1 00:00:00,120 --> 00:00:04,519 Speaker 1: You know, the thermal models were just completely wrong. That 2 00:00:04,639 --> 00:00:06,519 is really the only place we can start today. 3 00:00:06,719 --> 00:00:09,279 Speaker 2: Yeah, completely wrong. It's a well, it's a crisis in 4 00:00:09,320 --> 00:00:11,839 the modeling, but honestly in the best possible way. 5 00:00:12,000 --> 00:00:14,439 Speaker 1: Right because if you look at the standard commentary physics 6 00:00:14,480 --> 00:00:17,519 we've relied on for decades, I mean, the Whipple models, 7 00:00:17,559 --> 00:00:20,640 the sublimation curves, they all predicted that three il lasts 8 00:00:20,640 --> 00:00:23,480 would peak, put on a modest show, and it just 9 00:00:23,519 --> 00:00:25,960 sort of fade away as it rounded the Sun exactly. 10 00:00:26,359 --> 00:00:29,039 Speaker 2: But the data we're looking at now, this post perihelion 11 00:00:29,079 --> 00:00:31,920 analysis that just dropped from the combined Hubble and jada 12 00:00:32,039 --> 00:00:36,840 Ust teams, it's completely invalidates those initial projections. We aren't 13 00:00:36,920 --> 00:00:39,719 just looking at a rock that behaved unexpectedly. We are 14 00:00:39,759 --> 00:00:43,399 looking at a fundamental disconnect between how we thought interstellar 15 00:00:43,439 --> 00:00:45,960 objects age and how they actually behave when they wake up. 16 00:00:46,399 --> 00:00:49,000 Speaker 1: And for you listening, that is the hook. We have 17 00:00:49,039 --> 00:00:52,520 a visitor that traveled light years in complete silence, basically 18 00:00:52,600 --> 00:00:55,880 ignored the Sun during its closest approach, and then when 19 00:00:55,960 --> 00:00:58,479 it's supposed to be cooling down, it erupted with a 20 00:00:58,560 --> 00:01:01,399 violence that defies all the low thermodynamic norms. 21 00:01:01,880 --> 00:01:05,480 Speaker 2: It is the delayed fuse scenario, and it is cracked 22 00:01:05,519 --> 00:01:09,079 open a trove of chemical data that we frankly had 23 00:01:09,120 --> 00:01:09,879 no business sing. 24 00:01:10,319 --> 00:01:13,519 Speaker 1: Welcome to thrilling Threads. I am your host, and today 25 00:01:13,560 --> 00:01:15,319 we are pulling on a thread that leads all the 26 00:01:15,359 --> 00:01:18,959 way back to a stellar nursery billions of years old 27 00:01:19,000 --> 00:01:19,920 and light years. 28 00:01:19,719 --> 00:01:22,359 Speaker 2: Away, and I am here to help navigate the orbital 29 00:01:22,400 --> 00:01:26,040 mechanics and the deep chemistry of that journey. 30 00:01:26,319 --> 00:01:29,239 Speaker 1: We are, of course talking about the third interstellar object 31 00:01:29,519 --> 00:01:32,719 three IA LASS. Now, for those of you who track 32 00:01:32,760 --> 00:01:35,680 the minor Planet Center circulars, you probably know the basics, 33 00:01:36,200 --> 00:01:38,560 but the mainstream headlines, you know, the one screaming comment 34 00:01:38,560 --> 00:01:41,400 breaks up or alien rock, they really do not capture 35 00:01:41,400 --> 00:01:44,400 the nuance of this massive new data set. We're looking 36 00:01:44,439 --> 00:01:47,400 at a synthesis of observation spanning late twenty twenty five 37 00:01:47,719 --> 00:01:49,560 all the way through February twenty twenty six. 38 00:01:49,959 --> 00:01:54,239 Speaker 2: Right, this is the comprehensive update. We have photometry, spectroscopy, radar, 39 00:01:54,239 --> 00:01:57,200 cross section analysis, everything. It's a mountain of data from 40 00:01:57,239 --> 00:01:58,439 some of our best instruments. 41 00:01:58,719 --> 00:02:01,280 Speaker 1: So let's just skip the preambling gets straight into the physics. 42 00:02:01,920 --> 00:02:06,040 Because for months three Italia was essentially a ghost. We 43 00:02:06,079 --> 00:02:08,719 had the astrometry, we knew exactly where it was, but 44 00:02:08,800 --> 00:02:10,680 we didn't really know what it was. We couldn't resolve 45 00:02:10,719 --> 00:02:11,319 the nucleus. 46 00:02:11,520 --> 00:02:14,360 Speaker 2: And that is the standard frustration with any active commet. 47 00:02:14,400 --> 00:02:16,560 You have a solid body, the nucleus, which is the 48 00:02:16,599 --> 00:02:18,759 actual thing you want to measure, but as soon as 49 00:02:18,800 --> 00:02:21,680 it gets anywhere near the frost line, it starts sublimating. 50 00:02:22,039 --> 00:02:24,439 It surrounds itself in a coma. 51 00:02:24,000 --> 00:02:26,319 Speaker 1: Just a massive cloud of gas. 52 00:02:26,000 --> 00:02:29,240 Speaker 2: And dust exactly. It's an optical depth problem. The signal 53 00:02:29,280 --> 00:02:33,000 to noise ratio heavily favors the glowing gas, not the 54 00:02:33,120 --> 00:02:34,960 dark rock hiding inside it. 55 00:02:34,960 --> 00:02:37,759 Speaker 1: It is like trying to measure the exact dimensions of 56 00:02:37,800 --> 00:02:41,080 a light bulb while it is shining through an incredibly 57 00:02:41,080 --> 00:02:44,000 heavy fog. You see the glow, you don't see the glass. 