WEBVTT 1 00:00:03.439 --> 00:00:07.719 Welcome to Bedtime Astronomy. Explore the wonders of the cosmos 2 00:00:07.759 --> 00:00:12.279 with our soothing Bedtime Astronomie podcast. Each episode offers a 3 00:00:12.359 --> 00:00:16.320 gentle journey through the stars, planets, and beyond, perfect for 4 00:00:16.399 --> 00:00:20.239 unwinding after a long day. Let's travel through the mysteries 5 00:00:20.239 --> 00:00:22.440 of the universe as you drift off into a peaceful 6 00:00:22.480 --> 00:00:23.800 slumber under the night sky. 7 00:00:27.839 --> 00:00:29.440 I want you to take a second and like just 8 00:00:29.559 --> 00:00:33.479 visualize the most likely place we might finally find alien 9 00:00:33.520 --> 00:00:34.399 life in our solar system. 10 00:00:34.479 --> 00:00:35.759 Yeah, that's a big question. 11 00:00:35.600 --> 00:00:37.280 Right, And you know, if you ask one hundred people 12 00:00:37.280 --> 00:00:39.960 on the street, the vast majority are going to point 13 00:00:39.960 --> 00:00:41.000 straight to Mars. Oh. 14 00:00:41.079 --> 00:00:42.679 Absolutely, the red planet. 15 00:00:42.840 --> 00:00:45.079 Exactly, Mars. I mean it's right next door. We have 16 00:00:45.119 --> 00:00:48.560 all these rovers like leaving tire tracks in the dirt everywhere. 17 00:00:48.679 --> 00:00:50.640 We spend so much time looking at those dried up 18 00:00:50.719 --> 00:00:51.320 river beds. 19 00:00:51.479 --> 00:00:55.039 Yeah, just hoping to find, you know, a fossilized microbe 20 00:00:55.079 --> 00:00:57.479 from billions of years ago. But I want you to 21 00:00:57.520 --> 00:01:02.679 completely bypass Mars today, gipit entirely. Totally. Forget the red dust, 22 00:01:02.920 --> 00:01:06.239 forget looking for ghosts of a dead biosphere. We are 23 00:01:06.280 --> 00:01:10.280 heading much further out into deep space, past the. 24 00:01:10.239 --> 00:01:12.239 Asteroid belt, straight towards you. 25 00:01:12.319 --> 00:01:15.120 Straight to the gas giant. But you know, we aren't 26 00:01:15.120 --> 00:01:19.239 looking at the turbulent atmosphere of Jupiter itself. We are 27 00:01:19.280 --> 00:01:22.920 locking our sights on one of its icy moons, Europa, Europa, 28 00:01:23.000 --> 00:01:26.560 and like our mission today is to explore this massive, 29 00:01:27.000 --> 00:01:30.319 brand new reality check in astrobiology. 30 00:01:30.400 --> 00:01:32.359 It's a huge shift in how we think. 31 00:01:32.359 --> 00:01:35.480 It really is because, I mean, we've known for a 32 00:01:35.519 --> 00:01:39.480 while that Europa hides this global ocean beneath its frozen. 33 00:01:39.120 --> 00:01:41.599 Shell, right, that's not the new part, no, But. 34 00:01:41.599 --> 00:01:44.239 The new part is that getting to that water and 35 00:01:44.280 --> 00:01:46.840 you know, whatever complex chemistry might be swimming around in 36 00:01:46.879 --> 00:01:49.920 it is going to be a much tougher barrier than 37 00:01:49.959 --> 00:01:51.200 scientists ever assumed. 38 00:01:51.599 --> 00:01:54.560 It is arguably the most compelling piece of real estate 39 00:01:54.599 --> 00:01:56.439 in our entire planetary neighborhood. 40 00:01:56.480 --> 00:01:57.640 Why is that exactly? 41 00:01:57.760 --> 00:02:02.159 Primarily because it's not a fossil. It is active right now. 42 00:02:02.599 --> 00:02:05.280 Like when you look at high resolution images. 43 00:02:05.280 --> 00:02:07.680 Of Europa once from the Galileo probram yeah. 44 00:02:07.519 --> 00:02:09.520 The Galileo probe in the nineties, or even the more 45 00:02:09.560 --> 00:02:14.680 recent stuff from Juno, you immediately notice what is missing exactly. 46 00:02:14.719 --> 00:02:17.159 You don't see craters. If you look at our own Moon, 47 00:02:17.280 --> 00:02:21.159 it is absolutely pulverized, just covered in impact craters from 48 00:02:22.000 --> 00:02:25.439 billions of years of cosmic bombardment with the giant golf ball, right, 49 00:02:25.879 --> 00:02:29.719 But Europa doesn't have that. You see this brilliant, bright 50 00:02:29.960 --> 00:02:34.759 white sphere heavily scarred with these incredibly long, dark, sort 51 00:02:34.800 --> 00:02:36.319 of reddish brown fractures. 