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 --> 00:00:25.719 slumber under the night sky. 7 00:00:26.879 --> 00:00:29.359 I want you to just close your eyes for a second. 8 00:00:29.679 --> 00:00:32.719 Try to imagine the absolute most extreme environment you can 9 00:00:32.719 --> 00:00:35.679 possibly conceive of. Oh wow, okay, yeah, And I don't 10 00:00:35.719 --> 00:00:39.280 just mean like a place that's uncomfortably hot. I want 11 00:00:39.320 --> 00:00:43.000 you to picture an entirely different physical reality. 12 00:00:42.679 --> 00:00:44.600 Right, like completely alien exactly. 13 00:00:44.759 --> 00:00:47.759 Imagine you're standing on a shoreline, but the ocean stretching 14 00:00:47.759 --> 00:00:50.200 out in front of you, it isn't made of water. 15 00:00:50.600 --> 00:00:54.600 It is this vast, churning sea of molten silicate rock, 16 00:00:55.000 --> 00:00:57.679 just glowing this deep orange in the dark. 17 00:00:57.759 --> 00:00:59.280 That is terrifying it is. 18 00:00:59.600 --> 00:01:01.799 And you look up and the sky isn't blue, It's 19 00:01:01.799 --> 00:01:06.840 this thick, suffocating, opaque haze. And the smell, the smell 20 00:01:06.879 --> 00:01:09.760 of the air around you is just punishingly toxic. It's 21 00:01:09.840 --> 00:01:12.959 overwhelmingly dominated by the scent of rotting eggs. 22 00:01:13.159 --> 00:01:15.920 It is a literal sensory nightmare. I mean, it's a 23 00:01:15.920 --> 00:01:18.719 hellscape of the highest order where the very concept of 24 00:01:18.719 --> 00:01:21.000 a solid surface basically ceases to exist. 25 00:01:21.079 --> 00:01:22.959 It really does. But the crazy thing is we are 26 00:01:22.959 --> 00:01:25.640 talking about a very real place. It's a super earth 27 00:01:25.799 --> 00:01:28.280 known as L ninety eight fifty nine DY, which. 28 00:01:28.079 --> 00:01:30.920 Is about thirty five light years away from us, right, yeah, 29 00:01:30.920 --> 00:01:31.959 the constellation Vila. 30 00:01:32.239 --> 00:01:36.000 Yeah, exactly thirty five light years. But we aren't going 31 00:01:36.079 --> 00:01:38.879 on a mental journey to this world today just for 32 00:01:39.040 --> 00:01:43.159 the novelty of, you know, looking at a bizarre, stinky planet. 33 00:01:43.280 --> 00:01:46.120 No, definitely not. There's a much bigger reason, right, We. 34 00:01:46.079 --> 00:01:49.239 Are looking at this specific world because it actually happens 35 00:01:49.280 --> 00:01:52.439 to be the smoking gun that solves one of the 36 00:01:52.439 --> 00:01:55.159 most frustrating cold cases in modern astronomy. 37 00:01:55.159 --> 00:01:57.000 Oh absolutely, it's a total game changer. 38 00:01:57.200 --> 00:01:59.319 So before we even talk about the molten notions or 39 00:01:59.359 --> 00:02:01.519 the toxics guy, we kind of need to set the 40 00:02:01.519 --> 00:02:05.719 stakes for you because for years planetary scientists have basically 41 00:02:05.719 --> 00:02:09.120 been staring at this massive glaring hole in our map 42 00:02:09.159 --> 00:02:09.960 of the galaxy. 43 00:02:10.080 --> 00:02:13.000 Yeah, the Radius Valley, or some people call it the 44 00:02:13.039 --> 00:02:16.000 Fulton Gap that was the original name when the Kepler 45 00:02:16.039 --> 00:02:18.919 Space telescope data first brought it to light, the Fulton Gap, 46 00:02:19.120 --> 00:02:21.560 and it is one of the most profound mysteries in 47 00:02:21.680 --> 00:02:25.599 exoplanet demographics. I mean, when you plot out every single 48 00:02:25.639 --> 00:02:28.879 small exoplanet we have ever discovered on a graph, just 49 00:02:28.919 --> 00:02:32.479 based on their physical size, you expect to see relatively 50 00:02:32.520 --> 00:02:35.319 smooth distribution like a Bell curve, right exactly like a 51 00:02:35.319 --> 00:02:38.680 Bell curve, or maybe you know, a steady drop off 52 00:02:38.680 --> 00:02:40.599 as planets get larger and harder to form. 53 00:02:40.919 --> 00:02:43.639 But instead the graph looks, well, it looks like a 54 00:02:43.680 --> 00:02:46.680 mountain range with this massive canyon carved right down the 55 00:02:46.719 --> 00:02:47.280 middle of it. 56 00:02:47.280 --> 00:02:48.919 It's so weird, it really is a canyon. 