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

What’s a supervolcano? Neil deGrasse Tyson and comic co-host Matt Kirshen discover all types of volcanoes in the solar system with cosmochemist and author of Fire and Ice: The Volcanoes of the Solar System, Natalie Starkey. Is there such a thing as an ice volcano? Originally Aired October 5, 2021.

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:00Neil deGrasse Tyson?

  Hey Startalkians, Neil here. You're about to listen to an episode specially drawn from our archives to serve your cosmic curiosities. The archives run deep. If you enjoy this, take a peek at the full catalog on your favorite podcast platform. There's a lot there to tickle your geek underbelly. Check it out.

• 0:24Neil deGrasse Tyson?

  Welcome to StarTalk, your place in the universe where science and pop culture collide. StarTalk begins right now.

• 0:37Neil deGrasse Tyson?

  This is StarTalk. Neil deGrasse Tyson here, your personal astrophysicist. We're going to do another Cosmic Queries edition. These are becoming so much the favorite of our listening and viewing audience. And today, we're going to do Fire and Ice. Ooh, I love it. It's literary, it's scientific, and we'll get into it in just a moment. First, my co-host for this episode, Matt Kirshen. Matt, welcome back.

• 1:04Matt Kirshen?

  Hey, how's it going?

• 1:05Neil deGrasse Tyson?

  Matt, I love it when comedians are into science. You've got your own podcast called Probably Science. I think I get it right.

• 1:13Matt Kirshen?

  That is it?

• 1:14Neil deGrasse Tyson?

  I'm two for two. I did it last time, and I got it right.

• 1:16Matt Kirshen?

  Two in a row. I'm loving this. Yeah, the probably is in there for good reason.

• 1:23Neil deGrasse Tyson?

  Don't undersell what you got going there.

• 1:25Matt Kirshen?

  That's true. I like being described as a comedian that's into science and not a failed math student who fell backwards into comedy.

• 1:33Neil deGrasse Tyson?

  Even though that is exactly actually what happened there.

• 1:36Matt Kirshen?

  Which is exactly what happened.

• 1:38Neil deGrasse Tyson?

  So that means you do have math fluency. That's always good. Can't hurt.

• 1:41Matt Kirshen?

  I did at one point, yeah.

• 1:43Neil deGrasse Tyson?

  Well, always, always good to have you, have you back. And today, Fire and Ice, I'd love the literary reference that that makes. Just, you know, it just, it just makes you wonder, you know, what's, what's, is it good? Is it bad? And we have someone who's like an expert on the fire and ice of the solar system, and that is Natalie Starkey. Natalie, welcome back.

• 2:07Natalie Starkey?

  Hi, it's great to see you.

• 2:09Neil deGrasse Tyson?

  First StarTalk rodeo.

• 2:11Natalie Starkey?

  Not at all, no.

• 2:12Neil deGrasse Tyson?

  Yeah, it's excellent, excellent. You're coming to us from...

• 2:17Neil deGrasse Tyson?

  From the UK.

• 2:19Natalie Starkey?

  I am.

• 2:19Neil deGrasse Tyson?

  And let me get your official title, you're Public Engagement Officer at the Open University, which is an institution just outside of London, and you're a science communicator. That's just a beautiful thing, because we need more of that. Can we clone you? You'll be the first in line.

• 2:35Natalie Starkey?

  Do you know what? There's loads of us. There's so many of us out there, and it's amazing, you know, when I'm in this field.

• 2:40Neil deGrasse Tyson?

  Yes.

• 2:40Natalie Starkey?

  And all these other practitioners, there's so many of us.

• 2:43Neil deGrasse Tyson?

  We can call it a field, right?

• 2:45Natalie Starkey?

  Yeah, exactly.

• 2:46Neil deGrasse Tyson?

  A place to be. You're a geologist, and you specialize in volcanoes? Is that?

• 2:52Natalie Starkey?

  I do, yeah, yeah. Back, you know, it feels like it's decades ago now, but I started out as a geologist because I was fascinated by volcanoes.

• 3:00Neil deGrasse Tyson?

  I'm just wondering, how do you, if you're a geologist at all, how could you not be fascinated by volcanoes? Because that's.

• 3:06Natalie Starkey?

  Well, exactly.

• 3:07Neil deGrasse Tyson?

  That reshapes your planet, right?

• 3:09Natalie Starkey?

  Exactly. And I think the thing for me was that I didn't even really know what geology was when I was at school, because you don't really do it as a core subject. And then I learnt about volcanoes and was fascinated, and I read this amazing book called Surviving Galeras by this volcanologist called Stanley Williams. And it was his story about how he'd gone up this volcano, and it had unexpectedly erupted, and he'd taken all these people with him and ended up in these dire circumstances. And lots of people got killed and injured, and for some reason, that really inspired me to study volcanoes. And I was like, well, I don't know why, because I don't consider myself a risk taker, but I just really was fascinated by them. And I then learned that actually I needed to do geology to.

• 3:49Neil deGrasse Tyson?

  So the fact that volcanoes can kill you earned a certain level of respect.

• 3:53Natalie Starkey?

  Yeah, completely.

• 3:54Neil deGrasse Tyson?

  Personally, emotionally, and professionally. And just to be clear, Matt, in case you didn't know, a volcanologist, it's not about Spock or anything from Star Trek.

• 4:04Matt Kirshen?

  Okay, right.

• 4:05Neil deGrasse Tyson?

  Just want to make that one clear.

• 4:07Matt Kirshen?

  But am I right in thinking that you also thought in your career that volcanoes on Earth are just a little bit too dull?

• 4:14Natalie Starkey?

  Well, you know, there's always that because we know so much about them. No, it's not. It's not true. I mean, the thing is with my book, I've dedicated, you know, almost half the book to the volcanoes on Earth because we know them.

• 4:24Neil deGrasse Tyson?

  Well, I didn't mention that yet. You have a book called Fire and Ice.

• 4:26Natalie Starkey?

  I do. Oh, Sandy. I know. I don't know how I got that in there.

• 4:29Neil deGrasse Tyson?

  Yeah, yeah, yeah. You're supposed to let me talk about your book, not you talk about your book. Uh, Fire and Ice, it's a great title. And is it, you, like as Matt's saying, you were not content with just volcanoes on Earth?

• 4:43Natalie Starkey?

