WEBVTT 0 00:00:00.480 --> 00:00:03.400 Avery: Welcome to Astronomy Daily, the podcast that 1 00:00:03.400 --> 00:00:06.080 brings you the universe, one story at a time. 2 00:00:06.240 --> 00:00:07.200 I'm Avery. 3 00:00:07.360 --> 00:00:09.840 Anna: And I'm Anna. Ah, it's great to be with you. 4 00:00:10.240 --> 00:00:12.480 Today we've got news of a surprising 5 00:00:12.480 --> 00:00:15.160 discovery about one of Saturn's most famous 6 00:00:15.160 --> 00:00:18.120 moons to a cosmic crash that's rewriting 7 00:00:18.120 --> 00:00:20.240 our understanding of planet formation. 8 00:00:20.880 --> 00:00:22.960 Avery: Plus, we'll be talking again about our 9 00:00:22.960 --> 00:00:25.320 interstellar visitor, a mishap with the 10 00:00:25.320 --> 00:00:28.040 STARLink satellites, and NASA's incredible 11 00:00:28.040 --> 00:00:29.600 new map of the cosmos. 12 00:00:30.080 --> 00:00:31.450 So where are we starting, Ann? 13 00:00:31.450 --> 00:00:33.370 Anna: we're heading out to the Saturn system, 14 00:00:33.610 --> 00:00:36.490 specifically to its largest moon, Titan. 15 00:00:36.730 --> 00:00:39.330 For years, scientists have been excited by 16 00:00:39.330 --> 00:00:42.010 the theory that beneath Titan's icy crust 17 00:00:42.250 --> 00:00:44.730 lies a vast liquid water ocean, 18 00:00:44.970 --> 00:00:46.770 making it a prime candidate for 19 00:00:46.770 --> 00:00:48.090 extraterrestrial life. 20 00:00:48.810 --> 00:00:51.610 Avery: Right, the hidden ocean theory. It's been a 21 00:00:51.610 --> 00:00:54.050 cornerstone of astrobiology discussions for a 22 00:00:54.050 --> 00:00:54.330 while. 23 00:00:54.810 --> 00:00:56.730 Anna: Exactly. But a new study 24 00:00:56.890 --> 00:00:59.610 reanalyzing data from the Cassini mission 25 00:00:59.610 --> 00:01:02.370 is challenging that picture. It suggests 26 00:01:02.370 --> 00:01:05.110 Titans in interior might not be a liquid 27 00:01:05.110 --> 00:01:07.790 ocean after all. Instead, it could be a 28 00:01:07.790 --> 00:01:10.550 thick, warm and slowly freezing slush. 29 00:01:11.350 --> 00:01:14.270 Avery: Slush? So less of a swimming pool and 30 00:01:14.270 --> 00:01:16.990 more of a cosmic snow cone. What does that 31 00:01:16.990 --> 00:01:17.270 mean? 32 00:01:17.830 --> 00:01:20.310 Anna: Well, the data points to high pressure ice 33 00:01:20.310 --> 00:01:23.110 layers forming deep inside, which can trap 34 00:01:23.110 --> 00:01:25.510 liquid. So instead of one big 35 00:01:25.510 --> 00:01:28.190 interior ocean, we might be looking at 36 00:01:28.190 --> 00:01:30.870 smaller, isolated pockets of meltwater 37 00:01:30.950 --> 00:01:33.670 within a mostly solid icy mantle. 38 00:01:33.830 --> 00:01:36.810 It complicates the idea of a single habitable 39 00:01:36.810 --> 00:01:37.170 environment. 40 00:01:38.050 --> 00:01:40.610 Avery: That's a major shift in thinking. Does it 41 00:01:40.610 --> 00:01:42.530 lower the chances of finding life there? 