57 00:02:49.039 --> 00:02:52.759 Yeah. So we see this huge peak of rocky planets 58 00:02:53.000 --> 00:02:55.520 that are about the size of Earth up to maybe 59 00:02:55.759 --> 00:03:00.280 like one point four times Earth's radius, right the terrestrial worlds, 60 00:03:00.599 --> 00:03:04.039 and then further down the graph we see another huge 61 00:03:04.080 --> 00:03:06.599 peak of planets that are bigger around two to three 62 00:03:06.599 --> 00:03:08.199 times Earth's radius. 63 00:03:07.960 --> 00:03:11.960 The mini Neptunes. Those are the ones with thick, puffy atmospheres. 64 00:03:11.360 --> 00:03:14.960 AGAs exactly, but right in the middle between one point 65 00:03:15.000 --> 00:03:17.719 five and two times the size of Earth. The population 66 00:03:17.800 --> 00:03:19.879 of planets just absolutely plummet. 67 00:03:19.919 --> 00:03:20.960 It's complete dead zone. 68 00:03:21.039 --> 00:03:21.759 It's just empty. 69 00:03:22.000 --> 00:03:24.599 Yeah, the planets simply go missing in that size bracket. 70 00:03:24.599 --> 00:03:27.759 And the thing is, it is statistically impossible for that 71 00:03:27.879 --> 00:03:30.719 gap to be an accident of our observation methods. 72 00:03:30.919 --> 00:03:32.879 Like, it's not just a glitch in the telescopes. 73 00:03:33.120 --> 00:03:36.639 No, not at all. The universe is actively preventing planets 74 00:03:36.840 --> 00:03:41.039 from staying in that specific size range. Or and this 75 00:03:41.159 --> 00:03:44.360 was the leading idea, it's rapidly stripping them down so 76 00:03:44.400 --> 00:03:45.919 they fall into the smaller category. 77 00:03:46.000 --> 00:03:49.879 Right, So the leading theory for a long time was atmospheric. 78 00:03:49.240 --> 00:03:52.599 Loss yep photo evaporation, the idea being that a planet 79 00:03:52.680 --> 00:03:55.960 might form with a thick hydrogen envelope, which puts it 80 00:03:55.960 --> 00:03:59.240 in that larger mini neptune category, but if it orbits 81 00:03:59.280 --> 00:04:01.400 too close to its host star, the. 82 00:04:01.360 --> 00:04:04.680 Intense radiation just eventually boils that atmosphere away. 83 00:04:04.719 --> 00:04:08.319 It boils away, the planet shrinks, crosses that forbidden zone 84 00:04:08.319 --> 00:04:11.039 of the radius valley really quickly. It ends up just 85 00:04:11.080 --> 00:04:13.439 a bare, rocky core on the other. 86 00:04:13.319 --> 00:04:17.000 Side, exactly. And so the assumption for decades was that 87 00:04:17.079 --> 00:04:21.279 planetary evolution is fundamentally a story of subtractions attraction. 88 00:04:21.399 --> 00:04:23.519 Right, you start big, the star strips you, you end 89 00:04:23.560 --> 00:04:24.040 up small. 90 00:04:24.120 --> 00:04:27.199 It was this really neat binary framework. Path one you 91 00:04:27.480 --> 00:04:29.800 somehow hold onto your gas, maybe you're far enough away 92 00:04:29.839 --> 00:04:32.439 from the star and you stay a mini neptune. And 93 00:04:32.519 --> 00:04:34.800 path two, Path two is your star strips you naked 94 00:04:34.839 --> 00:04:36.439 and you become a bare rock, which. 95 00:04:36.199 --> 00:04:38.360 Is so intuitive it makes perfect physical sense. 96 00:04:38.600 --> 00:04:42.160 It does, especially based on how aggressive we know young 97 00:04:42.240 --> 00:04:45.639 stars can be, particularly the en dwarfs, the red dwarf stars. 98 00:04:45.399 --> 00:04:47.800 And those are the most common stars in our galaxy. 99 00:04:47.439 --> 00:04:51.480 Right by far, and they are notorious for violent stellar 100 00:04:51.519 --> 00:04:56.800 flares and this intense extreme ultraviolet radiation that basically acts 101 00:04:56.839 --> 00:04:59.759 like a blow torch on planetary atmosphere. 102 00:04:59.399 --> 00:05:01.199 A blow to That's a great way to put it, 103 00:05:01.240 --> 00:05:03.439 which brings us back to our target. L ninety eight 104 00:05:03.480 --> 00:05:06.759 fifty nine D yes the rule breaker. 105 00:05:06.519 --> 00:05:10.680 Because this specific planet, in this specific star system just 106 00:05:11.120 --> 00:05:14.639 completely breaks that binary framework. It literally forces us to 107 00:05:14.680 --> 00:05:18.279 rewrite the fundamental physics of how planets evolve and survived. 