52 00:02:36.400 --> 00:02:39.120 It literally looks like a cracked eggshell floating in the void. 53 00:02:39.360 --> 00:02:41.759 That's a perfect way to describe it, and the lack 54 00:02:41.840 --> 00:02:45.080 of craters tells us something vital. The surface is young, 55 00:02:45.560 --> 00:02:48.639 it is constantly refreshing and renewing itself. 56 00:02:48.400 --> 00:02:52.680 Because beneath that cracked shell, Europa is hiding a massive 57 00:02:52.759 --> 00:02:54.599 global ocean of liquid water. 58 00:02:55.039 --> 00:02:57.319 And not just a subterranean lake either, right. 59 00:02:57.319 --> 00:03:00.840 Not a slushy aquifer. It is a deep, earning ocean 60 00:03:01.240 --> 00:03:03.120 that wraps around the entire Moon. 61 00:03:03.120 --> 00:03:05.800 Which brings us to why astrobiologists are just so obsessed 62 00:03:05.840 --> 00:03:08.560 with this place. It comes down to what we consider 63 00:03:08.599 --> 00:03:11.439 the holy trinity for habitable environments. 64 00:03:10.960 --> 00:03:13.840 The three non negotiable ingredients for life. 65 00:03:13.960 --> 00:03:16.479 Exactly, if you are looking for life as we know it, 66 00:03:16.800 --> 00:03:20.319 first you need liquid water, not ice. Now, ice is rigid, 67 00:03:20.319 --> 00:03:23.080 it traps molecules and not vapor because that's too diffuse. 68 00:03:23.400 --> 00:03:26.960 You need a liquid medium where molecules can float, interact, bond. 69 00:03:27.080 --> 00:03:28.599 It's the universal solvent. Right. 70 00:03:29.000 --> 00:03:32.240 Second, you need the right chemistry. You need the building blocks. 71 00:03:31.919 --> 00:03:34.159 Like carbon, hydrogen, nitrogen. 72 00:03:33.759 --> 00:03:40.360 Oxygen, phosphorus, and sulfur. Thechnops elements chnops I always like 73 00:03:40.400 --> 00:03:41.000 that acronym. 74 00:03:41.080 --> 00:03:45.080 Yeah, And the assumption is that those elements are present 75 00:03:45.120 --> 00:03:47.479 on the rocky sea floor of Europa, right. 76 00:03:47.360 --> 00:03:48.240 That's the running theory. 77 00:03:48.280 --> 00:03:51.199 Yes, so the water is in direct contact with a 78 00:03:51.280 --> 00:03:55.400 silicate mantle, meaning the ocean is likely dissolving minerals and salts, 79 00:03:55.759 --> 00:03:57.599 creating this rich chemical soup. 80 00:03:57.800 --> 00:04:02.000 That direct contact is so crucial. It's what differentiates Europa 81 00:04:02.039 --> 00:04:04.400 from a moon like say Gannymat. 82 00:04:04.080 --> 00:04:05.800 Because Gannymat has an ocean too. 83 00:04:06.120 --> 00:04:09.759 It does, but Gannymat's ocean is likely sandwiched between two 84 00:04:09.840 --> 00:04:11.479 layers of impenetrable ice. 85 00:04:12.000 --> 00:04:14.159 Oh, so it never touches the rock exactly. 86 00:04:14.400 --> 00:04:17.920 Europa's ocean is interacting with the rock. But that brings 87 00:04:18.000 --> 00:04:21.120 us to the third crucial ingredient for life, energy and 88 00:04:21.360 --> 00:04:24.879 energy source. You need something to drive the chemical reactions 89 00:04:24.920 --> 00:04:27.800 to take those basic elements and force them to assemble 90 00:04:27.879 --> 00:04:29.959 into complex organic molecules. 91 00:04:30.079 --> 00:04:32.160 And on Earth, I mean, the vast majority of our 92 00:04:32.199 --> 00:04:33.800 biosphere relies on the Sun. 93 00:04:34.040 --> 00:04:34.920 Photosynthesis. 94 00:04:35.199 --> 00:04:37.800 Plants use the Sun, and then everything else basically eats 95 00:04:37.839 --> 00:04:40.800 the plants. Yeah, but out in the Jupiter system, the 96 00:04:40.839 --> 00:04:44.199 Sun is just like a bright star in the sky. 97 00:04:44.399 --> 00:04:46.000 It's incredibly faint out there. 98 00:04:46.360 --> 00:04:48.800 The solar radiation is just a fraction of what we 99 00:04:48.839 --> 00:04:51.199 get here on Earth. So the Sun isn't providing the 100 00:04:51.319 --> 00:04:52.680 energy for life. 101 00:04:52.560 --> 00:04:55.319 And it certainly isn't providing the heat to keep a 102 00:04:55.319 --> 00:04:57.120 global ocean from freezing. 