  No, no, not at all. Because after I did my geology degrees, I moved into space science. So I was basically doing chemistry on volcanic rocks to understand how the Earth formed. That was kind of my PhD thesis. And then I discovered that actually you could do the same chemistry on rocks from space. So that led me to analyzing pieces of comets and asteroids brought back by space missions. And so it kind of broadened my horizons. I'd never really thought about studying anything from space before. I never thought that was really an option for me. But then suddenly I'm combining all of these expertise. And so it kind of led on after my first book, which was about comets and asteroids, and I wrote all about those first. Then I was like, hold on, I'm going to combine this all and write about volcanoes in space because it just seemed like the natural thing to do.

• 5:28Neil deGrasse Tyson?

  And, and let, let the world know, if they didn't already, that you wrote the current space show at the Hayden Planetarium called Worlds Beyond Earth. So thanks for, thanks for agreeing to do that and, and bring some of your expertise across the pond, as we say, of the Atlantic Ocean. And we were delighted to collaborate with you on that. So thanks for bringing that collective expertise. If you were just a geologist, no, we wouldn't have had you.

• 5:57Natalie Starkey?

  Yeah, thank goodness. Okay.

• 5:59Neil deGrasse Tyson?

  We needed that space dimension that you brought to the table.

• 6:03Natalie Starkey?

  And that was such a fun show to write. Oh, my goodness. I learned so much in the process as well, like having to combine, you know, that kind of scientific expertise with, you know, basically space artists, people that can, you know, image this stuff that we write about and we talk about so much, and using all that kind of real data from NASA and ESA missions and, and using it to create this beautiful show. It was, yeah, it was a great experience.

• 6:25Neil deGrasse Tyson?

  Yeah, all your words on the page are actually happening visually on the dome. Yes, yes, yeah. And, and so, so I'm curious about something. Um, is there a? Um, you know, when we think of volcanoes, we think of hot things. And so why is the word ice in your title?

• 6:44Natalie Starkey?

  Yeah, good question. Okay, so a lot of people don't realize that actually most of the volcanoes out in the solar system, particularly when we go past the asteroid belt out to Jupiter and beyond. Most of the bodies out there are actually ice volcanoes. So these are, these are active places.

• 6:59Neil deGrasse Tyson?

  Wait, wait, wait, wait, wait. You're speaking like, okay, yeah, most of the volcanoes in the solar, yeah, yeah, that's cool. Like, do people even know we have volcanoes other places than Earth?

• 7:11Natalie Starkey?

  Oh, I'm sure they do.

• 7:13Neil deGrasse Tyson?

  Really?

• 7:14Natalie Starkey?

  I'm sure they do. So most people have heard of Olympus.

• 7:16Matt Kirshen?

  I don't know. I would, I would say maybe a fair proportion, a large proportion of the listeners of this show would know it. But I think if you polled the average person on the streets, I don't know if you would necessarily think of a volcano as being on other planets. I don't know if you'd even necessarily think of.

• 7:31Neil deGrasse Tyson?

  Maybe I've spoken to too many flat earthers. If people think Earth is flat, they're not thinking that there are volcanoes elsewhere. So I just have issues with believing that this is widespread.

• 7:40Matt Kirshen?

  But even, even people who have, you know, who have a acceptance, broad acceptance of science, but maybe answers as embedded in it. I, I would even say, and this is, this is even something, it's obviously, I know that the heat from volcanoes and the most rock isn't fire per se, but the idea of something that looks like fire coming in a vacuum in places that don't have air, that seems strange.

• 8:05Neil deGrasse Tyson?

  So all of this, okay, so we have fire in vacuum and we have ice in volcanoes. So explain yourself, Natalie.

• 8:11Natalie Starkey?

  Yeah, so I mean, I use fire, you know, to kind of just represent the fire-ness of volcanoes. And it's something I go into in, in the book a lot, but we can also use it to represent, you know, there are lots of fiery volcanoes out in the solar system. We, we had active worlds around us. Mars was massively active kind of three billion years ago. Venus, our next door neighbor, is probably still active today. It's probably got volcanoes erupting today, we think, but we just can't see them happening. But there's a lot of evidence that it probably is happening.

• 8:41Neil deGrasse Tyson?

  But why can't we see them?

• 8:42Natalie Starkey?

  Well, there's lots of issues with Venus. It's not a very nice place, basically. It's really hard to see. It's covered in this shroud of gas, basically, of carbon dioxide, which means, so its atmosphere is really, really thick and dense. So it's really hard to see through it. You can't see through it with visible light. You need like a radar to see through it, which we've done. We've sent spacecraft up to look through that really dense atmosphere and we looked at the surface of Venus. And we can see it's just covered in lava flows. So everything that's on its surface is basically basalt, which is the same kind of stuff that we find in places like Hawaii and Iceland, very, very standard volcanic rock that we see a lot on our own planet. But the whole of Venus is about the same age. It looks like it's about 500 million years old, which sounds really old, but actually, in kind

• 9:27Natalie Starkey?

  of the age of the solar system, that's not very old. It's been active quite recently.

• 9:31Neil deGrasse Tyson?

  And just to be clear, you call Venus our neighbor, but Mars is our neighbor too.

• 9:35Natalie Starkey?

  Yeah, so the thing about Venus is that it's a similar size. Yeah, it's just, the important thing is it's a similar size to Earth. And it was made of the very same ingredients as were all the terrestrial planets, all the ones within the inner solar system. So it should be very similar to Earth. Like, we should expect it to be very similar to our own planet. But it's not for some reason. It's turned into this hellhole. It's, you know, got a surface temperature of 450 degrees Celsius, hot enough to melt lead. It's got horrible pressure on the surface. So, you know, the Soviets sent spacecraft to land there decades ago, and these spacecraft lasted just a few hours on the surface before just being crushed to death. So it's not a place we're going to be sending humans anytime

• 10:17Natalie Starkey?

  soon. But it's a fascinating world because what we want to do is understand why it's ended up so different to Earth. Like, why hasn't it got oceans on its surface? And that's one of the big questions that we're actually trying to look at now. We're sending some missions there. NASA are going to send two missions there in the next decade. ESA are going to send one mission. I think the Indians have another mission going.

• 10:37Neil deGrasse Tyson?

  ESA, the European Space Agency, yeah.

• 10:39Natalie Starkey?

  Correct, yeah. And so we're going to find so much about Venus now. So it was Mars. I feel like Mars has had its day now. Like, we've done it. No, we haven't. There's lots still to find out about Mars. But Venus is going to be the next planet we're really going to delve.

• 10:50Neil deGrasse Tyson?

  And just a shout out to India, who's joining the fray there with sending probes to planets, so.

• 10:57Natalie Starkey?

  Yeah, they've done some amazing work. They're, you know, their space agency is doing great. So there's going to be so much information coming back. It's really exciting.

• 11:04Neil deGrasse Tyson?

  Okay, so now where does ice fit into this?

