WEBVTT 0 00:00:00.000 --> 00:00:02.880 Anna: Welcome back to Astronomy Daily, your go to 1 00:00:02.880 --> 00:00:05.400 podcast for all the latest happenings in our 2 00:00:05.400 --> 00:00:07.840 incredible universe. I'm Anna. 3 00:00:07.920 --> 00:00:10.640 Avery: And I'm Avery. We've got a big episode lined 4 00:00:10.640 --> 00:00:12.440 up for you today, packed with some truly 5 00:00:12.440 --> 00:00:14.160 fascinating cosmic updates. 6 00:00:14.480 --> 00:00:16.800 Anna: That's right, Avery. We'll be diving into new 7 00:00:16.800 --> 00:00:19.280 research about lunar seismic activity 8 00:00:19.440 --> 00:00:21.920 and what moonquakes could mean for future 9 00:00:21.920 --> 00:00:24.400 bases on our nearest celestial neighbour. 10 00:00:24.720 --> 00:00:27.520 Turns out the Moon is a lot shakier than you 11 00:00:27.520 --> 00:00:28.000 might think. 12 00:00:28.950 --> 00:00:31.270 Avery: And speaking of drama, we'll also explore the 13 00:00:31.270 --> 00:00:34.270 explosive end of a massive star that had a 14 00:00:34.270 --> 00:00:36.910 very close encounter with a black hole. It's 15 00:00:36.910 --> 00:00:39.630 a story straight out of a sci fi movie, but 16 00:00:39.630 --> 00:00:40.150 it's real. 17 00:00:40.550 --> 00:00:42.830 Anna: Plus, we're tackling some long standing 18 00:00:42.830 --> 00:00:45.550 cosmic mysteries, from the curious case of 19 00:00:45.550 --> 00:00:47.790 the universe's missing sulphur to 20 00:00:47.790 --> 00:00:50.630 groundbreaking new insights about Vesta, one 21 00:00:50.630 --> 00:00:53.030 of the largest objects in the asteroid belt. 22 00:00:53.110 --> 00:00:54.750 Which might be more than just an. 23 00:00:54.750 --> 00:00:57.470 Avery: Asteroid, but so buckle up because 24 00:00:57.470 --> 00:00:59.430 we're about to take a tour through the latest 25 00:00:59.430 --> 00:01:02.110 and greatest in space and astronomy news. 26 00:01:02.750 --> 00:01:05.150 Anna: Alright, let's kick things off with some big 27 00:01:05.150 --> 00:01:08.070 news about our own Moon. We often think 28 00:01:08.070 --> 00:01:10.870 of it as a quiet, unchanging place, but 29 00:01:10.870 --> 00:01:13.150 new research is challenging that idea, 30 00:01:13.390 --> 00:01:15.550 especially when we consider building long 31 00:01:15.550 --> 00:01:16.590 term bases there. 32 00:01:16.910 --> 00:01:19.670 Avery: That's right, Anna. It turns out our lunar 33 00:01:19.670 --> 00:01:22.030 neighbour is more seismically active than 34 00:01:22.030 --> 00:01:25.030 many might assume. A recent study focusing 35 00:01:25.030 --> 00:01:27.750 on the Lee Lincoln Fault in the Taurus 36 00:01:27.750 --> 00:01:30.230 Littrell Valley, where the Apollo 17 37 00:01:30.230 --> 00:01:32.470 astronauts landed in 1972, 38 00:01:32.870 --> 00:01:35.110 highlights that these moonquakes could pose 39 00:01:35.110 --> 00:01:37.710 significant risks to future permanent lunar 40 00:01:37.710 --> 00:01:38.150 structures. 41 00:01:38.550 --> 00:01:41.430 Anna: This research, led by Smithsonian Senior 42 00:01:41.430 --> 00:01:44.150 Scientist Emeritus Thomas R. Waters, 43 00:01:44.310 --> 00:01:47.150 emphasises that the global distribution of 44 00:01:47.150 --> 00:01:49.710 these young thrust faults and their potential 45 00:01:49.710 --> 00:01:52.550 to still be active needs to be seriously 46 00:01:52.550 --> 00:01:54.800 considered. We're talking about planning 47 00:01:54.800 --> 00:01:57.800 locations and assessing the stability of any 48 00:01:57.800 --> 00:01:59.600 permanent outposts on the Moon. 49 00:01:59.920 --> 00:02:02.120 Avery: And, um, the evidence isn't new. It's based 50 