103 00:04:56.800 --> 00:05:01.920 Solid because space is unimaginably So how does a moon 104 00:05:02.000 --> 00:05:04.759 floating hundreds of millions of miles away from the Sun 105 00:05:05.199 --> 00:05:07.839 out in the freezing depths of the outer Solar System 106 00:05:08.240 --> 00:05:09.879 actually managed to stay liquid? 107 00:05:10.199 --> 00:05:13.560 Well, if Europa were just floating out there in isolation, 108 00:05:14.199 --> 00:05:17.600 it would be a solid, inert block of ice all 109 00:05:17.639 --> 00:05:18.720 the way through to its. 110 00:05:18.519 --> 00:05:20.519 Core, just a giant ice cube. 111 00:05:20.600 --> 00:05:23.680 Literally. The surface temperature at europe A's equator never gets 112 00:05:23.759 --> 00:05:27.000 warmer than about minus two hundred and sixty degrees fahrenheit. Wow, 113 00:05:27.040 --> 00:05:29.839 And at the Poles it drops down to an agonizing 114 00:05:29.920 --> 00:05:31.639 minus three hundred and seventy degrees. 115 00:05:31.839 --> 00:05:34.639 That is just I can't even comprehend that level of cold. 116 00:05:34.800 --> 00:05:37.519 Any ambient heat from its formation of billions of years 117 00:05:37.519 --> 00:05:40.120 ago should have radiated away into the vacuum of space 118 00:05:40.160 --> 00:05:41.000 a long time ago. 119 00:05:41.160 --> 00:05:43.160 So the heat keeping that ocean liquid has to be 120 00:05:43.199 --> 00:05:45.040 continually generated from the inside out. 121 00:05:45.240 --> 00:05:47.519 Exactly. It's the engine keeping Europa alive. 122 00:05:47.600 --> 00:05:50.519 And that engine is driven entirely by gravity. Like we 123 00:05:50.600 --> 00:05:54.319 have to picture the sheer, overwhelming gravitational pull of Jupiter. 124 00:05:54.439 --> 00:05:57.680 Jupiter is a monster. It's three hundred and eighteen times 125 00:05:57.720 --> 00:05:58.839 more massive than Earth. 126 00:05:59.160 --> 00:06:02.759 Right, So Jupiter's gravity it completely dictates the physical reality 127 00:06:02.800 --> 00:06:03.839 of its moons. 128 00:06:03.639 --> 00:06:07.439 And Europa is caught in this very specific gravitational dance. 129 00:06:07.879 --> 00:06:10.319 It is in what we call an orbital resonance with 130 00:06:10.439 --> 00:06:14.399 two of Jupiter's other large moons, Io and Ganymede. 131 00:06:14.000 --> 00:06:15.800 Orbital resonance, so they are synced up. 132 00:06:16.040 --> 00:06:20.360 Yes, for every one time Ganymate orbits Jupiter Europa orbits 133 00:06:20.439 --> 00:06:23.040 twice and Io orbits four times. 134 00:06:23.079 --> 00:06:24.519 Okay, the four to two to one resonance. 135 00:06:24.680 --> 00:06:29.120 Right, This laplace resonance forces Europa's orbit to be elliptical 136 00:06:29.240 --> 00:06:31.839 or oval shaped rather than a perfect circle. 137 00:06:32.199 --> 00:06:35.920 So the distance between Europa and Jupiter is constantly changing exactly. 138 00:06:36.040 --> 00:06:39.160 Sometimes Europa swings in relatively close to the gas giant, 139 00:06:39.199 --> 00:06:41.800 and other times it swings much further out, And. 140 00:06:41.720 --> 00:06:45.040 That changing distance means a constantly changing gravitational pull. 141 00:06:45.240 --> 00:06:48.480 Yes, When Europa makes its closest approach to Jupiter, known 142 00:06:48.519 --> 00:06:51.639 as the parajove, Jupiter's gravity pulls on the Moon with 143 00:06:51.720 --> 00:06:52.600 immense force. 144 00:06:52.680 --> 00:06:54.600 It literally stretches the Moon, doesn't it. 145 00:06:54.600 --> 00:06:57.000 It does. The solid rock of the mantle and the 146 00:06:57.040 --> 00:07:00.920 thick ice shell actually bulge outward toward Jupiter by as 147 00:07:01.000 --> 00:07:02.040 much as thirty meters. 148 00:07:02.160 --> 00:07:04.800 It's like one hundred feet solid rock and ice bulging 149 00:07:04.879 --> 00:07:06.279 up one hundred feet right. 150 00:07:06.800 --> 00:07:09.920 And then as Europa swings further away in its orbit, 151 00:07:10.120 --> 00:07:14.439 reaching up a jove, that gravitational grip relaxes. 152 00:07:14.199 --> 00:07:16.720 And the moon shape settles back down exactly. So an 153 00:07:16.839 --> 00:07:20.399 entire planetary body is being physically stretched and compressed one 154 00:07:20.480 --> 00:07:23.879 hundred feet up and one hundred feet down every single orbit. 