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 --> 00:00:23.800 slumber under the night sky. 7 00:00:26.879 --> 00:00:28.480 I want you to close your eyes for a second. Well, 8 00:00:28.519 --> 00:00:31.879 don't close them if you're driving, obviously, but picture the 9 00:00:32.039 --> 00:00:35.359 absolute worst place you can possibly imagine. Okay, and I 10 00:00:35.359 --> 00:00:38.000 don't mean the DMV on a Friday afternoon, and I 11 00:00:38.039 --> 00:00:41.960 don't mean a crowded subway car where the ac has broken. 12 00:00:42.439 --> 00:00:46.000 I mean a place where the environment itself is actively 13 00:00:46.039 --> 00:00:49.200 trying to kill you in about four different ways. Simultaneously. 14 00:00:49.439 --> 00:00:50.759 You're painting a lovely picture. 15 00:00:50.920 --> 00:00:53.960 I try my dest but seriously, imagine a world where 16 00:00:53.960 --> 00:00:56.399 the air pressure is so heavy it would crush a 17 00:00:56.479 --> 00:00:59.920 nuclear submarine like an empty soda can. The temperature is 18 00:01:00.079 --> 00:01:03.759 hot enough to melt lead, literally, a pool of lead 19 00:01:03.799 --> 00:01:05.719 would be a liquid puddle on the ground. 20 00:01:05.840 --> 00:01:09.280 Four hundred and seventy five degrees celsius, just searing. 21 00:01:09.000 --> 00:01:10.760 And to top it off. The clouds aren't made of 22 00:01:10.760 --> 00:01:13.400 water vapor, they are made of concentrated sulfuric acid. 23 00:01:13.599 --> 00:01:16.959 You are describing, of course, Earth's so called evil. 24 00:01:16.719 --> 00:01:20.280 Twin Venus, the planet that has been the graveyard of 25 00:01:20.359 --> 00:01:22.319 so many robotic explorers. 26 00:01:22.840 --> 00:01:25.439 It is a fortress, that is the best way to 27 00:01:25.480 --> 00:01:29.200 describe it. Historically, when we send landers there, like the 28 00:01:29.239 --> 00:01:32.719 Soviet venera probes back in the day, they survive for 29 00:01:33.200 --> 00:01:36.439 maybe an hour maybe two, before the electronics fry or 30 00:01:36.480 --> 00:01:40.000 the whole buckles just get cooked and crushed instantly. It 31 00:01:40.079 --> 00:01:43.000 is a world that keeps its secrets very very well 32 00:01:43.079 --> 00:01:46.239 hidden under those thick, toxic clouds. 33 00:01:46.359 --> 00:01:51.560 Exactly. It's the ultimate look but don't touch scenario. But today, Monday, 34 00:01:51.760 --> 00:01:55.519 February nine, twenty twenty six, we are not just looking 35 00:01:55.560 --> 00:01:58.959 at the fortress walls. We are cracking them open because 36 00:01:59.000 --> 00:02:02.599 there is breaking news today that fundamentally shifts our understanding 37 00:02:02.640 --> 00:02:03.400 of this healthscape. 38 00:02:03.519 --> 00:02:05.439 It really does. This is one of those days when 39 00:02:05.439 --> 00:02:06.760 the textbooks get a little update. 40 00:02:06.879 --> 00:02:09.960 Researchers from the University of Trento have confirmed the first 41 00:02:10.000 --> 00:02:14.039 direct physical evidence of a subsurface lava tube, essentially a 42 00:02:14.080 --> 00:02:15.879 massive cave on Venus. 43 00:02:15.599 --> 00:02:17.479 And we need to be clear about the magnitude of this. 44 00:02:17.719 --> 00:02:20.520 We aren't talking about a suspicion. We aren't talking about 45 00:02:20.520 --> 00:02:23.719 a mathematical model that suggests maybe there are caves. 46 00:02:24.240 --> 00:02:26.840 This isn't a we think, No, we. 47 00:02:26.759 --> 00:02:29.680 Are talking about hard evidence, a direct observation. 48 00:02:30.159 --> 00:02:32.599 This is the difference between guessing your neighbor has a 49 00:02:32.639 --> 00:02:35.520 basement and actually seeing the stairs leading down into. 50 00:02:35.280 --> 00:02:39.319 The dark precisely, and finding this on Venus, of all places. Yea, 51 00:02:39.639 --> 00:02:42.599 the steaks are huge. We have seen lava tubes on Mars, 52 00:02:42.639 --> 00:02:45.039 we have seen them on the Moon. They are fascinating 53 00:02:45.080 --> 00:02:49.039 there right, But finding one on Venus hidden beneath that 54 00:02:49.120 --> 00:02:53.080 opaque atmosphere validates decades of geological theory. 