1 00:00:03,040 --> 00:00:06,800 Speaker 1: Welcome to Stuff to Blow Your Mind production of iHeartRadio. 2 00:00:13,560 --> 00:00:16,239 Speaker 2: Hello, and welcome to Stuff to Blow Your Mind. My 3 00:00:16,360 --> 00:00:19,480 Speaker 2: name is Joe McCormick. My regular co host, Robert Lamb 4 00:00:19,560 --> 00:00:21,880 Speaker 2: is out on vacation the day I'm recording this, but 5 00:00:21,960 --> 00:00:25,360 Speaker 2: he will be back again soon. Today we've got an 6 00:00:25,400 --> 00:00:28,040 Speaker 2: interview for you. This is a chat that I had 7 00:00:28,080 --> 00:00:33,040 Speaker 2: with planetary scientist doctor Sabine Stanley about her twenty twenty 8 00:00:33,080 --> 00:00:37,560 Speaker 2: three book called What's Hidden Inside Planets. This is a 9 00:00:37,600 --> 00:00:41,280 Speaker 2: wonderfully interesting book about the science of planet formation and 10 00:00:41,440 --> 00:00:44,800 Speaker 2: about what we know about the insides of planets near 11 00:00:44,920 --> 00:00:48,440 Speaker 2: and far. A quick bit of author bio before we 12 00:00:48,479 --> 00:00:52,280 Speaker 2: get started here. Doctor Sabine Stanley is a distinguished planetary 13 00:00:52,280 --> 00:00:56,400 Speaker 2: scientist and a key contributor to NASA's Mars Insight mission. 14 00:00:56,640 --> 00:00:59,800 Speaker 2: Holding a PhD in Earth and Planetary Sciences from Harvard 15 00:00:59,880 --> 00:01:03,720 Speaker 2: u University, she focuses on the complexities of planetary interiors. 16 00:01:04,240 --> 00:01:07,280 Speaker 2: Currently a faculty member at a top research university, she 17 00:01:07,360 --> 00:01:11,760 Speaker 2: leads innovative studies in her specialized field. Beyond academia, Doctor 18 00:01:11,800 --> 00:01:15,720 Speaker 2: Stanley is a regular speaker at international scientific conferences and 19 00:01:15,840 --> 00:01:19,560 Speaker 2: serves as a consultant for various space missions. Her research 20 00:01:19,560 --> 00:01:22,720 Speaker 2: has been published in leading scientific journals, earning her multiple 21 00:01:22,720 --> 00:01:26,520 Speaker 2: awards for her contributions to planetary science. With a career 22 00:01:26,520 --> 00:01:30,399 Speaker 2: that blends rigorous research and public engagement, Doctor Stanley remains 23 00:01:30,400 --> 00:01:33,720 Speaker 2: a pivotal voice in the scientific community committed to enhancing 24 00:01:33,840 --> 00:01:37,800 Speaker 2: our cosmic understanding. So I guess now let's jump right 25 00:01:37,880 --> 00:01:45,520 Speaker 2: into our conversation, Doctor Sabine Stanley, Welcome to the podcast. 26 00:01:46,040 --> 00:01:47,119 Speaker 3: Thanks so much for having me. 27 00:01:47,520 --> 00:01:51,680 Speaker 2: So I wanted to start off with the idea something 28 00:01:51,760 --> 00:01:54,280 Speaker 2: you bring up in the preface of your book, which 29 00:01:54,320 --> 00:01:57,280 Speaker 2: is that when non scientists look out at space and 30 00:01:57,320 --> 00:01:59,680 Speaker 2: find things to get excited about, one of the things 31 00:01:59,720 --> 00:02:03,080 Speaker 2: I think that really gets people stirring is the idea 32 00:02:03,120 --> 00:02:06,240 Speaker 2: of an exoplanet with liquid water at the surface, or 33 00:02:06,360 --> 00:02:10,440 Speaker 2: a planet with breathable atmosphere breathable to us. And yet 34 00:02:10,480 --> 00:02:13,600 Speaker 2: you say in your preface that quote, arguably a planet's 35 00:02:13,680 --> 00:02:17,919 Speaker 2: interior is more important than the surface in determining a 36 00:02:17,960 --> 00:02:21,600 Speaker 2: world's fitness for life or ability to withstand the pressures 37 00:02:21,639 --> 00:02:24,360 Speaker 2: put on it by its home star. I think this 38 00:02:24,440 --> 00:02:26,680 Speaker 2: might be really surprising to people. Could you explain this? 39 00:02:27,080 --> 00:02:29,280 Speaker 3: Sure, there are actually two parts to this I would 40 00:02:29,320 --> 00:02:32,840 Speaker 3: say the first is deep inside our planet, in the 41 00:02:32,880 --> 00:02:36,680 Speaker 3: iron core, we actually generate the Earth's magnetic field, and 42 00:02:36,760 --> 00:02:40,000 Speaker 3: magnetic fields when they are generating the core, they come 43 00:02:40,080 --> 00:02:41,520 Speaker 3: all the way out to the surface of the planet 44 00:02:41,560 --> 00:02:44,560 Speaker 3: and they basically surround the planet, and our magnetic field 45 00:02:44,639 --> 00:02:49,359 Speaker 3: acts as this amazing shield stopping these high energy solar 46 00:02:49,360 --> 00:02:52,720 Speaker 3: wind particles from hitting us. Now, when you have these 47 00:02:52,800 --> 00:02:56,160 Speaker 3: high energy particles coming from the Sun, if they actually 48 00:02:56,280 --> 00:02:58,839 Speaker 3: blast it into the planet without the magnetic field there, 49 00:02:58,919 --> 00:03:01,720 Speaker 3: they would work to strip off our atmosphere. They would 50 00:03:01,760 --> 00:03:05,360 Speaker 3: bring high radiation levels to the surface. It would essentially 51 00:03:05,400 --> 00:03:08,200 Speaker 3: not be a really great place to live if we 52 00:03:08,240 --> 00:03:10,600 Speaker 3: didn't have our magnetic field. So one really important thing 53 00:03:10,639 --> 00:03:14,000 Speaker 3: when thinking about is that planet going to be really 54 00:03:14,080 --> 00:03:16,800 Speaker 3: good for say, life to form, is does it have 55 00:03:16,840 --> 00:03:19,639 Speaker 3: a magnetic field and that's really created in deep inside 56 00:03:19,680 --> 00:03:23,600 Speaker 3: the planet. The other aspect of this is that most 57 00:03:23,680 --> 00:03:25,720 Speaker 3: of the reasons that we think the surface of Earth 58 00:03:25,760 --> 00:03:28,720 Speaker 3: is so nice and habitable, right the liquid water, that 59 00:03:28,919 --> 00:03:32,400 Speaker 3: breathable air, all of that is related to a kind 60 00:03:32,440 --> 00:03:36,600 Speaker 3: of recycling process that happens inside Earth. Earth's water a 61 00:03:36,640 --> 00:03:39,360 Speaker 3: lot of it came from outgassing a volcano. So there's 62 00:03:39,400 --> 00:03:43,360 Speaker 3: water deep inside the Earth. When you have volcanic flows 63 00:03:43,680 --> 00:03:46,280 Speaker 3: bringing up magma to the surface, there's lots of gas, 64 00:03:46,320 --> 00:03:49,200 Speaker 3: particles and water in that that eventually makes it out 65 00:03:49,240 --> 00:03:53,040 Speaker 3: into the atmosphere. Carbon dioxide is recycled this way. Water 66 00:03:53,080 --> 00:03:55,760 Speaker 3: is recycled this way. So you can't really just focus 67 00:03:55,800 --> 00:03:57,320 Speaker 3: on the surface. You have to ask how does that 68 00:03:57,400 --> 00:04:00,440 Speaker 3: surface interact with what's going on deep inside planet. 69 00:04:01,400 --> 00:04:04,360 Speaker 2: So when people imagine what's going on deep inside the 70 00:04:04,360 --> 00:04:06,880 Speaker 2: planet and the way it affects the surface, probably what 71 00:04:07,040 --> 00:04:10,080 Speaker 2: first comes to the average non scientist's mind would be 72 00:04:10,080 --> 00:04:13,760 Speaker 2: like earthquakes and volcanic eruptions, But actually it's much more 73 00:04:13,920 --> 00:04:14,680 Speaker 2: entangled than that. 74 00:04:15,320 --> 00:04:18,760 Speaker 3: Yeah. Absolutely, But those are also great examples of ways 75 00:04:18,800 --> 00:04:20,919 Speaker 3: that the interior of our planet is really connected to 76 00:04:20,960 --> 00:04:24,479 Speaker 3: how we experience the surface of a planet. Earthquakes, that's 77 00:04:24,520 --> 00:04:26,920 Speaker 3: because the plates on the surface of the Earth are 78 00:04:26,960 --> 00:04:29,400 Speaker 3: moving around and they descend back into the Earth at 79 00:04:29,480 --> 00:04:34,440 Speaker 3: subduction zones and create these frictional spots between plates that 80 00:04:34,520 --> 00:04:35,839 Speaker 3: create these earthquakes. Right. 81 00:04:35,960 --> 00:04:40,000 Speaker 2: Another great example, there's a false fact that I once 82 00:04:40,080 --> 00:04:42,800 Speaker 2: knew that your book corrected me on if you had 83 00:04:42,839 --> 00:04:46,600 Speaker 2: asked me what was the source of Earth's magnetic field 84 00:04:46,640 --> 00:04:48,960 Speaker 2: that you were just talking about. I would have said 85 00:04:49,000 --> 00:04:52,520 Speaker 2: that it was generated by the spinning of the molten 86 00:04:52,600 --> 00:04:56,520 Speaker 2: liquid core around the Earth's solid iron core because of 87 00:04:56,600 --> 00:04:59,720 Speaker 2: the image of spinning, and I guess there's general knowledge 88 00:04:59,720 --> 00:05:02,719 Speaker 2: that sort of dynamo effect, But in the book you 89 00:05:02,760 --> 00:05:05,640 Speaker 2: explained that that isn't exactly correct. That's not exactly what's 90 00:05:05,680 --> 00:05:08,880 Speaker 2: going on. So what does generate the Earth's magnetic field? 