• 11:07Natalie Starkey?

  Oh, yeah. I went off on a tangent, as I told you, but yeah. The ice part is going to represent all those volcanoes that are past the asteroid belt. So we've got basically a lot of moons around these giant planets out in the outer solar system. So we take Jupiter, Saturn, Uranus and Neptune. They've all got lots of moons around them, like Jupiter has about seventy nine moons that we've found so far. So it's just loads of them, you know, we just, we've just got one. And I'm like, okay, Jupiter's kind of greedy, but it is a big planet.

• 11:35Neil deGrasse Tyson?

  Aren't many of those moons kind of lame excuses for moons?

• 11:39Natalie Starkey?

  No, not at all. I was saying ours is a bit lame now. Now I've learnt about all these other ones, like.

• 11:46Neil deGrasse Tyson?

  I meant just in terms of how tiny they are.

• 11:48Natalie Starkey?

  No, no, no, not at all. So our, you know, some of the moons out there are actually as big as Mercury.

• 11:53Neil deGrasse Tyson?

  No, I meant among the seventy nine moons of Jupiter, some of them.

• 11:56Natalie Starkey?

  Some of them are not, you know, potentially so interesting. But if we take the Galilean moons, we've got, you know, Io, we've got Ganymede, Europa. These are all really cool places. Io is, is hot. It's very much like Earth was kind of four billion years ago. It's the most volcanically active object in the solar system. So it erupts these plumes of rock almost continuously off its surface. In fact, every space mission that's gone by has seen it erupting. Um, but then all the other moons there are kind of icy moons. So they've got these rocky interiors, but then they're either ocean worlds with an ice cap on the outside or they're just made of ice. Um, and these are the really interesting ones because in order to have sort of an ocean underneath the ice, we know that they must still be warm inside.

• 12:40Natalie Starkey?

  That rocky interior must still be warm somehow. It must be warm enough to heat the ice to turn it into a liquid. Um, and so this instantly tells us that these worlds are active and interesting places to go. And sure enough, the more we've looked, the more we've discovered that they have volcanoes on the surface. So they have plumes of material shooting out from their oceans, which shows us that there's a lot going on beneath the surface.

• 13:05Neil deGrasse Tyson?

  So we can call those ice volcanoes, I guess, is that right?

• 13:07Natalie Starkey?

  Yep, so they're all, the ice volcanoes are cryovolcanoes, cryo being the cold part. So, and there's loads of them, they're everywhere, they're everywhere we look. So actually, it's almost like the ice volcanoes are more common than the kind of the hot ones that we see in the inner solar system.

• 13:21Neil deGrasse Tyson?

  So your book is like long overdue. Somebody should have been talking about this long ago. It should be like in all the classes.

• 13:28Natalie Starkey?

  Well, this is the thing, it's quite, it's always quite recent that we've really learnt about all of these places. In fact, you know, the Voyager missions went out in the kind of nineteen seventies and eighties. And before that, we had no idea that these places were active. In fact, we didn't even know some of these moons existed. And as we got out there and we started to photograph them, we were then very surprised by the results. So I was at school during that time. And of course, that was, you know, cutting edge research happening at the time. That's not going to be in the school curriculum. So it takes a while for that to kind of filter down. But what we then discovered was actually some of the data that Voyager got, we didn't see some of this stuff at the time. So it needed kind of reprocessing. So we go back with other missions later and we spy this plume shooting off the surface

• 14:13Natalie Starkey?

  of Enceladus or somewhere. Then we can go back to earlier data that is still sitting in the archives and reprocess it and go, oh, look, we would have seen it there if we'd looked more carefully. We now have loads of evidence that these things have been active for decades. So really, it just takes incremental steps of missions going out and discovering this stuff. But we've barely been out to the outer solar system many times. Like, we've been there just, you know, a handful of missions. So there's still a lot of work to do.

• 14:39Neil deGrasse Tyson?

  Plus, there's an interesting fact that if you do flybys, you just have these snapshots of a moment in time.

• 14:44Natalie Starkey?

  Yeah.

• 14:44Neil deGrasse Tyson?

  Where you then have to generalize what the thing is doing all the rest of the time, which could be very hard. Like, I'm trying to think if an alien flew by Earth and I just happened to be in the bathroom when that happened. It would generalize my whole life, oh, he lives in the bathroom. Like, you need at least another data point or something. To capture that. Matt, did you collect questions for us for today?

• 15:07Matt Kirshen?

  Well, so I think you've sort of half answered this already, but I just want to pin down this question from Adam Smith, just to kick things off, because he says, "Is there such a thing as cold volcanoes or ice volcanoes? I imagine ice being spat out like in the way Mr. Freeze did in the 1997 Batman and Robin film, character played by Arnold Schwarzenegger, or is this illogical due to pressure causing heat?" I mostly wanted to ask that question because of how detailed he went in with the specificity of the film.

• 15:36Neil deGrasse Tyson?

  Okay.

• 15:36Matt Kirshen?

  He needed us to know exactly which iteration of Batman and Mr. Freeze he was doing.

• 15:40Neil deGrasse Tyson?

  Yeah, because you don't want to get confused with some other rendering and played by a different character. Actually, we got to take a quick break, but when we come back, we're going to get Natalie to explain to us how an ice volcano actually works, because that's a mystery to all of us here when we come back on StarTalk.

• 16:08Speaker 03

  I'm Joel Cherico, and I support StarTalk on Patreon. This is StarTalk with Neil deGrasse Tyson.

• 16:28Neil deGrasse Tyson?

  We're back. StarTalk Cosmic Queries, Fire and Ice.

• 16:34Neil deGrasse Tyson?

  I've got Natalie Starkey. There's a book with that title, geologist turned astro person. What she worked on became interesting when she stepped out into space. That happens whatever you're doing on Earth. If you add space to it, it's more interesting. That's my bias. I bet that's your bias too, Natalie, isn't it?

• 16:55Natalie Starkey?

  Yeah, definitely.

• 16:56Neil deGrasse Tyson?

  Okay, there you go. All right, Matt, you left off with a question about Arnold Schwarzenegger, was it?

• 17:02Matt Kirshen?

  Yes, this is from Adam Smith, and there's a lot of Batman-specific parts to the question, but the main part is, does- What is the deal with ice volcanoes? And does ice get spat out from these volcanoes? Or is this illogical due to pressure causing heat?

• 17:19Neil deGrasse Tyson?

  Yeah, yeah, because pressure, whether or not pressure even causes heat, pressure wouldn't have to cause heat. It just has to be pressure, right? I mean, if something gets spewed out of a volcano, it doesn't have to be heat that does it. Is that right?