108 00:05:18.319 --> 00:05:20.800 It really does, and the whole unraveling of this mystery, 109 00:05:20.839 --> 00:05:22.800 it actually started with a cosmic weight problem. 110 00:05:22.920 --> 00:05:26.439 A weight problem. I love that the severe density anomaly. 111 00:05:26.120 --> 00:05:28.000 Right, so L ninety eight fifty nine D was first 112 00:05:28.000 --> 00:05:31.720 discovered back in twenty nineteen by NASA's Tests satellite. 113 00:05:31.480 --> 00:05:34.279 Tests the Transiting Exoplanet Survey. 114 00:05:34.000 --> 00:05:37.199 Satellite exactly and tests uses the transit photometry method. It 115 00:05:37.199 --> 00:05:39.560 basically stares at a patch of sky and just waits 116 00:05:39.560 --> 00:05:40.560 for a star's light to. 117 00:05:40.519 --> 00:05:43.000 Dim just a tiny fraction of a percent, right, Yeah, 118 00:05:43.000 --> 00:05:46.360 a microscopic dip in light, and that indicates that a 119 00:05:46.360 --> 00:05:49.800 planet has crossed in front of it. And based on 120 00:05:49.839 --> 00:05:53.040 how much light is blocked, we can calculate the physical 121 00:05:53.120 --> 00:05:55.639 volume the size of the planet, and. 122 00:05:55.480 --> 00:05:57.680 Test told us that L ninety eight to fifty nine 123 00:05:57.759 --> 00:06:00.879 DY is roughly one point six times the size. 124 00:06:00.680 --> 00:06:03.000 Of Earth, which drops it squarely into the danger zone 125 00:06:03.079 --> 00:06:04.720 right in the middle of a canyon. It's sitting right 126 00:06:04.759 --> 00:06:07.360 on the edge of that forbidden radius valley. It is 127 00:06:07.360 --> 00:06:08.360 in the transition zone. 128 00:06:08.480 --> 00:06:11.399 But just knowing the physical volume of a planet is 129 00:06:11.480 --> 00:06:12.920 only the first step. 130 00:06:12.720 --> 00:06:15.519 Right, to understand what a planet is actually made of, 131 00:06:15.959 --> 00:06:16.920 you need its mass. 132 00:06:17.000 --> 00:06:18.560 You need to weigh it exactly. 133 00:06:19.000 --> 00:06:23.199 And for that astronomers use ground based spectrographs to measure 134 00:06:23.199 --> 00:06:27.319 the radial velocity. That's the tiny, tiny gravitational wobble. The 135 00:06:27.360 --> 00:06:29.319 planet induces on its host star. 136 00:06:29.439 --> 00:06:30.879 So the planet pulls on the star. 137 00:06:30.720 --> 00:06:32.600 A little bit. It does, and when you have the 138 00:06:32.680 --> 00:06:34.839 volume from the transit and you have the mass from. 139 00:06:34.680 --> 00:06:38.000 The wobble, you can calculate the overall bulk density. 140 00:06:37.639 --> 00:06:39.920 BINGO, and the density of L ninety eight to fifty 141 00:06:40.000 --> 00:06:42.800 nine D immediately set off alarm bells for everyone looking 142 00:06:42.800 --> 00:06:43.839 at the data. 143 00:06:43.480 --> 00:06:45.560 Because if you have a planet that's one point six 144 00:06:45.639 --> 00:06:48.439 times the size of Earth and it's sitting incredibly close 145 00:06:48.480 --> 00:06:52.800 to its host star, you expect a very specific composition. 146 00:06:52.480 --> 00:06:56.240 You really do. The radiation environment is so brutal there 147 00:06:56.399 --> 00:07:01.319 that any primordial fluffy envelope of hydrogen and helium it 148 00:07:01.360 --> 00:07:04.879 should have been photo evaporated away billions of years ago. 149 00:07:05.000 --> 00:07:09.360 So you expect to find a dense, bare terrestrial rock 150 00:07:09.839 --> 00:07:14.399 like an iron core surrounded by a solid silicate mantle, right. 151 00:07:14.480 --> 00:07:18.319 But the radio velocity measurements revealed something entirely different. The 152 00:07:18.360 --> 00:07:21.000 mass of the planet was just far, far too low 153 00:07:21.040 --> 00:07:22.079 for its physical. 154 00:07:21.720 --> 00:07:23.839 Size, so it's huge, but it's really light. 155 00:07:24.240 --> 00:07:27.319 The density was abnormally low. It was much lighter than 156 00:07:27.399 --> 00:07:29.680 a pure rocky world of that diameter. 157 00:07:29.360 --> 00:07:31.399 Should ever be Okay, let's unpack this for a second. 