91 00:05:09,600 --> 00:05:12,680 Speaker 3: Yeah, you're absolutely right. This is a common misunderstanding out there, 92 00:05:12,720 --> 00:05:15,520 Speaker 3: even some scientists have it. So it turns out in 93 00:05:15,640 --> 00:05:18,040 Speaker 3: order to generate magnetic fields, you do need to have 94 00:05:18,080 --> 00:05:20,560 Speaker 3: a good electrical conductor, and so having a metal like 95 00:05:20,640 --> 00:05:23,159 Speaker 3: iron in this center of the Earth that helps. You 96 00:05:23,200 --> 00:05:26,240 Speaker 3: do need to have it be liquid or fluid ability 97 00:05:26,279 --> 00:05:29,120 Speaker 3: to move around. But the key thing is the motions 98 00:05:29,240 --> 00:05:32,200 Speaker 3: that can create magnetic fields through, like this dynamo action 99 00:05:32,240 --> 00:05:34,800 Speaker 3: that you talked about. Those motions have to be much 100 00:05:34,839 --> 00:05:38,680 Speaker 3: more complex than just spinning around. So it's not just 101 00:05:38,720 --> 00:05:40,640 Speaker 3: that the Earth is spinning and that's causing it. It's 102 00:05:40,680 --> 00:05:44,719 Speaker 3: actually these like helical type flows that occur because of 103 00:05:44,760 --> 00:05:47,559 Speaker 3: the fact that the Earth is trying to cool down, 104 00:05:47,880 --> 00:05:50,600 Speaker 3: so space is cold. The inside of Earth is hot. 105 00:05:51,040 --> 00:05:53,640 Speaker 3: And so just like if you put a pot of 106 00:05:53,680 --> 00:05:56,279 Speaker 3: soup on the stove, the bottom of the pot is hot, 107 00:05:56,520 --> 00:05:58,200 Speaker 3: the top of the pot is cold. You get that 108 00:05:58,240 --> 00:06:01,680 Speaker 3: boiling action that rolling around. Same thing in the core 109 00:06:01,720 --> 00:06:04,440 Speaker 3: of the Earth, you get these churning motions as the 110 00:06:04,480 --> 00:06:06,960 Speaker 3: hot material at the center of the Earth tries to 111 00:06:07,000 --> 00:06:10,279 Speaker 3: make it up and out to cool down the core 112 00:06:10,440 --> 00:06:12,960 Speaker 3: and then the planet. So it's convection, that's what we 113 00:06:13,000 --> 00:06:16,960 Speaker 3: call it. It's convection. That's the motion that's actually creating 114 00:06:17,240 --> 00:06:18,760 Speaker 3: the magnetic field that Earth has. 115 00:06:19,320 --> 00:06:23,560 Speaker 2: So it's this magnetic dynamo that creates the field that 116 00:06:23,720 --> 00:06:26,480 Speaker 2: can in some ways permit and sustain life on Earth. 117 00:06:27,000 --> 00:06:29,800 Speaker 2: To what extent is Earth unique in this regard? What 118 00:06:29,880 --> 00:06:33,480 Speaker 2: do we know about the presence of a possible dynamo 119 00:06:33,640 --> 00:06:36,200 Speaker 2: in other planets or objects in our Solar system? 120 00:06:36,520 --> 00:06:39,520 Speaker 3: Yeah, great question. So lots of the other planets actually 121 00:06:39,520 --> 00:06:43,640 Speaker 3: do have magnetic field. So all the giant planets, Jupiter, Saturn, Uranus, 122 00:06:43,640 --> 00:06:46,560 Speaker 3: and Neptune, they all have these global magnetic fields generated 123 00:06:46,600 --> 00:06:49,839 Speaker 3: by a dynamo deep inside just like Earth. The smallest 124 00:06:49,839 --> 00:06:52,680 Speaker 3: of the planet's mercury also has a dynamo, and this 125 00:06:52,760 --> 00:06:55,920 Speaker 3: was actually quite a surprise when it was discovered. Now, 126 00:06:56,200 --> 00:06:58,919 Speaker 3: for Mars, it doesn't have a dynamo today, so it 127 00:06:58,920 --> 00:07:01,400 Speaker 3: doesn't have this global MAGNETELD, but it did have one 128 00:07:01,440 --> 00:07:04,800 Speaker 3: in the past. So about four billion years ago, the 129 00:07:04,920 --> 00:07:08,680 Speaker 3: rocks on the surface of Mars were magnetized from a 130 00:07:08,760 --> 00:07:12,320 Speaker 3: dynamo that was active at that time. And then there's Venus. 131 00:07:12,400 --> 00:07:15,360 Speaker 3: For Venus, we have no way to tell if it 132 00:07:15,360 --> 00:07:16,920 Speaker 3: ever had a dynamo in the past. It does not 133 00:07:17,040 --> 00:07:17,960 Speaker 3: have one today. 134 00:07:18,480 --> 00:07:20,280 Speaker 2: You bring up Venus, and there's a funny thing you 135 00:07:20,320 --> 00:07:22,480 Speaker 2: mentioned toward the end of the book, which is the 136 00:07:22,480 --> 00:07:27,120 Speaker 2: frustrations that Venus presents planetary scientists, especially the ones who 137 00:07:27,160 --> 00:07:30,040 Speaker 2: want to study the interior of the planet. Why is 138 00:07:30,120 --> 00:07:32,560 Speaker 2: Venus so frustrating? Why is it so hard to study? 139 00:07:33,040 --> 00:07:35,160 Speaker 3: Yeah, Venus is the worst planet in the Solar System. 140 00:07:35,200 --> 00:07:37,200 Speaker 3: I'm just going to put that out there right now. 141 00:07:38,480 --> 00:07:41,280 Speaker 3: Here's the issue, right, it's really hard to study the 142 00:07:41,320 --> 00:07:43,120 Speaker 3: insides of planets. You don't have access to it. You 143 00:07:43,160 --> 00:07:46,000 Speaker 3: can't drill down and study the core of a planet 144 00:07:46,080 --> 00:07:48,480 Speaker 3: that way, so you have to develop all these really 145 00:07:49,040 --> 00:07:51,320 Speaker 3: clever methods to try and figure out what's going on 146 00:07:51,360 --> 00:07:53,120 Speaker 3: deep inside the Earth. A lot of methods that are 147 00:07:53,200 --> 00:07:55,440 Speaker 3: kind of like what doctors use to figure out what's 148 00:07:55,480 --> 00:07:57,960 Speaker 3: going on inside the human body. Right, We do scans 149 00:07:57,960 --> 00:08:00,480 Speaker 3: of things, we use gravity, we use magnetic fields, we 150 00:08:00,560 --> 00:08:03,200 Speaker 3: use seismology. So then you try and use any of 151 00:08:03,200 --> 00:08:05,960 Speaker 3: these techniques on Venus, and they don't work for a 152 00:08:06,000 --> 00:08:08,200 Speaker 3: variety of different reasons. So first of all, let's say 153 00:08:08,520 --> 00:08:12,840 Speaker 3: we wanted to use seismology, right, So the waves that 154 00:08:12,960 --> 00:08:16,240 Speaker 3: pass through a planet when you have an earthquake, for example, 155 00:08:16,280 --> 00:08:20,400 Speaker 3: on Earth, the speed of those waves is completely determined 156 00:08:20,600 --> 00:08:22,800 Speaker 3: by the material properties they are passing through. So we 157 00:08:22,840 --> 00:08:25,920 Speaker 3: actually learn a lot about what the materials are inside 158 00:08:25,920 --> 00:08:28,280 Speaker 3: the Earth by looking at how fast these seismic waves 159 00:08:28,280 --> 00:08:31,280 Speaker 3: travel through it. You want to do this on Venus, Sorry, 160 00:08:31,320 --> 00:08:34,360 Speaker 3: the surface is a horrible temperature, and the atmosphere is 161 00:08:34,400 --> 00:08:36,520 Speaker 3: made of sulphuric acid, and the pressure is ninety two 162 00:08:37,040 --> 00:08:40,480 Speaker 3: atmospheric pressures, so it's just the materials are just going 163 00:08:40,559 --> 00:08:43,079 Speaker 3: to melt and dissolve basically, so no chance to do that. 164 00:08:43,440 --> 00:08:45,640 Speaker 3: Then you try and use a magnetic field, right, Having 165 00:08:45,640 --> 00:08:48,040 Speaker 3: a magnetic field is a great way to learn about 166 00:08:48,040 --> 00:08:49,840 Speaker 3: the interior of a planet. As soon as you know 167 00:08:49,840 --> 00:08:51,880 Speaker 3: a planet has a global magnetic field, you know, it's 168 00:08:51,880 --> 00:08:56,280 Speaker 3: got a liquid molten electrical conductor in its interior, and 169 00:08:56,320 --> 00:08:58,440 Speaker 3: it's got those churning motions. Well, Venus doesn't have that, 170 00:08:58,480 --> 00:09:01,400 Speaker 3: so we can't use that. And you try and say, okay, well, 171 00:09:01,400 --> 00:09:03,560 Speaker 3: why don't we just observe the surface and look at 172 00:09:03,559 --> 00:09:06,000 Speaker 3: the rotation of the surface, for example, while Venus has 173 00:09:06,040 --> 00:09:08,880 Speaker 3: this horribly opaque atmosphere that you can't actually look through 174 00:09:09,160 --> 00:09:11,760 Speaker 3: and try to do that. And then one of my 175 00:09:11,800 --> 00:09:14,160 Speaker 3: favorite things about Venus is that when you look at 176 00:09:14,200 --> 00:09:16,040 Speaker 3: all the planets, all the planets, you know we talk 177 00:09:16,080 --> 00:09:18,560 Speaker 3: about planets being spheres, they're not spheres. They're actually kind 178 00:09:18,600 --> 00:09:21,640 Speaker 3: of bulgy oblate spheroids, we call them. So they're fatter 179 00:09:21,760 --> 00:09:24,640 Speaker 3: across the equator than they are at the poles, and 180 00:09:24,640 --> 00:09:27,600 Speaker 3: that bulging of the equator is because of the fact 181 00:09:27,600 --> 00:09:32,000 Speaker 3: that the planet's spin. Now we can use that information 182 00:09:32,160 --> 00:09:35,880 Speaker 3: how bulgey a planet is to actually tell what material 183 00:09:35,960 --> 00:09:38,720 Speaker 3: is inside it, how dense it is inside it. And 184 00:09:38,760 --> 00:09:40,120 Speaker 3: you go and try and do this at Venus, and 185 00:09:40,200 --> 00:09:43,600 Speaker 3: Venus is rotating so slowly that it basically has no bulge. 186 00:09:43,640 --> 00:09:46,120 Speaker 3: So we can't use that either. Basically, Venus is just 187 00:09:46,240 --> 00:09:49,000 Speaker 3: very frustrating doesn't want us to know anything about its interior. 