, right? So did I characterize that accurately there? Yeah, perfect. So yeah, our outer core is actually molten and our inner core is solid. So it's that molten iron rotating around inside the planet that keeps our magnetic field alive. And without it, we wouldn't be here because life, we just would be bombarded with radiation. Or we'd be living just underwater.

41:04We'd maybe be living underwater because you would be, if you had an ice cover, like you find at Europa, which is obviously sitting next to Jupiter, which has this horrible magnetic field, if you're life. It could be life, if you're life. Otherwise, it's just fine. If you're a rock, what do you care? You don't care. I mean, if you're a robot, then you might be in trouble as well. So that's worth considering. Yeah, and we do have to really protect space equipment that we send out there from radiation in space because, you know, all this can damage cameras very easily. So, yeah, it's something we have to worry about.

41:36But Mars, if we go back to Mars, it did have a molten interior, and then it no longer does, so it's lost its magnetic fields. So this is why we talk about life might have been there in the past, because it had all the right conditions. But it also means terraforming Mars might have bigger challenges than we think, because you might be able to turn it into Earth, but to sustain it requires the rest of this shielding to happen. Yeah, we could live in caves, and I think it would be miserable, but, you know, maybe people want to go and do that. But we would need to live underground. to protect ourselves using the rock to basically shield us from the radiation.

42:10Okay. So my favorite thing about this show is I can make a stupid joke about robots and it turns out I actually at least said something smart. That's a very insightful point, Matt. Thank you. That's what I was going for. I appreciate that, two scientists there. Okay, keep it coming. What else do you have? We have a few more questions. This is also touching on Neil's expertise as well. Because Marcus Gustafsson says, from Sweden, asks, can asteroids develop volcanoes? and would that make its orbit unpredictable because of the thrust it would generate? Oh, cool. That's really cool. And yes, yes, yes, it can.

42:42So we've actually discovered that some of the asteroids, like some of the Ceres, and actually that's got ice volcanoes on it. And there's a mission called Psyche, which is a NASA mission. I think, I don't know when it's launching, not long now, it's going to this asteroid called Psyche 16. And they think it had iron volcanoes on it, potentially way in the past. Now, whether those volcanoes have affected... But just to be clear, and I don't want to be pedantic or anything, but Ceres got upgraded in its designation in the solar system. This is true, unlike Pluto. So Pluto got downgraded from planet.

43:18Ceres got upgraded from asteroids, and they're both dwarf planets now. So I will not accept you to cite Ceres as a place for asteroidal volcanoes. It's in the asteroid belt. I'm going to call it an asteroid. Right. It's a tall one on an asteroid. All right. Okay. I guess since location does matter to geologists, because magma outside of a volcano is called lava. Mm-hmm. Exactly. That's how you roll. So also, of course, comets, as they come near and far from the sun, plumes will develop that do alter their trajectories, right? Yes. And so with comets, predicting their orbits is a highly risky, not risky, it's highly uncertain activity simply because you don't know where the next plume is going to come out that will then have the comet recoil and give you a different kind of orbit than you were expecting.

44:13Yeah, and when they go near the sun, they can explode or pieces can come off. And then obviously they're a different size and shape to what they were before they went around the sun. I know, it's crazy. We're going to explode, disintegrate, or get eaten by the sun entirely. Yeah. Matt, time for a few more. Yeah, well, this is obviously the counterpart to this question from, and I hope I'm getting your name close to correct, Zenkuti Bentz asks, can an eruption have such power to send rocks to space? If a giant eruption happened in Yellowstone, would it send rocks to space, which would then fall back down on Earth, is the second part of that question.

44:48and that question comes from Hungary. Yeah, so I guess once you're in space, you're in space. You're not going to probably come back very easy, but that wouldn't really happen on our planet because we've got so much gravity that I just don't think we could have a strong enough, powerful enough eruption that you could get out into space. But obviously in other places, we know that Enceladus, its plumes go 200 kilometers high and make the E-ring of Saturn. So sure enough, that is eruptions going into space. But I may be wrong, but I don't think that could happen on Earth. But sure enough, like, our eruptions do go very high into the stratosphere quite often with these Plinian-style eruptions, which is what happened at Vesuvius.