58 00:02:44,120 --> 00:02:47,080 Speaker 2: That is a perfect analogy. The coma can be thousands 59 00:02:47,080 --> 00:02:50,439 of kilometers wide while the nucleus is tiny. But the 60 00:02:50,479 --> 00:02:54,400 Hubble team, specifically the group using the wide field camera three, 61 00:02:54,560 --> 00:02:58,159 they applied a new subtraction technique in this latest study 62 00:02:58,280 --> 00:03:00,520 that finally pierced that vein, and. 63 00:03:00,439 --> 00:03:02,719 Speaker 1: This wasn't just taking a better picture, right. They had 64 00:03:02,719 --> 00:03:04,560 to computationally strip away the gas. 65 00:03:04,879 --> 00:03:07,479 Speaker 2: Right. They took a series of exposures and used a 66 00:03:07,560 --> 00:03:11,400 point spread function subtraction to digitally remove the coma. It 67 00:03:11,479 --> 00:03:14,560 is a brilliant piece of image processing. They modeled the 68 00:03:14,599 --> 00:03:18,120 gas distribution based on the solar wind vectors, subtracted that 69 00:03:18,159 --> 00:03:20,560 glow from the pixel data, and were left with the 70 00:03:20,599 --> 00:03:22,840 point source, the naked nucleus itself. 71 00:03:23,039 --> 00:03:25,599 Speaker 1: And this is where the first major revision to our 72 00:03:25,639 --> 00:03:29,080 understanding comes in the size, because early estimates were just 73 00:03:29,120 --> 00:03:31,919 all over the map, but the subtraction data gives us 74 00:03:31,919 --> 00:03:34,479 a much tighter constraint. We're looking at a radius of 75 00:03:34,520 --> 00:03:36,199 one point three kilometers. 76 00:03:35,759 --> 00:03:38,759 Speaker 2: Which gives us a diameter of roughly two point six kilometers. 77 00:03:38,840 --> 00:03:40,840 Speaker 1: Let's put that into context for you listening, because that 78 00:03:41,000 --> 00:03:45,240 is significantly larger than the initial small fragment theories were suggesting. 79 00:03:45,639 --> 00:03:47,919 If you compare that to sixty seven p the churim 80 00:03:47,919 --> 00:03:50,759 Moffcrasamanco comet, which was the target of the Rosetta mission, 81 00:03:51,280 --> 00:03:54,360 that was about four kilometers across on its longest axis, 82 00:03:54,479 --> 00:03:57,159 so three ils absolutely in the same way it is. 83 00:03:57,199 --> 00:03:59,240 Speaker 2: It is a substantial world, And we have to remember 84 00:03:59,240 --> 00:04:02,199 that size s it hinges entirely on the albedo the 85 00:04:02,240 --> 00:04:06,719 surface reflectivity. These specific calculations assume a geometric albedo of 86 00:04:06,719 --> 00:04:09,240 about point zero four to point zero. 87 00:04:09,080 --> 00:04:12,879 Speaker 1: Five, which is standard for commentary nuclei. They are darker 88 00:04:12,879 --> 00:04:15,479 than fresh asphalt. They are darker than coal. 89 00:04:15,639 --> 00:04:19,560 Speaker 2: Yes, they are incredibly unreflective. Now, if the surface were brighter, 90 00:04:19,879 --> 00:04:22,800 say if it had a lot of fresh shiny ice expose, 91 00:04:23,240 --> 00:04:25,279 the object would actually have to be smaller than one 92 00:04:25,279 --> 00:04:28,600 point three kilometers to reflect that specific amount of light 93 00:04:28,639 --> 00:04:31,639 we measured. But given the spectral data we'll get into later, 94 00:04:32,120 --> 00:04:35,000 the dark organic crud model really holds up. So two 95 00:04:35,000 --> 00:04:38,240 point six kilometers is a very solid working number, but. 96 00:04:38,240 --> 00:04:40,800 Speaker 1: It is not a sphere. The light curve analysis, which 97 00:04:40,839 --> 00:04:43,360 is tracking how the brightness dips and peaks as it 98 00:04:43,480 --> 00:04:46,879 rotates tumbling through space, it shows an axis ratio of 99 00:04:46,879 --> 00:04:47,560 two to one. 100 00:04:47,800 --> 00:04:50,040 Speaker 2: Yes, this is the shape derived from the amplitude of 101 00:04:50,040 --> 00:04:52,199 that light curve. It is getting twice as bright and 102 00:04:52,240 --> 00:04:54,920 then twice as dim as it spins. That tells us 103 00:04:54,959 --> 00:04:58,120 definitively that it is elongated, which. 104 00:04:57,959 --> 00:05:01,079 Speaker 1: Is fascinating because it sits in this weird morphological valley 105 00:05:01,120 --> 00:05:05,160 between the two previous interstellar visitors we've had. We had Umuamua, 106 00:05:05,279 --> 00:05:07,560 which was extreme a ten to one cigar or maybe 107 00:05:07,639 --> 00:05:10,319 a pancake shape, and then we had Borisov, which was 108 00:05:11,279 --> 00:05:15,439 seemingly spherical, almost indistinguishable from a standard Solar System comet. 109 00:05:15,680 --> 00:05:18,079 Speaker 2: And three I Atlas is right in the middle. It 110 00:05:18,120 --> 00:05:20,399 is not an extreme splinter, but it's definitely not a 111 00:05:20,480 --> 00:05:25,240 round potato either. It is a prolate spheroid significantly. 112 00:05:24,519 --> 00:05:26,600 Speaker 1: Stretched, a thick baget, if you will. 113 00:05:26,439 --> 00:05:30,120 Speaker 2: A very large, very dark baguette hurtling through the void. 114 00:05:30,600 --> 00:05:32,959 And the shape is important because it hints at either 115 00:05:33,000 --> 00:05:37,079 its formation history or its erosional history. To get that 116 00:05:37,120 --> 00:05:40,519 two to one ratio, it likely underwent some significant tidal 117 00:05:40,600 --> 00:05:43,759 stresses in its home system, or perhaps a really violent 118 00:05:43,759 --> 00:05:46,800 collision event before it was ejected into interstellar space. 119 00:05:47,079 --> 00:05:48,879 Speaker 1: Or it could just be a fragment of a much 120 00:05:48,959 --> 00:05:50,439 larger body that got shattered. 121 00:05:50,480 --> 00:05:52,439 Speaker 2: That is a very strong possibility as well. 122 00:05:52,519 --> 00:05:54,399 Speaker 1: Now, the size and the shape are the stats, but 123 00:05:54,439 --> 00:05:58,000 the behavior is a real story here. You mentioned earlier 124 00:05:58,040 --> 00:06:01,240 that the thermal models failed really dig into this delayed 125 00:06:01,279 --> 00:06:02,040 fusee anomaly. 