188 00:09:51,280 --> 00:09:54,880 Speaker 2: So there's a great section in the chapter Gazing Outward 189 00:09:54,960 --> 00:09:57,880 Speaker 2: where in this chapter you're talking about the formation of 190 00:09:58,280 --> 00:10:01,960 Speaker 2: our Solar System from the orig original molecular cloud that 191 00:10:02,040 --> 00:10:03,880 Speaker 2: came together to make the Sun and the planets the 192 00:10:03,880 --> 00:10:10,559 Speaker 2: protoplanetary disc. And you talk about how the interesting ways 193 00:10:10,600 --> 00:10:14,640 Speaker 2: the connections between the features of that initial cloud and 194 00:10:14,880 --> 00:10:18,400 Speaker 2: features of the current Solar System and even everyday life 195 00:10:18,440 --> 00:10:21,320 Speaker 2: on Earth. So, for example, the elemental composition of that 196 00:10:21,440 --> 00:10:24,360 Speaker 2: vast cloud determines the elements that make our Solar System, 197 00:10:24,640 --> 00:10:27,760 Speaker 2: but also more interesting and subtle things like how the 198 00:10:27,800 --> 00:10:31,960 Speaker 2: slight initial rotation of that cloud governs so much about 199 00:10:32,000 --> 00:10:34,280 Speaker 2: our world. Could you talk about some of these connections 200 00:10:34,280 --> 00:10:37,120 Speaker 2: between the properties of the cloud and the way the 201 00:10:37,120 --> 00:10:38,319 Speaker 2: Solar System is now? 202 00:10:39,040 --> 00:10:43,960 Speaker 3: Yeah? Absolutely, So. I remember once sitting there and just thinking, 203 00:10:44,280 --> 00:10:47,000 Speaker 3: you know, okay, yeah, we know that the planet's orbit 204 00:10:47,320 --> 00:10:50,720 Speaker 3: around the Sun, we know that the planets are spinning. 205 00:10:50,760 --> 00:10:53,760 Speaker 3: Why is everything spinning all right? Why don't doesn't anything 206 00:10:53,840 --> 00:10:56,280 Speaker 3: just stay still? And the answer has to do with 207 00:10:56,320 --> 00:11:00,439 Speaker 3: this great concept in physics called angular momentum conservation. So basically, 208 00:11:00,480 --> 00:11:02,920 Speaker 3: you can't just change the spin of something without putting 209 00:11:02,960 --> 00:11:05,520 Speaker 3: a lot of torque on it, like forcing it. Right. 210 00:11:05,880 --> 00:11:07,680 Speaker 3: And so then you put something out in the middle 211 00:11:08,000 --> 00:11:11,280 Speaker 3: of nowhere, a molecular cloud, right, and you don't have 212 00:11:11,360 --> 00:11:14,000 Speaker 3: anything really torquing it or anything, and you ask, well, 213 00:11:14,000 --> 00:11:15,679 Speaker 3: how much spin is it going to have? And it's 214 00:11:15,720 --> 00:11:18,880 Speaker 3: going to have some random amount, right, like nothing's perfectly 215 00:11:18,960 --> 00:11:21,720 Speaker 3: isolated and still, so you take all those particles in 216 00:11:21,720 --> 00:11:24,320 Speaker 3: the molecular cloud and you add up all their spins, 217 00:11:24,360 --> 00:11:25,800 Speaker 3: and a lot of them will cancel out. Someone will 218 00:11:25,840 --> 00:11:28,199 Speaker 3: be spinning in one direction, other particles will be spinning 219 00:11:28,200 --> 00:11:30,720 Speaker 3: in the other direction. And you add it all up 220 00:11:30,760 --> 00:11:33,400 Speaker 3: and it almost all cancels out except for a little bit. 221 00:11:34,160 --> 00:11:36,920 Speaker 3: And that little bit in a molecular cloud. Here's the 222 00:11:36,960 --> 00:11:40,520 Speaker 3: amazing thing. Once gravity gets hold of that molecular cloud, 223 00:11:40,600 --> 00:11:44,520 Speaker 3: it starts gravitationally collapsing to eventually form our solar system. 224 00:11:44,880 --> 00:11:48,119 Speaker 3: That amount of spinning just increases and increases and increases 225 00:11:48,240 --> 00:11:50,640 Speaker 3: as the cloud gets smaller and smaller and smaller. And 226 00:11:50,720 --> 00:11:54,920 Speaker 3: you have a total understanding. People have a total understanding 227 00:11:54,920 --> 00:11:57,480 Speaker 3: of this effect. If you've ever watched, for example, figure 228 00:11:57,480 --> 00:12:00,320 Speaker 3: skaters who are about to do a jump with a 229 00:12:00,320 --> 00:12:02,240 Speaker 3: spin it and they pull their arms in. As soon 230 00:12:02,240 --> 00:12:05,280 Speaker 3: as you make something more compact, it spins faster, even 231 00:12:05,320 --> 00:12:07,320 Speaker 3: though you don't do anything to it. And the same 232 00:12:07,320 --> 00:12:10,320 Speaker 3: thing happened to the molecular cloud. As it became smaller 233 00:12:10,360 --> 00:12:12,640 Speaker 3: and smaller and smaller, it spin faster and faster and faster. 234 00:12:12,679 --> 00:12:15,280 Speaker 3: And that's what led to all the spinning we have 235 00:12:15,800 --> 00:12:18,120 Speaker 3: in the Solar System now. And this is true not 236 00:12:18,200 --> 00:12:20,320 Speaker 3: just of our Solar System. We can look out and 237 00:12:20,360 --> 00:12:23,400 Speaker 3: see other Solar systems forming. We can see other planets 238 00:12:23,440 --> 00:12:26,240 Speaker 3: around other stars. They're all spinning too. It's all the 239 00:12:26,440 --> 00:12:29,080 Speaker 3: kind of we share that among all the planets. 240 00:12:29,520 --> 00:12:33,880 Speaker 2: We call the roughly spherical objects that orbit stars planets, 241 00:12:33,920 --> 00:12:37,120 Speaker 2: and we call the objects that orbit planets moons. But 242 00:12:37,520 --> 00:12:41,480 Speaker 2: are there any other material differences between a planet and 243 00:12:41,520 --> 00:12:43,360 Speaker 2: the moon? Are there even any trends? 244 00:12:44,400 --> 00:12:47,680 Speaker 3: Yeah, it's a great question. So moons can be complicated. 245 00:12:47,720 --> 00:12:50,040 Speaker 3: So in reality, if you're someone like me who's interested 246 00:12:50,080 --> 00:12:53,079 Speaker 3: in the interior of planets, you're just as happy to 247 00:12:53,120 --> 00:12:56,240 Speaker 3: consider moon's planets. Right, Moons for their they're made of 248 00:12:56,360 --> 00:12:59,160 Speaker 3: similar stuff. They have the same laws of physics that 249 00:12:59,200 --> 00:13:02,800 Speaker 3: govern their interior. We have moons that have magnetic fields. Ganymede, 250 00:13:02,800 --> 00:13:04,840 Speaker 3: which is a moon of Jupiter, actually has a magnetic 251 00:13:04,880 --> 00:13:07,640 Speaker 3: field generated in its core. So we study the same 252 00:13:07,679 --> 00:13:12,120 Speaker 3: processes on these bodies. Where moons can be a little 253 00:13:12,120 --> 00:13:16,720 Speaker 3: bit different than planets, there's a lot bigger possibility of 254 00:13:16,760 --> 00:13:19,040 Speaker 3: where they came from compared to where they ended up. 255 00:13:19,320 --> 00:13:24,240 Speaker 3: So for example, the rocky planets in the Inner Solar System, Mercury, Venus, Earth, Mars, 256 00:13:24,640 --> 00:13:27,800 Speaker 3: they all pretty much formed close to where they are now. 257 00:13:28,480 --> 00:13:31,800 Speaker 3: Some moons actually come from very far away and then 258 00:13:31,840 --> 00:13:34,120 Speaker 3: get trapped in the gravitational field of a planet and 259 00:13:34,160 --> 00:13:36,160 Speaker 3: then become a moon there. And that happens a lot, 260 00:13:36,160 --> 00:13:38,600 Speaker 3: for example in the Outer Solar System. So if you 261 00:13:38,679 --> 00:13:41,480 Speaker 3: look at Jupiter or Neptune or any of these planets, 262 00:13:41,480 --> 00:13:43,600 Speaker 3: some of their moons are on these really weird orbits. 263 00:13:43,640 --> 00:13:46,600 Speaker 3: They're like orbiting in the opposite direction as the planet 264 00:13:46,679 --> 00:13:49,480 Speaker 3: is spinning. They're not around the equator at all. And 265 00:13:49,559 --> 00:13:52,800 Speaker 3: those moons we think are actually captured basically comets. They're 266 00:13:53,080 --> 00:13:56,320 Speaker 3: captured comets or asteroids that were doing their own thing 267 00:13:56,679 --> 00:13:59,640 Speaker 3: got gravitationally kicked into the Solar System a little bit 268 00:13:59,679 --> 00:14:02,600 Speaker 3: close in and then got trapped around a planet. So 269 00:14:02,640 --> 00:14:06,000 Speaker 3: you can actually find some bodies orbiting these planets that 270 00:14:06,000 --> 00:14:08,800 Speaker 3: were probably formed much further away, and so in that sense, 271 00:14:08,840 --> 00:14:20,960 Speaker 3: that's a little bit different than what you see with planets. 272 00:14:21,320 --> 00:14:24,520 Speaker 2: One of the most shocking facts that you discussed in 273 00:14:24,560 --> 00:14:28,880 Speaker 2: the book concerns the formation of the Earth's moon. Now, 274 00:14:29,000 --> 00:14:31,600 Speaker 2: I know the leading theory on the formation of the 275 00:14:31,600 --> 00:14:37,240 Speaker 2: Earth's moon is the giant impact idea, but specifically, the 276 00:14:37,320 --> 00:14:41,040 Speaker 2: thing that you introduced to me was how rapidly the 277 00:14:41,080 --> 00:14:44,640 Speaker 2: Earth's moon was probably formed according to the leading theory 278 00:14:44,640 --> 00:14:46,320 Speaker 2: of its origin. Could you explain this. 279 00:14:46,640 --> 00:14:50,120 Speaker 3: Yeah, this blows my mind. By the way, so we're 280 00:14:50,280 --> 00:14:52,400 Speaker 3: somewhat I think people have heard of this theory that 281 00:14:52,520 --> 00:14:57,480 Speaker 3: something about the size of Mars, usually called they crashed 282 00:14:57,520 --> 00:15:00,120 Speaker 3: into Earth, had this kind of glancing impact into pro 283 00:15:00,160 --> 00:15:02,480 Speaker 3: to Earth Earth. This was like four point five billion 284 00:15:02,560 --> 00:15:07,200 Speaker 3: years ago, and that crash caused some of that body 285 00:15:07,240 --> 00:15:10,720 Speaker 3: and some of the Earth to get kind of blasted 286 00:15:10,720 --> 00:15:14,160 Speaker 3: off the surface of the planet and small chunks were 287 00:15:14,160 --> 00:15:16,240 Speaker 3: put into orbit. And then you ask the question, Okay, 288 00:15:16,320 --> 00:15:19,040 Speaker 3: so now you have this disk of material surrounding the Earth. 