45:26And the material then, the ash and the gases, kind of encircle the planet, but within, you know, our atmosphere and can block out the sun for weeks and months to come. And that can create lots of kind of long-term damage to the planet in a way. Also, even if it did eject from the volcano at escape velocity, the atmosphere is going to tamp that down and it will not likely ever escape the Earth because it won't maintain that velocity as it ascends. Or maintain the velocity necessary to continue to escape the Earth. But there's more than one sci-fi film where we have astronauts on comet surfaces and on asteroidal surfaces where it rotates into view of the sun.

46:09there's a plume that busts forth, and people, hardware, get kicked completely off the asteroid, never to return. Yeah, and that is something they worry about with comet missions, with the Rosetta mission. They landed on that comet, and they had to choose somewhere that didn't look very active, didn't have an active plume coming out because they were genuinely worried that the spacecraft, a little lander, would get shot off the surface and be lost into space forever. So it is quite a worry. Yeah, yeah. That'd be a cool video, though. Yeah. It's like, wee! Like R2, you know, getting kicked out of the thing.

46:46I guess in the sci-fi world, if you're thinking about it, if you do have an ability to predict where these plumes are going to come from, that's a possible launching site to save the fuel by using that as a... Very good, man. As a trampoline. Oh, my gosh. So that would have to be a desperate situation where, oh, we're out of fuel. How are we ever going to get back? Wait a minute, there's a crash here. Let's do that. And then that saves them. That reminds me, there's a movie called Marooned, where it's back in the 60s, before we landed on the moon. And there's some astronauts in space and something goes wrong and they have to be rescued.

47:17But a hurricane was coming through Florida and over Cape Canaveral. So they couldn't launch a rescue mission. And then someone figures out, wait a minute, the eye of the hurricane is going to go over Cape Canaveral. So they connected the countdown to the, I was very young, so I didn't know hurricanes had eyes. I didn't know any, or that it's beautiful in the middle of a hurricane. I didn't know any of this. Or that Florida was hurricane prone, right? And so they actually launched it until you see this launch coming out from the center of the hurricane. It was beautiful. It was a beautiful concept.

47:50I'm not sure how exactly they wheel the rocket out through the hurricane waiting for the eye to get it. If I know anything about rocket launches, they're quite easily postponed. It doesn't take much for them to say, like, this isn't safe. We need to wait another couple of days. Yeah, but it was a cool move, though. Yeah. Okay, time for a couple more questions. Maybe one more question. Time for one more question, Matt. Okay, well, I like this one, because there's been some other questions that I think we've covered anyway, just through things that have come up naturally. So Boris Maganek, again, Maganek, I hope I'm getting your name close, says, okay, here's a silly and possibly ignorant one.

48:28I say it's not ignorant. I'm the one who asks the ignorant questions here, Boris. Stay in your lane. There's only one room for one ignorant person on this show. But Boris asks, is it possible that a regular mountain can become a volcano? Or are 100 % of volcanic mountains shapes and mass created by the first eruption itself? Yeah, yeah. So if you've just got a normal mountain that is created through normal mountain processes, which is usually from plate tectonics. So you've got two plates colliding and nothing gets melted. They just kind of crumple up against each other because they're being forced together, you know, a few centimetres per year.

49:03That's how we get the Himalayas. So those mountains and, you know, Mount Everest are not volcanic. They never will be. They're just getting taller and taller every year because, you know, those plates are crushing together and pushing up crust above the surface. So no, sorry, no, no big mountains will become volcanic. So the subcontinent, it didn't get the memo that, like, Russia's in the way, right? Yeah, exactly. It's like, I'm still moving. I'm still going. Just going to keep going. so natalie i'm wondering in the vein of that question could we actually take a spot on earth and drill to where the the molten rock is and sort of force a volcano to to erupt where we choose it to i guess if we knew the magma was there that would technically not technically be possible because that'd be really hard you're a geologist you know where this stuff is drilling into hot stuff is never going to be easy because everything's going to melt anyway but like if we knew there was a magma chamber there, we probably know a volcano is there anyway.

50:03Like you're not going to just get a magma chamber without a volcano. But actually what we do do a lot is kind of use the heat that's given out by these magmas sitting below the crust to generate electricity. So in Iceland, they do this a lot. Iceland is obviously all volcanic. It sits on the mid-ocean ridge and it's also got a mantle plume there. So it's a massively volcanic place. And they generate... We filmed many scenes in Cosmos there. Because you have, it looks like you aim the camera this way. It's like, Earth is forming. You aim it here, it's like there are these plumes. Where's the dinosaur?