55 00:02:53.560 --> 00:02:55.840 So we are basing this entire deep dive on the 56 00:02:55.840 --> 00:02:58.919 primary source material. A brand new paper published today in 57 00:02:59.000 --> 00:03:03.080 Nature Communications titled Radar based Observation of a Lava Tube 58 00:03:03.080 --> 00:03:06.360 on Venus. It's led by Lorenzo Bruzon and his team 59 00:03:06.400 --> 00:03:07.599 at the University of Trento. 60 00:03:07.840 --> 00:03:11.520 A fantastic piece of research. It is incredibly detailed. 61 00:03:11.039 --> 00:03:13.319 And our mission for this deep dive is to really 62 00:03:13.439 --> 00:03:15.800 unpack this discovery. We aren't just talking about a hole 63 00:03:15.800 --> 00:03:17.520 in the ground Now we need to talk about the 64 00:03:17.520 --> 00:03:20.280 detective story. How they found this using data that is 65 00:03:20.319 --> 00:03:23.039 technically older than I am. We need to talk about 66 00:03:23.039 --> 00:03:25.280 the sheer scale of this thing, because when I read 67 00:03:25.319 --> 00:03:28.520 the numbers, my jaw hit the floor. This isn't a 68 00:03:28.560 --> 00:03:30.680 crawl space, it's a tunnel large enough to fit a 69 00:03:30.719 --> 00:03:31.319 city block. 70 00:03:31.520 --> 00:03:35.439 It puts our terrestrial case to shame utterly. 71 00:03:35.639 --> 00:03:38.159 And finally, we're going to discuss what this tells us 72 00:03:38.159 --> 00:03:42.479 about the volcanic history of our planetary neighbor. So buckle up, 73 00:03:42.879 --> 00:03:44.280 we are going beneath. 74 00:03:43.960 --> 00:03:45.879 The clouds into the dark. 75 00:03:46.439 --> 00:03:50.280 Let's start with the detective story. Because usually when we 76 00:03:50.280 --> 00:03:52.960 get breaking space news in twenty twenty six, it's from 77 00:03:53.159 --> 00:03:57.759 a flashy new robot. Right, We're used to the James 78 00:03:57.759 --> 00:04:01.800 Webb Space Telescope beaming back higher images of galaxies, or 79 00:04:02.120 --> 00:04:04.439 a rover on Mars drilling a new hole. 80 00:04:04.560 --> 00:04:08.879 Correct, we are accustomed to fresh data, new photons, hitting 81 00:04:08.919 --> 00:04:09.520 a new sensor. 82 00:04:09.639 --> 00:04:12.039 But that is not what happened here. This discovery is 83 00:04:12.039 --> 00:04:13.080 a bit of a ghost story. 84 00:04:13.240 --> 00:04:15.759 It is to understand why you have to understand the 85 00:04:15.759 --> 00:04:19.600 fundamental problem with exploring Venus. If you orbit Mars, you 86 00:04:19.600 --> 00:04:22.600 can bring a nice optical camera basically a really expensive 87 00:04:22.680 --> 00:04:25.199 DSLR and take a photograph. 88 00:04:24.600 --> 00:04:26.160 Of the surface and you see the ground. 89 00:04:26.279 --> 00:04:28.399 You can see the red rocks, the dust devils, the 90 00:04:28.439 --> 00:04:30.920 crater rims. It's intuitive. We understand pictures. 91 00:04:30.959 --> 00:04:33.000 But if you orbit Venus and take a photo, you. 92 00:04:33.000 --> 00:04:36.680 See a cue ball. You see a bright, featureless white sphere. 93 00:04:37.040 --> 00:04:39.399 Maybe if you swirls in the upper atmosphere, but that's it. 94 00:04:39.480 --> 00:04:40.439 Because of the clouds. 95 00:04:40.720 --> 00:04:45.120 The atmosphere is incredibly thick and opaque. Visible light just 96 00:04:45.240 --> 00:04:47.399 bounces off the top of the cloud deck. You cannot 97 00:04:47.399 --> 00:04:49.480 see the ground. So if you want to map the 98 00:04:49.519 --> 00:04:52.519 surface of Venus, you cannot use a camera. You have 99 00:04:52.560 --> 00:04:53.160 to use radar. 100 00:04:53.240 --> 00:04:54.959 You have to scream at the planet and listen to 101 00:04:54.959 --> 00:04:55.399 the echo. 102 00:04:55.759 --> 00:04:58.199 That is a very aggressive way to put it, but yes, essentially, 103 00:04:58.319 --> 00:05:01.160 you bounce radio waves off the surface and measure how 104 00:05:01.160 --> 00:05:04.399 they come back to you, the timing, the strength that 105 00:05:04.519 --> 00:05:05.680 builds a picture. 