WEBVTT 1 00:00:03.399 --> 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 --> 00:00:23.839 slumber under the night sky. 7 00:00:26.879 --> 00:00:28.920 You know, when we usually talk about the search for 8 00:00:29.039 --> 00:00:33.439 life in the universe, we have this mental checklist. It's 9 00:00:33.439 --> 00:00:35.799 almost like a recipe for biology. 10 00:00:35.359 --> 00:00:38.079 Right, the standard astrobiology checklist Exactly. 11 00:00:38.240 --> 00:00:41.119 We look for liquid water, we look for a source 12 00:00:41.159 --> 00:00:43.880 of energy like the Sun or maybe a hot planetary core, 13 00:00:44.280 --> 00:00:47.640 and we look for time, time for things to actually evolve. 14 00:00:47.719 --> 00:00:50.399 And for the last twenty or thirty years, the moons 15 00:00:50.399 --> 00:00:54.399 of Jupiter, specifically Europa, Ganymede, and Callisto, have been ticking 16 00:00:54.479 --> 00:00:55.960 those boxes one by one. 17 00:00:56.079 --> 00:00:56.679 They really have. 18 00:00:56.880 --> 00:01:00.039 We've confirmed the subsurface oceans. We're pretty confident about the 19 00:01:00.119 --> 00:01:04.359 energy sources, mainly tidal heating. They are prime real estate 20 00:01:04.439 --> 00:01:06.239 in the astrobiology. 21 00:01:05.439 --> 00:01:08.519 Market, time real estate. Yeah, but there's always been this 22 00:01:08.560 --> 00:01:11.719 one nagging question mark, a gap in the resume, so 23 00:01:11.799 --> 00:01:15.560 to speak, and that is the chemistry, specifically the. 24 00:01:15.480 --> 00:01:17.959 Carbon, the actual stuff that life is built from. 25 00:01:17.879 --> 00:01:19.959 Right, the building blocks. Yeah, because you can have all 26 00:01:19.959 --> 00:01:22.239 the warm water in the universe and you can let 27 00:01:22.280 --> 00:01:24.359 us sit there for four billion years. But if it's 28 00:01:24.439 --> 00:01:28.359 just distilled water, you're not getting bacteria. You're just getting 29 00:01:28.400 --> 00:01:29.519 a really excellent bath. 30 00:01:29.799 --> 00:01:33.560 That is a very accurate, if slightly unscientific, way to 31 00:01:33.560 --> 00:01:38.760 put it. Biology is at its core complex carbon chemistry. 32 00:01:39.000 --> 00:01:39.799 It's not just water. 33 00:01:40.239 --> 00:01:43.400 No, it's not. And for a long time, the prevailing 34 00:01:43.439 --> 00:01:47.000 assumption in planetary science was that these moons formed as 35 00:01:47.079 --> 00:01:50.000 these pristine, almost sterile. 36 00:01:49.599 --> 00:01:51.840 Balls of ice, just pure water and rock. 37 00:01:51.799 --> 00:01:54.359 Just water and rock frozen solid. And if you wanted 38 00:01:54.359 --> 00:01:58.840 the good stuff, the amino acids, the complex organic molecules, 39 00:01:58.879 --> 00:02:01.239 you essentially had to wait for delivery. 40 00:02:00.879 --> 00:02:02.920 Like a cosmic delivery truck exactly. 41 00:02:03.040 --> 00:02:05.799 You had to hope a comet or a carbon rich 42 00:02:05.920 --> 00:02:09.439 asteroid would crash into the moon later on and deposit 43 00:02:09.479 --> 00:02:11.240 those ingredients on the surface, which. 44 00:02:11.080 --> 00:02:12.800 Is a bit of a depressing thought, isn't it. I mean, 45 00:02:12.840 --> 00:02:15.039 it makes life feel accidental. 46 00:02:14.520 --> 00:02:15.599 It makes it precarious. 47 00:02:15.719 --> 00:02:17.759 Certain, Now, like you built the house, but you have 48 00:02:17.800 --> 00:02:20.080 to wait for Amazon to deliver the furniture and the 49 00:02:20.199 --> 00:02:21.759 driver might get completely lost. 50 00:02:21.960 --> 00:02:24.759 It relies on chance. But the research we are doing 51 00:02:24.800 --> 00:02:27.879 a deep dive into today completely flips that narrative on 52 00:02:27.919 --> 00:02:30.199 its head. It suggests the furniture was built into the 53 00:02:30.199 --> 00:02:31.159 house from day one. 54 00:02:31.319 --> 00:02:34.439 I love that. So today we're exploring a really groundbreaking 55 00:02:34.479 --> 00:02:38.000 set of papers. This is collaborative research from the Southwest 56 00:02:38.080 --> 00:02:42.520 Research Institute x Marseille University in France and the Institute 57 00:02:42.599 --> 00:02:43.599 for Advanced. 