289 00:15:19,400 --> 00:15:21,360 Speaker 3: How long did it take for that disk of material 290 00:15:21,440 --> 00:15:24,680 Speaker 3: to become the Moon a single object? Now, that disk 291 00:15:24,720 --> 00:15:27,000 Speaker 3: of material followed the same laws of physics as the 292 00:15:27,040 --> 00:15:31,000 Speaker 3: planet's forming out of the disc. Initially on gravity caused collisions. 293 00:15:31,000 --> 00:15:33,720 Speaker 3: Some of those collisions caused things to clump together. Eventually, 294 00:15:33,880 --> 00:15:36,440 Speaker 3: the Moon grew and grew and grew, and estimates suggest 295 00:15:36,480 --> 00:15:39,280 Speaker 3: it took forty years for this to happen. Now, when 296 00:15:39,280 --> 00:15:42,520 Speaker 3: you're talking about things in astronomy and in Earth science, 297 00:15:43,000 --> 00:15:45,960 Speaker 3: you're working on millions of years, billions of years. Those 298 00:15:45,960 --> 00:15:48,360 Speaker 3: are the types of lengths of time we're used to. 299 00:15:48,800 --> 00:15:51,520 Speaker 3: So talking about a process that takes forty years is 300 00:15:51,600 --> 00:15:54,120 Speaker 3: just shocking. And so I always have this image in 301 00:15:54,120 --> 00:15:56,560 Speaker 3: my head, and this is obviously impossible because it was 302 00:15:56,560 --> 00:15:58,240 Speaker 3: four point five billion years ago, But I have this 303 00:15:58,280 --> 00:16:01,440 Speaker 3: image in my head of like some parents sitting down 304 00:16:01,480 --> 00:16:04,240 Speaker 3: with their kids and the parents going, you know, when 305 00:16:04,280 --> 00:16:06,320 Speaker 3: I was your age, there was no moon in the 306 00:16:06,360 --> 00:16:08,840 Speaker 3: sky kind of thing, right like that. It's on a 307 00:16:09,080 --> 00:16:12,480 Speaker 3: human generational timescale that this changed. 308 00:16:13,040 --> 00:16:16,400 Speaker 2: That's truly unbelievable. And you actually mentioned several other things 309 00:16:16,440 --> 00:16:19,200 Speaker 2: about the Moon that I didn't quite know about and 310 00:16:19,280 --> 00:16:22,480 Speaker 2: were so interesting one is that it's a parent magnitude 311 00:16:22,560 --> 00:16:25,960 Speaker 2: from the Earth was larger initially, I guess because it 312 00:16:26,000 --> 00:16:28,640 Speaker 2: was closer. But you also mentioned something called a fossil 313 00:16:28,920 --> 00:16:31,520 Speaker 2: bulge in the moon. Could you explain these? 314 00:16:31,920 --> 00:16:34,280 Speaker 3: So when the Moon formed, it was much closer to 315 00:16:34,320 --> 00:16:38,160 Speaker 3: the Earth, and since then it's been slowly receding away 316 00:16:38,200 --> 00:16:41,440 Speaker 3: from the Earth. And we can even measure this change 317 00:16:41,480 --> 00:16:43,840 Speaker 3: in distance of the Moon to the Earth. And that's 318 00:16:43,880 --> 00:16:47,680 Speaker 3: happening because of really interesting gravitational interaction between the Moon 319 00:16:48,200 --> 00:16:50,520 Speaker 3: and the Earth. And it's the same reason, for example, 320 00:16:50,560 --> 00:16:54,440 Speaker 3: that the Moon only shows us one face, so tidal interactions, 321 00:16:54,480 --> 00:16:57,440 Speaker 3: the fact that you know, the Earth's not a perfect sphere, 322 00:16:57,480 --> 00:16:59,360 Speaker 3: the Moon's not a perfect sphere, and they tug on 323 00:16:59,400 --> 00:17:02,000 Speaker 3: each other when are not kind of facing the right way. 324 00:17:02,760 --> 00:17:07,000 Speaker 3: That has caused the Moon to start moving further away. 325 00:17:07,040 --> 00:17:09,520 Speaker 3: It's also caused the Earth to start slowing down its 326 00:17:09,640 --> 00:17:12,480 Speaker 3: rotation a little bit, and so over time, the Moon's 327 00:17:12,560 --> 00:17:14,320 Speaker 3: moving further away and it's going to make it smaller 328 00:17:14,359 --> 00:17:17,040 Speaker 3: and smaller and smaller. And one reason we know all 329 00:17:17,080 --> 00:17:22,040 Speaker 3: of this is that the moon, if you look at 330 00:17:22,040 --> 00:17:24,080 Speaker 3: how bulgy it is, Like I talked about how spinning 331 00:17:24,119 --> 00:17:27,440 Speaker 3: objects have this bulge on them. The Moon is too 332 00:17:27,520 --> 00:17:30,399 Speaker 3: bulgy for how fast it's spinning right now, and the 333 00:17:30,440 --> 00:17:32,239 Speaker 3: only way to explain that is it must have been 334 00:17:32,280 --> 00:17:35,119 Speaker 3: spinning faster in the past. And the only way for 335 00:17:35,200 --> 00:17:37,159 Speaker 3: it to have been spinning faster in the past is 336 00:17:37,160 --> 00:17:39,439 Speaker 3: if it was much closer to the Earth, because we 337 00:17:39,560 --> 00:17:42,080 Speaker 3: know it's locked. It's day is locked to the Earth's 338 00:17:42,680 --> 00:17:45,200 Speaker 3: you know, it's always facing the Earth the same side, 339 00:17:45,359 --> 00:17:49,000 Speaker 3: so it had to have a much faster spin in 340 00:17:49,080 --> 00:17:50,920 Speaker 3: order to get that bulge that it had. 341 00:17:51,359 --> 00:17:55,639 Speaker 2: With exoplanets, we often hear about the habitable zone of 342 00:17:55,680 --> 00:17:58,600 Speaker 2: a star, the area of the distance out from a 343 00:17:58,640 --> 00:18:01,880 Speaker 2: star that we believe there could be the conditions possible 344 00:18:01,920 --> 00:18:05,440 Speaker 2: for life to arise. But an interesting fact you mentioned 345 00:18:05,600 --> 00:18:09,040 Speaker 2: is that if a faraway exoplanet astronomer we're looking at 346 00:18:09,119 --> 00:18:12,639 Speaker 2: our Solar system, they would see not one but three 347 00:18:12,840 --> 00:18:16,760 Speaker 2: planets within our habitable zone, Earth, Venus, and Mars. But 348 00:18:17,080 --> 00:18:19,080 Speaker 2: neither of the other two planets, Mars or Venus are 349 00:18:19,240 --> 00:18:23,520 Speaker 2: especially hospitable now, and Venus is really inhospitable. So what 350 00:18:23,760 --> 00:18:27,760 Speaker 2: does that tell us about looking for exoplanets that could 351 00:18:27,800 --> 00:18:29,440 Speaker 2: sustain life elsewhere? 352 00:18:29,880 --> 00:18:31,520 Speaker 3: I think it tells us that we have to be 353 00:18:32,560 --> 00:18:36,200 Speaker 3: a little more subtle in how we figure out whether 354 00:18:36,400 --> 00:18:38,800 Speaker 3: a planet is a good candidate for some of that 355 00:18:38,880 --> 00:18:42,520 Speaker 3: might have life or not. Right, totally, get why we 356 00:18:42,560 --> 00:18:45,240 Speaker 3: are using these criteria right now. Right, what's the distance 357 00:18:45,280 --> 00:18:49,119 Speaker 3: from a planet star at which the temperatures are just 358 00:18:49,200 --> 00:18:51,360 Speaker 3: right so that water could be liquid on the surface 359 00:18:51,400 --> 00:18:53,520 Speaker 3: if there was water there. That's kind of the condition 360 00:18:53,560 --> 00:18:58,200 Speaker 3: we're using now. But as mentioned, planets are complicated, and 361 00:18:58,440 --> 00:19:01,239 Speaker 3: you could have a planet that comple letly changes its 362 00:19:01,280 --> 00:19:04,520 Speaker 3: surface temperature through a greenhouse, a runaway greenhouse effect. That's 363 00:19:04,560 --> 00:19:07,560 Speaker 3: what happened on Venus. Right, Venus is getting not that 364 00:19:07,680 --> 00:19:10,520 Speaker 3: much more heat from the Sun as we are, but 365 00:19:10,760 --> 00:19:13,600 Speaker 3: it happened to go through this climate process, this runaway 366 00:19:13,600 --> 00:19:16,040 Speaker 3: greenhouse that made the temperture on the surface incredibly hot 367 00:19:16,080 --> 00:19:19,199 Speaker 3: and not able to sustain any water. The water all 368 00:19:19,240 --> 00:19:22,159 Speaker 3: evaporated off of Venus. So we have to be a 369 00:19:22,200 --> 00:19:24,639 Speaker 3: little bit more careful. We need to understand the dynamics 370 00:19:24,640 --> 00:19:27,640 Speaker 3: of what's going on inside the bodies and outside, because 371 00:19:27,640 --> 00:19:30,960 Speaker 3: that's what creates the atmospheres. Another great example of this, 372 00:19:31,040 --> 00:19:33,240 Speaker 3: I think we also need to kind of broaden the 373 00:19:33,320 --> 00:19:36,960 Speaker 3: search for habitable worlds, let's say, because if you look 374 00:19:37,000 --> 00:19:39,600 Speaker 3: in our Solar system, aside from Earth, the next best 375 00:19:39,640 --> 00:19:42,760 Speaker 3: place to possibly look for where life might form are 376 00:19:42,800 --> 00:19:45,920 Speaker 3: actually in the water oceans of some of the moons 377 00:19:45,920 --> 00:19:48,680 Speaker 3: in the outer Solar System. Now, these oceans are buried 378 00:19:48,960 --> 00:19:52,480 Speaker 3: like miles beneath the surface, but they're liquid water, they 379 00:19:52,480 --> 00:19:57,520 Speaker 3: have energy sources, they have complex carbon molecules, all the 380 00:19:57,600 --> 00:19:59,879 Speaker 3: kind of ingredients that we think might be important for life. 381 00:20:00,040 --> 00:20:03,280 Speaker 3: So I think we need to think more carefully about 382 00:20:03,280 --> 00:20:06,480 Speaker 3: what the conditions are for life on exoplanets out there, 383 00:20:07,440 --> 00:20:10,119 Speaker 3: and we might end up finding life in places we 384 00:20:10,160 --> 00:20:10,920 Speaker 3: didn't expect. 