106 00:05:05.519 --> 00:05:08.160 And that brings us to the time capsule aspect of 107 00:05:08.160 --> 00:05:12.079 today's news. The data that the University of Trento team 108 00:05:12.279 --> 00:05:16.839 used it didn't come from a ship currently orbiting Venus. No, no, 109 00:05:17.439 --> 00:05:19.399 it came from NASA's Magellan. 110 00:05:19.000 --> 00:05:21.920 Spacecraft, which is a name that should trigger some nostalgia 111 00:05:21.920 --> 00:05:22.839 for some of our listeners. 112 00:05:22.879 --> 00:05:26.879 Seriously, Magellan launched in nineteen eighty nine. It was deployed 113 00:05:26.879 --> 00:05:29.319 from the Space Shuttle Atlantis. I mean we're talking about 114 00:05:29.319 --> 00:05:32.000 a different era of space exploration, pre Internet. 115 00:05:32.199 --> 00:05:36.120 Practically, it mapped Venus between nineteen ninety and nineteen ninety two. 116 00:05:36.120 --> 00:05:38.439 Okay, nineteen ninety to nineteen ninety two, and then. 117 00:05:38.319 --> 00:05:41.079 It was intentionally steered into the atmosphere and burned up 118 00:05:41.120 --> 00:05:42.000 in nineteen ninety four. 119 00:05:42.360 --> 00:05:45.639 So let's pause and appreciate this. The spacecraft has been 120 00:05:45.680 --> 00:05:47.360 vaporized for over thirty years. 121 00:05:47.480 --> 00:05:49.120 It's gone completely gone. 122 00:05:49.000 --> 00:05:51.800 But we are still making headline discoveries in twenty twenty 123 00:05:51.839 --> 00:05:54.160 six from the data it's sent back when the Internet 124 00:05:54.199 --> 00:05:55.279 was barely a concept. 125 00:05:55.399 --> 00:05:57.519 It is a testament to the quality of that mission. 126 00:05:58.120 --> 00:06:01.600 Magellan was a workhorse, mapped about ninety eight percent of 127 00:06:01.639 --> 00:06:05.160 the Venusian surface with its radar. But it also highlights 128 00:06:05.160 --> 00:06:09.120 a very important concept in modern science data archaeology. 129 00:06:09.240 --> 00:06:11.959 Data archaeology. I love that term. It makes me picture 130 00:06:12.000 --> 00:06:14.199 Indiana Jones, but instead of a whip, he has a hard. 131 00:06:14.079 --> 00:06:18.920 Drive, ideally with fewer movie traps. But the concept is sound. 132 00:06:19.079 --> 00:06:22.439 The pixels, so to speak, the raw radar returns were 133 00:06:22.439 --> 00:06:26.319 always there. They were sitting in NASA's Planetary Data System archives, 134 00:06:26.439 --> 00:06:29.399 just waiting, just waiting. But in nineteen ninety two, we 135 00:06:29.480 --> 00:06:32.480 didn't have the processing power we had today. We didn't 136 00:06:32.519 --> 00:06:35.639 have the sophisticated algorithms to filter out noise and enhance 137 00:06:35.639 --> 00:06:38.120 the signal. It was cutting edge for its time, but 138 00:06:38.199 --> 00:06:39.519 by our standards, it's. 139 00:06:39.360 --> 00:06:41.240 Like trying to play a modern video game on a 140 00:06:41.240 --> 00:06:42.680 computer from nineteen ninety two. 141 00:06:42.720 --> 00:06:45.399 You just can't exactly. The hardware and software couldn't do 142 00:06:45.439 --> 00:06:46.439 what we can do now. 143 00:06:46.720 --> 00:06:49.560 So the picture didn't change, but our glasses got better. 144 00:06:49.839 --> 00:06:53.160 That's a perfect analogy. The data is a fixed asset, 145 00:06:53.439 --> 00:06:57.000 it doesn't rot, but our ability to understand it evolves. 146 00:06:57.720 --> 00:07:01.319 Lorenzo Bruzon and his team at the Remote Sensing Laboratory 147 00:07:01.720 --> 00:07:04.959 that's the University of Trento. They didn't just casually scroll 148 00:07:05.000 --> 00:07:06.079 through the old images. 149 00:07:06.199 --> 00:07:07.399 No, this wasn't an accident. 150 00:07:07.519 --> 00:07:12.240 No, they developed a specific new imaging technique. They created 151 00:07:12.319 --> 00:07:14.600 new tools to look at this old information. 152 00:07:14.759 --> 00:07:16.160 They were looking for something specific, right. 