58 00:02:43.159 --> 00:02:47.400 Studies Right they published two complementary studies, one in the 59 00:02:47.400 --> 00:02:51.199 Planetary Science Journal and another in the Monthly Notices of 60 00:02:51.240 --> 00:02:53.120 the Royal Astronomical Society. 61 00:02:53.520 --> 00:02:58.039 These are major publications and their core thesis is pretty revolutionary. 62 00:02:58.199 --> 00:03:02.080 It is they are arguing that you Ropa, Ganymede, Callisto, 63 00:03:02.199 --> 00:03:05.840 and even Eo were not formed as clean white snowballs. 64 00:03:06.680 --> 00:03:09.960 They argue that these loons likely accreted, meaning they gathered 65 00:03:10.039 --> 00:03:14.000 up significant inventories of life building organic materials right from 66 00:03:14.039 --> 00:03:16.599 the start, right as they were forming. And these materials 67 00:03:16.639 --> 00:03:18.879 came from both the massive cloud that formed the Sun 68 00:03:19.159 --> 00:03:21.520 and from the local disc of gas and dust spinning 69 00:03:21.560 --> 00:03:22.719 around Jupiter itself. 70 00:03:22.840 --> 00:03:25.840 So no waiting for a comet. The ingredients were baked. 71 00:03:25.520 --> 00:03:28.199 In bacon and frozen in exactly before we get into 72 00:03:28.199 --> 00:03:31.759 the how, and the how involves some incredibly cool simulation 73 00:03:31.840 --> 00:03:34.240 work that we're going to break down. Let's define what 74 00:03:34.319 --> 00:03:35.680 we are actually talking about here. 75 00:03:35.560 --> 00:03:39.120 Good idea. We keep saying organics or ingredients, but I'm 76 00:03:39.120 --> 00:03:42.840 guessing we aren't talking about, you know, sandwich meat floating 77 00:03:42.879 --> 00:03:43.360 in space. 78 00:03:43.560 --> 00:03:46.000 No, definitely not sandwich meat, though that would make space 79 00:03:46.039 --> 00:03:50.599 exploration much more appetizing. We are talking about COMMS. That 80 00:03:50.680 --> 00:03:54.120 stands for complex organic molecules COMBS. 81 00:03:54.400 --> 00:03:57.400 Which sounds a bit like corporate jargon. But in astrobiology 82 00:03:57.439 --> 00:03:59.199 that's a very specific term, right, It is. 83 00:03:59.199 --> 00:04:02.879 A very specification. Now, complex is a relative term here. 84 00:04:02.960 --> 00:04:06.759 Ahso well, in a high school biology class, complex might 85 00:04:06.840 --> 00:04:10.639 mean a protein with thousands of atoms, a massive structure, 86 00:04:11.199 --> 00:04:13.919 but in the context of deep space chemistry, the bar 87 00:04:14.080 --> 00:04:17.120 is quite a bit lower. We generally define a COLM 88 00:04:17.160 --> 00:04:20.600 as a carbon based molecule that has at least six atoms. 89 00:04:20.800 --> 00:04:23.720 Six atoms that's the threshold, that is the magic number. 90 00:04:23.839 --> 00:04:28.519 But crucially, it's not just carbon. It's carbon integrated with oxygen, nitrogen, 91 00:04:28.560 --> 00:04:29.199 and hydrogen. 92 00:04:29.279 --> 00:04:31.680 So we aren't just talking about methane, which is H four. 93 00:04:31.800 --> 00:04:34.199 That's too simple, right, Methane is simple. We're talking about 94 00:04:34.240 --> 00:04:37.879 things like methanol or dimethyl ether. These are molecules that 95 00:04:37.920 --> 00:04:41.160 act as the structural precursors, the lego bricks, if you will, 96 00:04:41.199 --> 00:04:45.079 for amino acids and nucleotides. So, if life is the castle, 97 00:04:45.800 --> 00:04:48.199 the comms are the individual plastic bricks. 98 00:04:48.360 --> 00:04:51.800 Precisely, you cannot build the castle without them. They form 99 00:04:51.839 --> 00:04:55.240 the essential foundation for anything that could eventually become biological. 100 00:04:55.800 --> 00:04:58.879 Okay, so where do these lego bricks actually come from? 101 00:05:00.199 --> 00:05:04.480 Because space is it's space. It's a vacuum, it's freezing cold, 102 00:05:05.000 --> 00:05:06.519 it's bombarded by radiation. 103 00:05:07.000 --> 00:05:08.360 It's a hostile environment. 104 00:05:08.720 --> 00:05:10.839 Yeah, it doesn't seem like a great place to do 105 00:05:10.920 --> 00:05:11.920 delicate chemistry. 