155 00:07:23.720 --> 00:07:25.759 Which takes about three and a half earthdays. 156 00:07:25.879 --> 00:07:29.600 That is insane. Just think about the mechanical stress of that. 157 00:07:29.639 --> 00:07:32.519 I mean, it's like, okay, if you take a thick 158 00:07:32.680 --> 00:07:37.160 metal paper clip, Okay, and you just hold it, nothing happens. Yeah, 159 00:07:37.240 --> 00:07:40.000 But if you start bending it back and forth rapidly 160 00:07:40.040 --> 00:07:41.319 and repeatedly. 161 00:07:40.839 --> 00:07:42.600 The metal right at the bend gets hot. 162 00:07:42.800 --> 00:07:45.120 Right, you can actually burn your fingers on it. The 163 00:07:45.160 --> 00:07:50.560 friction of the metallic crystalline structure grinding against itself generates internal. 164 00:07:50.120 --> 00:07:53.040 Heat that translates perfectly to a planetary scale. 165 00:07:53.079 --> 00:07:56.240 So Jupiter is basically bending Europa like a paper clip. 166 00:07:56.360 --> 00:08:00.279 The continuous squeezing and stretching is bending that planetary paper clip. 167 00:08:00.519 --> 00:08:03.839 The massive amounts of rock deep in the Moon's silicate 168 00:08:03.920 --> 00:08:06.240 mantle are grinding against each other, and. 169 00:08:06.199 --> 00:08:08.040 The layers of deep ice are flexing too. 170 00:08:08.399 --> 00:08:13.360 Yes, all of that incredible internal friction generates an enormous 171 00:08:13.399 --> 00:08:17.480 amount of thermal energy deep within the Moon's interior tidal heating, 172 00:08:17.920 --> 00:08:22.879 exactly tidal heating. It is a ceaseless, powerful geologic engine. 173 00:08:22.920 --> 00:08:26.360 So this immense heat is radiating outward from the rocky core. 174 00:08:26.759 --> 00:08:29.240 It hits the bottom of the frozen crust, melting it 175 00:08:29.279 --> 00:08:29.600 from the. 176 00:08:29.560 --> 00:08:34.080 Inside out, creating this massive, warm global ocean hidden in 177 00:08:34.120 --> 00:08:34.519 the dark. 178 00:08:34.679 --> 00:08:37.399 Right, the ocean exists in this state of tension. Its 179 00:08:37.399 --> 00:08:41.399 sandwiched between the hot, volcanically active rocky seafloor below and 180 00:08:41.440 --> 00:08:43.919 the frozen ice shell above. Yes, but wait, I have 181 00:08:43.960 --> 00:08:46.000 to push back here. If there is so much heat 182 00:08:46.000 --> 00:08:49.039 being generated inside this moon, enough to melt a volume 183 00:08:49.080 --> 00:08:52.480 of water twice the size of all of Earth's oceans combined, 184 00:08:52.879 --> 00:08:54.879 why doesn't the heat just melt the rest of the ice. 185 00:08:55.039 --> 00:08:56.039 That's a great question. 186 00:08:56.159 --> 00:08:58.440 Why is the outside still frozen solid? It seems like 187 00:08:58.440 --> 00:08:59.000 it should. 188 00:08:58.759 --> 00:09:01.279 Just be a water world because you are witnessing a 189 00:09:01.279 --> 00:09:04.519 stalemate between two extreme thermodynamic forces. 190 00:09:04.600 --> 00:09:05.440 Okay, stalemate. 191 00:09:05.759 --> 00:09:08.639 You have the intense, constant tidal heating pushing up from 192 00:09:08.639 --> 00:09:12.000 the seafloor, but you also have the brutal, unforgiving cold 193 00:09:12.000 --> 00:09:14.039 of deep space pressing down from above. 194 00:09:14.399 --> 00:09:16.159 Right, The minus two hundred and sixty. 195 00:09:15.879 --> 00:09:19.320 Degrees thorodynamics dictates that heat will always move to where 196 00:09:19.320 --> 00:09:22.200 it is cold. The thermal energy from the ocean is 197 00:09:22.240 --> 00:09:25.559 constantly trying to bleed away into the vacuum of space. 198 00:09:25.480 --> 00:09:29.159 And as a result, the outermost layer of the water freezes. 199 00:09:28.960 --> 00:09:30.559 Creating the thick ice shell. 200 00:09:30.639 --> 00:09:33.639 And once that ice forms, it changes the dynamic Right. 201 00:09:33.919 --> 00:09:36.679 Because ice is a remarkably good insulator. 