42 00:01:43.090 --> 00:01:45.490 Anna: It makes it more challenging. A large, 43 00:01:45.650 --> 00:01:48.450 stable ocean allows for the free movement of 44 00:01:48.450 --> 00:01:50.930 nutrients and potential life. Small, 45 00:01:51.009 --> 00:01:53.930 isolated pockets are less dynamic. It 46 00:01:53.930 --> 00:01:56.210 doesn't rule life out, but it definitely 47 00:01:56.210 --> 00:01:58.610 changes where and how we would look for it. 48 00:01:58.930 --> 00:02:00.850 It's a fantastic reminder that our 49 00:02:00.850 --> 00:02:03.410 assumptions are always being tested by new 50 00:02:03.410 --> 00:02:03.730 data. 51 00:02:04.530 --> 00:02:07.290 Avery: Absolutely. From the far reaches of the solar 52 00:02:07.290 --> 00:02:09.610 system. Let's come a little closer to home 53 00:02:09.610 --> 00:02:10.610 for our next story. 54 00:02:10.850 --> 00:02:13.610 It involves SpaceX's Starlink constellation, 55 00:02:13.610 --> 00:02:15.410 which had a bit of a hiccup recently. 56 00:02:15.970 --> 00:02:17.860 Anna: Mm I saw the headlines on this. What 57 00:02:17.860 --> 00:02:18.340 happened? 58 00:02:18.900 --> 00:02:21.260 Avery: One other satellites experienced what they're 59 00:02:21.260 --> 00:02:23.650 calling an, anomaly. It essentially broke 60 00:02:23.650 --> 00:02:26.130 apart, creating a small amount of trackable 61 00:02:26.130 --> 00:02:28.010 debris and of course, cutting off 62 00:02:28.010 --> 00:02:29.810 communication with the satellite itself. 63 00:02:30.730 --> 00:02:33.570 Anna: Space debris is always a concern. Is this 64 00:02:33.570 --> 00:02:35.770 a major risk to other satellites? 65 00:02:36.330 --> 00:02:38.810 Avery: Fortunately, in this case, the risk is very 66 00:02:38.810 --> 00:02:41.170 low. SpaceX has confirmed that the satellite 67 00:02:41.170 --> 00:02:43.690 is in a very low orbit and is expected to 68 00:02:43.690 --> 00:02:45.890 completely deorbit and burn up in Earth's 69 00:02:45.890 --> 00:02:48.650 atmosphere within a few weeks. So it's A self 70 00:02:48.650 --> 00:02:50.410 cleaning problem. Which is good news. 71 00:02:50.890 --> 00:02:53.090 Anna: That's a relief. But it does highlight the 72 00:02:53.090 --> 00:02:55.610 growing debate around these massive satellite 73 00:02:55.610 --> 00:02:57.930 mega constellations and the long term 74 00:02:57.930 --> 00:03:00.690 sustainability of low Earth orbit. One 75 00:03:00.690 --> 00:03:03.350 anomaly. But thousands of 76 00:03:03.350 --> 00:03:05.510 satellites increase the odds of future 77 00:03:05.510 --> 00:03:06.150 problems. 78 00:03:06.710 --> 00:03:09.270 Avery: And the numbers are truly staggering. We're 79 00:03:09.270 --> 00:03:11.070 not talking about hundreds of satellites 80 00:03:11.070 --> 00:03:13.390 anymore, but tens of thousands planned for 81 00:03:13.390 --> 00:03:15.550 launch in the coming years. It raises the 82 00:03:15.550 --> 00:03:17.750 specter of the Kessler Syndrome, doesn't it? 83 00:03:17.909 --> 00:03:20.350 Where the density of objects becomes so high 84 00:03:20.350 --> 00:03:22.590 that collisions create a cascading chain 85 00:03:22.590 --> 00:03:23.750 reaction of debris. 86 00:03:24.150 --> 00:03:26.830 Anna: It absolutely does. That's the nightmare 87 00:03:26.830 --> 00:03:29.280 scenario for space agencies. A runaway 88 00:03:29.280 --> 00:03:32.280 cascade could render certain orbits unusable. 89 00:03:32.280 --> 00:03:34.580 For that's why international 90 00:03:34.820 --> 00:03:37.740 cooperation on space traffic management and 91 00:03:37.740 --> 00:03:40.340 debris mitigation is becoming so critical. 