126 00:06:02,199 --> 00:06:04,399 Speaker 2: This is the part that had everyone scratching their heads. 127 00:06:04,480 --> 00:06:07,879 In a standard cometary approach, activity which is the sublimation 128 00:06:07,920 --> 00:06:12,240 of ices turning into gas, tracks very predictably with heliocentric distance. 129 00:06:12,879 --> 00:06:15,800 As the distance to the Sun decreases, the temperature increases 130 00:06:15,839 --> 00:06:19,120 and gas production goes up. The peak usually happens right 131 00:06:19,199 --> 00:06:22,480 at or just slightly after perihelion. 132 00:06:22,160 --> 00:06:24,439 Speaker 1: Because that is when the heat flucks from the Sun 133 00:06:24,600 --> 00:06:26,000 is at its absolute highest. 134 00:06:26,160 --> 00:06:29,279 Speaker 2: Right, it is simple thermodynamics. But three ilists did not 135 00:06:29,360 --> 00:06:32,120 do that. It swung past the Sun, its perihelium was 136 00:06:32,439 --> 00:06:35,079 reasonably close, well inside the orbit of Mars, and it 137 00:06:35,120 --> 00:06:36,720 was just quiet. 138 00:06:37,040 --> 00:06:40,519 Speaker 1: I remember reading the papers from late twenty twenty five. 139 00:06:40,839 --> 00:06:44,360 The headlines were all saying, three ietless underwhelms. Is it 140 00:06:44,399 --> 00:06:46,480 a dud? Has it lost all its ice? 141 00:06:46,720 --> 00:06:50,600 Speaker 2: It was active technically, but the production rates were strangely low. 142 00:06:50,680 --> 00:06:53,160 It looked like a highly evolved comet, something that had 143 00:06:53,199 --> 00:06:55,720 been around the Sun hundreds of times and had already 144 00:06:55,720 --> 00:06:57,319 lost most of its volatile ices. 145 00:06:57,639 --> 00:07:00,680 Speaker 1: But then post perihelium, when it is moving away from 146 00:07:00,720 --> 00:07:04,240 the Sun. Late October early November, the activity curve just 147 00:07:04,279 --> 00:07:05,399 goes vertical. 148 00:07:05,160 --> 00:07:08,040 Speaker 2: Completely vertical. We saw a surge and water production that 149 00:07:08,079 --> 00:07:11,920 completely defied the cooling trend. By December, the production rate 150 00:07:11,920 --> 00:07:13,319 of water jumped by a factor of. 151 00:07:13,240 --> 00:07:16,959 Speaker 1: Forty forty times the output while actively moving away from 152 00:07:17,000 --> 00:07:19,199 the heat source. That is wild. 153 00:07:19,319 --> 00:07:22,399 Speaker 2: The so Swan instrument recorded rates hitting one point eight 154 00:07:22,399 --> 00:07:24,720 times ten to the twenty eighth molecules per second. 155 00:07:25,000 --> 00:07:27,959 Speaker 1: Let's translate that number ten to the twenty eighth molecules 156 00:07:27,959 --> 00:07:31,040 per second into something we can visualize. We often hear 157 00:07:31,079 --> 00:07:34,040 the Olympic swimming pools metric in these press releases. I 158 00:07:34,040 --> 00:07:35,600 think the number was two pools per hour. 159 00:07:35,720 --> 00:07:39,120 Speaker 2: That's the volumetric equivalent. Yes, it was ejecting about five 160 00:07:39,160 --> 00:07:42,959 million liters of water every single hour. But scientifically speaking, 161 00:07:43,199 --> 00:07:46,240 that specific production rate puts it firmly in the category 162 00:07:46,279 --> 00:07:47,480 of a hyperactive comet. 163 00:07:47,720 --> 00:07:51,759 Speaker 1: And hyperactive usually means a really significant percentage of the 164 00:07:51,800 --> 00:07:53,319 surface area is actively venting. 165 00:07:53,439 --> 00:07:57,439 Speaker 2: Right, yes, exactly. For most local commets, the act diffraction 166 00:07:57,600 --> 00:08:00,920 of the surface is actually very small. One to five 167 00:08:00,959 --> 00:08:03,519 percent of the surface is vent in gas. The rest 168 00:08:03,560 --> 00:08:06,279 is covered in an inert layer of dust. To get 169 00:08:06,279 --> 00:08:09,040 these kinds of numbers from a two point six kilometer object, 170 00:08:09,279 --> 00:08:11,560 a much much larger portion of the surface had to 171 00:08:11,560 --> 00:08:13,639 detonate and vent simultaneously. 172 00:08:13,959 --> 00:08:16,439 Speaker 1: So why the delay. Why did it wait until it 173 00:08:16,480 --> 00:08:19,000 was heading back out into the freezing cold to suddenly 174 00:08:19,000 --> 00:08:20,439 turn into a massive geyser. 175 00:08:20,680 --> 00:08:24,240 Speaker 2: This brings us to the irradiation mental hypothesis, or, as 176 00:08:24,279 --> 00:08:27,480 we've been casually calling it, the crust theory. But we 177 00:08:27,560 --> 00:08:30,079 need to be very specific about what this crust actually is. 178 00:08:30,199 --> 00:08:32,360 It is not just a layer of rock, right. 179 00:08:32,360 --> 00:08:34,840 Speaker 1: We aren't talking about a mineral shell like a turtle. 180 00:08:35,120 --> 00:08:37,159 We're talking about complex chemistry. 181 00:08:37,279 --> 00:08:40,960 Speaker 2: We're talking about the effects of galactic cosmic rays GCRs. 182 00:08:41,320 --> 00:08:44,679 These are highly energetic protons and atomic nuclei moving at 183 00:08:44,759 --> 00:08:48,080 nearly the speed of light in the interstellar medium. When 184 00:08:48,080 --> 00:08:51,120 you are outside the protective magnetic bubble of a star, 185 00:08:51,679 --> 00:08:55,720 an object is constantly bombarded by these GCRs for millions, 186 00:08:55,799 --> 00:08:57,159 sometimes billions of years. 