202 00:09:36.200 --> 00:09:39.720 It acts as planetary armour. The ice shell traps the 203 00:09:39.759 --> 00:09:42.799 remaining heat inside, preventing the rest of the ocean from 204 00:09:42.840 --> 00:09:47.600 freezing solid. Wow, it is a delicate equilibrium. The ice 205 00:09:47.600 --> 00:09:50.480 shell is estimated to be anywhere from ten to fifteen 206 00:09:50.519 --> 00:09:54.120 miles thick fifteen miles, perhaps even thicker in certain regions, 207 00:09:54.120 --> 00:09:56.519 depending on the localized heat flow from the mantle. 208 00:09:56.720 --> 00:09:59.639 So we have this incredible, potentially life bearing ocean, complete 209 00:09:59.679 --> 00:10:01.840 with the care, chemistry, and the energy needed to sustain 210 00:10:01.879 --> 00:10:05.080 a biosphere. Yes, but it is locked inside a planetary 211 00:10:05.120 --> 00:10:08.279 vault with walls made of miles thick rock hard. 212 00:10:08.080 --> 00:10:12.279 Ice, which creates an absolute nightmare for planetary scientists and engineers. 213 00:10:12.399 --> 00:10:14.440 I can imagine, how do you sample an ocean you 214 00:10:14.480 --> 00:10:17.279 can't reach. We don't have the technology to pack a 215 00:10:17.320 --> 00:10:21.240 fifteen mile long drill onto a rocket, No, we definitely don't, 216 00:10:21.279 --> 00:10:24.159 and then fly it to Jupiter, land it softly on 217 00:10:24.200 --> 00:10:27.559 the ice, and power it for years as it grinds 218 00:10:27.600 --> 00:10:30.440 through cryogenic ice. That's just science fiction. 219 00:10:30.399 --> 00:10:34.080 Completely, which is exactly why the scientific community has spent 220 00:10:34.240 --> 00:10:37.519 the last few decades clinging to the dream of the shortcut. 221 00:10:37.679 --> 00:10:40.720 The shortcut. Okay, let's unpack this. What was the assumption here? 222 00:10:40.840 --> 00:10:44.879 The shortcut was a highly optimistic yet theoretically grounded assumption 223 00:10:45.000 --> 00:10:47.519 about the mechanics of the ice shell, hoping. 224 00:10:47.320 --> 00:10:49.960 We wouldn't need a gargantuan drilling operation. Right. 225 00:10:50.360 --> 00:10:52.799 The hope was that the ocean was actively doing the 226 00:10:52.799 --> 00:10:55.639 hard work for us, that the ocean might be migrating 227 00:10:55.720 --> 00:10:56.399 up to meet us. 228 00:10:56.559 --> 00:10:59.240 Because we're looking at a surface covered in thousands of 229 00:10:59.279 --> 00:11:01.759 miles of caaotic fractures, ridges. 230 00:11:01.480 --> 00:11:03.879 And bands, the shell is clearly active. 231 00:11:04.159 --> 00:11:07.000 So the theory was that deep ocean water could travel 232 00:11:07.080 --> 00:11:09.799 upward through narrow vertical fractures in. 233 00:11:09.720 --> 00:11:12.759 The ice geological features known as dikes, yes. 234 00:11:12.679 --> 00:11:16.559 And that this pressurized water would pool in shallow reservoirs 235 00:11:16.759 --> 00:11:19.440 much closer to the surface, like maybe just a few 236 00:11:19.440 --> 00:11:20.360 dozen meters down. 237 00:11:20.519 --> 00:11:23.960 That was the dream. The scientific framework for this is cry. 238 00:11:23.919 --> 00:11:25.559 Volcanism ice vulcanism. 239 00:11:25.840 --> 00:11:29.840 Exactly to conceptualize it, scientists naturally look at the geologic 240 00:11:29.919 --> 00:11:31.759 processes we understand. 241 00:11:31.240 --> 00:11:33.080 Best traditional vulcanism. 242 00:11:33.159 --> 00:11:36.799 Here on Earth, right beneath our feet, we have incredibly hot, 243 00:11:37.120 --> 00:11:42.360 pressurized molten rock magma moving through the lithosphere. 244 00:11:41.679 --> 00:11:46.159 And when this magma encounters weak points, faults or tectonic 245 00:11:46.200 --> 00:11:48.440 fractures in the Earth's crust. 246 00:11:48.120 --> 00:11:52.679 The immense lithostatic pressure forces it upward. Sometimes it erupts 247 00:11:52.720 --> 00:11:54.159 explosively on the surface as. 248 00:11:54.240 --> 00:11:57.360 Lava, or it pools in shallow magma chambers just below 249 00:11:57.399 --> 00:11:59.600 the crust, creating geothermal anomalies. 250 00:11:59.720 --> 00:12:04.080 Exactly, cry vulcanism takes that entire Earth based plumbing system 251 00:12:04.120 --> 00:12:06.080 and applies it to an ice world. 