153 00:07:16.199 --> 00:07:18.879 They weren't just browsing, No, this was a targeted hunt. 154 00:07:19.319 --> 00:07:22.240 Their goal, as stated in the paper, was to detect 155 00:07:22.240 --> 00:07:24.560 and characterize underground conduits. 156 00:07:24.959 --> 00:07:28.360 Conduits a fancy geological word for tunnels. 157 00:07:27.959 --> 00:07:31.199 In this context, Yes, lavitat. They were looking for specific 158 00:07:31.199 --> 00:07:33.800 surface anomalies that would hint at a hollow space beneath 159 00:07:33.839 --> 00:07:34.160 the rock. 160 00:07:34.399 --> 00:07:37.600 So they are combing through this massive noisy data set 161 00:07:37.639 --> 00:07:40.639 from the early nineties, applying these new algorithms to clean 162 00:07:40.680 --> 00:07:42.600 it up, to filter out the static. 163 00:07:42.319 --> 00:07:45.279 Exactly, and they focused their attention on a region called 164 00:07:45.399 --> 00:07:49.759 nix Mons. Nex Mons a fitting name for a dark discovery. 165 00:07:49.839 --> 00:07:51.319 Why is that? What does it mean? 166 00:07:51.759 --> 00:07:54.079 Nix is the Greek goddess of the night. 167 00:07:54.439 --> 00:07:57.319 Spooky like it, so a mountain of night. 168 00:07:57.720 --> 00:08:01.399 Nix Mons is a large vulcanic rise in the northern 169 00:08:01.480 --> 00:08:05.759 hemisphere of Venus. It's a place that has fascinated geologists 170 00:08:05.839 --> 00:08:09.639 for a while because it shows signs of heavy volcanic activity, 171 00:08:10.160 --> 00:08:13.560 lots of lava flows, lots of fractures. It's a geologically 172 00:08:13.639 --> 00:08:14.319 interesting place. 173 00:08:14.399 --> 00:08:16.319 So if you're going to find a giant lava tube, 174 00:08:16.360 --> 00:08:18.439 a big volcano is a good place to start looking, 175 00:08:18.519 --> 00:08:20.639 the best place. Okay, so they are looking at nix 176 00:08:20.680 --> 00:08:23.160 Bond's But here is the part that confuses people, and 177 00:08:23.240 --> 00:08:26.759 it confused me at first. You said, Magellan used radar 178 00:08:26.839 --> 00:08:27.839 to map the surface. 179 00:08:28.160 --> 00:08:28.600 That's right. 180 00:08:28.800 --> 00:08:31.920 Radar bounces off to ground. It doesn't go through the ground. 181 00:08:31.959 --> 00:08:35.320 That is correct. At least Magellan's specific radar frequency could 182 00:08:35.320 --> 00:08:38.120 not penetrate deep into the rock. It just tells you 183 00:08:38.159 --> 00:08:40.279 what the surface looks like. It's roughness, it's slope. 184 00:08:40.360 --> 00:08:42.600 So if there is a tunnel underground and the roof 185 00:08:42.679 --> 00:08:45.600 is solid rock, Magellan would just see a flat plane. 186 00:08:45.679 --> 00:08:47.399 It wouldn't see the tunnel exactly. 187 00:08:47.480 --> 00:08:49.039 You would fly right over it and never know it 188 00:08:49.080 --> 00:08:49.440 was there. 189 00:08:49.480 --> 00:08:50.519 So how did they find it? 190 00:08:50.559 --> 00:08:52.279 What was the clue they had to look for? The 191 00:08:52.320 --> 00:08:55.919 smoking gun? In planetary geology, when you were hunting for 192 00:08:56.000 --> 00:08:58.519 lava tubes, you're actually hunting for skylights. 193 00:08:58.799 --> 00:09:02.279 A skylight oka that when I hear skylight, I think 194 00:09:02.279 --> 00:09:04.159 of a nice window in a kitchen to let some 195 00:09:04.279 --> 00:09:04.679 sun in. 196 00:09:05.440 --> 00:09:08.840 Not quite though. The principle of letting light in is similar, 197 00:09:08.960 --> 00:09:10.519 or in this case, letting radar in. 198 00:09:10.639 --> 00:09:10.960 Got it. 199 00:09:11.080 --> 00:09:13.279 Think about how a lava tube forms. You have a 200 00:09:13.360 --> 00:09:16.960 river of lava, the top cools and hardens into a 201 00:09:17.039 --> 00:09:21.399 roof because it's exposed to the air. The lava inside 202 00:09:21.480 --> 00:09:25.720 keeps flowing and drains away, leaving a long hollow tunnel like. 203 00:09:25.679 --> 00:09:27.879 A subway tunnel, but made of basalt. 