106 00:05:12.160 --> 00:05:12.639 Yeah. 107 00:05:12.800 --> 00:05:14.759 I usually think a chemistry happening in a beaker with 108 00:05:14.759 --> 00:05:16.839 a Bunsen burner, not in the empty void. 109 00:05:17.279 --> 00:05:20.079 You're entirely right. Space is a terrible place to do chemistry, 110 00:05:20.079 --> 00:05:20.680 at least in the. 111 00:05:20.639 --> 00:05:22.480 Gas phase, because things are too spread out. 112 00:05:22.680 --> 00:05:25.839 Exactly, if you have two atoms floating in a vast vacuum, 113 00:05:26.079 --> 00:05:28.199 the odds of them bumping into each other and deciding 114 00:05:28.240 --> 00:05:31.480 to stick together to form a complex bond are astronomically low. 115 00:05:32.000 --> 00:05:34.639 Nature needs a work space, a work. 116 00:05:34.439 --> 00:05:36.839 Bench, and that work bench is dusty. 117 00:05:36.639 --> 00:05:41.639 Icy grains, tiny microscopic particles. Think of them like dust bunnies, 118 00:05:41.680 --> 00:05:44.279 but made of silicate's rock and coated in an incredibly 119 00:05:44.319 --> 00:05:45.160 thin layers of ice. 120 00:05:45.240 --> 00:05:47.160 Okay, so little frosted rocks. 121 00:05:47.160 --> 00:05:50.680 Right, And in the early solar system, these grains are everywhere. 122 00:05:51.120 --> 00:05:54.560 They are the fog that fills the protoplanetary system, and 123 00:05:54.600 --> 00:05:57.279 the ice on them isn't just pure water ice. 124 00:05:57.680 --> 00:05:58.519 It's dirty ice. 125 00:05:58.800 --> 00:06:03.519 Very dirty ice contains volatiles, things like carbon monoxide, carbon dioxide, 126 00:06:03.519 --> 00:06:06.680 and ammonia, all frozen together on the surface of this 127 00:06:06.800 --> 00:06:07.480 tiny rock. 128 00:06:07.800 --> 00:06:10.639 So you have a microscopic rock, it's coated in this 129 00:06:10.680 --> 00:06:14.120 dirty ice mixture containing carbon and nitrogen. It's floating in 130 00:06:14.160 --> 00:06:17.399 the dark. How does that turn into the precursor for 131 00:06:17.439 --> 00:06:20.319 an amino acid. It needs a spark because otherwise it 132 00:06:20.360 --> 00:06:21.600 would just sit there frozen forever. 133 00:06:22.000 --> 00:06:24.720 What it needs energy. You need a catalyst to get 134 00:06:24.720 --> 00:06:28.879 those atoms moving and rearranging themselves into new structures. The 135 00:06:28.959 --> 00:06:34.000 research identifies two primary external stimuli that drive the synthesis. 136 00:06:33.480 --> 00:06:34.959 In space, and the first one. 137 00:06:34.839 --> 00:06:39.279 Is ultraviolet radiation UV photons from the young Sun. From 138 00:06:39.279 --> 00:06:42.120 the Sun, yes, but also from the interstellar environment. In general, 139 00:06:42.160 --> 00:06:46.120 the galaxy is full of UV radiation from massive young. 140 00:06:45.959 --> 00:06:48.879 Stars, so the whole nebula is bathed in it exactly. 141 00:06:49.199 --> 00:06:52.439 And when a high energy UV photon hits that icy grain, 142 00:06:52.839 --> 00:06:56.759 it acts like a microscopic wrecking ball. It smashes into 143 00:06:56.759 --> 00:06:59.560 the simple molecule, say a molecule of methanol frozen on 144 00:06:59.600 --> 00:07:02.920 the surface, and it breaks the chemical bonds holding it together. 145 00:07:03.000 --> 00:07:05.079 It snaps the legos bus, snaps them apart, and it 146 00:07:05.120 --> 00:07:07.800 creates what we call radicals in chemistry, radicals. 147 00:07:07.879 --> 00:07:10.839 I've heard of free radicals in health and diet discussions, 148 00:07:10.920 --> 00:07:14.079 usually things we are told to avoid eating. But in space, 149 00:07:14.279 --> 00:07:14.879 what are they? 150 00:07:15.199 --> 00:07:20.839 They are essentially unhappy molecules or highly anxious molecules. 151 00:07:20.920 --> 00:07:22.120 Unhappy molecules I like that. 152 00:07:22.319 --> 00:07:27.360 Chemically speaking, they are fragments of molecules that have unpaired electrons. 153 00:07:28.120 --> 00:07:31.600 Because they have an unpaired electron, they are highly aggressive. 154 00:07:31.720 --> 00:07:36.360 They want to bond with something, anything, immediately, to stabilize themselves. 155 00:07:36.399 --> 00:07:39.160 Okay, so you have this ice grain. The UV light hits, 156 00:07:39.160 --> 00:07:41.480 it breaks a bunch of bonds, and suddenly you have 157 00:07:41.560 --> 00:07:46.199 this swarm of highly reactive radicals trapped in the ice matrix. 