158 00:07:31.439 --> 00:07:33.800 It's like it's like picking up a bowling ball right 159 00:07:33.839 --> 00:07:35.839 and expecting it to be super heavy, but you realize 160 00:07:35.879 --> 00:07:37.759 it weighs as much as a styrofoam block. 161 00:07:37.839 --> 00:07:39.079 That is a perfect analogy. 162 00:07:39.279 --> 00:07:42.480 Your brain immediately knows something is just fundamentally wrong with 163 00:07:42.519 --> 00:07:44.240 the recipe. The math just doesn't add up. 164 00:07:44.439 --> 00:07:49.120 It really doesn't. You have this massive volume but missing mass. Wow, 165 00:07:49.319 --> 00:07:52.120 And the traditional models they basically leave you with two 166 00:07:52.120 --> 00:07:53.800 options for a low density world. 167 00:07:53.839 --> 00:07:54.600 Okay, what's option A. 168 00:07:54.879 --> 00:07:58.360 Option eight is the gas dwarf scenario. We just discussed 169 00:07:59.000 --> 00:08:03.839 a small rocky with a huge, puffy hydrogen atmosphere. 170 00:08:03.839 --> 00:08:05.879 Well, we already ruled that out right exactly. 171 00:08:05.920 --> 00:08:08.560 We ruled it out because the red dwarf's high energy 172 00:08:09.079 --> 00:08:12.680 X ray and UV emissions would have stripped a lightweight 173 00:08:12.800 --> 00:08:15.199 hydrogen atmosphere away eons ago. 174 00:08:15.600 --> 00:08:18.800 I mean, the system is five billion years old. A 175 00:08:18.839 --> 00:08:22.040 primordial hydrogen envelope simply cannot survive there. 176 00:08:22.160 --> 00:08:24.959 It's physically impossible. The stellar wind would act like a 177 00:08:25.000 --> 00:08:28.240 sand blaster over those timescales. The retention of a primordial 178 00:08:28.319 --> 00:08:30.959 envelope at that orbital distance is just untenable. 179 00:08:31.000 --> 00:08:33.279 Okay, so option A is out. That leaves option B 180 00:08:33.440 --> 00:08:36.480 for a low density planet, the water world. 181 00:08:36.639 --> 00:08:37.840 Right, the water world. 182 00:08:37.720 --> 00:08:41.000 A planet with a smaller rocky core, but it's enveloped 183 00:08:41.039 --> 00:08:44.919 by this massive, deep ocean of liquid water, or maybe 184 00:08:44.960 --> 00:08:47.440 an incredibly thicked shell of high pressure ice. 185 00:08:47.559 --> 00:08:50.000 And that makes sense on paper because water is significantly 186 00:08:50.039 --> 00:08:51.879 less dense than iron and silicate rock. 187 00:08:52.240 --> 00:08:55.440 So incorporating a huge fraction of water into the planet's 188 00:08:55.440 --> 00:08:59.519 bulk composition perfectly explains the missing mass. Right. It expands 189 00:08:59.600 --> 00:09:01.440 the volume without adding heavy metals. 190 00:09:01.679 --> 00:09:03.879 It solves the density equation beautifully. 191 00:09:04.240 --> 00:09:05.960 But there's always a butt. 192 00:09:06.080 --> 00:09:09.159 There's always a butt. In astronomy, the problem is the 193 00:09:09.159 --> 00:09:12.799 thermodynamic reality of the planet's orbit. L ninety eight fifty 194 00:09:12.879 --> 00:09:16.279 nine D is tuck in so incredibly close to its 195 00:09:16.279 --> 00:09:21.279 star that the stellar irradiation it receives is just astronomical. 196 00:09:21.360 --> 00:09:24.600 Oh right, We're talking surface temperatures estimated around nineteen hundred 197 00:09:24.639 --> 00:09:25.879 degrees celsius. 198 00:09:25.440 --> 00:09:27.039 Over thirty five hundred degrees fahrenheit. 199 00:09:27.200 --> 00:09:30.600 Liquid water cannot exist in that regime, not even close. 200 00:09:30.360 --> 00:09:32.919 No way. I mean, even if the planet had somehow 201 00:09:33.000 --> 00:09:36.000 formed further out in the star system, like beyond the 202 00:09:36.039 --> 00:09:39.399 snow line and then migrated inward over millions of years. 203 00:09:39.559 --> 00:09:41.320 Water wouldn't stick around, it would. 204 00:09:41.080 --> 00:09:44.519 Not remain stable. It would vaporize into this massive steam atmosphere, 205 00:09:44.600 --> 00:09:48.159 and water vapor in the upper atmosphere is highly susceptible 206 00:09:48.159 --> 00:09:49.159 to photoed association. 207 00:09:49.360 --> 00:09:51.639 Wait, photo association explain that process. 