204 00:09:28.159 --> 00:09:31.320 Right now, imagine a million years pass, maybe a meteor 205 00:09:31.360 --> 00:09:34.080 hits the area, maybe a venus quake shakes the ground, 206 00:09:34.320 --> 00:09:36.720 or maybe gravity just wins and a section of that 207 00:09:36.799 --> 00:09:37.840 roof becomes unstable. 208 00:09:37.919 --> 00:09:38.519 It caves in. 209 00:09:38.679 --> 00:09:41.360 It caves in, and that collapse creates a pit on 210 00:09:41.399 --> 00:09:45.639 the surface, a hole. That pit is the skylight. It 211 00:09:45.679 --> 00:09:47.519 connects the surface world to the underworld. 212 00:09:47.559 --> 00:09:49.320 So if you spot the hole, you can infer the 213 00:09:49.399 --> 00:09:50.120 room below it. 214 00:09:50.120 --> 00:09:50.639 It's the one. 215 00:09:50.679 --> 00:09:53.240 You can't see the tunnel directly with Magellan's radar, but 216 00:09:53.279 --> 00:09:54.559 you can see where the roof failed. 217 00:09:54.799 --> 00:09:58.440 That is the logic. And in the Magellan data, specifically 218 00:09:58.519 --> 00:10:01.039 in the next Mons region, they found a series of 219 00:10:01.080 --> 00:10:04.559 these features called pit chains, but they focused on one 220 00:10:04.600 --> 00:10:08.080 specific feature. It's marked as a in the study figures 221 00:10:08.279 --> 00:10:11.120 that looked exactly like a skylight into a massive void. 222 00:10:11.679 --> 00:10:14.559 But here is the tricky part. I've seen radar images. 223 00:10:14.960 --> 00:10:17.559 They are weird. They don't look like normal photos. 224 00:10:17.559 --> 00:10:18.399 They're not intuitive. 225 00:10:18.440 --> 00:10:21.240 No bright means rough, dark means smooth. 226 00:10:22.240 --> 00:10:24.799 It's all backwards. How can they tell it's a deep 227 00:10:24.799 --> 00:10:27.720 hole and not just a shallow dish or a regular 228 00:10:27.759 --> 00:10:28.399 impact crater. 229 00:10:28.879 --> 00:10:31.519 It is all about the shadows. This is where the 230 00:10:31.600 --> 00:10:35.039 detective work gets mathematical. In the study, they point out 231 00:10:35.080 --> 00:10:38.399 a white arrow in the imagery. That arrow indicates the 232 00:10:38.440 --> 00:10:42.440 direction the radar illumination is coming from. Magellan wasn't directly overhead. 233 00:10:42.960 --> 00:10:45.399 It's radar beam hit the surface at an angle. 234 00:10:45.200 --> 00:10:48.320 The direction the spacecraft was shining its radio flashlight exactly. 235 00:10:48.679 --> 00:10:51.559 Now, imagine a deep vertical shaft. If you shine a 236 00:10:51.559 --> 00:10:54.039 flashlight across the top of it from the side, the 237 00:10:54.120 --> 00:10:55.840 far wall is going to catch the light and be 238 00:10:55.919 --> 00:10:57.240 very bright in your radar image. 239 00:10:57.279 --> 00:10:59.759 Okay, it reflects the signal right back. But the near 240 00:11:00.279 --> 00:11:02.720 the ring closest to you is going to cast a 241 00:11:02.759 --> 00:11:05.879 shadow down into the hole, and the floor of the 242 00:11:05.919 --> 00:11:08.799 pit will be in that shadow. It will look dark. 243 00:11:09.000 --> 00:11:11.000 Ah, okay, I'm visualizing that. 244 00:11:11.159 --> 00:11:15.080 By analyzing how that shadow falls and specifically measuring the 245 00:11:15.159 --> 00:11:17.840 length and intensity of the shadow within the pit, you 246 00:11:17.879 --> 00:11:20.840 can calculate geometry. You can figure out that this isn't 247 00:11:20.840 --> 00:11:24.279 a bowl shape like a crater. A crater has slope sides. 248 00:11:24.480 --> 00:11:25.960 Right, the shadow would look different. 249 00:11:26.080 --> 00:11:28.320 It looked very different. The only model that fit the 250 00:11:28.399 --> 00:11:31.440 data they were seeing was a deep, steep walled shaft. 251 00:11:31.720 --> 00:11:33.960 It's amazing what you can do with shadows. It feels 252 00:11:34.039 --> 00:11:38.159 very Sherlock Holmes. The shadow is three pixels long, Watson. 