158 00:07:46.360 --> 00:07:48.399 And since they're trapped in the ice, they can't just 159 00:07:48.480 --> 00:07:50.519 fly away. They grab the nearest. 160 00:07:50.240 --> 00:07:53.040 Partner, and when they grab a partner, they build something new. Right. 161 00:07:53.839 --> 00:07:56.519 When they recombine, they rarely go back to being the 162 00:07:56.519 --> 00:08:00.360 simple molecule they were before. They form larger, weird chain es. 163 00:08:00.560 --> 00:08:04.439 They form more complex structures. You smash two small things 164 00:08:04.800 --> 00:08:08.000 and the pieces reassemble into one bigger thing. That is 165 00:08:08.040 --> 00:08:10.040 the first mechanism for calmformation. 166 00:08:10.680 --> 00:08:13.240 Okay, so UV light is the wrecking ball. What is 167 00:08:13.240 --> 00:08:14.120 the second mechanism? 168 00:08:14.240 --> 00:08:18.639 Thermal processing? Heat? But very specifically not too much heat. 169 00:08:18.720 --> 00:08:21.519 This is a classic Goldilock situation. 170 00:08:21.759 --> 00:08:24.759 Because if it's too hot, the ice just evaporates, right exactly. 171 00:08:24.800 --> 00:08:27.839 If the temperature rises too much, the ice sublimates into gas. 172 00:08:28.120 --> 00:08:31.160 The radicals fly away into the vacuum, and the chemistry stops. 173 00:08:31.480 --> 00:08:32.240 Nothing happens. 174 00:08:32.399 --> 00:08:33.360 But if it's too cold. 175 00:08:33.559 --> 00:08:36.039 If it's too cold, the radicals are frozen strictly in 176 00:08:36.120 --> 00:08:38.519 place and can't reach each other to bond. But if 177 00:08:38.559 --> 00:08:40.879 you warm it up just enough, the ice lattice, the 178 00:08:40.879 --> 00:08:43.639 crystal structure of the ice loosens up. 179 00:08:43.639 --> 00:08:44.759 It gets kind of slushy. 180 00:08:44.919 --> 00:08:47.360 At a molecular level, yes, it acts a bit like 181 00:08:47.399 --> 00:08:50.759 a highly viscous liquid. The molecules can wiggle around. That 182 00:08:50.879 --> 00:08:54.000 allows those trapped radicals to migrate slowly through the ice 183 00:08:54.039 --> 00:08:55.399 and find each other to react. 184 00:08:55.600 --> 00:08:58.399 So you need a kitchen that is irradiated by UV 185 00:08:59.080 --> 00:09:01.960 and slightly warm, but definitely not an oven. 186 00:09:02.399 --> 00:09:06.600 Perfect analogy, and the study points out that a protoplanetary disk, 187 00:09:06.720 --> 00:09:10.200 which is the swirling disk of gas and dust around 188 00:09:10.200 --> 00:09:13.960 a new born star, is basically a giant factory, perfectly 189 00:09:14.000 --> 00:09:17.879 designed to create exactly these conditions because it's turbulent, highly 190 00:09:18.000 --> 00:09:22.320 turbulent screens are constantly moving from cold, dark areas of 191 00:09:22.360 --> 00:09:26.320 the disk into warmer, brighter areas and then getting swept 192 00:09:26.360 --> 00:09:27.039 back out again. 193 00:09:27.279 --> 00:09:29.399 Okay, so we have the mechanism, we know how to 194 00:09:29.399 --> 00:09:31.919 make the molecules, we have the factory floor, which is 195 00:09:31.960 --> 00:09:34.639 the disc. But the big mystery has always been how 196 00:09:34.639 --> 00:09:36.480 do they actually get to Jupiter's mooms? 197 00:09:36.559 --> 00:09:38.720 Right? Because Jupiter is really far out from the Sun. 198 00:09:38.759 --> 00:09:41.279 It's far out, it's cold, and the early Solar system 199 00:09:41.320 --> 00:09:44.080 was a chaotic mess. Just because you make a complex 200 00:09:44.159 --> 00:09:47.639 molecule out by Neptune doesn't mean it gently lands on Europa. 201 00:09:47.720 --> 00:09:50.639 Transport is the killer variable here, and this is where 202 00:09:50.679 --> 00:09:53.720 the studies methodology gets really impressive. They didn't just guess 203 00:09:53.759 --> 00:09:56.639 at how the transport happened. They built a digital time machine, 204 00:09:56.679 --> 00:10:00.559 a computational model. Yes, but it's important under stand this 205 00:10:00.639 --> 00:10:04.759 wasn't just one simple simulation. It was a complex coupling 206 00:10:04.879 --> 00:10:08.879 of two massive physical models that traditionally don't even talk 207 00:10:08.919 --> 00:10:10.600 to each other in planetary science. 