92 00:03:40.660 --> 00:03:42.860 It's not just about protecting individual 93 00:03:42.860 --> 00:03:45.540 assets anymore. It's about preserving access 94 00:03:45.620 --> 00:03:47.060 to space for everyone. 95 00:03:47.860 --> 00:03:50.660 Avery: Precisely. The technology is incredible. But 96 00:03:50.660 --> 00:03:52.900 the responsibility that comes with it is 97 00:03:52.900 --> 00:03:55.780 equally immense. A crucial topic for our 98 00:03:55.780 --> 00:03:56.100 times. 99 00:03:56.820 --> 00:03:59.460 Anna: So it's less about a single failure and more 100 00:03:59.460 --> 00:04:01.940 about the cumulative risk of having so much 101 00:04:01.940 --> 00:04:04.700 hardware orbiting above us. It's a delicate 102 00:04:04.700 --> 00:04:07.360 balance between enabling global connectivity 103 00:04:07.360 --> 00:04:09.920 and creating a long term environmental 104 00:04:09.920 --> 00:04:12.160 problem right on our cosmic doorstep. 105 00:04:12.400 --> 00:04:14.960 Avery: That's the bigger conversation for sure. It's 106 00:04:14.960 --> 00:04:17.080 a test case for how companies manage their 107 00:04:17.080 --> 00:04:18.080 orbital footprint. 108 00:04:18.640 --> 00:04:21.640 Speaking of managing space, our next topic 109 00:04:21.640 --> 00:04:23.240 shifts from the corporate to the 110 00:04:23.240 --> 00:04:25.770 governmental. Anna. you're taking us into the 111 00:04:25.770 --> 00:04:27.050 world of space policy. 112 00:04:27.530 --> 00:04:29.970 Anna: That's right. President Trump issued an 113 00:04:29.970 --> 00:04:31.970 executive order that significantly 114 00:04:31.970 --> 00:04:34.700 reorganized national space policy. The 115 00:04:34.700 --> 00:04:37.140 headline grabbing goals set by the order was 116 00:04:37.140 --> 00:04:39.940 a 2028 landing for astronauts on the moon. 117 00:04:40.180 --> 00:04:43.020 Avery: 2028. That's an incredibly 118 00:04:43.020 --> 00:04:45.220 ambitious timeline. Even more aggressive than 119 00:04:45.220 --> 00:04:46.820 NASA's own initial plans. 120 00:04:46.980 --> 00:04:49.420 Anna: Extremely. The order was designed to 121 00:04:49.420 --> 00:04:51.900 accelerate things. Reinforcing NASA's 122 00:04:51.900 --> 00:04:54.140 Artemis program which is the framework for 123 00:04:54.140 --> 00:04:56.740 that lunar return. Beyond the moon landing. 124 00:04:56.740 --> 00:04:59.060 The order also called for a comprehensive 125 00:04:59.060 --> 00:05:01.620 space security strategy addressing the 126 00:05:01.620 --> 00:05:04.260 increasing militarization and competition in 127 00:05:04.260 --> 00:05:04.580 space. 128 00:05:05.100 --> 00:05:07.500 Avery: That makes sense. It's about planting a flag 129 00:05:07.660 --> 00:05:10.220 both literally on the moon m and figuratively 130 00:05:10.220 --> 00:05:12.980 in terms of geopolitical standing. Did the 131 00:05:12.980 --> 00:05:14.380 order have lasting effects? 132 00:05:14.540 --> 00:05:17.140 Anna: It certainly solidified the Artemis program's 133 00:05:17.140 --> 00:05:19.580 direction and injected a sense of urgency. 134 00:05:19.900 --> 00:05:22.380 While the 2028 timeline has since been 135 00:05:22.380 --> 00:05:25.220 adjusted to be more realistic, the core focus 136 00:05:25.220 --> 00:05:27.700 on a sustainable lunar presence and preparing 137 00:05:27.700 --> 00:05:30.540 for Mars remains central to US space policy. 