253 00:11:38.240 --> 00:11:40.399 Therefore the hole is four hundred meters deep. 254 00:11:40.559 --> 00:11:43.120 It is essentially trigonometry in physics. Yeah, but yes, it 255 00:11:43.159 --> 00:11:46.519 is detective work. They model the radar signals against different shapes, 256 00:11:46.679 --> 00:11:49.960 a shallow crater, a deep pit, a cone, and the 257 00:11:50.000 --> 00:11:52.559 only model that fit the data from Magellan was a 258 00:11:52.600 --> 00:11:55.840 deep vertical skylight connecting to a subsurface void. 259 00:11:56.080 --> 00:11:58.200 And that void. Well, that's the part that really blew 260 00:11:58.200 --> 00:11:59.799 my mind when I was reading the briefing, because we 261 00:11:59.840 --> 00:12:01.360 are talking about a little cross space. 262 00:12:01.559 --> 00:12:02.399 No, we're not. 263 00:12:03.039 --> 00:12:05.480 We really need to get into the numbers here. The 264 00:12:05.519 --> 00:12:07.720 scale of this thing is hard to wrap your head around. 265 00:12:08.039 --> 00:12:11.000 It is massive, genuinely geologically massive. 266 00:12:11.120 --> 00:12:13.600 Start with the diameter. How wide is this tube? 267 00:12:13.759 --> 00:12:17.159 The study estimates that diameter is approximately one kilometer one 268 00:12:17.639 --> 00:12:20.159 one kilometer, yes, one thousand meters. 269 00:12:20.240 --> 00:12:23.360 Okay, stop and visualize that. Seriously, A kilometer is a 270 00:12:23.360 --> 00:12:26.320 distinct distance. If you are driving on a highway, a 271 00:12:26.399 --> 00:12:30.519 kilometer takes a moment to pass. Imagine a tunnel that wide. 272 00:12:30.840 --> 00:12:33.840 You could fit the Burje Khalifa inside its sideways with 273 00:12:33.960 --> 00:12:34.679 room to spare. 274 00:12:35.120 --> 00:12:37.919 It is vastly larger than terrestrial lava tubes. It's not 275 00:12:37.960 --> 00:12:39.320 even in the same ballpark. Right. 276 00:12:39.600 --> 00:12:42.360 I've been to lava tubes in Hawaii, that Casumora Cave. 277 00:12:42.440 --> 00:12:45.879 It's amazing. It's a fantastic experience, but it's human scale. 278 00:12:45.919 --> 00:12:47.960 I mean, some parts are big, like a subway station, 279 00:12:48.279 --> 00:12:49.519 but some parts you have to duck. 280 00:12:49.679 --> 00:12:54.399 Exactly. On Earth, a large lava tube might be ten twenty, 281 00:12:54.480 --> 00:12:55.720 maybe thirty meters wide. 282 00:12:55.759 --> 00:12:57.399 Thirty meters would be a big one, and. 283 00:12:57.440 --> 00:12:59.559 Finding one that is one hundred meters wide would be 284 00:12:59.559 --> 00:13:03.519 a headline, a major discovery. This Venusian structure is on 285 00:13:03.519 --> 00:13:06.919 a completely different scale. It is an order of magnitude larger. 286 00:13:07.200 --> 00:13:10.480 And it's not just the width, it's the protection. How 287 00:13:10.519 --> 00:13:11.720 thick is the roof. 288 00:13:11.600 --> 00:13:14.720 Right, the roof thickness. They estimated that there is at 289 00:13:14.799 --> 00:13:18.639 least one hundred and fifty meters of solid rock shielding 290 00:13:18.679 --> 00:13:19.919 this void from the surface. 291 00:13:20.279 --> 00:13:23.320 That's a fifty story building worth of rock above your head, 292 00:13:23.600 --> 00:13:25.399 just solid basalt, and. 293 00:13:25.399 --> 00:13:28.559 The void itself. The empty space below that roof is 294 00:13:28.559 --> 00:13:30.759 at least three hundred and seventy five meters. 295 00:13:30.399 --> 00:13:33.279 Deep, So from the floor of the tube to the 296 00:13:33.320 --> 00:13:36.840 ceiling is three hundred and seventy five meters at a minimum. 297 00:13:36.879 --> 00:13:38.480 That's what they can model from the shadows. 298 00:13:38.559 --> 00:13:42.120 It's cavernous. It's practically an underground canyon. It's a cathedral geology. 299 00:13:42.240 --> 00:13:44.879 And while the direct observation is limited to the area 300 00:13:44.960 --> 00:13:47.600 around the skylight, because that's where we can see the shadow, 301 00:13:48.120 --> 00:13:51.080 the morphology of the terrain suggests the tube extends for 302 00:13:51.159 --> 00:13:54.080 a long way. You can see these chains of pits, 303 00:13:54.200 --> 00:13:55.679 these other potential collapses. 