208 00:10:10.879 --> 00:10:12.240 What do you mean they don't talk to each other. 209 00:10:12.480 --> 00:10:16.080 Well, usually in astrophysics you have research groups who model 210 00:10:16.159 --> 00:10:20.120 the protosolar nebula that's the huge, massive disc of gas 211 00:10:20.120 --> 00:10:23.159 and dust that formed the Sun and the entire planetary 212 00:10:23.159 --> 00:10:27.360 system the macroscale right the grand scale, And then completely separately, 213 00:10:27.679 --> 00:10:31.279 you have researchers who model the circumplanetary disc that is 214 00:10:31.320 --> 00:10:35.600 the localized, much smaller subdisc spinning around Jupiter where the 215 00:10:35.679 --> 00:10:38.320 gas giant and its specific moons formed. 216 00:10:38.399 --> 00:10:40.759 So it's like a disc within a disc, a small 217 00:10:40.799 --> 00:10:42.279 gear inside a massive. 218 00:10:41.960 --> 00:10:45.200 Machine exactly, and the physics work very differently at those 219 00:10:45.200 --> 00:10:49.120 different scales. It is notoriously difficult to simulate both at 220 00:10:49.159 --> 00:10:52.039 the exact same time. It's akin to trying to simulate 221 00:10:52.080 --> 00:10:55.200 the global weather patterns of the Earth and the specific 222 00:10:55.279 --> 00:10:57.679 airflow in your living room in the same computer program. 223 00:10:57.759 --> 00:10:59.600 That sounds computationally. 224 00:10:58.919 --> 00:11:03.200 Expensive, dably so, but these researchers managed to do it. 225 00:11:03.240 --> 00:11:06.879 They modeled the evolution of the massive protosolar nebula and 226 00:11:06.919 --> 00:11:10.879 the local Jovian circumplanetary disk, and then they mathematically link 227 00:11:10.960 --> 00:11:11.440 them together. 228 00:11:11.559 --> 00:11:14.000 Oh kay, so they have the wind currents basically, Yeah, 229 00:11:14.039 --> 00:11:16.559 how did they track the actual chemistry? Did they just 230 00:11:16.639 --> 00:11:18.639 look at the average temperature of the whole system. 231 00:11:18.720 --> 00:11:22.240 Now, they went much more granular than that. They utilized 232 00:11:22.360 --> 00:11:27.919 a particle transport module. They essentially released thousands upon thousands 233 00:11:27.919 --> 00:11:32.639 of digital dust grains into this massive simulation and track 234 00:11:32.720 --> 00:11:35.559 their individual lives over millions of years. 235 00:11:35.440 --> 00:11:38.679 Like putting tiny GPS trackers on individual specks of dust. 236 00:11:38.840 --> 00:11:42.279 Precisely, they tracked every single time a specific grain moved 237 00:11:42.360 --> 00:11:44.320 up or down in the disk, every time it drifted 238 00:11:44.320 --> 00:11:47.679 inward toward the sun, every single photon of UV radiation 239 00:11:47.799 --> 00:11:51.360 it absorbed, and every fractional degree of temperature change it experienced. 240 00:11:51.639 --> 00:11:54.600 That is incredible fidelity. So they can say grain number 241 00:11:54.600 --> 00:11:57.759 four do seventy two started in the deep outer Solar system, 242 00:11:58.039 --> 00:12:01.159 drifted inward for a million years, lasted by UV light, 243 00:12:01.480 --> 00:12:03.120 and then got sucked into Jupiter's orbit. 244 00:12:03.480 --> 00:12:06.200 They can track exactly that life cycle, and by summing 245 00:12:06.279 --> 00:12:10.480 up that incredibly detailed history for millions of particles, they 246 00:12:10.519 --> 00:12:14.519 could calculate precisely how much organic material was being cooked 247 00:12:14.600 --> 00:12:17.279 up and exactly where it was ending up within the 248 00:12:17.360 --> 00:12:18.159 Jovian system. 249 00:12:18.519 --> 00:12:21.279 They integrated the physics of the disc evolution with the 250 00:12:21.279 --> 00:12:25.279 transport data to quantify the environmental history of the entire 251 00:12:25.320 --> 00:12:26.679 grain population exactly. 252 00:12:26.679 --> 00:12:28.120 It removes a lot of the guesswork. 253 00:12:28.279 --> 00:12:32.120 And did they validate this against actual physical data or 254 00:12:32.200 --> 00:12:33.679 is it purely a math exercise? 