385 00:20:11,720 --> 00:20:15,240 Speaker 2: So when trying to understand what's inside planets, we've talked 386 00:20:15,240 --> 00:20:20,280 Speaker 2: about using detection methods for like magnetic fields and seismic 387 00:20:20,320 --> 00:20:23,720 Speaker 2: research and things like that. But what can isolated pieces 388 00:20:23,760 --> 00:20:28,160 Speaker 2: of physical evidence like meteorites and diamonds tell us about 389 00:20:28,240 --> 00:20:30,440 Speaker 2: how planets are formed and what's inside them. 390 00:20:30,920 --> 00:20:32,920 Speaker 3: Yeah, this is one of my favorite things in the world. 391 00:20:32,960 --> 00:20:35,320 Speaker 3: So I'm going to start with the diamonds thing. We 392 00:20:35,440 --> 00:20:37,760 Speaker 3: really would like to actually have samples from deep inside 393 00:20:37,760 --> 00:20:39,199 Speaker 3: the Earth, because that would be the best way to 394 00:20:39,200 --> 00:20:42,439 Speaker 3: study it. It's impossible to do this, we can't drill 395 00:20:42,600 --> 00:20:45,199 Speaker 3: deeper than about eight miles or something like that, right, 396 00:20:45,280 --> 00:20:49,080 Speaker 3: and the earth goes down about almost three thousand miles, right, 397 00:20:49,160 --> 00:20:52,960 Speaker 3: So this is just not possible, luckily for us. Sometimes 398 00:20:52,960 --> 00:20:55,400 Speaker 3: the Earth brings samples from the deep up to the surface, 399 00:20:55,520 --> 00:20:57,720 Speaker 3: and one thing it does is it brings up diamonds. 400 00:20:57,920 --> 00:21:00,639 Speaker 3: Lots of people know about diamonds because they're important in 401 00:21:00,840 --> 00:21:03,719 Speaker 3: say the jewelry industry, things like that, And when you're 402 00:21:03,760 --> 00:21:05,840 Speaker 3: someone who's a jeweler, what you really care about are 403 00:21:05,880 --> 00:21:08,520 Speaker 3: these pure diamonds, the things that are just pure carbon 404 00:21:08,560 --> 00:21:11,600 Speaker 3: and diamond form. When you're a geologist or someone who's 405 00:21:11,600 --> 00:21:13,560 Speaker 3: studying the in tier of the earth, you want the 406 00:21:13,680 --> 00:21:17,600 Speaker 3: impure diamonds. You want the diamonds where some little bit 407 00:21:17,640 --> 00:21:19,159 Speaker 3: of the interior of the Earth got stuck in the 408 00:21:19,160 --> 00:21:21,399 Speaker 3: middle of the diamond as it was forming. And because 409 00:21:21,400 --> 00:21:25,000 Speaker 3: diamonds are so hard, they actually maintain their pressure, and 410 00:21:25,040 --> 00:21:27,639 Speaker 3: so when they come up to the surface, that little 411 00:21:27,680 --> 00:21:30,240 Speaker 3: bit of material from deep inside the Earth actually stays 412 00:21:30,280 --> 00:21:33,520 Speaker 3: preserved in the inside of that diamond. And so we 413 00:21:33,520 --> 00:21:36,160 Speaker 3: can actually study materials how they are in the deep 414 00:21:36,160 --> 00:21:38,800 Speaker 3: interior of the Earth by looking at these inclusions in 415 00:21:38,840 --> 00:21:41,080 Speaker 3: the diamonds when they come to the surface. So that's 416 00:21:41,080 --> 00:21:45,400 Speaker 3: one thing. Now, meteorites are like the best Christmas gift 417 00:21:45,440 --> 00:21:48,919 Speaker 3: anyone could ever get from other planets. Right. Basically, you 418 00:21:49,040 --> 00:21:51,960 Speaker 3: have some sort of collision or something that happened far 419 00:21:52,040 --> 00:21:54,479 Speaker 3: away that caused a piece of a planet or an 420 00:21:54,520 --> 00:21:57,080 Speaker 3: asteroid to get knocked off. Eventually that piece of the 421 00:21:57,080 --> 00:22:00,120 Speaker 3: asteroid came near Earth and some of it landed on 422 00:22:00,119 --> 00:22:04,560 Speaker 3: Earth and we can go and collect it. That's rarely 423 00:22:04,560 --> 00:22:07,240 Speaker 3: where you have samples of the insides of other planets, 424 00:22:07,240 --> 00:22:10,080 Speaker 3: and we even have meteorites that are very iron rich 425 00:22:10,160 --> 00:22:14,800 Speaker 3: that come from the cores of previous planetary asteroid like 426 00:22:14,880 --> 00:22:18,280 Speaker 3: bodies that got broken up. So one of the best 427 00:22:18,280 --> 00:22:20,800 Speaker 3: pieces of evidence we have for what's in our core 428 00:22:21,040 --> 00:22:23,120 Speaker 3: is actually looking at the cores of other bodies. They're 429 00:22:23,119 --> 00:22:27,000 Speaker 3: all very similar. They all have this iron rich cores 430 00:22:27,040 --> 00:22:29,480 Speaker 3: that eventually come to Earth and we get to study them. 431 00:22:30,080 --> 00:22:32,960 Speaker 2: This reminds me there's an object that you mentioned several 432 00:22:33,000 --> 00:22:35,120 Speaker 2: times in the book that I feel like I can 433 00:22:35,160 --> 00:22:38,760 Speaker 2: tell you are especially excited about, and it is the 434 00:22:39,440 --> 00:22:43,960 Speaker 2: asteroid sixteen Psyche. What makes Psyche so exciting? 435 00:22:44,400 --> 00:22:46,399 Speaker 3: So, first of all, there is a mission on its 436 00:22:46,440 --> 00:22:48,199 Speaker 3: way to Psyche right now, So we are going to 437 00:22:48,200 --> 00:22:50,600 Speaker 3: study this asteroid up close and personal, and I'm very 438 00:22:50,640 --> 00:22:53,239 Speaker 3: excited about that. I think in our Solar System, we're 439 00:22:53,320 --> 00:22:55,320 Speaker 3: used to different kinds of worlds. Right You've got the 440 00:22:55,400 --> 00:22:58,320 Speaker 3: rocky worlds of the inner planets in the Solar System, 441 00:22:58,520 --> 00:23:00,719 Speaker 3: You've got the gas giants like that Are and Saturn. 442 00:23:00,880 --> 00:23:03,320 Speaker 3: You've got the water worlds like you're in a a Neptune, 443 00:23:03,320 --> 00:23:05,160 Speaker 3: and even some of the moons we can consider water 444 00:23:05,200 --> 00:23:09,679 Speaker 3: World's Europa Enceladus moons like that. Sixteen. Psyche is a 445 00:23:09,720 --> 00:23:13,400 Speaker 3: metal world. So this is a body that is mostly 446 00:23:13,440 --> 00:23:16,920 Speaker 3: made of iron. It's mostly metal, and we just haven't 447 00:23:16,960 --> 00:23:20,400 Speaker 3: seen that before. And I'm really excited about what it's 448 00:23:20,440 --> 00:23:22,920 Speaker 3: going to be like to go look at this thing 449 00:23:23,040 --> 00:23:25,439 Speaker 3: and you know, answer questions like, hmm, what does a 450 00:23:25,440 --> 00:23:28,320 Speaker 3: crater look like on a body that's mostly made of metal? Is? 451 00:23:28,359 --> 00:23:30,320 Speaker 3: What does a volcano look like on this thing? Does 452 00:23:30,320 --> 00:23:32,919 Speaker 3: it have a magnetic field? What's really going on on 453 00:23:32,960 --> 00:23:35,600 Speaker 3: the surface. So it's very exciting. It's a new type 454 00:23:35,600 --> 00:23:38,280 Speaker 3: of planetary body that we've never gotten to see up 455 00:23:38,280 --> 00:23:39,080 Speaker 3: close and personal. 456 00:23:40,359 --> 00:23:43,120 Speaker 2: I think you mentioned the idea of a metal volcano. 457 00:23:44,440 --> 00:23:47,040 Speaker 2: That's a real thing. What does that mean? 458 00:23:47,480 --> 00:23:49,720 Speaker 3: We're going to find out, But imagine this is you know, 459 00:23:49,800 --> 00:23:52,880 Speaker 3: this is an asteroid that's big enough that it could 460 00:23:52,880 --> 00:23:54,919 Speaker 3: have stuff going on in the interior. You could have 461 00:23:55,240 --> 00:23:58,200 Speaker 3: some of them iron from the interior being liquid and 462 00:23:58,600 --> 00:24:02,480 Speaker 3: getting kind of taken up out of the interior onto 463 00:24:02,520 --> 00:24:05,960 Speaker 3: the surface at these volcanic vents. So, yeah, we might 464 00:24:06,080 --> 00:24:08,399 Speaker 3: get to see a metal volcano up close. 