304 00:13:55.799 --> 00:13:58.440 So this one skylight is just one window into a 305 00:13:58.440 --> 00:14:01.000 whole subway system, a huge one. How long do they 306 00:14:01.039 --> 00:14:01.480 think it is? 307 00:14:01.759 --> 00:14:05.000 They estimate this specific segment based on this rounding geology, 308 00:14:05.200 --> 00:14:07.039 is at least forty five kilometers long. 309 00:14:07.200 --> 00:14:10.879 A forty five kilometer tunnel one kilumeter wide, buried under 310 00:14:10.919 --> 00:14:13.799 a mountain of rock. That is some serious infrastructure. 311 00:14:13.960 --> 00:14:16.600 The researchers use the term pyroduct. 312 00:14:16.159 --> 00:14:18.000 Pyroduct that sounds like a heavy metal band. 313 00:14:18.080 --> 00:14:21.519 It is the formal scientific term pyro meaning fire duct, 314 00:14:21.600 --> 00:14:23.519 meaning channel, a channel of fire. 315 00:14:23.720 --> 00:14:27.200 The pyroducks of nix Mon's I'd buy that album. 316 00:14:27.360 --> 00:14:29.519 It does have a certain ring to it, but it 317 00:14:29.639 --> 00:14:32.480 describes exactly what this was. It was a massive plumbing 318 00:14:32.519 --> 00:14:35.240 system for magma on a scale we just don't have 319 00:14:35.320 --> 00:14:35.759 on Earth. 320 00:14:35.919 --> 00:14:39.240 But this brings up the question of why why is 321 00:14:39.440 --> 00:14:41.320 everything on Venus so extra? 322 00:14:41.440 --> 00:14:42.200 It's a good question. 323 00:14:42.480 --> 00:14:45.159 Why is the atmosphere so thick, the temperature so hot, 324 00:14:45.320 --> 00:14:49.200 and now the cave's so enormous? Why is this tube 325 00:14:49.360 --> 00:14:51.480 so much bigger than what we see on Earth or 326 00:14:51.519 --> 00:14:52.159 even Mars? 327 00:14:52.720 --> 00:14:55.919 Because we share a lot of DNA with Venus planet wise, we. 328 00:14:55.960 --> 00:14:58.399 Do, and this is where we get into the fascinating 329 00:14:58.440 --> 00:15:01.960 field of comparative planetology. It shows how the unique environment 330 00:15:02.000 --> 00:15:04.720 of a planet dictates its geology. It's not just about 331 00:15:04.720 --> 00:15:07.279 the rock, it's about the air and the gravity too. 332 00:15:07.519 --> 00:15:09.600 We know lava tubes aren't unique to Venus, right, We've 333 00:15:09.600 --> 00:15:12.440 seen them elsewhere correct, As we said, We see them 334 00:15:12.440 --> 00:15:15.159 on Earth, usually in places with the saltic lava flows 335 00:15:15.240 --> 00:15:19.159 like Hawaii, Iceland, the Canary Islands. We see them on Mars. 336 00:15:19.559 --> 00:15:22.200 We've seen skylights on the slopes of the giant Martian 337 00:15:22.279 --> 00:15:24.879 volcanoes like Rga Monds and the moon, and we see 338 00:15:24.919 --> 00:15:27.399 them on the Moon. They're called sinuous rills. So the 339 00:15:27.399 --> 00:15:31.000 recipe is the same lava flows, top cools, tube forms. 340 00:15:31.120 --> 00:15:32.559 The mechanism is universal. 341 00:15:32.639 --> 00:15:36.639 The mechanism is universal, but the ingredients, the environmental variables 342 00:15:36.960 --> 00:15:40.039 are different. And the expert analysis in the paper points 343 00:15:40.080 --> 00:15:43.279 to two main factors driving this massive scale on Venus. 344 00:15:43.480 --> 00:15:44.960 Okay, hit me with them. What's the first? 345 00:15:44.960 --> 00:15:46.600 One factor? One gravity? 346 00:15:46.720 --> 00:15:49.240 Venus is slightly smaller than Earth, right. 347 00:15:49.159 --> 00:15:52.440 Very slightly. It's gravity is about ninety percent of Earth's. Now, 348 00:15:52.440 --> 00:15:54.200 that might not sound like a huge difference to you 349 00:15:54.320 --> 00:15:55.960 or me. If you weigh one hundred pounds on Earth, 350 00:15:56.000 --> 00:15:57.399 you'd weigh ninety on Venus. 