255 00:12:33.919 --> 00:12:38.679 No validation is crucial here. Doctor Olivier Moses from seissuer 256 00:12:38.720 --> 00:12:41.759 Ari made a very specific point of this. They compared 257 00:12:41.759 --> 00:12:45.720 their model outputs with physical laboratory experiments. As you, they 258 00:12:45.799 --> 00:12:48.799 essentially asked, if our computer model says a grain gets 259 00:12:48.840 --> 00:12:51.960 exactly this much UV radiation and this much heat over time, 260 00:12:52.200 --> 00:12:55.480 does the physical laboratory show that those specific conditions actually 261 00:12:55.480 --> 00:12:56.919 produce complex organics? 262 00:12:57.000 --> 00:12:58.039 And the answer was yes. 263 00:12:58.120 --> 00:13:01.399 The answer was a definitive yes. The simulation confirms that 264 00:13:01.440 --> 00:13:04.519 the dynamic physical environment of the early Solar System was 265 00:13:04.639 --> 00:13:07.759 highly conducive to the synthesis of these specific molecules. 266 00:13:08.000 --> 00:13:12.240 Okay, so this methodological framework, the time machine, leads us 267 00:13:12.279 --> 00:13:16.240 to the study central finding regarding the origins of Jovian organics. 268 00:13:16.559 --> 00:13:18.600 And this is what they call the dual source model. 269 00:13:18.960 --> 00:13:21.759 Yes, the dual source model. This is the absolute headline 270 00:13:21.799 --> 00:13:24.840 of the paper. They found that the organic material on 271 00:13:25.000 --> 00:13:28.679 moons like Europa and Ganymede did not originate from a 272 00:13:28.720 --> 00:13:30.399 single solitary location. 273 00:13:30.720 --> 00:13:32.480 It came from two distinct reservoirs. 274 00:13:32.720 --> 00:13:34.639 Right, Source A and Source B. 275 00:13:34.960 --> 00:13:38.879 Let's break those down sequentially. Source A is the protosolar neibula, 276 00:13:38.960 --> 00:13:41.000 the big main solar disc correct. 277 00:13:41.320 --> 00:13:45.240 The simulation demonstrated that a massive amount of organic synthesis 278 00:13:45.320 --> 00:13:49.120 happened way out in the general Solar System, long before 279 00:13:49.120 --> 00:13:51.200 the material ever got anywhere near Jupiter. 280 00:13:51.440 --> 00:13:52.519 Out in the deep freeze. 281 00:13:52.639 --> 00:13:56.159 Right, the icy grains were drifting slowly through the outer regions, 282 00:13:56.200 --> 00:14:01.000 getting hammered by background interstellar UV radiation. They were literally 283 00:14:01.039 --> 00:14:04.519 accumulating calms just by floating there over millions of years. 284 00:14:04.519 --> 00:14:06.879 Well, wait, I thought Jupiter creates a gap when a 285 00:14:06.919 --> 00:14:10.559 giant planet forms, doesn't its massive gravity clear its orbit 286 00:14:10.759 --> 00:14:12.200 like a snowplow clearing a street. 287 00:14:12.480 --> 00:14:16.159 It absolutely does, and for a long time planetary scientists 288 00:14:16.159 --> 00:14:19.000 assumed that gap was a hard barrier, that it would 289 00:14:19.000 --> 00:14:21.679 effectively cut off the supply line of material from the 290 00:14:21.679 --> 00:14:22.799 outer Solar. 291 00:14:22.480 --> 00:14:26.720 System, like a moat around a castle. If Jupiter clears 292 00:14:26.759 --> 00:14:29.759 the gap, how does fresh organic, rich dust from the 293 00:14:29.799 --> 00:14:30.840 outside get in. 294 00:14:31.320 --> 00:14:34.480 It is a moat, But the advanced hydrodynamic simulations in 295 00:14:34.519 --> 00:14:38.519 this study show that the moat is surprisingly leaky leaky. Yes, 296 00:14:39.240 --> 00:14:42.399 the gas and dust don't just stop. The pressure builds 297 00:14:42.480 --> 00:14:44.919 up and the material actually spills over the edges of 298 00:14:44.960 --> 00:14:48.039 the gap. It flows across the gap at higher altitudes 299 00:14:48.080 --> 00:14:51.919 and spirals rapidly down into Jupiter's personal circumplanetary disk. 300 00:14:52.080 --> 00:14:54.480 So the cosmic delivery trucks can actually cross the bridge. 301 00:14:54.559 --> 00:14:57.600 They can cross the bridge, But the real variable was survival. 