• 17:31Natalie Starkey?

  So, no, yeah, this is kind of a tricky one to answer. It's a great question for that reason. But basically, there's lots of different ways that volcanoes can erupt. And I think what we need to get away from is thinking, having to think of a volcano as a conical shaped mountain like we see on Earth. Because actually, when we go out into space, we don't need that. We don't need a conical shaped mountain to have a volcano. Because we have to just define better what a volcano is. We're sort of skewed towards what we have on Earth. Because that's where we first studied volcanoes. So we think they have to look a certain way. But we go out into the solar system and we look at these other objects around us. And we start going, okay, well, this is a volcano. This is material coming out from the inside of this world. And it's spewing out onto the surface.

• 18:15Natalie Starkey?

  And that's happening because there's heat within inside that world. And it's producing a molten material or gas. And it's forcing it, ejecting it out. And that is basically a volcanic type of activity. So we see this at Enceladus. Basically, what's happening there is that there is heat generated within that world. Because as Enceladus goes about its orbit around Saturn, it's sort of pulled and pushed on the inside by the gravity of Saturn. So it kind of gets a bit closer, a bit further away from Saturn. And so it's called tidal heating. It's very much like we get with the Earth and the Moon. That we kind of squash slightly and our tides move. But within Enceladus, for example, they actually, the insides of it are squashed. So it's rock creates friction and heat. And that then heats the ocean above it.

• 18:59Natalie Starkey?

  And eventually, kind of opens cracks in the surface that then allow material to escape. So you'll see it as a plume. That material ends up raining back down onto the surface of Enceladus and, you know, resurfacing that body. But not only that, but these are kind of, what we're actually spewing out is basically gases, ice particles, little pieces of silica grains, which come from the very bottom of that ocean. And some of these ice particles actually start to make Saturn's E-ring. So they get sent so high up into space that that is the reason we have Saturn's E-ring, within which Enceladus kind of orbits. So That's, yeah, a much longer answer, and that's only one way that we can kind of make volcanoes on these bodies.

• 19:41Natalie Starkey?

  But yeah, in a, in a way, I kind of think that's like the Mr. Freeze character, that we're spewing out ice particles into space. And that's by sampling those, which we did with the Cassini mission, um, we know where they're coming from because they're salty. We know they're from a salty liquid ocean below the crust. Um, so that's really cool.

• 19:58Neil deGrasse Tyson?

  Right, so, so if there were fish there, could fish be spewed out too? You get a fish in the E-ring?

• 20:03Natalie Starkey?

  Yeah, exactly. I love this. Now then we need to go back because.

• 20:08Neil deGrasse Tyson?

  I was just kidding. You're telling.

• 20:09Natalie Starkey?

  No, it's like, well.

• 20:11Matt Kirshen?

  But living things could be shot out.

• 20:13Natalie Starkey?

  Anything could. So whatever's down there is going to come out in these plumes. Now, the thing is, when Cassini went, it didn't know it needed to measure this stuff that was coming out in the plumes because we didn't know they were happening. So this is one of these things with space missions. We then learn stuff and we go, oh, we need another mission. We need to go back and specifically look at these plumes and the material that's in them. What we do know is that there's all the right materials for organic content being there. So we know that there's chemical reactions happening within that ocean that can create organic molecules. Now, it's a step then to say, okay, we need to find life, but there's every chance that it could be down there. It's got all the right conditions for life to form. Okay, not human-like life, but other kinds of life that we might find at the bottom of Earth's oceans, for example, which is going to be a very similar environment.

• 20:58Natalie Starkey?

  So, yeah, every chance. We need to get down there and, and have a look, basically.

• 21:02Neil deGrasse Tyson?

  So it must be hard enough for a fish in an earth ocean to be caught, you know, with a line and then thrown back and have to explain to other fish what they saw. That's gotta be hard enough. And now we're gonna have a fish spewed into orbit around Saturn when they were happily swimming beneath the ice.

• 21:24Matt Kirshen?

  Yeah, just be sort of orbiting around the fish on the, on the ground. Just like, get that, get back, get back, get back here.

• 21:31Neil deGrasse Tyson?

  Crazy, right?

• 21:32Matt Kirshen?

  Stop messing around.

• 21:34Neil deGrasse Tyson?

  All right.

• 21:34Matt Kirshen?

  Justify yourself.

• 21:35Neil deGrasse Tyson?

  So there you go. All right. So Matt, what more do you have?

• 21:37Matt Kirshen?

  That's a great, that was a great question. My biggest takeaway from your answer there is that the Batman Robin film was scientifically accurate. So that's nice to know. I like the, I always love it when a question comes from the children of listeners. I like the idea that there's some young kids who are interested in this stuff. So this is from Wes Denham's seven-year-old son Silas, who asks, what is the process that magma goes through to be able to rise to the surface before it explodes?

• 22:04Natalie Starkey?

  Oh my goodness. What a question. That's amazing. I always love the ones from the kids because they're always the hardest to answer. You're like, oh, it's, you know, everyone's like, oh, it'll be a really simple question. Like, no, that's not simple to answer.

• 22:16Neil deGrasse Tyson?

  Well, just to be clear, what you call magma, we call lava, is that right?

• 22:21Natalie Starkey?

  So yeah, basically magma is before it's erupted. So below the surface, if we have molten rock, it will be called magma. As soon as it goes above the surface and's erupted out of a volcano, it becomes a lava. Now-

• 22:33Neil deGrasse Tyson?

  Even though it's the same stuff, we just have a different word for it.

• 22:35Natalie Starkey?

  Exactly the same stuff.

• 22:37Neil deGrasse Tyson?

  And then after it hardens, then you call it basalt?

• 22:41Natalie Starkey?

  Well, it's, yeah, it will be a basaltic lava. And then when it hardens, it's, yeah, it's a basaltic rock or basalt. Yeah.

• 22:48Neil deGrasse Tyson?

  You geologist, damn.

• 22:50Natalie Starkey?

  I know, I know. You just like to make life complicated.

• 22:52Neil deGrasse Tyson?

  Okay, okay. So, okay, so now let's, and who asked this question again, Matt?

• 22:57Matt Kirshen?

  This is young Silas, seven-year-old Silas.

• 22:59Neil deGrasse Tyson?

  Seven. Oh, my gosh. Okay.

• 23:01Natalie Starkey?