138 00:05:30.940 --> 00:05:32.780 It really framed the narrative for this 139 00:05:32.780 --> 00:05:34.220 decade of space exploration. 140 00:05:34.540 --> 00:05:37.180 Avery: It's fascinating how policy can shape science 141 00:05:37.180 --> 00:05:40.020 on such a grand scale. And from grand 142 00:05:40.020 --> 00:05:42.540 policy to a grand cosmic mystery. 143 00:05:42.860 --> 00:05:45.300 Our next story feels like a detective novel. 144 00:05:45.300 --> 00:05:47.660 Set in space. We're talking about the 145 00:05:47.660 --> 00:05:49.660 exoplanet Fomalhaut B. 146 00:05:49.740 --> 00:05:52.690 Anna: Ah, the zombie planet. I love this story. It 147 00:05:52.690 --> 00:05:54.610 was one of the first exoplanets to be 148 00:05:54.610 --> 00:05:57.570 directly imaged. But it behaved so strangely 149 00:05:57.570 --> 00:05:58.290 over the years. 150 00:05:58.610 --> 00:06:01.490 Avery: Exactly. It was dimming and had a weird 151 00:06:01.490 --> 00:06:04.210 orbit. Well, astronomers using the Hubble 152 00:06:04.210 --> 00:06:06.750 Space Telescope finally cracked the case. 153 00:06:07.070 --> 00:06:10.070 Fomalhaut B was never a planet. What they had 154 00:06:10.070 --> 00:06:12.390 been tracking was the expanding cloud of 155 00:06:12.390 --> 00:06:14.990 debris from a massive cosmic crash between 156 00:06:14.990 --> 00:06:16.590 two large icy bodies. 157 00:06:17.070 --> 00:06:19.110 Anna: So they were literally watching the dust 158 00:06:19.110 --> 00:06:21.470 settle from a collision. That's incredible. 159 00:06:21.630 --> 00:06:24.070 Avery: It gets even better. They realized that they 160 00:06:24.070 --> 00:06:26.470 had also witnessed a second more recent 161 00:06:26.470 --> 00:06:28.910 collision in the same system. This means 162 00:06:28.910 --> 00:06:31.510 we're getting a rare real time look at how 163 00:06:31.510 --> 00:06:34.160 planetary systems are built through violent 164 00:06:34.160 --> 00:06:36.680 chaotic collisions. We're not just finding 165 00:06:36.680 --> 00:06:38.680 planets, we're watching the construction 166 00:06:38.680 --> 00:06:39.080 zone. 167 00:06:39.160 --> 00:06:41.800 Anna: It really is a construction zone, and a messy 168 00:06:41.800 --> 00:06:43.920 one at that. What kind of scale are we 169 00:06:43.920 --> 00:06:45.720 talking about for these colliding objects? 170 00:06:45.720 --> 00:06:47.800 Are these planet sized bodies? 171 00:06:48.120 --> 00:06:50.160 Avery: Based on the models, they estimate the 172 00:06:50.160 --> 00:06:53.160 objects were both around 200 km in diameter. 173 00:06:53.240 --> 00:06:55.720 So large asteroids or protoplanets. 174 00:06:56.040 --> 00:06:58.360 The impact would have been catastrophic, 175 00:06:58.520 --> 00:07:01.040 vaporizing them and creating an expanding 176 00:07:01.040 --> 00:07:03.560 cloud of extremely fine dust particles 177 00:07:03.800 --> 00:07:06.300 smaller than grains of sand. That's what 178 00:07:06.300 --> 00:07:07.780 Hubble was actually seeing. 