302 00:14:58.039 --> 00:15:00.639 You are taking a very cold ice cre from deep 303 00:15:00.679 --> 00:15:04.519 space and dropping it into the highly chaotic, dynamic, and 304 00:15:04.600 --> 00:15:07.639 shockingly hot environment of a forming gas giant. 305 00:15:07.720 --> 00:15:09.200 That sounds like a violent transition. 306 00:15:09.360 --> 00:15:12.639 It is extremely violent. You have massive shock waves, intense 307 00:15:12.679 --> 00:15:15.600 frictional heating. You would intuitively think the sudden heat would 308 00:15:15.639 --> 00:15:17.559 just destroy the delicate organic. 309 00:15:17.360 --> 00:15:21.559 Molecules, vaporize them, entirely, sterilize the package before it even 310 00:15:21.639 --> 00:15:23.080 arrives at the Moon exactly. 311 00:15:23.480 --> 00:15:27.960 But the model showed something counterintuitive. It showed that nearly 312 00:15:28.159 --> 00:15:31.679 half fifty percent of the particles actually survived the trip. 313 00:15:32.080 --> 00:15:32.519 Half of them. 314 00:15:32.720 --> 00:15:36.399 Yes, they managed to stay just cold enough during the transition. 315 00:15:36.960 --> 00:15:40.440 They successfully transferred their entire cargo of colms from the 316 00:15:40.559 --> 00:15:44.919 larger solar nebula down into Jupiter's disk without undergoing major 317 00:15:45.000 --> 00:15:47.320 chemical alteration or thermal destruction. 318 00:15:48.039 --> 00:15:51.279 That is a surprisingly high survival rate. So half the 319 00:15:51.480 --> 00:15:55.000 organic material on the Galilean moons is basically imported from 320 00:15:55.000 --> 00:15:56.240 the rest of the Solar System. 321 00:15:56.279 --> 00:16:00.759 Correct that ancient interstellar heritage is source A. But then 322 00:16:00.799 --> 00:16:04.399 there is source B, the Jovian's circumplanetary. 323 00:16:03.679 --> 00:16:05.519 Disc itself the local neighborhood, right. 324 00:16:05.799 --> 00:16:08.919 The research found that Jupiter wasn't just passively collecting material 325 00:16:08.960 --> 00:16:12.039 from the outside. It was functioning as its own chemical factory. 326 00:16:12.120 --> 00:16:13.759 It was making its own organics locally. 327 00:16:14.080 --> 00:16:19.759 Yes, the circumplanetary disc that swirling nursery directly around Jupiter 328 00:16:20.039 --> 00:16:24.159 had its own localized Goldilock zones. If you think about 329 00:16:24.240 --> 00:16:28.200 the physics happening there. You have massive amounts of gas 330 00:16:28.240 --> 00:16:30.559 swirling incredibly fast into Jupiter's. 331 00:16:30.200 --> 00:16:32.159 Gravity well, and that creates friction. 332 00:16:32.159 --> 00:16:35.159 Massive friction like rubbing your hands together vigorously on a 333 00:16:35.200 --> 00:16:38.720 cold day, but on a planetary scale. This creates what 334 00:16:38.759 --> 00:16:40.919 physicists call viscous heating. 335 00:16:41.360 --> 00:16:42.159 Viscous heating. 336 00:16:42.320 --> 00:16:46.559 Yes, this viscous heating raised the ambient temperature in certain 337 00:16:46.600 --> 00:16:49.759 specific regions of Jupiter's disk just enough to trigger that 338 00:16:49.840 --> 00:16:53.000 exact thermal processing we talked about earlier, the slushy ice 339 00:16:53.279 --> 00:16:56.279 exactly so, even if the material crossing the gap from 340 00:16:56.279 --> 00:16:59.840 the outside was completely dead and sterile Jupiter's local disc environment, 341 00:17:00.039 --> 00:17:03.120 but have cooked that raw material into complex organics anyway. 342 00:17:03.600 --> 00:17:05.920 This is a redundancy mentioned in the research. It's a 343 00:17:05.920 --> 00:17:06.880 built in fail safe. 344 00:17:07.240 --> 00:17:09.599 It is a brilliant natural fail safe. It means you 345 00:17:09.640 --> 00:17:12.839 don't need to be exceptionally lucky to get organics. If 346 00:17:12.880 --> 00:17:16.519 the solar nebula source fails, say the interstellar radiation wasn't 347 00:17:16.519 --> 00:17:19.480 strong enough, the local viscous heating source kicks in and 348 00:17:19.519 --> 00:17:20.119 does the job. 349 00:17:20.400 --> 00:17:23.200 And if the local source is too weak, the solar 350 00:17:23.240 --> 00:17:25.519 nebula source covers the shortfall. 