208 00:09:52.039 --> 00:09:55.440 Basically, the intense UV light from the red dwarf would 209 00:09:55.480 --> 00:09:58.399 act like a hammer. It would literally shatter the water 210 00:09:58.480 --> 00:10:01.399 molecules apart in to hydrogen and oxygen. 211 00:10:01.639 --> 00:10:04.440 Oh wow, so it just breaks the water apart exactly. 212 00:10:04.720 --> 00:10:08.080 The lighter hydrogen escapes into space, the heavier oxygen falls 213 00:10:08.080 --> 00:10:11.879 down and oxidizes the crust, and eventually the entire planet desiccates. 214 00:10:11.919 --> 00:10:15.000 It just rusts and dries out completely if the dead end. 215 00:10:15.279 --> 00:10:18.080 So it can't be rock because it's too light, right. 216 00:10:18.320 --> 00:10:20.840 It can't be a gas dwarf because the stellar wind 217 00:10:20.879 --> 00:10:23.200 would strip the hydrogen right again. And it can't be 218 00:10:23.240 --> 00:10:26.279 a water world because the temperature would boil the oceans 219 00:10:26.320 --> 00:10:29.519 and the star would shatter the steam exactly. So what 220 00:10:29.759 --> 00:10:32.320 is it? I mean? The planetary science community was essentially 221 00:10:32.360 --> 00:10:35.679 looking at a ghost. Something was taking up a massive 222 00:10:35.720 --> 00:10:39.240 amount of physical space around that rocky core, puffing the 223 00:10:39.279 --> 00:10:43.559 planet's volume up to one point six earth radii. 224 00:10:43.519 --> 00:10:45.960 But resisting the blow torch of the red dwarf star 225 00:10:46.320 --> 00:10:48.960 for five billion years. It's just wild. 226 00:10:49.000 --> 00:10:50.600 How do you even begin to solve that? 227 00:10:50.879 --> 00:10:54.159 Well, honestly, it was an intractable problem with the observatories 228 00:10:54.159 --> 00:10:56.000 we had available in twenty nineteen. 229 00:10:55.960 --> 00:10:58.840 Because we only had tests and ground based telescopes. 230 00:10:58.919 --> 00:11:01.840 Right, we could measure sure the bulk parameters, you know, 231 00:11:01.879 --> 00:11:04.519 the mass and the radius. Yeah, but those numbers only 232 00:11:04.559 --> 00:11:06.440 offered contradictory boundary conditions. 233 00:11:06.559 --> 00:11:08.720 They just told us what it could be exactly. 234 00:11:09.200 --> 00:11:12.000 To figure out what was actually inflating this planet, we 235 00:11:12.080 --> 00:11:14.639 had to stop looking at its gravitational footprint and start 236 00:11:14.639 --> 00:11:16.000 looking directly at its chemistry. 237 00:11:16.080 --> 00:11:18.720 We needed to read the chemical bar code of whatever 238 00:11:18.879 --> 00:11:20.360 envelope was clinging to this. 239 00:11:20.320 --> 00:11:22.840 World, which requires transmissions Pictrosky. 240 00:11:22.919 --> 00:11:26.440 And doing that on a small, rocky super Earth thirty 241 00:11:26.440 --> 00:11:29.279 five light years away, I mean, that is an entirely 242 00:11:29.360 --> 00:11:32.720 different ballgame than looking at a giant, puffy hot Jupiter. 243 00:11:32.840 --> 00:11:36.320 Oh, it's exponentially harder. The atmospheric signal you were trying 244 00:11:36.320 --> 00:11:40.480 to isolate is microscopic. The scale of the measurement is. 245 00:11:40.480 --> 00:11:43.240 Just staggering right, because when L ninety eight to fifty 246 00:11:43.320 --> 00:11:46.840 nine D transits its host star, the solid body of 247 00:11:46.879 --> 00:11:48.559 the planet blocks a fraction of the. 248 00:11:48.480 --> 00:11:51.519 Starlight, but the atmosphere, assuming it even has one, is 249 00:11:51.600 --> 00:11:54.320 just a razor thin halo around that solid sphere. 250 00:11:54.440 --> 00:11:57.480 Okay, I have an analogy for this. To visualize this, 251 00:11:57.639 --> 00:12:00.320 I want you to imagine holding up a thick piece 252 00:12:00.360 --> 00:12:04.120 of stained glass to a blindingly bright searchlight. 253 00:12:04.240 --> 00:12:04.840 Oh, I like this. 254 00:12:05.320 --> 00:12:07.919 So the solid metal frame of the glass blocks the 255 00:12:08.000 --> 00:12:11.399 light entirely right, It casts a hard shadow, but the 256 00:12:11.440 --> 00:12:15.200 translucent colored glass lets a tiny, tiny fraction of that 257 00:12:15.240 --> 00:12:16.279 search light bleed through. 