187 00:08:57,240 --> 00:09:00,000 Speaker 1: And when those high energy particles slam into the surface 188 00:09:00,440 --> 00:09:05,960 ices like methane, ammonia, water, what actually happens chemically? 189 00:09:06,080 --> 00:09:09,399 Speaker 2: They literally break the chemical bonds apart. Specifically, they knock 190 00:09:09,440 --> 00:09:12,480 the hydrogen atoms right out of the molecular lattice. This 191 00:09:12,519 --> 00:09:16,320 process is called dehydrogenation. And when you strip the hydrogen away. 192 00:09:16,559 --> 00:09:18,879 The remaining carbon atoms are left looking for something to 193 00:09:18,919 --> 00:09:21,480 bond with, so they bond with each other, they polymerize. 194 00:09:21,519 --> 00:09:24,360 Speaker 1: So you are basically taking simple ices and forcing them 195 00:09:24,399 --> 00:09:27,399 to turn into complex, long chain carbon structures. 196 00:09:27,639 --> 00:09:30,840 Speaker 2: Exactly, you create a thick layer of highly disordered carbon. 197 00:09:31,279 --> 00:09:34,399 It is essentially an asphalt or a tar like substance. 198 00:09:34,919 --> 00:09:38,039 It is incredibly dark, it is hard, and structurally it 199 00:09:38,080 --> 00:09:41,240 is very strong. This is the crust, and it can 200 00:09:41,279 --> 00:09:44,159 easily be ten to fifteen meters thick, depending on exactly 201 00:09:44,200 --> 00:09:46,159 how long the object drifted in the void. 202 00:09:46,320 --> 00:09:48,559 Speaker 1: Okay, so three I at leaves arrives in our solar 203 00:09:48,600 --> 00:09:51,879 system wearing this fifteen meter thick suit of armor made 204 00:09:51,879 --> 00:09:53,200 of cosmic asphalt. 205 00:09:52,960 --> 00:09:56,799 Speaker 2: And that cosmic asphalt happens to be an absolutely excellent insulator. 206 00:09:56,840 --> 00:09:59,399 It has a very very low thermal conductivity. 207 00:09:59,519 --> 00:10:02,399 Speaker 1: I see. So the sun shines on the comet, the 208 00:10:02,399 --> 00:10:06,679 outer surface gets hot, maybe pushing three hundred kelvin, but 209 00:10:06,720 --> 00:10:09,840 that heat does not immediately reach the pristine ice buried below, 210 00:10:10,120 --> 00:10:10,600 not at all. 211 00:10:10,639 --> 00:10:12,799 Speaker 2: It takes a significant amount of time for that thermal 212 00:10:12,799 --> 00:10:17,440 wave to propagate down through fifteen meters of disorganized insulating carbon. Material, 213 00:10:17,759 --> 00:10:20,039 there is a massive thermodynamic lag the lang. 214 00:10:20,080 --> 00:10:21,759 Speaker 1: Okay, so the delayed fuse we were talking about is 215 00:10:21,799 --> 00:10:23,840 literally just the travel time of the heat wave moving 216 00:10:23,879 --> 00:10:24,480 through the crust. 217 00:10:24,639 --> 00:10:28,080 Speaker 2: That fits the observational data perfectly. It took months for 218 00:10:28,120 --> 00:10:31,440 the intense heat pulse from perihelium to finally conduct its 219 00:10:31,440 --> 00:10:34,240 way down to the pristine ice layer. By the time 220 00:10:34,240 --> 00:10:36,759 it actually hit that volable reservoir, the comet was already 221 00:10:36,759 --> 00:10:39,279 physically moving away from the Sun, but the heat had 222 00:10:39,320 --> 00:10:40,200 finally arrived. 223 00:10:40,399 --> 00:10:44,840 Speaker 1: And when that intense heat finally hits super volatile interstellar 224 00:10:44,960 --> 00:10:49,240 ice that has been trapped under immense pressure for billions 225 00:10:49,240 --> 00:10:50,120 of years. 226 00:10:50,080 --> 00:10:53,200 Speaker 2: It sublemates instantly. The phase change from solid ice to 227 00:10:53,320 --> 00:10:57,559 gas creates a massive sudden spike in internal pressure. The crust, 228 00:10:57,600 --> 00:11:01,240 which is rigid and can't really expand, fails. It is 229 00:11:01,279 --> 00:11:05,279 a catastrophic structural failure. The shell cracks wide open, and 230 00:11:05,320 --> 00:11:08,320 you get that sudden forty X surge and outgassing activity. 231 00:11:08,399 --> 00:11:10,840 Speaker 1: It is quite literally a pressure cooker explosion in space. 232 00:11:10,960 --> 00:11:13,600 Speaker 2: It is. And what's truly fascinating is that this validates 233 00:11:13,600 --> 00:11:17,240 the idea that interstellar objects have fundamentally different surfaces than 234 00:11:17,279 --> 00:11:20,480 our local commets, our local comments haven't been exposed to 235 00:11:20,519 --> 00:11:23,120 deep space GCRs for that long. They just don't have 236 00:11:23,240 --> 00:11:25,720 this thick, blackened polymerized armor. 237 00:11:26,000 --> 00:11:29,080 Speaker 1: So three I Alis is essentially a pristine time capsule 238 00:11:29,120 --> 00:11:32,360 wrapped in thick asphalt. And when it finally cracked open, 239 00:11:32,600 --> 00:11:34,879 we got a fresh sample of what was locked inside. 240 00:11:35,240 --> 00:11:38,039 And this is where the James Webb Space Telescope really 241 00:11:38,080 --> 00:11:39,080 flexed its muscles. 242 00:11:39,120 --> 00:11:42,440 Speaker 2: The spectral analysis from JWST was just breathtaking. 243 00:11:42,600 --> 00:11:45,320 Speaker 1: We've seen water obviously, we talked about the swimming pools, 244 00:11:45,679 --> 00:11:48,360 but the trace gases are where the real story of 245 00:11:48,399 --> 00:11:52,919 its origin lies. The detection of methane is the absolute 246 00:11:52,960 --> 00:11:53,600 headline here. 247 00:11:53,759 --> 00:11:56,600 Speaker 2: It is the first definitive detection of methane in an 248 00:11:56,600 --> 00:11:59,360 interstellar comment. And this is critical for you to understand. 