351 00:17:25.720 --> 00:17:30.000 Exactly. The convergence of these two distinct mechanisms implies that 352 00:17:30.039 --> 00:17:34.359 having organic rich moons isn't some rare anomaloust fluke. It 353 00:17:34.440 --> 00:17:37.319 is a highly robust feature of the system. 354 00:17:37.519 --> 00:17:40.440 It's an inevitable outcome of the physics. If you build 355 00:17:40.480 --> 00:17:43.720 a gas giant, you are almost guaranteed to build organic 356 00:17:43.799 --> 00:17:44.720 rich moons around it. 357 00:17:44.839 --> 00:17:48.640 The presence of comms is essentially a structural guarantee. 358 00:17:48.799 --> 00:17:50.720 That is huge. I want to pause on that for 359 00:17:50.759 --> 00:17:53.519 a second because we always talk about the habitable zone 360 00:17:53.559 --> 00:17:57.240 in astrobiology strictly in terms of distance from a host star. 361 00:17:57.680 --> 00:17:59.920 We say Earth is in the zone, Mars is on 362 00:18:00.119 --> 00:18:02.160 the edge, Venus is too close. 363 00:18:01.920 --> 00:18:03.559 The traditional liquid water zone. 364 00:18:03.680 --> 00:18:06.920 Right. But this research suggests that gas giants carry their 365 00:18:06.960 --> 00:18:10.279 own portable habitable chemistry sets with them regardless of where 366 00:18:10.319 --> 00:18:10.640 they are. 367 00:18:11.079 --> 00:18:13.279 That is a phenomenal way to put it. A portable 368 00:18:13.359 --> 00:18:17.640 chemistry set. The disc itself provides the necessary gradients of 369 00:18:17.680 --> 00:18:18.599 heat and radiation. 370 00:18:19.039 --> 00:18:21.359 So let's talk about the final customers in this process. 371 00:18:21.440 --> 00:18:26.000 The Galilean moves themselves Europa, Ganymede, Callisto, and Io. They 372 00:18:26.000 --> 00:18:29.279 are sitting there in this disk growing, sweeping up all 373 00:18:29.279 --> 00:18:29.880 this material. 374 00:18:30.079 --> 00:18:33.079 They grow through a process called pebble accretion. That is 375 00:18:33.160 --> 00:18:37.720 the current most accepted model in planetary science, pebble accretion. Yes, 376 00:18:38.279 --> 00:18:41.720 they aren't just getting randomly hit by massive asteroids to grow. 377 00:18:42.119 --> 00:18:45.920 They are constantly sweeping up these centimeter sized pebbles of 378 00:18:45.960 --> 00:18:48.200 ice and dust as they orbit through the. 379 00:18:48.160 --> 00:18:50.400 Disc like a vacuum cleaner, very much like that. 380 00:18:51.000 --> 00:18:53.440 And thanks to this dual source modeling, we now know 381 00:18:53.640 --> 00:18:57.200 with high confidence that those pebbles were heavily loaded with colms. 382 00:18:57.359 --> 00:19:01.279 So when Europa initially formed, it wasn't a pristine white 383 00:19:01.279 --> 00:19:03.880 ball of ice that slowly got dirty over billions of 384 00:19:03.960 --> 00:19:08.200 years of comet impacts. It was what a dirty snowball 385 00:19:08.319 --> 00:19:09.160 right from the start. 386 00:19:09.279 --> 00:19:13.079 It would have been a profoundly muddy, organic rich slurry, 387 00:19:13.519 --> 00:19:16.400 a dark mix of silicate rock, water, ice, and this 388 00:19:16.519 --> 00:19:19.839 complex organic tar, all mixed together from day one. 389 00:19:19.960 --> 00:19:23.119 And this directly challenges the older pristine hypothesis. 390 00:19:23.200 --> 00:19:27.240 It completely dismantles it. The pristine hypothesis assumed the foundational 391 00:19:27.279 --> 00:19:30.079 water was pure H two O, but this new model 392 00:19:30.119 --> 00:19:33.839 is accurate. These moons were chemically complex from their very inception, and. 393 00:19:33.799 --> 00:19:36.079 That matters tremendously because of what happens next in a 394 00:19:36.079 --> 00:19:38.759 moon's life cycle differentiation. 395 00:19:38.440 --> 00:19:41.359 Yes, the crucial stage of internal differentiation. 396 00:19:41.519 --> 00:19:44.400 That's when the moon gets hot and separates into layers. 397 00:19:45.000 --> 00:19:47.279 The heavy stuff sinks to the metal, the light stuff 398 00:19:47.279 --> 00:19:48.440 floats to the top. Right. 399 00:19:48.759 --> 00:19:51.759 As these large moons grew, the immense pressure of their 400 00:19:51.839 --> 00:19:56.000 own gravity, combined with heat from radioactive decay inside the rocks, 401 00:19:56.440 --> 00:20:00.160