465 00:24:09,560 --> 00:24:12,800 Speaker 2: Coming back to looking inside planets, if you go beyond 466 00:24:12,880 --> 00:24:15,679 Speaker 2: Earth and even beyond the rocky planets, one of the 467 00:24:15,680 --> 00:24:20,240 Speaker 2: most fascinating questions to ponder is what's inside the gas 468 00:24:20,280 --> 00:24:24,800 Speaker 2: planets and the ice giants. I suspect you've seen the 469 00:24:24,840 --> 00:24:27,600 Speaker 2: many variations on the article or video. What is it 470 00:24:27,720 --> 00:24:30,720 Speaker 2: like to fall into Jupiter or something like that. It's 471 00:24:30,760 --> 00:24:34,040 Speaker 2: clearly a captivating question because we see these outer cloud 472 00:24:34,080 --> 00:24:37,760 Speaker 2: layers and there's just this you question, like, obviously, you 473 00:24:37,840 --> 00:24:40,639 Speaker 2: imagine you're denser than some outer part of that cloud 474 00:24:40,720 --> 00:24:42,879 Speaker 2: layer and you could sync down into it, and you've 475 00:24:42,920 --> 00:24:45,919 Speaker 2: got to wonder what's inside. So what do we know 476 00:24:45,960 --> 00:24:49,760 Speaker 2: about what is inside the gas giants and the ice giants? 477 00:24:50,160 --> 00:24:52,280 Speaker 3: Yeah, this is one of my favorite things to talk about. 478 00:24:52,400 --> 00:24:55,960 Speaker 3: So we are so accustomed to how materials behave in 479 00:24:56,000 --> 00:24:57,800 Speaker 3: the types of conditions we have here on the surface 480 00:24:57,840 --> 00:24:59,800 Speaker 3: of the Earth. If I just say the word water, 481 00:25:00,200 --> 00:25:02,639 Speaker 3: you have a natural instinctive reaction to what water is. 482 00:25:02,680 --> 00:25:04,960 Speaker 3: It's either that liquid in my glass, or maybe it's 483 00:25:04,960 --> 00:25:08,400 Speaker 3: frozen on some ice somewhere, or it's water vapor that's 484 00:25:08,400 --> 00:25:12,240 Speaker 3: causing fog. Right, you put water under the high pressures 485 00:25:12,280 --> 00:25:14,240 Speaker 3: and high temperatures that are deep inside planets, it's a 486 00:25:14,280 --> 00:25:17,159 Speaker 3: completely different beast. Same thing is true for hydrogen. So 487 00:25:17,240 --> 00:25:19,840 Speaker 3: let's start there. Hydrogen the most kind of the simplest 488 00:25:19,880 --> 00:25:22,560 Speaker 3: element we have, thing that we're used to being in 489 00:25:22,640 --> 00:25:26,119 Speaker 3: gaseous form. Now in Jupiter and in Saturn. As you 490 00:25:26,240 --> 00:25:29,959 Speaker 3: keep descending into the planet, temperatures are rising, you get 491 00:25:30,000 --> 00:25:32,720 Speaker 3: to millions of degrees, you can get to millions of 492 00:25:32,760 --> 00:25:36,440 Speaker 3: atmospheres of pressure. Hydrogen is a very different material under 493 00:25:36,440 --> 00:25:39,160 Speaker 3: that pressure, and in fact, is you squeeze a hydrogen molecule, 494 00:25:39,440 --> 00:25:42,159 Speaker 3: you basically allow So imagine hydrogen molecule. You got a 495 00:25:42,200 --> 00:25:44,440 Speaker 3: proton at the center and the nucleus, and you got 496 00:25:44,440 --> 00:25:47,359 Speaker 3: this electron floating around. You squeeze enough of those close 497 00:25:47,400 --> 00:25:51,040 Speaker 3: together the electrons essentially get freed from the protons and 498 00:25:51,040 --> 00:25:53,159 Speaker 3: you create what's called what we call a metal. So 499 00:25:53,200 --> 00:25:57,120 Speaker 3: you can actually have metallic hydrogen going on inside Jupiter 500 00:25:57,200 --> 00:26:00,560 Speaker 3: and Saturn, and it's a great electrical Conductor's actually where 501 00:26:00,640 --> 00:26:03,840 Speaker 3: Jupiter creates its magnetic field, same with Saturn. So that's 502 00:26:03,920 --> 00:26:06,760 Speaker 3: kind of a material we're not expected. Interestingly, helium take 503 00:26:06,800 --> 00:26:11,080 Speaker 3: another one, the second most simple element we have, helium. 504 00:26:11,760 --> 00:26:14,440 Speaker 3: You do the same thing. The helium. Turns out that 505 00:26:14,520 --> 00:26:17,400 Speaker 3: in the outer layers of Jupiter and Saturn in the atmosphere, 506 00:26:17,440 --> 00:26:20,080 Speaker 3: helium and hydrogen are nicely mixed. Right. It's kind of 507 00:26:20,160 --> 00:26:22,840 Speaker 3: like if you put salt in water or sugar in 508 00:26:22,880 --> 00:26:25,320 Speaker 3: water warm water and you stir it. They're nicely mixed. 509 00:26:25,320 --> 00:26:27,520 Speaker 3: You can't kind of separate them, but you put them 510 00:26:27,600 --> 00:26:31,320 Speaker 3: under high enough pressure. When this hydrogen becomes a nice metal, 511 00:26:31,600 --> 00:26:33,600 Speaker 3: the helium no longer wants to stay mixed in it, 512 00:26:33,840 --> 00:26:37,359 Speaker 3: and so helium will actually kind of exolt out of 513 00:26:37,359 --> 00:26:40,119 Speaker 3: the hydrogen and become these droplets, and then helium's heavier 514 00:26:40,119 --> 00:26:44,240 Speaker 3: than hydrogen, so they drop out. It rains helium inside 515 00:26:44,320 --> 00:26:46,879 Speaker 3: Jupiter and Saturn. So I think that's really cool. Then 516 00:26:46,920 --> 00:26:48,520 Speaker 3: you get to the ice giants, where you have a 517 00:26:48,520 --> 00:26:53,600 Speaker 3: lot more complicated molecules methane, ammonia, and you say, okay, 518 00:26:53,680 --> 00:26:56,000 Speaker 3: what happens to those things under high pressure, and you 519 00:26:56,040 --> 00:27:00,440 Speaker 3: can get things, for example, like super ionic water that's 520 00:27:00,440 --> 00:27:03,960 Speaker 3: actually formed in where all the oxygen atoms form a 521 00:27:04,000 --> 00:27:06,920 Speaker 3: nice lattice and all the hydrogen the protons that would 522 00:27:06,960 --> 00:27:09,240 Speaker 3: make up water in the H two O flow freely 523 00:27:09,320 --> 00:27:11,240 Speaker 3: between it, something we've never seen on the surface of 524 00:27:11,280 --> 00:27:15,600 Speaker 3: the Earth. And you can even make a diamond ocean 525 00:27:15,720 --> 00:27:19,360 Speaker 3: deep inside Neptune and Uranus. It's been hypothesized that the 526 00:27:19,400 --> 00:27:23,560 Speaker 3: carbon in things like carbon dioxide and methane ends up 527 00:27:23,920 --> 00:27:26,200 Speaker 3: in the diamond phase deep inside, but then it melts, 528 00:27:26,200 --> 00:27:29,320 Speaker 3: so you actually get a liquid diamond ocean. Diamond actually 529 00:27:29,359 --> 00:27:31,560 Speaker 3: has this really cool property that water on the surface 530 00:27:31,560 --> 00:27:34,040 Speaker 3: of the Earth also has, and that's right near that 531 00:27:34,080 --> 00:27:38,600 Speaker 3: freezing point. The solid phase is slightly less dense than 532 00:27:38,640 --> 00:27:40,439 Speaker 3: the liquid phase, which is why we have, for example, 533 00:27:40,480 --> 00:27:45,080 Speaker 3: icebergs that can float on water. Here. The same is 534 00:27:45,119 --> 00:27:48,920 Speaker 3: true deep inside Uranus and Neptune. Diamond bergs would actually 535 00:27:48,960 --> 00:27:52,320 Speaker 3: float on a diamond seed deep inside Uranus and Neptune. 536 00:27:52,359 --> 00:27:55,720 Speaker 3: So these are just material behavior that we just have 537 00:27:55,880 --> 00:27:57,600 Speaker 3: no experience with here on the surface of the Earth, 538 00:27:57,600 --> 00:27:58,680 Speaker 3: and I love thinking about it. 539 00:27:59,119 --> 00:28:03,320 Speaker 2: Yeah, simultaneously wonderful and frustrating that it violates our intuition, 540 00:28:03,440 --> 00:28:05,960 Speaker 2: so you can't really picture it. You want to be 541 00:28:06,000 --> 00:28:09,840 Speaker 2: able to, but you can't with the idea of superheated 542 00:28:09,840 --> 00:28:12,119 Speaker 2: ices and things like that. But it reminds me of 543 00:28:12,200 --> 00:28:15,119 Speaker 2: actually things closer to home. You talk about other ways 544 00:28:15,119 --> 00:28:19,159 Speaker 2: that even the interior of the Earth also violates our 545 00:28:19,200 --> 00:28:24,120 Speaker 2: intuitions about how materials work. For example, I think there's 546 00:28:24,160 --> 00:28:25,680 Speaker 2: a part in the book where you talk about how 547 00:28:26,600 --> 00:28:30,800 Speaker 2: it's hard for people to understand sometimes that parts of 548 00:28:30,840 --> 00:28:34,720 Speaker 2: the mantle migrate up and down even though the mantle 549 00:28:34,920 --> 00:28:37,360 Speaker 2: is solid not liquid. Is that right? 550 00:28:37,920 --> 00:28:41,320 Speaker 3: That's absolutely right. So I think there's also a big 551 00:28:41,360 --> 00:28:44,400 Speaker 3: misunderstanding out there that you think because you see at volcanos, 552 00:28:44,440 --> 00:28:46,880 Speaker 3: you see this magma coming up being all liquid, you 553 00:28:46,920 --> 00:28:49,160 Speaker 3: think that means that the interior of the earth, the mantle, 554 00:28:49,560 --> 00:28:52,400 Speaker 3: is all liquid, And that's absolutely not true. The rock 555 00:28:52,560 --> 00:28:56,040 Speaker 3: inside the mantle of the Earth is solid, it's very solid. 556 00:28:56,680 --> 00:28:59,920 Speaker 3: That doesn't mean it can't flow. So we do see 557 00:29:00,440 --> 00:29:05,200 Speaker 3: that rock move around, it moves on really slow timescales, 558 00:29:05,240 --> 00:29:07,440 Speaker 3: so it can take hundreds of millions of years for 559 00:29:07,480 --> 00:29:09,920 Speaker 3: a rock to make it from say the core mantle boundary, 560 00:29:10,000 --> 00:29:12,440 Speaker 3: up to the surface of the Earth. But it does flow, 561 00:29:12,480 --> 00:29:14,600 Speaker 3: it does move around, and the only reason we see 562 00:29:14,960 --> 00:29:17,960 Speaker 3: it in its liquid state at the surface is because 563 00:29:18,160 --> 00:29:21,240 Speaker 3: it was under a lot of pressure deep inside the Earth. 