249 00:11:59,480 --> 00:12:03,639 Because methane is hyper volatile, its sublimation temperature is incredibly low. 250 00:12:03,679 --> 00:12:05,200 We're talking around thirty kelvin. 251 00:12:05,320 --> 00:12:08,320 Speaker 1: Thirty kelvin that is barely above absolute zero. 252 00:12:08,519 --> 00:12:11,960 Speaker 2: Right, if this object had ever gotten warm, even slightly warm, 253 00:12:12,080 --> 00:12:14,679 during its billions of years of travel, or even during 254 00:12:14,679 --> 00:12:18,240 its initial formation, that methane should be completely gone. It 255 00:12:18,279 --> 00:12:20,200 should have outgassed eons ago. 256 00:12:20,679 --> 00:12:22,600 Speaker 1: So the fact that we are seeing it now means 257 00:12:22,639 --> 00:12:23,600 what exactly. 258 00:12:23,720 --> 00:12:27,440 Speaker 2: It means two very important things. One, the crust theory 259 00:12:27,600 --> 00:12:30,919 is absolutely correct. It was hermetically sealed in that tarshell. 260 00:12:31,600 --> 00:12:36,320 And two, this object formed in a very very cold environment. 261 00:12:36,519 --> 00:12:40,559 We're talking about the extreme outer fringes of a protoplanetary disc, 262 00:12:41,000 --> 00:12:43,919 far far beyond the co line of its home star. 263 00:12:44,120 --> 00:12:46,399 It formed in the d freeze, the absolute DeFreeze, and 264 00:12:46,480 --> 00:12:48,919 it stayed there. It was likely ejected from its home 265 00:12:48,960 --> 00:12:52,960 star system very early on in its life, well before 266 00:12:53,000 --> 00:12:56,000 it could migrate inward and lose those precious volatiles. 267 00:12:56,240 --> 00:12:59,320 Speaker 1: The report also dives into a really strange ratio of 268 00:12:59,480 --> 00:13:02,720 nickel time iron, and the gaseous emissions. Now, I know 269 00:13:02,799 --> 00:13:05,240 metallicity is basically a fingerprint for stars. 270 00:13:05,000 --> 00:13:07,000 Speaker 2: Right it is in our Solar system we have a 271 00:13:07,120 --> 00:13:10,279 very specific ratio of heavy elements because everything here formed 272 00:13:10,320 --> 00:13:12,480 from a specific cloud of gas that was enriched by 273 00:13:12,519 --> 00:13:16,120 specific previous supernova. When we look at the vaporized metals 274 00:13:16,159 --> 00:13:19,279 coming off three ilus, specifically the atomic nickel and iron 275 00:13:19,320 --> 00:13:22,559 emission lines, the ratio is completely skewed compared to our 276 00:13:22,559 --> 00:13:23,200 solar value. 277 00:13:23,279 --> 00:13:24,799 Speaker 1: It is definitely not the solar standard. 278 00:13:25,159 --> 00:13:27,879 Speaker 2: No, not at all. It is enriched in certain heavy 279 00:13:27,879 --> 00:13:32,240 elements and severely depleted in others. This tells us definitively 280 00:13:32,399 --> 00:13:36,480 that the star system three Ilis originally came from had 281 00:13:36,519 --> 00:13:39,759 a totally different chemical recipe than ours. Maybe the molecular 282 00:13:39,759 --> 00:13:42,320 cloud it formed from was seated by a different type 283 00:13:42,320 --> 00:13:46,399 of supernova, or it just had a different initial abundance 284 00:13:46,440 --> 00:13:47,000 of elements. 285 00:13:47,039 --> 00:13:50,240 Speaker 1: Overall, we are effectively doing remote archaeology on a star 286 00:13:50,279 --> 00:13:51,759 system we have never even seen. 287 00:13:51,919 --> 00:13:54,480 Speaker 2: We are we're tasting the soup and realizing the chef 288 00:13:54,600 --> 00:13:56,600 used a completely different set of spices. 289 00:13:56,919 --> 00:13:59,440 Speaker 1: There is another aspect of the material coming off this 290 00:13:59,480 --> 00:14:03,679 comment that caught my eye. The dust. The polarization curves 291 00:14:03,720 --> 00:14:06,240 the teams recorded were just really weird, right. 292 00:14:06,279 --> 00:14:10,080 Speaker 2: So, polarization measures the geometry of how light scatters off particles. 293 00:14:10,320 --> 00:14:12,320 It tells you a lot about the surface roughness and 294 00:14:12,360 --> 00:14:13,919 crucially the size of those particles. 295 00:14:14,039 --> 00:14:17,879 Speaker 1: Usually, comet dust is micron sized, right, like superfine talicumpowder 296 00:14:17,919 --> 00:14:18,799 or cigarette smoke. 297 00:14:19,000 --> 00:14:21,840 Speaker 2: Correct, But the polarization phase curve for three IAD lists 298 00:14:21,960 --> 00:14:25,399 was noticeably flatter and deeper than typical solar system commets. 299 00:14:25,879 --> 00:14:28,759 This implies that the scattering particles are unusually large. 300 00:14:28,759 --> 00:14:29,759 Speaker 1: How large are we talking. 301 00:14:30,000 --> 00:14:33,480 Speaker 2: We're looking at models suggesting grains that are millimeters across, 302 00:14:33,879 --> 00:14:36,320 maybe even up to centimeters in some cases. 303 00:14:36,399 --> 00:14:38,759 Speaker 1: Oh wait, so it is not ejecting a cloud of smoke. 304 00:14:39,200 --> 00:14:41,639 It is ejecting a cloud of gravel or what we. 305 00:14:41,559 --> 00:14:47,279 Speaker 2: Call fluffy aggregates. Think of cosmic dust bunnies, large highly 306 00:14:47,360 --> 00:14:50,879 porous clumps of material that have been stuck together. And 307 00:14:50,919 --> 00:14:54,519 this perfectly supports the idea of the crust breaking up violently. 308 00:14:55,000 --> 00:14:57,480 We aren't just seeing the gentle sublimation of ice. We 309 00:14:57,519 --> 00:15:03,399 are seeing the mechanical, violent sintegration of that solid irradiation mantle. 