  Yeah. When we go to the outer solar system and go to these icy worlds, remember our view of volcanoes is skewed towards what we have on Earth. So we think volcanoes need to be rocky. And then we go out there and go, oh, no, they don't, they can be icy. So basically, when we talk about magma or lava on, for example, Pluto, let's take Pluto because that's a great example, it's not rocky. The stuff that Pluto is made of is all ice. So when we talk about Pluto's magma, it's basically just the molten version of whatever it's made of. Its bedrock is water, ice, and ammonia, and methane, and nitrogen. So when we melt those materials, which it's easier to do because they have lower melting points, we basically make-

• 23:43Natalie Starkey?

  magma or lava of those materials. So that's that's their magma, that's their lava. So it just depends where you are. We just need to center ourselves on the right world. So whatever happens, basically, you need to heat the stuff. So if you've got rock within inside a planet, which we do, if you delve down into our planet, it's hard and it's rocky. And we need to melt that stuff in order to make it rise. As soon as you make a liquid of a of a solid thing, then it's more buoyant and it just wants to naturally rise through that body. So that's generally what happens. Now, the other thing with magmas is that they often contain a lot of gases. And and these gases just want to escape. So they kind of overpressure this magma as it rises up and that causes it to just keep rising and keep rising and melting its way through the crust until it gets to the surface.

• 24:27Natalie Starkey?

  And then basically what happens is those gases want to just erupt out of that lava very quickly. And that's generally what makes the explosion at the surface. If we see something, you know, like mountains and hellens or somewhere. That was just that magma basically exploding as it got to the surface and blowing that mountain apart. And as that pressure is released when you get to that.

• 24:46Neil deGrasse Tyson?

  Wait, wait. So if the explosion blows a mountain apart, how do we get the mountain in the first place?

• 24:50Natalie Starkey?

  So the mountain initially was built up from very like continuous eruptions of lava and ash. And so we call these strato-volcanoes. And so they generally build up quite slowly over years and years and and then, you know, trees grow on them and they look just like a mountain and we don't think they're scary. And this is partly why volcanoes are very dangerous because

• 25:09Neil deGrasse Tyson?

  It's like Mount Fuji has a very nice shape, very beautiful.

• 25:12Natalie Starkey?

  Oh, it's beautiful. Yeah, you know, I loved with the Olympics coverage.

• 25:15Neil deGrasse Tyson?

  Yes, it was gorgeous. It was so iconic.

• 25:16Natalie Starkey?

  Beautiful. They use that image all the time and Snowcat Mountain. And I think that's

• 25:21Matt Kirshen?

  It's the volcano that looks most like a child's drawing.

• 25:23Neil deGrasse Tyson?

  Yes.

• 25:24Natalie Starkey?

  Exactly.

• 25:25Neil deGrasse Tyson?

  It doesn't even look real, right? It's like, yeah.

• 25:27Matt Kirshen?

  Yeah.

• 25:28Natalie Starkey?

  It's beautiful. And I think that's why we we sort of forget as humans, because these, you know, volcanoes can erupt not very often, but they're still classed as active. So ten thousand years is usually the timeframe where we say, if it hasn't erupted for ten thousand years, then it it might be not active any longer. But the problem is, we don't as humans remember that kind of timeframe. So people live close to volcanoes for many different reasons. Um, the that the land around volcanoes is often very fertile. So it's really good to make crops and everything and grow stuff. And also the land is cheap because it is known not to be very safe.

• 26:01Neil deGrasse Tyson?

  Really, you think?

• 26:02Natalie Starkey?

  So, but people have to live in these places.

• 26:05Neil deGrasse Tyson?

  Location, location, location.

• 26:07Natalie Starkey?

  Exactly, and they're beautiful. So, you know, I would quite like to live there.

• 26:10Neil deGrasse Tyson?

  It's got good schools, it's got good roads, but you're on the side of a volcano.

• 26:15Matt Kirshen?

  As much fossils as you need.

• 26:18Neil deGrasse Tyson?

  I, we, uh, we went on a trip to Italy and visited Vesuvius, you know, 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.

• 26:31Natalie Starkey?

  Yeah.

• 26:31Neil deGrasse Tyson?

  I was like, whoa.

• 26:33Natalie Starkey?

  And that obviously is very famous for Pompeii.

• 26:35Neil deGrasse Tyson?

  Very famous, infamous.

• 26:36Natalie Starkey?

  Did you visit the ruins? Yeah.

• 26:38Neil deGrasse Tyson?

  Yeah, yeah, of course, of course.

• 26:39Natalie Starkey?

  Yeah.

• 26:39Neil deGrasse Tyson?

  There are vineyards on this side of Vesuvius that are dustily identified on the label. So if you want to get a, so it tastes a bit of ash, I think, I don't know.

• 26:49Natalie Starkey?

  That's the thing about ash, it's really, it's really, really good for soil. So, you know, whilst a huge amount of it coming down the mountain like at Pompeii, um, you know, is rather devastating. Um, 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, and helps to create these amazing crops.

• 27:09Neil deGrasse Tyson?

  Fertilized and irrigated, very, very interesting, yeah, cool. All right, Matt, give me some more.

• 27:14Matt Kirshen?

  Yeah, well, so this is Nicholas Gudlove, and along these lines, Nicholas is asking, should we be worried or afraid of the supervolcanoes of Earth? And what is the most menacing volcano to you in our solar system?

• 27:25Neil deGrasse Tyson?

  Good one.

• 27:26Natalie Starkey?

  Okay, uh, so yeah, supervolcanoes, 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 gonna erupt, you know, it's gonna erupt next year and it's gonna devastate everything. But the reality is that.

• 27:41Matt Kirshen?

  Right, and that thing of like, it's due is how it's always described, like we do an eruption.

• 27:44Natalie Starkey?

  And it is always due, you know, but, um, 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. Um. 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. Um. But the thing is with these.

• 28:10Neil deGrasse Tyson?

  But that area still has good schools, right? We can still.

• 28:14Natalie Starkey?

  It's quite a place, isn't it?

• 28:16Neil deGrasse Tyson?

  It could blow up completely, but before that happens, you've got.

• 28:20Natalie Starkey?

  Thing is with supervolcanoes, whilst they have the potential to do that, and 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.

• 28:30Neil deGrasse Tyson?

  You're a geologist. Why don't you know this?

• 28:32Natalie Starkey?

  Well, we do, but there's smaller eruptions.

• 28:35Neil deGrasse Tyson?

  Ground and find oil. Why can't you thump the ground and find where the magma chamber is that might bust?

• 28:41Natalie Starkey?

  So we know that. We can do 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. It could be that it has smaller eruptions and lets off a bit of steam. And then it 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, you know, a million years. So then 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.

• 29:11Neil deGrasse Tyson?

  Okay, that's encouraging because otherwise to say, oh, it might erupt in the next four thousand years. That's not helpful.