00:02:02.120 --> 00:02:04.800 on moonquakes in the region over the past 90 51 00:02:04.880 --> 00:02:07.360 million years. Much of this evidence comes 52 00:02:07.360 --> 00:02:09.360 from material gathered by the Apollo 53 00:02:09.360 --> 00:02:11.960 astronauts themselves. Things like chunks of 54 00:02:11.960 --> 00:02:14.720 rocks and landslides are silent. But clear 55 00:02:14.720 --> 00:02:17.280 proof of the power of even magnitude 56 00:02:17.280 --> 00:02:19.880 3.0 quakes to shift surface 57 00:02:19.880 --> 00:02:22.680 materials around it really points to the Moon 58 00:02:22.680 --> 00:02:24.640 still being geologically active. 59 00:02:25.000 --> 00:02:27.280 Anna: It makes you wonder, why does the Moon even 60 00:02:27.280 --> 00:02:29.640 have quakes here on Earth? We're very 61 00:02:29.640 --> 00:02:32.000 familiar with earthquakes, primarily caused 62 00:02:32.000 --> 00:02:34.600 by plate tectonics and volcanic activity. 63 00:02:34.840 --> 00:02:37.200 Think of the San Andreas Fault or the Ring of 64 00:02:37.200 --> 00:02:40.080 Fire. Magma movement also causes tremors, 65 00:02:40.080 --> 00:02:42.680 like the recent events in Hawaii and Iceland. 66 00:02:43.160 --> 00:02:45.960 Avery: But the Moon operates differently. Its quakes 67 00:02:45.960 --> 00:02:47.880 are most Likely caused by two main 68 00:02:48.680 --> 00:02:50.760 Earth's tidal pulling and the Moon's 69 00:02:50.760 --> 00:02:53.450 continuous cooling and shrinking. The deep 70 00:02:53.450 --> 00:02:55.930 moonquakes occurring hundreds of miles inside 71 00:02:56.250 --> 00:02:58.770 are due to Earth's gravity pulling on her 72 00:02:58.770 --> 00:02:59.370 satellite. 73 00:02:59.450 --> 00:03:01.810 Anna: And the weaker quakes closer to the surface 74 00:03:01.810 --> 00:03:03.890 are generally attributed to the Moon's 75 00:03:03.890 --> 00:03:06.490 gradual cooling and shrinking. Since its 76 00:03:06.490 --> 00:03:09.210 formation billions of years ago, the Moon has 77 00:03:09.210 --> 00:03:12.050 actually lost about 150ft of 78 00:03:12.050 --> 00:03:14.730 its diameter. There are also minor tremors 79 00:03:14.730 --> 00:03:17.450 from meteoroid impacts or surface rocks 80 00:03:17.450 --> 00:03:19.690 reacting to heating and cooling from the sun. 81 00:03:20.320 --> 00:03:22.320 So it's a world that's constantly shaking. 82 00:03:22.720 --> 00:03:25.200 Avery: When we talk about the risks to future bases, 83 00:03:25.280 --> 00:03:27.840 it becomes quite significant. Short term 84 00:03:27.840 --> 00:03:30.040 missions like the Apollo landings, where 85 00:03:30.040 --> 00:03:32.160 astronauts were on the Moon for less than two 86 00:03:32.160 --> 00:03:35.040 weeks, didn't face much danger. But for 87 00:03:35.040 --> 00:03:37.680 permanent bases, the chances of damage during 88 00:03:37.680 --> 00:03:40.480 a quake go up simply due to the extended 89 00:03:40.480 --> 00:03:41.200 exposure. 90 00:03:41.680 --> 00:03:44.400 Anna: Nicholas Schmer put it into perspective. He 91 00:03:44.400 --> 00:03:46.800 said if astronauts are there for a day, 92 00:03:46.800 --> 00:03:49.000 they'd just have very bad luck. If there was 93 00:03:49.000 --> 00:03:51.210 a damaging event, they. But if you have a 94 00:03:51.210 --> 00:03:53.690 habitat or crewed mission up on the Moon for 95 00:03:53.690 --> 00:03:55.410 a whole decade, that's 96 00:03:55.410 --> 00:03:58.330 3,650 days times 1 97 00:03:58.330 --> 00:04:01.130 in 20 million. Or the risk of a hazardous 98 00:04:01.130 --> 00:04:03.970 moonquake becoming about 1 in 5,500. 