564 00:29:21,280 --> 00:29:23,959 Speaker 3: Pressures increase incredibly as you go down, and so that 565 00:29:24,320 --> 00:29:26,760 Speaker 3: it was basically pressure frozen. It was basically made a 566 00:29:26,880 --> 00:29:29,160 Speaker 3: solid because of the high pressure, and then you bring 567 00:29:29,200 --> 00:29:31,200 Speaker 3: that up to the surface and you release the pressure 568 00:29:31,400 --> 00:29:34,320 Speaker 3: and everything kind of expands out and becomes the magma 569 00:29:34,400 --> 00:29:35,600 Speaker 3: the liquid that you see. 570 00:29:35,760 --> 00:29:39,840 Speaker 2: There is a strange feature Towards the end of your book. 571 00:29:39,840 --> 00:29:41,800 Speaker 2: There's a great section where you just sort of like 572 00:29:42,360 --> 00:29:47,880 Speaker 2: explore all of the different strange aspects of planets, especially 573 00:29:47,920 --> 00:29:50,520 Speaker 2: like the ice giants and the gas giants. So you 574 00:29:50,560 --> 00:29:53,160 Speaker 2: talk about the helium ray and the diamond rain. You 575 00:29:53,200 --> 00:29:57,840 Speaker 2: also talk about why Uranus and Neptune have strange multi 576 00:29:57,880 --> 00:30:01,160 Speaker 2: polar magnetic fields. Does does that mean? Where does that 577 00:30:01,200 --> 00:30:01,760 Speaker 2: come from? 578 00:30:02,240 --> 00:30:04,360 Speaker 3: Imagine back to when we only really knew about the 579 00:30:04,360 --> 00:30:07,800 Speaker 3: Earth's magnetic field, right, and Earth's magnetic field the most 580 00:30:07,800 --> 00:30:11,280 Speaker 3: common feature about it is it looks like a die pole. 581 00:30:11,320 --> 00:30:13,600 Speaker 3: So there's a north pole and there's a south pole, 582 00:30:13,920 --> 00:30:17,120 Speaker 3: and the magnetic field lines connect them. When we started 583 00:30:17,160 --> 00:30:20,280 Speaker 3: exploring other planetary bodies, we started to see this happen 584 00:30:20,320 --> 00:30:24,920 Speaker 3: a lot. So Jupiter and Saturn also very dipolar. Mercury dipolar. 585 00:30:25,720 --> 00:30:28,400 Speaker 3: When the Voyager two mission, which was the only mission 586 00:30:28,440 --> 00:30:30,000 Speaker 3: that we have that has gone out to Uranus and 587 00:30:30,080 --> 00:30:32,840 Speaker 3: Neptune and basically just flew by for a little while, 588 00:30:33,280 --> 00:30:36,640 Speaker 3: when it got to first Urinus, which is closer, it 589 00:30:36,680 --> 00:30:39,560 Speaker 3: didn't see a dipolar field. It saw this multipolar fields. 590 00:30:39,600 --> 00:30:41,200 Speaker 3: There were a bunch of North poles and a bunch 591 00:30:41,240 --> 00:30:43,920 Speaker 3: of South poles all over the planet. I remember reading 592 00:30:43,960 --> 00:30:46,800 Speaker 3: about some of this history of when this happened in 593 00:30:46,800 --> 00:30:49,680 Speaker 3: the eighties, and people, you know, weren't expecting that. So 594 00:30:49,720 --> 00:30:51,680 Speaker 3: the first question you have is, all, well, maybe maybe 595 00:30:51,800 --> 00:30:55,040 Speaker 3: something broke, maybe the magnetometer is not working properly or 596 00:30:55,080 --> 00:30:56,680 Speaker 3: something like that, and they did lots of tests and 597 00:30:56,680 --> 00:30:58,640 Speaker 3: they make sure that wasn't the case. Then you get 598 00:30:58,640 --> 00:31:01,800 Speaker 3: out to Neptune and it's also this multipolar field, and 599 00:31:01,840 --> 00:31:03,960 Speaker 3: so you got to say, hmm, well, were we just 600 00:31:04,080 --> 00:31:06,680 Speaker 3: wrong about the fact that magnetic fields are supposed to 601 00:31:06,680 --> 00:31:11,040 Speaker 3: be dipolar, and the fact that Uranus and Neptune happen 602 00:31:11,120 --> 00:31:14,240 Speaker 3: to be the only water rich planets in the Solar System, 603 00:31:14,240 --> 00:31:17,120 Speaker 3: these ice giants, and they happen to be the only 604 00:31:17,120 --> 00:31:19,120 Speaker 3: ones with multipolar fields, then you got to start saying, 605 00:31:19,160 --> 00:31:22,320 Speaker 3: maybe there's a causal relationship with there, right, So I've 606 00:31:22,360 --> 00:31:24,160 Speaker 3: spent a lot of time thinking about that and trying 607 00:31:24,160 --> 00:31:26,720 Speaker 3: to think about how you create multipolar fields in an 608 00:31:26,760 --> 00:31:28,920 Speaker 3: ice giant, And it turns out that there are some 609 00:31:28,960 --> 00:31:31,560 Speaker 3: features in an ice giant that might make multipolar fields 610 00:31:31,600 --> 00:31:34,680 Speaker 3: more likely to occur. Turns out that the dynamo region 611 00:31:34,880 --> 00:31:37,280 Speaker 3: can be really thin in these bodies, so you just 612 00:31:37,320 --> 00:31:40,360 Speaker 3: have this really thin shell where the conditions are just 613 00:31:40,480 --> 00:31:44,479 Speaker 3: right for convection to occur in a good electrical conductor 614 00:31:44,480 --> 00:31:47,040 Speaker 3: and create a magnetic field. When you have this really 615 00:31:47,080 --> 00:31:51,760 Speaker 3: thin shell, you can't make big global dipolar fields. Nothing's 616 00:31:51,800 --> 00:31:54,280 Speaker 3: communicating the right way. All the length skills are too small. 617 00:31:54,440 --> 00:31:57,120 Speaker 3: So maybe you get more multipolar fields that way. People 618 00:31:57,120 --> 00:31:59,960 Speaker 3: are still studying this that we're really looking forward to 619 00:32:00,160 --> 00:32:03,520 Speaker 3: new mission, hopefully to Uranus sometime in the next decade, 620 00:32:04,080 --> 00:32:06,000 Speaker 3: so that we can study the magnetic field up close 621 00:32:06,000 --> 00:32:07,479 Speaker 3: and the interior of the planet, so that we can 622 00:32:07,560 --> 00:32:08,400 Speaker 3: understand the connection. 623 00:32:09,040 --> 00:32:12,080 Speaker 2: We have a basic idea of the types of planets 624 00:32:12,080 --> 00:32:15,040 Speaker 2: that can exist from our own Solar system. We have, 625 00:32:15,080 --> 00:32:17,400 Speaker 2: you know, the inner rocky planets. We have the gas giants, 626 00:32:17,440 --> 00:32:19,160 Speaker 2: we have the ice giants, and then we have these 627 00:32:19,200 --> 00:32:22,840 Speaker 2: other planets that we're familiar with from looking at other stars, 628 00:32:23,240 --> 00:32:26,080 Speaker 2: like the hot Jupiters and the super earths and so forth. 629 00:32:26,640 --> 00:32:29,400 Speaker 2: But there is a new planet type that you introduced 630 00:32:29,400 --> 00:32:31,720 Speaker 2: me to in this book. I don't think i'd ever 631 00:32:31,760 --> 00:32:35,840 Speaker 2: heard of it before, the hypothetical carbon planet. That sounds 632 00:32:35,920 --> 00:32:37,920 Speaker 2: so strange. What is the deal with this? 633 00:32:38,720 --> 00:32:41,680 Speaker 3: Yeah, you know, it's interesting when you look in our 634 00:32:41,680 --> 00:32:43,920 Speaker 3: Solar system, and let's say you look at the rocks 635 00:32:44,000 --> 00:32:48,000 Speaker 3: inside the Earth. They're mostly made of what we call silicates, 636 00:32:48,160 --> 00:32:52,680 Speaker 3: so they have silicon and oxygen atoms combined together, magnesium silicates, 637 00:32:52,720 --> 00:32:55,680 Speaker 3: aluminum silicates. This is kind of what defines the chemistry 638 00:32:55,720 --> 00:32:58,080 Speaker 3: of the rocks on the Earth, and all of that 639 00:32:58,240 --> 00:33:01,280 Speaker 3: was determined by the ratio of carbon to oxygen to 640 00:33:01,360 --> 00:33:06,360 Speaker 3: magnesium in the protoplanetary disk that formed and eventually became 641 00:33:06,400 --> 00:33:08,640 Speaker 3: all the materials we have. Now, if you go to 642 00:33:08,680 --> 00:33:12,800 Speaker 3: some other solar systems out there, they might have slightly 643 00:33:12,840 --> 00:33:18,880 Speaker 3: different ratios. And if nebula out there that eventually forms 644 00:33:18,880 --> 00:33:20,720 Speaker 3: a star with planets around it happened to have a 645 00:33:20,760 --> 00:33:23,920 Speaker 3: little bit more carbon, then the types of rocks that 646 00:33:23,960 --> 00:33:25,600 Speaker 3: you form, the types of minerals that you form, can 647 00:33:25,600 --> 00:33:28,040 Speaker 3: be very different, and you can actually create planets that 648 00:33:28,080 --> 00:33:30,520 Speaker 3: are mostly made of carbon, that have a much higher 649 00:33:30,560 --> 00:33:32,720 Speaker 3: carbon content than what we have here on Earth. It's 650 00:33:32,760 --> 00:33:36,920 Speaker 3: a geologist kind of like dreamscape to think about, what 651 00:33:37,040 --> 00:33:39,280 Speaker 3: if the chemistry was just slightly different because there's just 652 00:33:39,320 --> 00:33:42,640 Speaker 3: a little bit more of some tiny sub element. Right, Remember, 653 00:33:42,680 --> 00:33:45,680 Speaker 3: our solar system was mostly hydrogen and helium, and it 654 00:33:45,720 --> 00:33:48,200 Speaker 3: was just little bits of these rocks that eventually became 655 00:33:48,800 --> 00:33:52,840 Speaker 3: the Earth. And now you just slightly tweak the ratio 656 00:33:52,920 --> 00:33:56,240 Speaker 3: of those elements in extrasolar planets and you could create 657 00:33:56,240 --> 00:33:57,280 Speaker 3: completely different worlds. 