• 29:17Natalie Starkey?

  Yeah.

• 29:17Neil deGrasse Tyson?

  Just saying, I should say. And how about the other half of that question?

• 29:22Natalie Starkey?

  What was that? I've already forgotten.

• 29:24Matt Kirshen?

  Oh, that was what is the most menacing volcano to you in our solar system?

• 29:28Natalie Starkey?

  Menacing? Oh, but I do like to give the menacing titles because either they're all lovely, but no.

• 29:33Neil deGrasse Tyson?

  No, stop.

• 29:37Natalie Starkey?

  I guess it's going to be.

• 29:38Neil deGrasse Tyson?

  You're not supposed to feel for the volcano, Dan. They don't have feelings for you. They will melt you in an instant. Okay, vaporize you.

• 29:49Natalie Starkey?

  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.

• 30:03Neil deGrasse Tyson?

  Well, 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?

• 30:10Natalie Starkey?

  Yeah, it's massive. You 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, you know, on Mauna Loa and Mauna Kea, it's a very similar type of volcano. And actually, they're not particularly scary. When it erupts, like 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 just scary.

• 30:41Neil deGrasse Tyson?

  I never heard that sentence before. Let's, Matt, let's outwalk the lava.

• 30:47Matt Kirshen?

  Just go for a nice stroll. Morning constitutional away from the burning rocks.

• 30:52Neil deGrasse Tyson?

  Very cool. Very cool. So Matt, let's slip in one more question before we take our second break.

• 30:59Matt Kirshen?

  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?

• 31:26Natalie Starkey?

  Yeah, 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, it 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. It's a thing that's very uh 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.

• 32:11Natalie Starkey?

  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, but.

• 32:20Neil deGrasse Tyson?

  And by the way, just to be clear, y'all only fully embrace that within the last sixty years, right? That's not a forever ago thing.

• 32:29Natalie Starkey?

  Yeah, it was literally, I think it's nineteen sixties, wasn't it?

• 32:32Neil deGrasse Tyson?

  Yeah, yeah, so sixty years ago.

• 32:33Natalie Starkey?

  Suggested that it was a thing and people were like, no, the man's crazy, you know, he.

• 32:37Neil deGrasse Tyson?

  Yeah, no, I think the suggestion predates that, but before the evidence really gathered to start.

• 32:42Matt Kirshen?

  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.

• 32:49Natalie Starkey?

  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. And 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. And 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 we have, 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 one's the Mount Enermata. Now, in Mars, we've got exactly the same thing.

• 33:33Neil deGrasse Tyson?

  Yeah, so this is an archipelago, right? Isn't that what an archipelago is?

• 33:35Natalie Starkey?

  Yeah, exactly.

• 33:37Neil deGrasse Tyson?

  And and many of the Caribbean islands are, so what you're saying is it's not a continuous busting through of the of the plate. It busts through and then it stays calm for a while and over that period, this plate shift and it's okay, time to bust through again. Up, there you go. And so.

• 33:53Matt Kirshen?

  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. But you're saying it's it's almost more like a sort of. Like a factory line where they're moving up, like the earth is moving along on a conveyor box and every cell that it punches a hole through it and it moves on a bit more and punches another hole through it.

• 34:13Natalie Starkey?

  Precisely. And so if you go to Honolulu and people are like, "Oh, it's volcanic, could it erupt?" You're like, "No, you can't because it's nowhere near that plume now." So that is almost certainly not going to happen.

• 34:21Neil deGrasse Tyson?

  But that other island, that's the one.

• 34:23Natalie Starkey?

  Yeah, that's the one we need to worry about with the molten lava crater at the top.

• 34:28Neil deGrasse Tyson?

  And also, I think I'm right in that the big island of 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 through, 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 it's half of it is sitting in water. Does that exactly make sense?

• 34:50Natalie Starkey?

  Yeah, exactly. Yeah, because I think people forget with those islands that, you know, what we see above is not even half of it.

• 34:56Neil deGrasse Tyson?

  And in the middle of the frickin' Pacific Ocean, right.

• 34:58Natalie Starkey?

  Yeah.

• 34:59Neil deGrasse Tyson?

  Where it goes really, really deep.

• 35:00Natalie Starkey?

  It was very deep.

• 35:01Neil deGrasse Tyson?

  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 astro person, the keeper on StarTalk.

• 35:27Neil deGrasse Tyson?

  We're back. StarTalk. Neil deGrasse Tyson here. Matt, where can we find you on social media?

• 35:32Matt Kirshen?

  You can find me at Matt Kirshen on the various things and probably Science is my podcast.

• 35:38Neil deGrasse Tyson?

  Okay.

• 35:39Matt Kirshen?

  And that's on all the podcast platforms.

• 35:40Neil deGrasse Tyson?

  Wherever podcasts are sold near you. Yes, okay.

• 35:43Matt Kirshen?

  Yeah. Yeah, I'll just get your local bookshop for my podcast.

• 35:46Neil deGrasse Tyson?

  There you go. And Natalie, where can we find you on social media?

• 35:49Natalie Starkey?

  I'm at Starkey Stardust on, yeah, all the platforms. And yeah.

• 35:54Neil deGrasse Tyson?

  Starkey Stardust, S.T.A.R.K.E.Y.

• 35:58Natalie Starkey?

  E.Y., yeah.

• 35:59Neil deGrasse Tyson?

  Starkey Stardust, I love it. Yeah, yeah. So I think, I think we had to take a break before you completed the answer to why Olympus Mons is so big on Mars. So, so we learned that the Hawaiian...

• 36:14Neil deGrasse Tyson?

  Chain of islands, they're all volcanic, and that's just magma punching through in a new spot. And as the plate tectonics take it by. So Mars, I think, doesn't have plate tectonics. So is that what happened there?

• 36:25Natalie Starkey?

  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. So 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 gonna carry on erupting for millions of years.

• 36:53Neil deGrasse Tyson?

  Through the same hole. Through the same hole.

• 36:55Natalie Starkey?

  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.

• 37:03Neil deGrasse Tyson?

  Hmm, alright, cool. Cool. Which is the largest volcanic mountain in the solar system, I think?

• 37:09Natalie Starkey?

  I think it's the largest mountain, isn't it?

• 37:11Neil deGrasse Tyson?

  Yeah, yeah, yeah. Okay, good, good. Alright, Mac, keep them coming.

• 37:14Matt Kirshen?

  Okay, 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 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 gonna give us in a few billion years?

• 37:40Neil deGrasse Tyson?

  Ooh, wow. Man, what an apocalyptic touch. Did he get any sleep at night?