351 00:15:57.559 --> 00:15:58.919 Nice instant diet. 352 00:15:58.879 --> 00:16:02.000 Sure, But when we are talking about millions of tons 353 00:16:02.000 --> 00:16:04.879 of molten rock flowing across a landscape, that ten percent 354 00:16:04.919 --> 00:16:08.639 difference in gravity matters. Lower gravity allows lava flows to 355 00:16:08.679 --> 00:16:11.720 be somewhat taller and wider because the fluid isn't being 356 00:16:11.759 --> 00:16:14.879 pulled down quite as hard. The rock itself can support 357 00:16:14.960 --> 00:16:17.759 larger structures that they're collapsing under its own weight. 358 00:16:17.960 --> 00:16:20.000 So the roof can be wider without caving in. 359 00:16:20.320 --> 00:16:23.320 Precisely, we see this effect on the Moon, where gravity 360 00:16:23.399 --> 00:16:26.360 is very low one sixth the Earth's. The tubes there 361 00:16:26.360 --> 00:16:28.639 are huge hundreds of meters wide, but. 362 00:16:28.639 --> 00:16:31.840 Venus's gravity is pretty close to Earth's. That ten percent 363 00:16:31.879 --> 00:16:33.679 can't be the only reason we're going from a thirty 364 00:16:33.679 --> 00:16:35.200 meter tube to a one thousand meters two. 365 00:16:35.480 --> 00:16:38.279 You are right, gravity helps, but it's not the main driver. 366 00:16:38.559 --> 00:16:41.840 The main driver is likely factor too, the atmosphere. This soup, 367 00:16:42.039 --> 00:16:45.799 the soup the pressure cooker. Venus has an incredibly dense 368 00:16:45.799 --> 00:16:49.519 atmosphere ninety times the pressure of Earth, and it is hot, 369 00:16:49.559 --> 00:16:52.480 surface temperatures around four hundred and seventy five degrees celsius. 370 00:16:53.000 --> 00:16:55.120 Now, intuition tells me that if it's hot outside, the 371 00:16:55.159 --> 00:16:57.840 lava wouldn't cool as fast. Like if I pour coffee 372 00:16:57.840 --> 00:16:59.720 in asuna, it stays hot longer than in. 373 00:16:59.720 --> 00:17:02.840 A free That is true for the liquid itself, but 374 00:17:02.879 --> 00:17:06.279 the paper argues that the dense atmosphere and the specific 375 00:17:06.279 --> 00:17:09.839 conditions favor the rapid creation of a thick, insulating crust 376 00:17:10.440 --> 00:17:12.599 immediately after the lava leaves the vent. 377 00:17:12.559 --> 00:17:15.839 Wait, so the crust forms faster. That feels counterintuitive. 378 00:17:15.960 --> 00:17:18.599 It forms a more robust crust. Think of the lava 379 00:17:18.640 --> 00:17:22.400 flow emerging onto the surface. The heavy, dense atmosphere pushes 380 00:17:22.440 --> 00:17:25.480 against it from all sides. The interaction between the hot 381 00:17:25.559 --> 00:17:29.519 lava and this incredibly dense hot gas creates a coherent 382 00:17:29.599 --> 00:17:30.480 lid very. 383 00:17:30.359 --> 00:17:32.720 Quickly, like putting a heavy lid on a pot. 384 00:17:32.599 --> 00:17:35.880 Exactly, and rock is a great insulator. Once that thick 385 00:17:35.920 --> 00:17:39.279 crust forms, it acts as a thermal blanket. It traps 386 00:17:39.319 --> 00:17:42.200 the heat inside the flow incredibly efficiently. 387 00:17:41.759 --> 00:17:44.599 So it becomes a super thermos The outside cools just 388 00:17:44.720 --> 00:17:47.519 enough to make a shell, and the inside stays molten. 389 00:17:47.319 --> 00:17:51.559 Precisely a natural geological pipeline. Because that crust forms so 390 00:17:51.599 --> 00:17:55.359 effectively and creates such good insulation, the lava inside stays 391 00:17:55.400 --> 00:17:57.920 hot and liquid for a very very long time. This 392 00:17:58.000 --> 00:18:00.799 will was Lasa to flow for huge distances hundreds of 393 00:18:00.839 --> 00:18:02.359 kilometers without freezing up. 394 00:18:02.400 --> 00:18:04.640 And because it keeps flowing for so long and stays 395 00:18:04.640 --> 00:18:05.400 so hot. 396 00:18:05.440 --> 00:18:09.160 It creates a process called thermal erosion. The lava is 397 00:18:09.279 --> 00:18:12.119 so hot and flows for so long that it actually 398 00:18:12.160 --> 00:18:15.000 melts the ground beneath it. It carves its way down into 399 00:18:15.000 --> 00:18:15.559 the bedrock. 400 00:18:15.759 --> 00:18:18.559 It digs its own grave or its own tunnel. 401 00:18:18.599 --> 00:18:21.079