258 00:12:16.519 --> 00:12:16.679 Yep. 259 00:12:17.080 --> 00:12:19.720 And if you stand far enough back and analyze the 260 00:12:19.759 --> 00:12:22.360 exact wavelengths of light that make it through the glass, 261 00:12:22.799 --> 00:12:25.919 you can reverse engineer the chemical dyes used to color it. 262 00:12:26.000 --> 00:12:29.320 Because certain chemicals absorb red light and others absorb blue. 263 00:12:29.519 --> 00:12:32.639 Exactly, the missing colors tell you the composition of the barrier. 264 00:12:32.840 --> 00:12:37.000 That is precisely the essence of transmission spectroscopy. It's so cool, 265 00:12:37.159 --> 00:12:40.039 it really is. As the starlight from the red dwarf 266 00:12:40.080 --> 00:12:43.960 filters through the incredibly thin atmospheric limb of L ninety 267 00:12:44.000 --> 00:12:47.639 eight fifty nine D. The specific molecules suspended in that 268 00:12:47.720 --> 00:12:50.320 alien air act as chemical filters. 269 00:12:50.159 --> 00:12:51.159 Just like the stained glass. 270 00:12:51.240 --> 00:12:54.879 Exactly like the stained glass, they absorb very specific, quantifiable 271 00:12:54.919 --> 00:12:56.320 wavelengths of infrared light. 272 00:12:56.440 --> 00:12:58.799 And to see that, we needed a serious upgrade in 273 00:12:58.840 --> 00:12:59.240 our tech. 274 00:12:59.519 --> 00:13:03.120 We need it the James Webb Space Telescope. When JWST 275 00:13:03.240 --> 00:13:06.919 captures that filtered starlight, its near infrared spectram graph in 276 00:13:07.039 --> 00:13:10.840 iro spec disperses the light into a high resolution spectrum, 277 00:13:11.159 --> 00:13:12.840 and we just looked for the absorption. 278 00:13:12.519 --> 00:13:14.240 Bands, the missing slivers of light. 279 00:13:14.200 --> 00:13:16.919 Missing slivers exactly, and this signal. 280 00:13:16.600 --> 00:13:19.679 To noise ratio required to detect those missing slavers on 281 00:13:19.720 --> 00:13:22.559 a planet this small. I mean, that's literally why we 282 00:13:22.600 --> 00:13:25.240 had to wait for a ten billion dollar Berrillium Mirror 283 00:13:25.240 --> 00:13:27.360 observatory parked a million miles from Earth. 284 00:13:27.759 --> 00:13:30.519 Previous telescopes just didn't have the sensitivity in the infrared 285 00:13:30.559 --> 00:13:34.080 to see through the glare of the host star. JWFT 286 00:13:34.240 --> 00:13:37.600 represents a total paradigm shift to our diagnostic capabilities. 287 00:13:37.960 --> 00:13:40.879 So what happened when they actually pointed JWST at it. 288 00:13:41.240 --> 00:13:44.360 Well, the international team led by researchers at the University 289 00:13:44.399 --> 00:13:47.879 of Oxford, they pointed jawst at this system analyze the 290 00:13:47.879 --> 00:13:51.000 transmission spectrum, and the absorption features that popped out of 291 00:13:51.039 --> 00:13:53.519 the data were entirely unexpected. 292 00:13:53.600 --> 00:13:56.440 Like they didn't find the lightweight signatures of primordial hydrogen 293 00:13:56.480 --> 00:13:59.200 and helium Nope, none, And they didn't find a saturated 294 00:13:59.279 --> 00:14:01.480 signal of water vapor right right. 295 00:14:02.000 --> 00:14:07.720 What they found were profound undeniable absorption bands corresponding to 296 00:14:08.559 --> 00:14:13.759 heavy sulfur compounds sulfur specifically sulfur dioxide and hydrogen sulfide. 297 00:14:13.879 --> 00:14:17.080 Hydrogen sulfide. Okay, here's where it gets really interesting. For 298 00:14:17.120 --> 00:14:20.120 anyone who has ever been near a geyser or a 299 00:14:20.200 --> 00:14:24.399 volcanic vent or you know, simply smelled or rotting egg. 300 00:14:24.320 --> 00:14:26.799 You know the visceral impact of hydrogen sulfide. 301 00:14:27.120 --> 00:14:31.559 It is a highly toxic, incredibly pungent gas. Finding it 302 00:14:31.559 --> 00:14:34.440 out in the cosmos isn't necessarily strange, right, Like we 303 00:14:34.480 --> 00:14:38.480 see sulfur in planetary nebulas and young star forming regions. 