252 00:12:06.159 --> 00:12:08.960 So instead of molten silicate rock moving through a rocky 253 00:12:09.000 --> 00:12:12.399 granite crust, you have liquid water moving through cracks in 254 00:12:12.440 --> 00:12:13.879 a solid water ice crust. 255 00:12:13.960 --> 00:12:16.759 Yes, the deep ocean is highly pressurized by the weight 256 00:12:16.799 --> 00:12:17.039 of the. 257 00:12:16.960 --> 00:12:19.960 Ice above it, the ice shell flexes, a crack opens 258 00:12:20.039 --> 00:12:22.360 up at the bottom, and that pressure squeezes the liquid 259 00:12:22.399 --> 00:12:23.559 water up into the fracture. 260 00:12:23.679 --> 00:12:26.200 That was the prevailing model for a long time. If 261 00:12:26.240 --> 00:12:30.240 cryovulcanism operates on Europa with the same fundamental mechanics as 262 00:12:30.320 --> 00:12:33.799 vulcanism on Earth, you would expect these vertical dikes to 263 00:12:33.960 --> 00:12:35.200 act as natural. 264 00:12:34.879 --> 00:12:40.559 Pipelines, continuously ferrying deep, mineral rich ocean water up into 265 00:12:40.600 --> 00:12:43.320 shallow pockets just beneath the surface. 266 00:12:43.159 --> 00:12:46.240 Or even erupting onto the surface to create the smooth, 267 00:12:46.480 --> 00:12:49.320 renewed planes we see in the orbital imagery. 268 00:12:49.519 --> 00:12:52.360 I mean, this would be the ultimate game changer for exploration. 269 00:12:52.519 --> 00:12:56.480 If this shortcut exists, future space missions wouldn'tne a fifteen 270 00:12:56.519 --> 00:12:57.039 mile drill. 271 00:12:57.320 --> 00:13:00.240 They could simply use ground penetrating radar from orbit to 272 00:13:00.360 --> 00:13:02.039 map out these shallow pockets. 273 00:13:02.120 --> 00:13:05.159 Right then, you land a relatively small, simple probe equipped 274 00:13:05.159 --> 00:13:06.519 with like a thermal melt probe. 275 00:13:06.600 --> 00:13:10.039 You melt through maybe ten, twenty or fifty feet of ice. 276 00:13:09.840 --> 00:13:12.960 And suddenly you are sampling the deep ocean. You're tasting 277 00:13:13.000 --> 00:13:16.559 the exact chemical environment where life might be thriving without 278 00:13:16.600 --> 00:13:19.080 having to breach the primary fifteen mile vault. 279 00:13:19.200 --> 00:13:23.840 It was an incredibly elegant solution to an impossible engineering problem. Look, but, 280 00:13:24.039 --> 00:13:27.759 as we often find in planetary science, mapping the mechanics 281 00:13:27.759 --> 00:13:30.799 of one planet directly onto another is fraught with peril. 282 00:13:31.080 --> 00:13:34.360 I mean, wait, ice and liquid water are fundamentally different 283 00:13:34.360 --> 00:13:36.960 materials from solid rock and molten lava. 284 00:13:36.559 --> 00:13:37.519 Completely different. 285 00:13:37.639 --> 00:13:40.240 Can we really assume they behave the same way under pressure? 286 00:13:40.440 --> 00:13:45.720 No, we can't. They possess completely different thermodynamic properties, different densities, 287 00:13:45.960 --> 00:13:48.600 and they transfer heat in entirely different ways. 288 00:13:48.679 --> 00:13:51.840 And this is where the dream of the shortcut collides 289 00:13:52.320 --> 00:13:55.799 with a massive, sobering reality check. 290 00:13:56.159 --> 00:13:59.639 A major twenty twenty six study has completely dismantled the 291 00:13:59.639 --> 00:14:00.799 system yeah. 292 00:14:00.919 --> 00:14:04.480 Led by lejendro Oshaw, a planetary scientist at the Rutger 293 00:14:04.519 --> 00:14:06.200 School of Arts and Sciences. 294 00:14:05.799 --> 00:14:10.480 They finally ran the brutal, unfiltered physics on this concept. 295 00:14:10.159 --> 00:14:13.639 Because they didn't want to rely on Earth based analogies anymore. 296 00:14:14.039 --> 00:14:16.600 They wanted to know exactly what happens when liquid water 297 00:14:16.679 --> 00:14:18.519 tries to force its way through deep. 298 00:14:18.279 --> 00:14:21.440 Space ice, and their methodology was focused entirely on the 299 00:14:21.519 --> 00:14:24.679 journey itself. The core question they tackled was whether liquid 300 00:14:24.720 --> 00:14:28.799 water could realistically rise from Europa's deep, highly pressurized ocean, 301 00:14:29.360 --> 00:14:32.480 travel vertically through narrow fractures in the ice shell, and 302 00:14:32.559 --> 00:14:35.879 reach the shallow subsurface without freezing solid along the way. 303 00:14:36.159 --> 00:14:38.600 And to answer a question like that, you can't just 304 00:14:38.679 --> 00:14:41.679 rely on telescope observations. You have to build the environment 305 00:14:41.799 --> 00:14:42.440 in a computer. 