658 00:33:57,920 --> 00:34:02,920 Speaker 2: Last question. You already mentioned why the upcoming study of 659 00:34:03,040 --> 00:34:05,800 Speaker 2: asteroid sixteen Psyche is going to be so exciting, but 660 00:34:06,000 --> 00:34:08,759 Speaker 2: what are some of the other upcoming missions and experiments 661 00:34:09,239 --> 00:34:11,560 Speaker 2: that you think are likely to teach us the most 662 00:34:11,600 --> 00:34:14,359 Speaker 2: about planetary science. What are you most excited to learn 663 00:34:14,400 --> 00:34:15,200 Speaker 2: in the near future. 664 00:34:15,719 --> 00:34:17,799 Speaker 3: Okay, there are two missions that I'm most excited about, 665 00:34:17,800 --> 00:34:19,520 Speaker 3: and I actually have nothing to do with these missions, 666 00:34:19,520 --> 00:34:22,359 Speaker 3: so I'm just a super fan of these missions. The 667 00:34:22,400 --> 00:34:25,480 Speaker 3: first one is the Europa Clipper mission, which is going 668 00:34:25,480 --> 00:34:28,200 Speaker 3: to go to a moon of Jupiter named Europa, scheduled 669 00:34:28,239 --> 00:34:32,919 Speaker 3: launch next year. And Europa is an exciting place because 670 00:34:32,960 --> 00:34:35,719 Speaker 3: it's this icy moon of Jupiter and we know that 671 00:34:35,760 --> 00:34:38,840 Speaker 3: it has a liquid water ocean buried beneath the surface, 672 00:34:39,400 --> 00:34:41,719 Speaker 3: and we think it has all the ingredients you might 673 00:34:41,719 --> 00:34:44,640 Speaker 3: think of as necessary for life. So the plan is 674 00:34:44,680 --> 00:34:47,959 Speaker 3: to go there and see try to get a sense 675 00:34:48,000 --> 00:34:50,480 Speaker 3: of what that ocean is made of. Are there complex 676 00:34:50,520 --> 00:34:52,680 Speaker 3: molecules in there that are kind of what we would 677 00:34:52,719 --> 00:34:54,840 Speaker 3: consider the building blocks of life, things like that. So 678 00:34:54,880 --> 00:34:57,879 Speaker 3: that's one really exciting. The other one is actually another moon. 679 00:34:58,960 --> 00:35:02,479 Speaker 3: There's a mission called Drag and Fly, which is scheduled. Yeah, 680 00:35:02,480 --> 00:35:03,719 Speaker 3: you know it's going to be a good mission when 681 00:35:03,719 --> 00:35:06,480 Speaker 3: it has a cool name, right, So Dragonfly is scheduled 682 00:35:06,520 --> 00:35:10,280 Speaker 3: to go to Saturn's moon Titan. Now Titan, in my opinion, 683 00:35:10,400 --> 00:35:12,960 Speaker 3: is probably one of the coolest places in the Solar 684 00:35:12,960 --> 00:35:17,720 Speaker 3: System to think about. It's the only other planetary body 685 00:35:17,760 --> 00:35:22,319 Speaker 3: out there to have nitrogen as its main based thick atmosphere. 686 00:35:22,360 --> 00:35:24,160 Speaker 3: So the Earth is the other planet, right, so it 687 00:35:24,160 --> 00:35:26,680 Speaker 3: has some similarities to it. It's the only other body 688 00:35:26,719 --> 00:35:29,280 Speaker 3: out there that we have seen liquids running on the surface. 689 00:35:29,520 --> 00:35:31,560 Speaker 3: So just like on Earth we have rivers and seas 690 00:35:31,600 --> 00:35:34,160 Speaker 3: and oceans, Titan has rivers and seas and oceans on 691 00:35:34,200 --> 00:35:37,560 Speaker 3: the surface. Now there's a catch, they're not water. Those 692 00:35:37,640 --> 00:35:39,640 Speaker 3: rivers and season oceans are actually made of things like 693 00:35:39,760 --> 00:35:43,440 Speaker 3: methane and ethane, so not you know, fun places. But 694 00:35:43,520 --> 00:35:47,720 Speaker 3: Titan has this thick atmosphere and it's also incredibly small, 695 00:35:47,920 --> 00:35:50,760 Speaker 3: so it has a really low gravity. So my favorite 696 00:35:50,760 --> 00:35:53,560 Speaker 3: fact about Titan is that it's really easy to fly there. 697 00:35:54,000 --> 00:35:58,040 Speaker 3: So you could strap some cardboard on your arms and 698 00:35:58,120 --> 00:36:01,359 Speaker 3: flap them on the surface of Titan could fly right. 699 00:36:01,400 --> 00:36:03,880 Speaker 3: So this is amazing. So the Dragonfly mission has decided 700 00:36:03,920 --> 00:36:07,480 Speaker 3: to take advantage of it. So it's sending essentially an octacopper, 701 00:36:07,600 --> 00:36:09,800 Speaker 3: so it's two quad copters, so think of a helicopter, 702 00:36:09,840 --> 00:36:13,120 Speaker 3: but with eight different blade things. It's sending this thing 703 00:36:13,160 --> 00:36:15,520 Speaker 3: out there. It's going to be able to land on 704 00:36:15,560 --> 00:36:18,200 Speaker 3: the surface, do a bunch of science and then take 705 00:36:18,239 --> 00:36:20,759 Speaker 3: off again, look around, figure out where it wants to 706 00:36:20,760 --> 00:36:23,520 Speaker 3: go next, travel quite long distances, and then land again 707 00:36:23,560 --> 00:36:24,920 Speaker 3: and do more science. So this is going to be 708 00:36:24,920 --> 00:36:29,719 Speaker 3: the first time we're able to study this world very locally, right, 709 00:36:29,840 --> 00:36:32,560 Speaker 3: like touch it, and also fly around to very different 710 00:36:32,600 --> 00:36:35,319 Speaker 3: parts of it. And Titans exciting because it has all 711 00:36:35,360 --> 00:36:37,360 Speaker 3: the building blocks of life. We know there's a liquid 712 00:36:37,360 --> 00:36:40,799 Speaker 3: water ocean underneath. We know it has complex chemicals, those 713 00:36:40,840 --> 00:36:44,200 Speaker 3: hydrocarbons like methane and ethane. We know it has energy sources. 714 00:36:44,280 --> 00:36:46,960 Speaker 3: So we really want to understand a lot of the 715 00:36:47,000 --> 00:36:49,279 Speaker 3: processes that we think are important in the creation of 716 00:36:49,320 --> 00:36:51,719 Speaker 3: life are going to be happening on Titan, and we're 717 00:36:51,760 --> 00:36:53,040 Speaker 3: excited to study them up close. 718 00:36:53,560 --> 00:36:56,520 Speaker 2: Doctor Sabine Stanley, thank you so much for joining us today. 719 00:36:56,520 --> 00:36:57,880 Speaker 2: It's been a real pleasure to talk. 720 00:36:58,320 --> 00:36:58,799 Speaker 3: Thanks so much. 721 00:36:58,880 --> 00:37:03,880 Speaker 2: This was fun, all right. If you would like to 722 00:37:03,960 --> 00:37:06,800 Speaker 2: check out the book for yourself again, it is called 723 00:37:07,040 --> 00:37:11,960 Speaker 2: What's Hidden Inside Planets from twenty twenty three, available in 724 00:37:12,000 --> 00:37:15,280 Speaker 2: audiobook form as well if that's your medium of choice. 725 00:37:16,440 --> 00:37:18,880 Speaker 2: Quick note about our show if you are new to it. 726 00:37:18,880 --> 00:37:21,440 Speaker 2: Stuff to Blow your Mind is a science and culture 727 00:37:21,480 --> 00:37:26,560 Speaker 2: podcast with core episodes on Tuesdays and Thursdays of every week. 728 00:37:26,680 --> 00:37:29,680 Speaker 2: Usually I'm joined by my co host, Robert Lamb. He's 729 00:37:29,680 --> 00:37:32,399 Speaker 2: out on vacation this week, but he will be back 730 00:37:32,440 --> 00:37:35,879 Speaker 2: again soon, let's see. Mondays of each week we read 731 00:37:35,920 --> 00:37:39,280 Speaker 2: back messages from the Stuff to Blow your Mind email address, 732 00:37:39,320 --> 00:37:42,200 Speaker 2: which I'll give out in just a moment. On Wednesdays 733 00:37:42,200 --> 00:37:45,799 Speaker 2: of each week, we feature a short form scripted podcast 734 00:37:45,880 --> 00:37:50,080 Speaker 2: called The Artifact or the Monster Fact or even There 735 00:37:50,080 --> 00:37:53,600 Speaker 2: are some new types of facts coming online. You'll learn 736 00:37:53,640 --> 00:37:58,080 Speaker 2: about them soon. Also, we have a show that airs 737 00:37:58,120 --> 00:38:01,080 Speaker 2: every Friday that is a movie. This is sort of 738 00:38:01,120 --> 00:38:04,800 Speaker 2: a more informal thing that Rob and I do every Friday. 739 00:38:04,840 --> 00:38:07,640 Speaker 2: It is called Weird House Cinema, where we just watch 740 00:38:07,960 --> 00:38:12,839 Speaker 2: and discuss strange films, good or bad, well known or obscure. 741 00:38:12,880 --> 00:38:15,840 Speaker 2: We take them all weird movies on Weird House Cinema, 742 00:38:15,880 --> 00:38:18,880 Speaker 2: and then on Saturdays we run an episode from the Vault, 743 00:38:19,000 --> 00:38:22,240 Speaker 2: an older episode of the show. Huge thanks as always 744 00:38:22,280 --> 00:38:26,200 Speaker 2: to our excellent audio producer JJ Posway. If you would 745 00:38:26,280 --> 00:38:28,400 Speaker 2: like to get in touch with us with feedback on 746 00:38:28,520 --> 00:38:30,960 Speaker 2: this episode or any other, to suggest a topic for 747 00:38:31,000 --> 00:38:33,760 Speaker 2: the future, or just to say hello. You can email 748 00:38:33,840 --> 00:38:45,240 Speaker 2: us at contact at stuff to Blow your Mind dot com. 749 00:38:45,360 --> 00:38:48,279 Speaker 1: Stuff to Blow Your Mind is production of iHeartRadio. For 750 00:38:48,360 --> 00:38:51,160 Speaker 1: more podcasts from my heart Radio, visit the iHeartRadio app, 751 00:38:51,320 --> 00:38:54,040 Speaker 1: Apple Podcasts, or wherever you listening to your favorite shows. 752 00:39:05,000 --> 00:39:05,600 Speaker 1: Ratt