179 00:07:07.940 --> 00:07:10.180 Anna: And that dust cloud is what tricked everyone 180 00:07:10.180 --> 00:07:12.940 into thinking it was a planet for so long. It 181 00:07:12.940 --> 00:07:15.020 was bright enough to be seen, but as the 182 00:07:15.020 --> 00:07:17.620 cloud expanded and dispersed, the object 183 00:07:17.620 --> 00:07:20.180 appeared to dim and eventually fade away. 184 00:07:20.420 --> 00:07:22.500 Which is not something a planet does. 185 00:07:22.740 --> 00:07:25.220 Avery: Exactly. It's a perfect example of the 186 00:07:25.220 --> 00:07:27.780 scientific process in action. An observation, 187 00:07:27.940 --> 00:07:30.740 a hypothesis, and then 188 00:07:30.740 --> 00:07:33.310 more observations that don't fit, leading to 189 00:07:33.310 --> 00:07:35.750 a completely new and even more exciting 190 00:07:35.830 --> 00:07:38.270 conclusion. The universe is full of 191 00:07:38.270 --> 00:07:40.790 surprises. And sometimes a, disappearing act 192 00:07:40.790 --> 00:07:43.030 is more interesting than a discovery that 193 00:07:43.030 --> 00:07:43.270 gives. 194 00:07:43.270 --> 00:07:45.470 Anna: You such a sense of perspective. It's a 195 00:07:45.470 --> 00:07:47.590 reminder of the dynamic and sometimes 196 00:07:47.590 --> 00:07:49.870 destructive processes that shaped our own 197 00:07:49.870 --> 00:07:52.710 solar system billions of years ago. What a 198 00:07:52.710 --> 00:07:53.390 discovery. 199 00:07:53.710 --> 00:07:56.190 And speaking of things passing through, our 200 00:07:56.190 --> 00:07:58.710 next story is about a visitor that won't be 201 00:07:58.710 --> 00:07:59.700 staying right. 202 00:07:59.780 --> 00:08:01.230 Avery: An, interstellar traveler. 203 00:08:01.310 --> 00:08:04.110 Anna: Indeed. The interstellar comet 3I 204 00:08:04.110 --> 00:08:06.510 ATLAS is currently making its closest 205 00:08:06.510 --> 00:08:08.990 approach to Earth. This is an object that was 206 00:08:08.990 --> 00:08:11.470 born in another solar system and has been 207 00:08:11.470 --> 00:08:13.470 traveling through the galaxy for millions, 208 00:08:13.630 --> 00:08:16.030 maybe billions of years before wandering into 209 00:08:16.030 --> 00:08:16.830 our neighborhood. 210 00:08:16.910 --> 00:08:19.030 Avery: Can we see it? Is this another naked eye 211 00:08:19.030 --> 00:08:19.950 comet opportunity? 212 00:08:20.270 --> 00:08:23.270 Anna: Unfortunately, no. It's far too faint for the 213 00:08:23.270 --> 00:08:26.270 naked eye or even backyard telescopes. But 214 00:08:26.270 --> 00:08:28.070 for those who want to follow its journey, 215 00:08:28.070 --> 00:08:29.950 there are numerous online tools and 216 00:08:29.950 --> 00:08:32.650 observatories providing tracking data and 217 00:08:32.650 --> 00:08:35.050 even live streams as it makes its flyby. 218 00:08:35.450 --> 00:08:38.260 Avery: So we can still watch it just digitally. And 219 00:08:38.220 --> 00:08:39.820 this is a one time show, right? 220 00:08:40.060 --> 00:08:42.460 Anna: Correct. Its trajectory is hyperbolic, 221 00:08:42.700 --> 00:08:44.740 meaning it has more than enough speed to 222 00:08:44.740 --> 00:08:47.460 escape the sun's gravity. Once it passes us, 223 00:08:47.460 --> 00:08:49.580 it's heading back out into interstellar 224 00:08:49.580 --> 00:08:52.220 space, never to return. It's a fleeting 225 00:08:52.220 --> 00:08:54.620 chance for scientists to study a pristine 226 00:08:54.700 --> 00:08:56.700 sample from another star system. 