• 37:43Matt Kirshen?

  Right. So I think he's basically then asking, like, as heat is coming out through these volcanoes, is it cooling down the inside of the Earth? And is it doing it at such a rate that it's gonna start changing how the Earth?

• 37:53Neil deGrasse Tyson?

  And let me simplify that question to Natalie. Why is Earth still hot?

• 37:57Natalie Starkey?

  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.

• 38:10Neil deGrasse Tyson?

  Which means we are cooling down.

• 38:11Natalie Starkey?

  We are cooling down. So, 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 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. Outside of the core, we've got a mantle which is made of silicate rock. So these are kind of the basals 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

• 38:53Natalie Starkey?

  retain. Now, the other way that we create heat is actually continuous process and 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.

• 39:23Neil deGrasse Tyson?

  So why isn't Mars also creating heat?

• 39:25Natalie Starkey?

  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.

• 39:38Neil deGrasse Tyson?

  Okay, so we have volcanoes and Venus still has volcanoes.

• 39:41Natalie Starkey?

  Exactly.

• 39:42Neil deGrasse Tyson?

  And we're sister planets.

• 39:43Natalie Starkey?

  Yeah, Venus is probably a similar 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 have the ice on its surface.

• 39:54Neil deGrasse Tyson?

  So I love that. And another

• 39:55Natalie Starkey?

  Inside is still molten.

• 39:56Neil deGrasse Tyson?

  Another side of that question was, if it does cool down, we might lose our magnetic field. Because you, what you drive a magnetic field by the movement of conducting materials.

• 40:08Natalie Starkey?

  Yeah.

• 40:08Neil deGrasse Tyson?

  And when you move charges, you, within a field, you generate, within an electric field, you can generate a magnetic field. And so we rely on a molten inner region of iron itself a conducting material to generate a magnetic field, which shields us from certain forms of solar wind that could then strip our, our, our atmosphere of, of a very

• 40:38Neil deGrasse Tyson?

  Of molecules that we care about, okay? Including the water molecule, right? So, so did I characterize that accurately there?

• 40:48Natalie Starkey?

  Yeah, perfect. 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.

• 41:02Neil deGrasse Tyson?

  Or we'd be living just underwater.

• 41:04Natalie Starkey?

  We'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 alive. And it could be life, if you're alive.

• 41:17Neil deGrasse Tyson?

  Otherwise, it's just fine. If you're a rock, what do you care?

• 41:20Natalie Starkey?

  Yeah.

• 41:21Matt Kirshen?

  I mean, if you're a robot, then you might be in trouble as well. So that's worth considering.

• 41:24Natalie Starkey?

  Yeah, no, and that's, we do have to really protect space equipment that we send out there

• 41:29Neil deGrasse Tyson?

  Good point, man.

• 41:29Natalie Starkey?

  from radiation in space because, you know, you know, all this can damage cameras very easily. So, yeah, it's something we have to worry about. But Mars, if we go back to Mars, it was, it did have a molten interior and then it no longer does. So it's lost its magnetic field. So this is why we talk about life might have been there in the past because it had all the right conditions.

• 41:47Neil deGrasse Tyson?

  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.

• 41:59Natalie Starkey?

  Yeah, we'd probably have to 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.

• 42:10Neil deGrasse Tyson?

  Okay.

• 42:11Matt Kirshen?

  So my favorite thing about the show is I can make a stupid joke about robots. It turns out I actually said something smart.

• 42:16Neil deGrasse Tyson?

  That's a very insightful point, Matt.

• 42:19Matt Kirshen?

  Thank you. That's what I was going for. I appreciate that, two scientists there.

• 42:23Neil deGrasse Tyson?

  Okay, keep it coming. What else you have? We have a few more questions.

• 42:26Matt Kirshen?

  This is, this is also touching on Neil's expertise as well. Because Marcus Gustafson says from Sweden asks, can asteroids develop volcanoes?

• 42:35Matt Kirshen?

  And would that make its orbit unpredictable because of the thrust it would generate?

• 42:39Neil deGrasse Tyson?

  Oh, cool.

• 42:40Natalie Starkey?

  That's really cool. And yes, yes, yes, it can. So we've actually discovered that some of this, 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, not long now, it's going to this asteroid called Psyche 16. And they think it had iron volcanoes on it, potentially, way in, way in the past. Now, whether those volcanoes have affected-

• 43:06Neil deGrasse Tyson?

  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.

• 43:14Natalie Starkey?

  This is true, unlike Pluto.

• 43:15Neil deGrasse Tyson?

  Yeah, so Pluto got downgraded from planet, Ceres got upgraded from asteroids, and they're both dwarf planets now. So, so I will not accept you to cite Ceres as a place for asteroidal volcanoes.

• 43:28Natalie Starkey?

  It's in the asteroid belt. I'm going to call it an asteroid. It's a dwarf and an asteroid.

• 43:37Neil deGrasse Tyson?

  Okay. I guess since location does matter to geologists, because magma outside of a volcano is called lava. So that's how you go, 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, their trajectories, right?

• 43:55Natalie Starkey?

  Yes.

• 43:55Neil deGrasse Tyson?

  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.

• 44:13Natalie Starkey?

  Yeah, and when they go near the sun, they can explode, or pieces can come off. And then obviously there are different size and shape to what they were before they went around the sun. I know, it's crazy.

• 44:20Neil deGrasse Tyson?

  They're going to explode, disintegrate, or get eaten by the sun entirely. Yeah.

• 44:25Natalie Starkey?

  Yeah.

• 44:27Neil deGrasse Tyson?

  Matt, time for a few more.

• 44:28Matt Kirshen?

  Well, 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. And that question comes from Hungary.

• 44:51Natalie Starkey?

  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, you know, go 200 kilometers high and make the E-ring of Saturn, so sure enough, that is, you know, eruptions going into space. But I may be wrong, but I don't, 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. And the material then, the ash and the gases, kind of encircle the planet, but within, you

• 45:32Natalie Starkey?

  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.

• 45:40Neil deGrasse Tyson?

  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, there's a plume that busts forth, and people, hardware, get kicked completely off the asteroid, never to return.

• 46:17Natalie Starkey?

  Yeah, and that it's 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, you know, an active plume coming out because, you know, they were genuinely worried that spacecraft, you know, little lander would get shot off the surface and be lost into space forever. So it is quite a worry.

• 46:36Neil deGrasse Tyson?

  Yeah, yeah. That'd be a cool, a cool video, though.

• 46:40Natalie Starkey?

  Yeah.

• 46:41Neil deGrasse Tyson?