306 00:14:42.759 --> 00:14:47.480 They utilized advanced computational fluid dynamics to simulate the localized 307 00:14:47.559 --> 00:14:50.240 physics of this upward journey, modeling. 308 00:14:49.879 --> 00:14:52.840 The pressure, the temperature gradient of the ice shell, the 309 00:14:52.879 --> 00:14:54.799 specific heat capacity of the water. 310 00:14:54.759 --> 00:14:56.879 And the geometry of the fractures. 311 00:14:56.519 --> 00:15:00.159 And in doing so they exposed a critical flaw in 312 00:15:00.200 --> 00:15:04.480 the older models, the models that it generated so much optimism. 313 00:15:04.679 --> 00:15:09.240 Yes, the previous models relied heavily on a mathematical simplification. 314 00:15:09.759 --> 00:15:12.159 They treated the rising water as if it moved in 315 00:15:12.200 --> 00:15:13.039 a laminar flow. 316 00:15:13.200 --> 00:15:16.000 Laminar flow. Okay, let's make sure we have a vivid 317 00:15:16.000 --> 00:15:18.000 picture of this, because it is the lynchpin of the 318 00:15:18.000 --> 00:15:22.279 old theory. It is Laminar flow is smooth, It's highly orderly, 319 00:15:22.440 --> 00:15:24.000 like if you turn on your kitchen fauce. It just 320 00:15:24.039 --> 00:15:26.240 a tiny bit and the water glides out in this 321 00:15:26.440 --> 00:15:30.440 perfect clear glass like cylinder where all the water molecules 322 00:15:30.480 --> 00:15:31.960 are moving perfectly parallel to. 323 00:15:31.840 --> 00:15:33.960 One another with no class currents or mixing. 324 00:15:34.120 --> 00:15:35.840 Right. That is laminar flow. 325 00:15:36.080 --> 00:15:39.120 The old models effectively assumed that water from the deep 326 00:15:39.120 --> 00:15:42.159 ocean would behave like that faucet. It would gently and 327 00:15:42.200 --> 00:15:44.480 smoothly slide up these fractures. 328 00:15:44.039 --> 00:15:46.120 In the ice, which sounds nice in theory. 329 00:15:46.360 --> 00:15:49.759 In a laminar flow regime, the water maintains its thermal 330 00:15:49.840 --> 00:15:53.919 energy relatively well because the fluid isn't mixing, so only 331 00:15:53.960 --> 00:15:54.559 the very. 332 00:15:54.399 --> 00:15:58.120 Outer layer of the water touches the freezing ice walls exactly. 333 00:15:58.200 --> 00:16:01.080 It acts as an insulating buffer for the warmer water 334 00:16:01.200 --> 00:16:02.480 in the center of the flow. 335 00:16:02.559 --> 00:16:05.919 But Ojcha's team realized there was a fundamental physics element 336 00:16:06.000 --> 00:16:07.240 missing from those assumptions. 337 00:16:07.279 --> 00:16:10.720 Applying laminar flow to a highly pressurized extrusion event on 338 00:16:10.759 --> 00:16:15.200 an active moon was a mathematically convenient, but physically impossible assumption. 339 00:16:15.440 --> 00:16:19.840 Because space isn't to controlled laboratory. You can't expect millions 340 00:16:19.840 --> 00:16:23.000 of gallons of pressurized water to flow up a jagged, 341 00:16:23.080 --> 00:16:26.600 dynamic freezing pipe in a smooth straight line. 342 00:16:26.679 --> 00:16:30.840 The older models were completely ignoring the chaotic, unpredictable nature 343 00:16:30.840 --> 00:16:31.879 of fluid dynamics. 344 00:16:31.919 --> 00:16:33.240 They were ignoring turbulence. 345 00:16:33.399 --> 00:16:36.919 Purbulence dictates the reality of the flow. When you factor 346 00:16:36.960 --> 00:16:39.120 in the intense pressures at the bottom of the ocean, 347 00:16:39.559 --> 00:16:43.639 the narrow, jagged constraints of these tectonic fractures, and the 348 00:16:43.679 --> 00:16:46.759 immense vertical distance the water must traverse. 349 00:16:46.720 --> 00:16:50.120 A gentle laminar stream is physically impossible. 350 00:16:50.480 --> 00:16:54.519 The fluid dynamics simulations proved that the water wouldn't rise peacefully. 