227 00:08:57.150 --> 00:08:59.990 Avery: Incredible. It's like a cosmic postcard from 228 00:08:59.990 --> 00:09:01.230 a place we'll never visit. 229 00:09:01.790 --> 00:09:04.150 For our final story, we're zooming out from a 230 00:09:04.150 --> 00:09:06.430 single object to look at the entire sky, 231 00:09:06.430 --> 00:09:08.110 thanks to a new NASA mission. 232 00:09:08.320 --> 00:09:10.640 Anna: This is about the Spherex telescope, right? 233 00:09:10.720 --> 00:09:13.600 Avery: That's the one. The Spherex Space Telescope 234 00:09:13.600 --> 00:09:16.400 has just completed its first all sky infrared 235 00:09:16.400 --> 00:09:18.960 map. This isn't just a picture. It's a map 236 00:09:18.960 --> 00:09:21.560 taken in 102 different colors of 237 00:09:21.560 --> 00:09:24.000 infrared light. Think of it as giving us a 238 00:09:24.000 --> 00:09:26.360 new set of eyes to see the universe's heat 239 00:09:26.360 --> 00:09:28.310 signature in unprecedented detail. 240 00:09:28.380 --> 00:09:30.580 Anna: Detail. And what will scientists do with that 241 00:09:30.580 --> 00:09:32.820 data? What questions can this map help 242 00:09:32.820 --> 00:09:33.180 answer? 243 00:09:33.340 --> 00:09:35.100 Avery: It's going to tackle some of the biggest 244 00:09:35.100 --> 00:09:37.820 questions in cosmology. First, by looking at 245 00:09:37.820 --> 00:09:39.860 the large scale structure of the universe, it 246 00:09:39.860 --> 00:09:42.140 will help us study the rapid expansion period 247 00:09:42.220 --> 00:09:45.220 right after the Big Bang. Second, it will map 248 00:09:45.220 --> 00:09:47.540 how galaxies have formed and evolved over 249 00:09:47.540 --> 00:09:48.380 cosmic time. 250 00:09:48.540 --> 00:09:49.980 Anna: That alone is huge. 251 00:09:50.300 --> 00:09:52.780 Avery: It is. And third, and perhaps most 252 00:09:52.780 --> 00:09:55.060 excitingly for many, it will map the 253 00:09:55.060 --> 00:09:57.660 distribution of water and organic molecules, 254 00:09:57.660 --> 00:10:00.140 the key ingredients for life throughout our 255 00:10:00.280 --> 00:10:02.520 galaxy's stellar nurseries and planet forming 256 00:10:02.520 --> 00:10:04.840 disks. This map will be a foundational 257 00:10:04.920 --> 00:10:07.000 resource for astronomers for decades. 258 00:10:07.320 --> 00:10:09.440 Anna: From the origins of the universe to the 259 00:10:09.440 --> 00:10:12.360 origins of life. That's an incredible scope. 260 00:10:12.440 --> 00:10:14.840 A perfect big picture story to end on. 261 00:10:15.080 --> 00:10:17.560 Avery: And that's a wrap for today's episode. We've 262 00:10:17.560 --> 00:10:20.200 gone from a slushy moon to a phantom planet. 263 00:10:20.200 --> 00:10:22.080 And all the way out to an interstellar 264 00:10:22.080 --> 00:10:22.600 visitor. 265 00:10:22.680 --> 00:10:25.360 Anna: Thanks for joining us on Astronomy Daily. You 266 00:10:25.360 --> 00:10:27.760 can find us on all major podcast platforms 267 00:10:27.760 --> 00:10:30.480 and our DMs are always open for questions and 268 00:10:30.480 --> 00:10:31.560 future show ideas. 269 00:10:31.910 --> 00:10:33.630 Avery: We'll be back next time with more news from 270 00:10:33.630 --> 00:10:36.030 across the cosmos. Until then, keep looking 271 00:10:36.030 --> 00:10:36.390 up.