  It's like, whee! Like R2, you know, getting kicked out of the thing.

• 46:46Matt Kirshen?

  I 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 fuel by using that as a...

• 46:55Neil deGrasse Tyson?

  Very good, man!

• 46:57Matt Kirshen?

  As a trampoline.

• 46:58Neil deGrasse Tyson?

  Oh my god, so that would have to be a desperate situation where, oh, we're out of fuel, how are we ever gonna 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, but 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 gonna 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

• 47:43Neil deGrasse Tyson?

  launched it, so you see this launch coming out from the center of the hurricane, it was beautiful, it was beautiful. Beautiful concept.

• 47:50Matt Kirshen?

  I'm not sure how exactly they wheel the rocket out through the hurricane, waiting for the eye to get in. If I know anything about rocket launches, they're quite easily postponed, it doesn't take much, it doesn't take much for them to say like, this isn't safe, we need to wait another couple of days.

• 48:05Neil deGrasse Tyson?

  Yeah, but it was a cool, it was a cool move, though, yeah.

• 48:07Matt Kirshen?

  Yeah.

• 48:08Neil deGrasse Tyson?

  Okay, time for a couple more questions. Maybe one more question. Time for one more question, Matt.

• 48:13Matt Kirshen?

  Okay, well, I like, I like this one, because there's been some other questions that I think we've covered anyway, just through questions, things that have come up naturally. So Boris Maganik, again, I'm Maganik, I hope I'm getting your name close, says, okay, here's a silly and possibly ignorant one, I say it's not ignorance, I'm the one who asked the ignorance question, Boris, stay in your lane.

• 48:35Matt Kirshen?

  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 a hundred percent of volcanic mountain shapes and mass created by the first eruption itself?

• 48:47Natalie Starkey?

  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. That's how we get the Himalayas. So those mountains, 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, we, sorry, no, no, no big mountains will become volcanoes.

• 49:20Neil deGrasse Tyson?

  So the subcontinent, no, it didn't get the memo that like Russia's in the way, right?

• 49:25Natalie Starkey?

  Yeah, exactly.

• 49:28Neil deGrasse Tyson?

  It's like, I'm still moving, I'm still going.

• 49:30Natalie Starkey?

  Just keep going.

• 49:32Neil deGrasse Tyson?

  So Natalie, I'm wondering, in the vein of that question, could we actually take a spot on Earth and drill to where the molten rock is and sort of force a volcano to erupt where we choose it to?

• 49:47Natalie Starkey?

  I guess if we knew the magma was there, that would technically, not technically be possible because that'd be really hard to do.

• 49:52Neil deGrasse Tyson?

  You're a geologist, you know where this stuff is.

• 49:55Natalie Starkey?

  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. Like 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 region. It's also got a mantle plume there. So it's a massively volcanic place and they generate...

• 50:23Neil deGrasse Tyson?

  We film 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? You know? They had all manner of earth formation scenarios, all without any kind of set design. It was all, it was already there.

• 50:44Natalie Starkey?

  And the great thing is that there's so much heat, just literally just under the crust there, that they, 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.

• 50:57Neil deGrasse Tyson?

  By the way, that, as I learned, that was only in recent decades, until the nineties, I think. They were still using fossil fuels. And somebody said, what the hell are you doing?

• 51:05Natalie Starkey?

  You've got all this heat, yeah, do something with it. And they have so much.

• 51:09Neil deGrasse Tyson?

  I, I think they actually send heat on their roads.

• 51:11Natalie Starkey?

  I was gonna say, because it is cold.

• 51:13Neil deGrasse Tyson?

  Yeah, yeah, they, they send heat on the roads and it melts all the ice, so then.

• 51:16Natalie Starkey?

  Yeah, so they don't, yeah, they don't have to grip the roads, so, yeah.

• 51:20Matt Kirshen?

  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.

• 51:33Neil deGrasse Tyson?

  Yeah, and if you, and, and if you just tap and heat out, you, you leave the lights on, who cares?

• 51:38Natalie Starkey?

  And then they, you can, 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 gonna be horrible, but it's great.

• 51:49Neil deGrasse Tyson?

  Right, right, right. Uh, so let me, uh, just to end with, can I reverse that question? And, um, if, I, I heard that the name of a, of a fraternity, uh, I mean, it was a, it was a joke name. It's called I Tap a Keg, right? Okay, so.

• 52:09Neil deGrasse Tyson?

  Can we, 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?

• 52:26Natalie Starkey?

  No, I think the problem is we just still don't know enough about volcanoes to be able to predict their behavior.

• 52:31Neil deGrasse Tyson?

  Damn Natalie, I thought you knew, Natalie.

• 52:34Natalie Starkey?

  I know, I'm sorry, I'm trying my best.

• 52:39Natalie Starkey?

  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, mashed together. And that can destabilize the magma chamber underneath and then create a massive eruption. So 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 a medal. 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.

• 53:13Neil deGrasse Tyson?

  That's so defeatist. Wait, 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. We get that the volcano will never erupt and we got to, we're good. Wait till the next generation, they'll figure it out.

• 53:30Matt Kirshen?

  But 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?

• 53:40Natalie Starkey?

  Yeah, I guess Io is the closest one to that. And it's almost like our planet four billion years ago. So our planet four 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, like you definitely, it's just, it's got, 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. So.

• 54:14Neil deGrasse Tyson?

  And let me just put this to bed right here. So in, in the old days, we would, 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 they, that's all wrong, I guess. Is that correct?

• 54:40Natalie Starkey?

  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.

• 54:48Neil deGrasse Tyson?

  Right, right. It's not every direction you look. There's a dinosaur chewing the...

• 54:51Natalie Starkey?

  No, exactly. They needed plants to eat and stuff. And plants don't like volcanoes very much, so.

• 54:55Neil deGrasse Tyson?

  Okay.

• 54:56Matt Kirshen?

  But there are dinosaurs on Io?

• 54:57Natalie Starkey?

  Well, we don't know.

• 54:58Neil deGrasse Tyson?

  That's not what we said, Matt.

• 55:00Natalie Starkey?

  We haven't seen them yet. We need to get back.

• 55:04Neil deGrasse Tyson?

  All right, we 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 with 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.

• 55:18Matt Kirshen?

  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.

• 55:26Neil deGrasse Tyson?

  All right, very pleased to hear that invitation get extorted from you.

• 55:32Matt Kirshen?

  Very much the other way around. Anytime, anytime.

• 55:35Neil deGrasse Tyson?

  I'm Neil deGrasse Tyson, director of that planetarium where Natalie Starkey wrote the latest space show. As always, four-star talk. I beg you to keep looking out.