99 00:04:04.450 --> 00:04:06.489 Avery: He likened it to, uh, going from the 100 00:04:06.489 --> 00:04:09.250 extremely low odds of winning a lottery 101 00:04:09.330 --> 00:04:12.170 to the much higher odds of being dealt a four 102 00:04:12.170 --> 00:04:14.810 of a kind poker hand. It really illustrates 103 00:04:14.810 --> 00:04:17.250 how much the probability increases over time. 104 00:04:18.179 --> 00:04:21.139 Anna: And it's not just habitats. Countries like 105 00:04:21.139 --> 00:04:24.139 Russia, China and the US are planning to put 106 00:04:24.139 --> 00:04:26.699 nuclear power plants on the Moon. These 107 00:04:26.699 --> 00:04:29.059 facilities would supply massive amounts of 108 00:04:29.059 --> 00:04:31.499 power, but they'd also be susceptible to 109 00:04:31.499 --> 00:04:34.179 quake damage. This means any construction 110 00:04:34.179 --> 00:04:36.779 will need tough safety margins and shouldn't 111 00:04:36.779 --> 00:04:38.979 be located near active fault lines. 112 00:04:39.699 --> 00:04:42.019 Avery: Which is a tall order considering how many 113 00:04:42.019 --> 00:04:44.650 fault lines thread through the Moon. That's 114 00:04:44.650 --> 00:04:47.170 why this study of lunar paleoseismology 115 00:04:47.490 --> 00:04:50.250 looking at evidence of past quakes is so 116 00:04:50.250 --> 00:04:53.010 crucial. It will help us chart the safest 117 00:04:53.010 --> 00:04:55.370 places to build these long term habitats and 118 00:04:55.370 --> 00:04:57.770 power plants. It's all about understanding 119 00:04:57.770 --> 00:04:59.090 our cosmic neighbourhood. 120 00:04:59.250 --> 00:05:01.930 Before we make ourselves at home from 121 00:05:01.930 --> 00:05:04.130 lunar shaking, let's zoom out to something 122 00:05:04.210 --> 00:05:06.610 truly dramatic happening in the cosmos. 123 00:05:06.930 --> 00:05:09.890 Scientists have captured the explosive end of 124 00:05:09.890 --> 00:05:12.450 a massive star in a scenario unlike 125 00:05:12.450 --> 00:05:13.810 anything they've seen before. 126 00:05:14.370 --> 00:05:17.090 Anna: That's right, Avery. This event, more than 127 00:05:17.170 --> 00:05:20.170 700 million light years away, began as 128 00:05:20.170 --> 00:05:22.890 a faint flicker. Within days, the light 129 00:05:22.890 --> 00:05:25.650 flared, faded, and then, surprisingly, 130 00:05:25.650 --> 00:05:28.370 flared again. It was completely 131 00:05:28.370 --> 00:05:31.010 unlike the standard playbook for dying stars. 132 00:05:31.810 --> 00:05:34.050 Avery: What makes this even more incredible is that 133 00:05:34.050 --> 00:05:36.730 an artificial intelligence System flagged the 134 00:05:36.730 --> 00:05:39.410 event in real time. This allowed scientists 135 00:05:39.410 --> 00:05:42.130 to capture every phase of what may be the 136 00:05:42.130 --> 00:05:44.410 first recorded case of a massive star 137 00:05:44.410 --> 00:05:47.230 exploding as it tried to devour a black 138 00:05:47.230 --> 00:05:50.030 hole companion. Talk about cosmic drama. 139 00:05:50.510 --> 00:05:51.910 This supernova, named 140 00:05:51.910 --> 00:05:54.830 SN2023ZKD, was 141 00:05:54.830 --> 00:05:57.830 first spotted in July 2023 by the Zwicky 142 00:05:57.830 --> 00:06:00.470 Transient Facility and then analysed by a 143 00:06:00.470 --> 00:06:02.550 team from the Centre for Astrophysics at 144 00:06:02.550 --> 00:06:05.270 Harvard and Smithsonian mit. Their 145 00:06:05.270 --> 00:06:07.350 findings, published in the Astrophysical 146 00:06:07.350 --> 00:06:10.030 Journal, provide the clearest evidence yet 147 00:06:10.030 --> 00:06:12.750 that such extreme binary interactions can 148 00:06:12.750 --> 00:06:15.610 actually trigger a stellar detonation. It 149 00:06:15.610 --> 00:06:18.410 was part of the Young Supernova Experiment, a 150 00:06:18.410 --> 00:06:20.450 project designed to catch these exploding 151 00:06:20.450 --> 00:06:23.410 stars in their earliest stages. The AI system 152 00:06:23.410 --> 00:06:25.410 gave astronomers a crucial head start, 153 00:06:25.730 --> 00:06:28.170 allowing them to follow the explosion in near 154 00:06:28.170 --> 00:06:30.490 real time from both ground and space 155 00:06:30.490 --> 00:06:31.409 observatories. 