310 00:15:03,559 --> 00:15:05,759 Speaker 1: It is shedding its skin in giant. 311 00:15:05,480 --> 00:15:07,879 Speaker 2: Chunks, which, by the way, would make a flyby mission 312 00:15:07,919 --> 00:15:10,759 incredibly dangerous. If you flew a probe through that tail 313 00:15:10,840 --> 00:15:13,000 trying to get a sample, you wouldn't just get dusted, 314 00:15:13,039 --> 00:15:15,360 your spacecraft would get completely sam blasted. 315 00:15:15,480 --> 00:15:17,960 Speaker 1: That is an amazing image. But let's pivot to the 316 00:15:17,960 --> 00:15:21,039 topic that inevitably comes up. Whenever we find something strange 317 00:15:21,240 --> 00:15:24,159 with an object this shape and with this bizarre delayed 318 00:15:24,200 --> 00:15:27,759 fuse behavior, the question of artificiality is always going to 319 00:15:27,759 --> 00:15:31,960 be on the table the classic von Neumann probe hypothesis. 320 00:15:31,519 --> 00:15:34,799 Speaker 2: And it is a completely valid scientific question to ask. 321 00:15:35,279 --> 00:15:37,679 If you were sending a probe between stars, you might 322 00:15:37,840 --> 00:15:40,399 very well coat it in a protective shield. You might 323 00:15:40,399 --> 00:15:43,480 even see non gravitational acceleration as it maneuvers. 324 00:15:43,759 --> 00:15:47,799 Speaker 1: So we looked. The astronomical community didn't just ignore the possibility. 325 00:15:48,080 --> 00:15:51,039 The Green Bank Telescope and the Allen Telescope array did 326 00:15:51,080 --> 00:15:52,519 some serious heavy lifting here. 327 00:15:52,720 --> 00:15:55,480 Speaker 2: They absolutely did. This wasn't just a casual listen for 328 00:15:55,559 --> 00:16:00,240 a few hours. They dedicated significant premium observation time to 329 00:16:00,320 --> 00:16:02,919 perform a highly rigorous narrowband search. 330 00:16:03,240 --> 00:16:05,960 Speaker 1: Explain the concept of narrowband for us. Why is that 331 00:16:06,039 --> 00:16:09,759 considered the absolute gold standard for finding techno signatures. 332 00:16:10,039 --> 00:16:13,679 Speaker 2: Well, nature is inherently broadband. When a star, a pulsar, 333 00:16:13,840 --> 00:16:16,679 or a quasar amidst radio waves, it is messy. It's 334 00:16:16,679 --> 00:16:19,679 spread across a huge range of frequencies. Technology, on the 335 00:16:19,720 --> 00:16:22,600 other hand, is narrowband. When we transmit a signal, we 336 00:16:22,720 --> 00:16:26,360 squeeze all that energy into a very specific tight frequency 337 00:16:26,480 --> 00:16:29,759 like one oh one point five fm to maximize efficiency. 338 00:16:30,000 --> 00:16:31,559 If you see a signal that is only a few 339 00:16:31,639 --> 00:16:34,120 hurts wide, Nature simply did not make that. 340 00:16:34,279 --> 00:16:37,000 Speaker 1: So they scan the one to ten gigahertz range looking 341 00:16:37,000 --> 00:16:38,000 for that tight signal. 342 00:16:38,360 --> 00:16:42,440 Speaker 2: Yes, the classic waterhole frequencies and well beyond, and the 343 00:16:42,519 --> 00:16:47,080 sensitivity they achieved was just extraordinary. They could have detected 344 00:16:47,080 --> 00:16:49,879 an omnidirectional transmitter with a power output of just zero 345 00:16:49,879 --> 00:16:50,919 point one watts. 346 00:16:51,120 --> 00:16:53,720 Speaker 1: You own one watts. Let that sink in for a second. Yeah, 347 00:16:53,759 --> 00:16:56,799 that is less power than the little led flashlight on 348 00:16:56,840 --> 00:16:57,519 my smartphone. 349 00:16:57,559 --> 00:17:00,759 Speaker 2: It's roughly the transmit power of a standard self pe handset. 350 00:17:01,159 --> 00:17:03,759 If there is a piece of electronics sitting on that rock, 351 00:17:03,840 --> 00:17:06,440 even just in a low power standby mode, trying to 352 00:17:06,559 --> 00:17:08,039 ping a signal. 353 00:17:07,680 --> 00:17:09,279 Speaker 1: Home, we would have heard it loud and clear. 354 00:17:09,480 --> 00:17:13,480 Speaker 2: Absolutely. The Green Bank telescope is an absolute monster. It's 355 00:17:13,480 --> 00:17:15,960 a one hundred meter dish. The game is. 356 00:17:15,880 --> 00:17:18,599 Speaker 1: Immense and the result of all that listening. 357 00:17:18,480 --> 00:17:19,839 Speaker 2: Completely null results. 358 00:17:19,880 --> 00:17:22,960 Speaker 1: But I read the report and it did mention candidate signals. 359 00:17:23,440 --> 00:17:24,799 People hear that in their minds go. 360 00:17:24,839 --> 00:17:28,480 Speaker 2: Wild, right, But in radio astronomy you always get candidate signals. 361 00:17:28,480 --> 00:17:32,039 That's just RFI radio frequency interference. It's our own technology 362 00:17:32,039 --> 00:17:36,000 bouncing back at US Starlink satellites GPS signals, aircraft, radar, 363 00:17:36,200 --> 00:17:39,440 even researchers using microwave ovens down the hall. The key 364 00:17:39,480 --> 00:17:42,759 to filtering that out is looking for the Doppler drift, because. 365 00:17:42,519 --> 00:17:45,279 Speaker 1: The comet is physically moving relative. 