304 00:14:38.519 --> 00:14:41.200 Sure, sulfur is common, but finding it dominating the thick 305 00:14:41.200 --> 00:14:44.279 atmosphere of a blazing hot super Earth that changes the 306 00:14:44.399 --> 00:14:46.000 entire physical model of the planet. 307 00:14:45.840 --> 00:14:48.120 Because it immediately resolves the density anomaly. 308 00:14:48.279 --> 00:14:51.080 It does, but and this is a big butt. It 309 00:14:51.159 --> 00:14:53.440 introduces a severe dynamic paradox. 310 00:14:53.480 --> 00:14:55.919 Okay, let's break that down. How does it resolve the density? 311 00:14:56.200 --> 00:14:59.600 Well, a heavily metallic, volatile rich atmosphere like one dominated 312 00:14:59.600 --> 00:15:02.120 by sulfur to oxide and hydrogen sulfide has a much 313 00:15:02.159 --> 00:15:05.039 higher mean molecular weight than a hydrogen helium envelope. 314 00:15:05.080 --> 00:15:06.360 So it's heavier, it's denser. 315 00:15:06.600 --> 00:15:10.000 It's denser, it hugs the planet tighter, and it is 316 00:15:10.080 --> 00:15:12.879 significantly harder for the stellar wind to strip away. 317 00:15:13.080 --> 00:15:16.200 It's like wearing heavier armor. It resists the photo of 318 00:15:16.240 --> 00:15:19.559 operation blow towards much better than fluffy hydrogen exactly. 319 00:15:20.080 --> 00:15:24.320 And the sheer volume of this thick, heavy, hazy sulfur 320 00:15:24.440 --> 00:15:26.919 envelope explains why the planet is puffed up to one 321 00:15:26.919 --> 00:15:29.519 point six times the size of Earth without adding the 322 00:15:29.559 --> 00:15:30.600 mass of solid rock. 323 00:15:30.759 --> 00:15:34.240 So the static math works. The puzzle pieces finally fit together. 324 00:15:34.320 --> 00:15:39.159 The static math works, Yes, but planetary atmospheres are not static, 325 00:15:39.559 --> 00:15:42.240 especially not in a compact orbit around a red dwarf. 326 00:15:42.559 --> 00:15:45.679 Right, because even with the heavier molecular weight of sulfur 327 00:15:45.720 --> 00:15:50.399 compounds the extreme ultraviolet radiation and the relentless stellar wind 328 00:15:50.559 --> 00:15:55.600 over five billion years, it would still inexorably erode that atmosphere. 329 00:15:55.639 --> 00:15:58.159 It might be harder to strip than hydrogen, but over 330 00:15:58.240 --> 00:16:00.279 billions of years, it should still be gone. 331 00:16:00.360 --> 00:16:02.320 It has to be bleeding into space. The physics of 332 00:16:02.320 --> 00:16:04.080 the stellar wind literally demand it. 333 00:16:04.120 --> 00:16:07.840 They do. Therefore, the fact that JWST observes a thick, 334 00:16:07.919 --> 00:16:12.480 opaque sulfur envelope today, five billion years into the system's lifespan, 335 00:16:12.879 --> 00:16:17.039 implies a terrifying reality. The atmosphere is not a primordial remnant. 336 00:16:17.519 --> 00:16:19.759 It is not a leftover shell of gas from the 337 00:16:19.759 --> 00:16:25.240 planet's berth. It is being actively, aggressively and continuously replenished. 338 00:16:25.360 --> 00:16:28.320 Wow, so the planet is bleeding sulfur into the sky 339 00:16:28.559 --> 00:16:30.320 faster than the star can strip it away. 340 00:16:30.440 --> 00:16:33.559 Exactly. It is a planetary scale out gassing engine. 341 00:16:33.600 --> 00:16:37.960 And to fuel an engine that massive, to continuously pump 342 00:16:38.159 --> 00:16:41.320 millions of tons of hydrogen, sulfide and sulfur dioxide into 343 00:16:41.399 --> 00:16:45.320 the atmosphere for five eons, you need a reservoir of 344 00:16:45.559 --> 00:16:46.919 unthinkable proportions. 345 00:16:47.039 --> 00:16:49.960 Right. You can't just have a few active volcanoes dotting 346 00:16:49.960 --> 00:16:51.480 a solid crust. That wouldn't cut it. 347 00:16:51.559 --> 00:16:55.279 A localized volcanic network would exhaust its volatile supply way 348 00:16:55.360 --> 00:16:56.440 too quickly. 349 00:16:56.120 --> 00:16:59.279 Far too quickly, And that's where the geodynamic simulations come in. 350 00:16:59.519 --> 00:17:02.080 The model presented in the March twenty twenty six Nature 351 00:17:02.120 --> 00:17:06.200 Astronomy paper takes the jawst atmospheric data and couples it 352 00:17:06.240 --> 00:17:08.319 with interior geodynamic simulations. 