351 00:16:54.639 --> 00:16:57.399 It would be injected into the fracture at high velocity, 352 00:16:57.840 --> 00:16:59.960 resulting in violently turbulent flow. 353 00:17:00.200 --> 00:17:02.639 And if the water is turbulent, the molecules aren't moving 354 00:17:02.639 --> 00:17:05.519 in a straight parallel line anymore. The fluid is tearing 355 00:17:05.559 --> 00:17:06.160 itself apart. 356 00:17:06.240 --> 00:17:09.160 It is moving left and right, surging up and dropping down. 357 00:17:09.319 --> 00:17:13.960 It is swirling aggressively, creating massive eddies and vortices inside 358 00:17:13.960 --> 00:17:14.400 the crack. 359 00:17:14.640 --> 00:17:18.440 Picture a raging whitewater river violently rushing through a narrow, 360 00:17:18.559 --> 00:17:22.000 jagged slot canyon. Oh wow, Yeah, the water is crashing 361 00:17:22.039 --> 00:17:25.640 against the rock walls, folding over on itself, constantly churning 362 00:17:25.680 --> 00:17:26.200 and mixing. 363 00:17:26.319 --> 00:17:29.599 Now take that chaotic energy and place it inside a 364 00:17:29.720 --> 00:17:32.680 vertical crack in Europa's ice shell. 365 00:17:32.880 --> 00:17:36.599 You have a churning, swirling mass of liquid water violently 366 00:17:36.640 --> 00:17:39.480 scraping and mixing against the walls of the fracture, and. 367 00:17:39.720 --> 00:17:43.119 We have to focus on the thermal reality of those walls. 368 00:17:43.799 --> 00:17:46.400 This isn't a rocky canyon in Arizona. 369 00:17:45.880 --> 00:17:48.640 No, And it isn't the relatively warm ice you'd find 370 00:17:48.680 --> 00:17:49.799 in an Earth glacier either. 371 00:17:50.279 --> 00:17:53.000 This is deep space ice. As you move up through 372 00:17:53.000 --> 00:17:56.480 the shell, the temperature of the ice drops precipitously, plunging 373 00:17:56.519 --> 00:17:59.279 down toward that surface temperature of minus two hundred and 374 00:17:59.279 --> 00:18:00.000 sixty degrees fair. 375 00:18:00.519 --> 00:18:04.319 It is a cryogenic environment which triggers the fatal mechanism 376 00:18:04.359 --> 00:18:07.240 that destroys the shortcut right catastrophic heat loss. 377 00:18:07.359 --> 00:18:07.559 Yes. 378 00:18:08.240 --> 00:18:11.240 In our earlier laminar flow example, the water in the 379 00:18:11.279 --> 00:18:14.440 center was insulated, but in a turbulent flow there. 380 00:18:14.319 --> 00:18:16.519 Is no center because it's constantly mixing. 381 00:18:16.920 --> 00:18:20.200 The swirling motion constantly takes the relatively warm water from 382 00:18:20.240 --> 00:18:23.359 the interior of the crack and violently throws it outward, 383 00:18:23.440 --> 00:18:26.279 smashing it directly against the freezing cryogenic walls. 384 00:18:26.400 --> 00:18:29.599 So the water rapidly surrenders its thermal energy into the 385 00:18:29.599 --> 00:18:30.279 surrounding ice. 386 00:18:30.599 --> 00:18:34.279 The rate of heat transfer is staggering, far faster than 387 00:18:34.319 --> 00:18:37.079 any of the older simplified models had accounted for. 388 00:18:37.440 --> 00:18:41.720 The water is rushing up, furiously, churning and rapidly harringing 389 00:18:41.799 --> 00:18:45.000 its heat into the walls of the fracture. It cools 390 00:18:45.119 --> 00:18:48.599 down at a phenomenal rate as it climbs towards the surface. 391 00:18:48.359 --> 00:18:52.039 And this rapid cooling in a chaotic environment leads to 392 00:18:52.119 --> 00:18:55.680 a state of matter that dictates the final outcome super 393 00:18:55.720 --> 00:19:00.240 cooling super cooling. It is a fascinating thermodynamic. 394 00:18:59.400 --> 00:19:01.920 State because, as we generally assume that the instant water 395 00:19:01.960 --> 00:19:06.039 reaches thirty two degrees fahrenheit or zero degree celsius. It 396 00:19:06.119 --> 00:19:08.440 immediately transitions into a solid state. 397 00:19:08.880 --> 00:19:12.359 Right, But the phase change from liquid to solid requires 398 00:19:12.359 --> 00:19:15.599 a starting point, a nucleation site for the ice crystals 399 00:19:15.640 --> 00:19:16.359 to begin forming. 400 00:19:16.440 --> 00:19:17.920 And if it doesn't have one, if. 401 00:19:17.799 --> 00:19:21.359