366 00:17:44,839 --> 00:17:47,960 Speaker 2: To us exactly. The comet is moving very fast relative 367 00:17:48,000 --> 00:17:50,880 to Earth, so any actual signal originating from it should 368 00:17:50,920 --> 00:17:55,160 show a distinct Doppler drift. The frequency should slightly change 369 00:17:55,160 --> 00:17:57,000 over time as it moves, like the pitch of a 370 00:17:57,039 --> 00:18:01,599 siren passing by terrestrial interference is mostly stationary relative to 371 00:18:01,640 --> 00:18:04,920 the ground. When the teams applied the Doppler filters to 372 00:18:04,960 --> 00:18:08,319 those candidates, every single one of them disappeared, So. 373 00:18:08,759 --> 00:18:11,319 Speaker 1: No aliens today. It is a rock. 374 00:18:11,599 --> 00:18:15,599 Speaker 2: It is a rock, a genuinely fascinating, chemically complex, violently 375 00:18:15,720 --> 00:18:19,039 erupting rock. But it is definitively not a. 376 00:18:18,960 --> 00:18:22,559 Speaker 1: Machine, which honestly I find almost more compelling in a 377 00:18:22,599 --> 00:18:25,759 way because it means nature alone is capable of manufacturing 378 00:18:25,759 --> 00:18:29,000 these incredible imposters that mimic our ideas of technology. 379 00:18:29,039 --> 00:18:31,599 Speaker 2: It means the galaxy is wonderfully messy. It creates things 380 00:18:31,599 --> 00:18:34,599 that look structured or behave oddly just through the sheer 381 00:18:34,680 --> 00:18:38,279 chaos of formation, ejection, and billions of years of radiation. 382 00:18:38,519 --> 00:18:40,920 Speaker 1: Three a Alis is currently on its way up. We 383 00:18:41,000 --> 00:18:42,920 missed the chance for a rendezvous, but there was a 384 00:18:42,960 --> 00:18:45,640 moment in the orbital projections where the dynamics got very, 385 00:18:45,759 --> 00:18:46,400 very spicy. 386 00:18:46,720 --> 00:18:50,519 Speaker 2: The Jupiter encounter OH March twenty twenty six. The trajectory 387 00:18:50,559 --> 00:18:53,240 takes it out to about thirty six AU, but the 388 00:18:53,319 --> 00:18:56,880 key metric we looked at was the hyperbolic excess velocity. 389 00:18:57,000 --> 00:18:59,200 It is moving incredibly fast. 390 00:18:59,000 --> 00:19:02,599 Speaker 1: But it passes tantingly near Jupiter's hill sphere right. 391 00:19:02,640 --> 00:19:05,519 Speaker 2: The hillsphere is the specific volume of space where a 392 00:19:05,599 --> 00:19:09,759 planet's gravity completely dominates over the Sun's gravity. If an 393 00:19:09,799 --> 00:19:12,720 object enters that sphere with low enough kinetic energy, it 394 00:19:12,759 --> 00:19:15,559 gets captured. It ceases to be a comet and becomes 395 00:19:15,599 --> 00:19:17,880 a temporary or sometimes permanent moon. 396 00:19:18,200 --> 00:19:21,039 Speaker 1: We've seen this happen with local commets before, right like 397 00:19:21,200 --> 00:19:24,119 comet Shoemaker Levy nine, which was captured by Jupiter right 398 00:19:24,160 --> 00:19:25,640 before it famously crashed into it. 399 00:19:25,680 --> 00:19:28,640 Speaker 2: Correct, Jupiter is the great vacuum cleaner of our Solar system. 400 00:19:29,079 --> 00:19:32,880 The trajectory analysis showed that three I lists passed incredibly 401 00:19:32,920 --> 00:19:35,960 close to that exact capture threshold. If it had entered 402 00:19:36,000 --> 00:19:38,720 the Jovian System just a few kilometers per second. 403 00:19:38,480 --> 00:19:40,400 Speaker 1: Slower, Jupiter would have grabbed it out of the sky. 404 00:19:40,480 --> 00:19:42,680 Speaker 2: We would have had a permanent, or at least semi 405 00:19:42,720 --> 00:19:45,119 permanent interstellar satellite, or didting Jupiter. 406 00:19:45,319 --> 00:19:47,720 Speaker 1: Just think about the mission potential of that. We wouldn't 407 00:19:47,720 --> 00:19:49,880 have to chase it down into deep space. We could 408 00:19:49,920 --> 00:19:52,799 have sent a dedicated sample return mission. We could have 409 00:19:52,880 --> 00:19:55,480 landed on it, drilled through that asphalt crust. 410 00:19:55,559 --> 00:19:57,799 Speaker 2: It would have been the scientific prize of the century, 411 00:19:58,119 --> 00:20:02,279 a captive interstellar laboratory. But unfortunately it just had too 412 00:20:02,359 --> 00:20:06,240 much kinetic energy. It is doing a hyperbolic flyby and 413 00:20:06,319 --> 00:20:09,839 actually gaining a gravity assist out of the Solar System. 414 00:20:09,599 --> 00:20:11,519 Speaker 1: The Obirth effect in action right there. 415 00:20:11,640 --> 00:20:15,640 Speaker 2: Effectively, Yes, it stole a tiny bit of angular momentum 416 00:20:15,640 --> 00:20:18,960 from Jupiter and is currently flinging itself back into the 417 00:20:18,960 --> 00:20:21,240 interstellar void even faster than before. 418 00:20:21,440 --> 00:20:23,319 Speaker 1: So let's zoom out for a minute and recap what 419 00:20:23,400 --> 00:20:26,640 we have here. We have a two point six kilometer object. 420 00:20:26,880 --> 00:20:29,680 It is shaped like a giant dark baguette. It has 421 00:20:29,720 --> 00:20:33,039 a thick crust of cosmic gas, fold baked by billions 422 00:20:33,039 --> 00:20:36,880 of years of radiation it's full of ancient hypervoltle methane 423 00:20:36,880 --> 00:20:38,960 and nickel rich gas that proves it came from a 424 00:20:38,960 --> 00:20:41,880 different star, and when it finally got warm, it erupted 425 00:20:41,880 --> 00:20:42,799 a cloud of gravel. 426 00:20:42,920 --> 00:20:45,400 Speaker 2: That is the complete peer reviewed profile. 427 00:20:45,680 --> 00:20:47,960 Speaker 1: So what does this tell us about the actual population 428 00:20:48,119 --> 00:20:50,119 of these things out there? Because this is the third 429 00:20:50,119 --> 00:20:52,799 one we've seen in less than a decade. We had 430 00:20:52,920 --> 00:20:57,839 Umoa in twenty seventeen, Boresov in twenty nineteen, and now ATLS. 431 00:20:58,160 --> 00:21:02,519 Speaker 2: Statistically, it suggests the number density of interstellar objects floating 432 00:21:02,519 --> 00:21:05,880 out there is much much higher than we ever previously estimated. 