50:35You know? We had all manner of Earth formation scenarios without any kind of set design. It was already there. And the great thing is that there's so much heat just literally just under the crust there that they just generate all their electricity for free because they can use geothermal energy. So they pump down water into the crust, it gets heated up and gets shot back up, and they could use that to... But by the way, as I learned, that was only in recent decades, until the 90s, I think. They were still using fossil fuels. And somebody said, what the hell are you doing? You've got all this heat.

51:06Yeah, do something with it. And they have so much... I think they actually send heat on their roads. I was going to say, because it is cold. Yeah, they send heat on the roads and it melts all the ice. So then nobody has to shovel. Yeah, they don't have to grit the roads. So, yeah. I found out recently that Iceland has the highest electricity use per capita of any country in the world by quite some way. which makes them sound like they're not green, but it's the opposite because they do everything with basically fossil fuel-free electricity. Yeah, and if you just tap and heat out, you leave the lights on, who cares?

51:38And then you can have all these saunas everywhere and hot swimming pools and everything. So they have loads of swimming pools just because they can heat them really easily. And they're all outdoor pools. And, you know, when it's really cold and you're like, oh, that's going to be horrible, but it's great. Right, right, right. Because it's just warm water. So let me, just to end with, can I reverse that question? And if I heard the name of a fraternity, I mean, it was a joke name. It was called I Tap a Keg, right? Okay, so can there be a volcano that we think is going to erupt? And then can we tap it off the side and have it kind of like a release of the pressure to delay what might be a larger singular eruption of the cone?

52:26No, I think the problem is we just still don't know enough about volcanoes to be able to predict their behavior. Damn, Natalie. I thought you knew. Natalie. I'm sorry. I'm trying my best. But basically, with a lot of volcanoes, like there's the Montserrat in the Caribbean is a classic example. It's this volcanic dome which sits above the surface, but it's really unstable. So, you know, even a lot of rainfall can destabilize the slopes of that volcano because it's just not very well consolidated and mashed together. and that can destabilize the magma chamber underneath and then create a massive eruption.

52:59So basically you're taking off kind of the lid of the pressure cooker a little bit. You're just releasing a bit of pressure and then it can then erupt really badly. So we wouldn't want to meddle. I think we have to leave nature to do its thing and the best way for us to get away is just to move people away. That's so defeatist. Wait till your kids become geologists and say, ma, that's so old-fashioned. Yeah, we just tap this energy here. We run the energy needs of the town. the volcano will never erupt, and we're good. Wait till the next generation, they'll figure it out. There is one possible, I don't know if you have time, but just to squeeze in one extra question from Moses Conrad Norman, who asks, can you have a planet that is entirely volcanoes and volcanic activity?

53:40Yeah, I guess Io is the closest one to that. And it's almost like our planet 4 billion years ago. So our planet 4 billion years ago was almost certainly covered in volcanoes. And most of the surface was just very hot, probably molten, and volcanoes were going off all over the place. So that is what's happening at Io still. It's not quite that bad, but it is very, very active. So yeah, definitely. Again, it's got that kind of tidal energy inside because it's right next to Jupiter, this massive planet. So it's being squashed and squeezed. Friction is happening inside and it's creating heat. And that's just a continuous process.

54:14And let me just put this to bed right here. So in the old days, well, maybe even in modern times, we would see drawings of dinosaurs, and there was always a volcano on the horizon, as though dinosaurs, which was 100 million years ago, somehow Earth was covered with volcanoes 100 million years ago. But that's like yesterday compared to the geologic timescale. So that's all wrong, I guess. Is that correct? Yeah. I mean, yeah, there were volcanoes, obviously, at the time, but not like that kind of era that we see where they're just, you know, it's all volcanic. Right, right. It's not every direction you look.

54:50There's a dinosaur chewing the... No, it's not here. They're needing plants to eat and stuff, and plants don't like volcanoes very much. But there are dinosaurs on Io? That's not what we said, Matt. We haven't seen them yet. We need to get back. You heard it here first. All right, we've got to call it quits there. Natalie, it's always great to have you. And again, thanks for being the author of our current space show at the Hayden Planetarium, Worlds Beyond Earth. Matt, we'll find you on Probably Science. Still waiting for my next invitation to appear as a guest. The second you have anything you want to come on and talk about, your next book, or just a whim, the door is wide open for you, Neil.

55:27I'm very pleased to hear that invitation get extorted from you. Very much the other way. Anytime. I'm Neil deGrasse Tyson, director of That Planetarium, where Natalie Starkey wrote the latest space show. As always, for StarTalk, I bid you to keep looking out. Thank you.