353 00:17:08.400 --> 00:17:11.559 They basically calculated what kind of internal structure is actually 354 00:17:11.559 --> 00:17:14.039 required to sustain this level of outgassing, and. 355 00:17:14.000 --> 00:17:17.839 The simulations converged on a singular extreme structural model. 356 00:17:17.880 --> 00:17:19.519 The permanent magma ocean. 357 00:17:19.319 --> 00:17:22.720 A global, deep seated layer of molten silicate rock. 358 00:17:23.039 --> 00:17:25.720 And we aren't just talking about a surface phenomenon right now. 359 00:17:25.759 --> 00:17:28.799 No, No. The nineteen hundred degree surface temperature guarantees that 360 00:17:28.839 --> 00:17:32.000 the crust itself is a glowing liquid. Sure, but the 361 00:17:32.039 --> 00:17:36.359 simulations dictate that this molten state extends thousands of kilometers 362 00:17:36.400 --> 00:17:37.839 deep into the planet's mantle. 363 00:17:37.960 --> 00:17:39.759 Okay, wait, I want to pause here and really dig 364 00:17:39.799 --> 00:17:42.519 into the geophysics, because when you say the word ocean, 365 00:17:43.119 --> 00:17:46.720 the human brain immediately defaults to the mechanics of water. 366 00:17:47.000 --> 00:17:49.720 Of course, you picture waves, right. 367 00:17:49.720 --> 00:17:54.319 We picture a sloshing fluid sphere, but a magma ocean 368 00:17:54.440 --> 00:17:58.599 extending thousands of kilometers down into a super Earth involves 369 00:17:58.640 --> 00:18:02.960 pressure regimes that fundamentally alter how matter behaves, oh completely. 370 00:18:03.119 --> 00:18:06.279 So how does a planet maintain its structural integrity if 371 00:18:06.359 --> 00:18:09.359 half of its volume is essentially a liquid like Why 372 00:18:09.359 --> 00:18:11.920 doesn't the tidal stress or the centrifugal force of its 373 00:18:12.000 --> 00:18:14.160 rotation just tear it apart into space? 374 00:18:14.640 --> 00:18:17.039 That is a great question. It comes down to the 375 00:18:17.079 --> 00:18:20.759 concept of reology. Reology, Yeah, reology the study of how 376 00:18:20.799 --> 00:18:24.599 matter flows under pressure. As you descend into the interior 377 00:18:24.640 --> 00:18:28.000 of L ninety eight fifty nine D, the gravitational pressure 378 00:18:28.039 --> 00:18:30.119 increases exponentially. 379 00:18:29.519 --> 00:18:32.119 Because there's so much weight pressing down from above. 380 00:18:32.519 --> 00:18:34.839 Exactly so, even though the temperature is high enough to 381 00:18:34.880 --> 00:18:38.480 melt silicate rock at the surface, the immense pressure at 382 00:18:38.519 --> 00:18:41.440 depth actively combats that melting. 383 00:18:41.160 --> 00:18:44.680 Because pressure forces atoms together, fighting the thermal energy that 384 00:18:44.759 --> 00:18:46.119 is trying to spread them apart. 385 00:18:46.119 --> 00:18:48.759 Spot on, and the result is a state of matter 386 00:18:48.839 --> 00:18:52.000 that is partially molten. It isn't a low viscosity liquid 387 00:18:52.079 --> 00:18:55.279 like water. The mantle is often described in these high pressure, 388 00:18:55.359 --> 00:18:57.000 high temperature regimes. 389 00:18:56.920 --> 00:19:00.799 As a mush, a mush that sounds unappealing. 390 00:19:01.000 --> 00:19:04.160 It behaves more like an unimaginably dense, glowing molasses. 391 00:19:04.279 --> 00:19:06.920 Glowing molasses. Okay, that's a brilliant visual. 392 00:19:06.759 --> 00:19:10.200 It flows, it convects, it churns, but it possesses enough 393 00:19:10.279 --> 00:19:14.079 viscosity and structural cohesion, bound by the immense gravity of 394 00:19:14.079 --> 00:19:16.799 the core, to maintain a perfect spherical shape. 395 00:19:16.799 --> 00:19:19.920 So the planet is essentially a giant convecting sphere of 396 00:19:20.039 --> 00:19:23.799 ultra pressurized, mushy liquid rock. Yes, but how does this 397 00:19:23.920 --> 00:19:27.759 molten state solve the sulfur problem? Like, how does glowing 398 00:19:27.799 --> 00:19:30.400 molasses act as a reservoir for toxic. 399 00:19:30.119 --> 00:19:33.559 Gas because magma is an incredibly efficient solvent for volatiles. 400 00:19:33.680 --> 00:19:34.319 A solvent. 401 00:19:34.480 --> 00:19:37.200