433 00:21:06,160 --> 00:21:09,279 But there is a massive catch to that assumption. Three 434 00:21:09,359 --> 00:21:13,960 Ils and Borisov were highly active eventually, and Umongole was 435 00:21:14,039 --> 00:21:16,880 weirdly shiny and tumbling in a way that caught the light. 436 00:21:17,160 --> 00:21:19,960 Speaker 1: They drew attention to themselves, they made themselves visible. 437 00:21:19,680 --> 00:21:22,920 Speaker 2: Exactly, which brings up a relatively new concept in the 438 00:21:22,920 --> 00:21:24,480 community known as the dark River. 439 00:21:24,799 --> 00:21:26,960 Speaker 1: The dark River that sounds incredibly. 440 00:21:26,559 --> 00:21:29,160 Speaker 2: Ominous, It is a bit haunting. The idea is that 441 00:21:29,200 --> 00:21:32,640 for every active interstellar object like three Als that eventually 442 00:21:32,759 --> 00:21:35,200 lights up and releases enough gas for us to spot, 443 00:21:35,359 --> 00:21:37,240 there might be one hundred or even a thousand that 444 00:21:37,279 --> 00:21:40,119 are truly dead. They have those thick tar crusts, but 445 00:21:40,119 --> 00:21:43,279 their crusts simply never crack. They passed through our solar 446 00:21:43,279 --> 00:21:45,720 system completely dark and silent. 447 00:21:45,720 --> 00:21:48,240 Speaker 1: Because if they don't outgas, they never form a coma. 448 00:21:48,559 --> 00:21:50,640 They don't form a coma, they don't reflect much sunlight, 449 00:21:50,880 --> 00:21:53,440 and if their bare surface is as dark as coal, 450 00:21:53,559 --> 00:21:54,279 we never see them. 451 00:21:54,279 --> 00:21:56,079 Speaker 2: There are perfect stealth transits. 452 00:21:56,200 --> 00:21:59,160 Speaker 1: That is a deeply haunting thought. We are sitting here 453 00:21:59,160 --> 00:22:02,039 in this lit room our solar system, and we tend 454 00:22:02,079 --> 00:22:03,680 to think we're alone in the dark, but they are 455 00:22:03,680 --> 00:22:06,559 ghosts passing through the room constantly. We just can't see 456 00:22:06,599 --> 00:22:08,000 them because they don't reflect the light. 457 00:22:08,200 --> 00:22:11,480 Speaker 2: The galaxy is absolutely teeming with debris. We are only 458 00:22:11,519 --> 00:22:12,880 seeing the ones that scream. 459 00:22:13,319 --> 00:22:15,960 Speaker 1: So the next great mission is to figure out how 460 00:22:16,000 --> 00:22:17,079 to find the quiet ones. 461 00:22:17,480 --> 00:22:21,000 Speaker 2: The Verra Reuben Observatory, which is finally coming online fully, 462 00:22:21,359 --> 00:22:23,359 is going to be our best bet for that. It's 463 00:22:23,400 --> 00:22:28,559 specifically designed to spot these incredibly faint, fast moving transients 464 00:22:28,720 --> 00:22:31,079 that previous surveys would just miss entirely. 465 00:22:31,599 --> 00:22:33,119 Speaker 1: I want to leave you listening with a thought on 466 00:22:33,160 --> 00:22:35,960 that crust theory we discussed. We so often think of 467 00:22:36,000 --> 00:22:39,079 deep space as just being empty and inert, But this 468 00:22:39,200 --> 00:22:43,160 object proves that the emptiness is actually chemically active. It 469 00:22:43,240 --> 00:22:46,960 processes matter over eons. It actively builds armor on these 470 00:22:47,039 --> 00:22:47,839 drifting rocks. 471 00:22:48,480 --> 00:22:52,240 Speaker 2: It transforms them completely. The object that originally left its 472 00:22:52,240 --> 00:22:54,960 home Star billions of years ago is not the exact 473 00:22:54,960 --> 00:22:58,680 same object that arrived here. The journey itself changed its 474 00:22:58,759 --> 00:22:59,759 fundamental nature. 475 00:23:00,160 --> 00:23:01,839 Speaker 1: I really want to hear from you guys on this one, 476 00:23:02,200 --> 00:23:05,160 because the implications are huge. If a comic can be 477 00:23:05,200 --> 00:23:08,119 shielded by a crust that hides its true nature until 478 00:23:08,160 --> 00:23:11,960 the very last moment, how many other totally dark objects 479 00:23:11,960 --> 00:23:15,119 pass through our system unnoticed because they never wake up? 480 00:23:15,720 --> 00:23:18,759 Are we surrounded by dormant interstellar travelers? 481 00:23:18,920 --> 00:23:21,519 Speaker 2: And also, how do you feel about that near miss 482 00:23:21,519 --> 00:23:24,599 with Jupiter? Does the physics of a lost opportunity sting? 483 00:23:24,720 --> 00:23:27,440 Or is it just the way orbital mechanics crumbles? 484 00:23:27,640 --> 00:23:30,720 Speaker 1: Drop your thoughts down in the comments. We read the papers, 485 00:23:30,839 --> 00:23:33,160 but we also love reading the comments. It is where 486 00:23:33,200 --> 00:23:34,839 the best theories sometimes pop up. 487 00:23:35,160 --> 00:23:37,680 Speaker 2: Honestly, sometimes the comments are harder to decipher than the 488 00:23:37,720 --> 00:23:38,559 academic papers. 489 00:23:38,680 --> 00:23:41,279 Speaker 1: Ain't they have the truth? Three at Aisles is heading 490 00:23:41,319 --> 00:23:43,640 out but the sky is big, and our surveys are 491 00:23:43,640 --> 00:23:46,559 getting better every single day. It won't be long until 492 00:23:46,599 --> 00:23:47,559 number four shows up. 493 00:23:47,680 --> 00:23:49,240 Speaker 2: Keep looking up, everyone. 494 00:23:49,079 --> 00:23:51,279 Speaker 1: Stay curious, and stay thrilled. We'll see you in the 495 00:23:51,279 --> 00:23:51,799 next thread.