156 00:06:32.130 --> 00:06:35.130 Anna: Alexander Agliano, the lead author of 157 00:06:35.130 --> 00:06:37.610 the study, stated that their analysis shows 158 00:06:37.610 --> 00:06:39.930 the blast was sparked by a catastrophic 159 00:06:39.930 --> 00:06:41.890 encounter with a black hole companion, 160 00:06:42.380 --> 00:06:44.860 providing the strongest evidence to date that 161 00:06:44.860 --> 00:06:47.420 such close interactions can indeed 162 00:06:47.420 --> 00:06:48.540 detonate a star. 163 00:06:49.500 --> 00:06:51.900 Avery: The leading explanation is that this massive 164 00:06:51.900 --> 00:06:54.060 star and black hole were locked in a decaying 165 00:06:54.060 --> 00:06:56.820 orbit. As they drew closer, the black hole's 166 00:06:56.820 --> 00:06:59.780 immense gravity pulled gas from the star into 167 00:06:59.780 --> 00:07:02.780 a surrounding disc. This intense stress is 168 00:07:02.780 --> 00:07:04.540 believed to have triggered the explosion 169 00:07:04.540 --> 00:07:06.860 before the star could fully engulf the black 170 00:07:06.860 --> 00:07:07.260 hole. 171 00:07:08.230 --> 00:07:10.470 Anna: Another possibility is that the black hole 172 00:07:10.550 --> 00:07:12.830 completely shredded the star, with the 173 00:07:12.830 --> 00:07:15.110 debris's collisions then powering the 174 00:07:15.110 --> 00:07:17.950 supernova's light. In either scenario, 175 00:07:17.950 --> 00:07:20.670 the aftermath left behind a heavier black 176 00:07:20.670 --> 00:07:21.110 hole. 177 00:07:21.910 --> 00:07:24.069 Avery: What really stood out to astronomers were the 178 00:07:24.069 --> 00:07:26.390 unusual light patterns from Earth. 179 00:07:26.470 --> 00:07:29.430 SN2023ZKD initially 180 00:07:29.430 --> 00:07:31.710 looked like a normal supernova. A single 181 00:07:31.710 --> 00:07:34.150 burst of light followed by a gradual fade. 182 00:07:34.620 --> 00:07:36.860 But then, months later, it did something 183 00:07:36.860 --> 00:07:39.580 truly extraordinary. It brightened again. 184 00:07:40.540 --> 00:07:43.300 Anna: Archival records showed that the system had 185 00:07:43.300 --> 00:07:45.740 actually been slowly brightening for more 186 00:07:45.740 --> 00:07:48.460 than four years before the explosion, 187 00:07:48.700 --> 00:07:51.180 a rare and telling sign of pre death 188 00:07:51.180 --> 00:07:54.180 instability. The analysis revealed that the 189 00:07:54.180 --> 00:07:57.020 supernova's light was shaped by layers of gas 190 00:07:57.020 --> 00:07:59.180 shed by the star in its final years. 191 00:07:59.500 --> 00:08:01.460 Avery: The first brightening came from the blast 192 00:08:01.460 --> 00:08:03.820 wave colliding with diffused gas, while while 193 00:08:03.820 --> 00:08:05.820 that second peak was fueled by a slower 194 00:08:05.820 --> 00:08:08.220 collision with a dense disc shaped cloud. 195 00:08:08.700 --> 00:08:10.740 The structure and timing of these events 196 00:08:10.740 --> 00:08:12.860 strongly point to extreme gravitational 197 00:08:12.860 --> 00:08:15.100 forces from a nearby compact object. 198 00:08:15.340 --> 00:08:18.060 Anna: It's clear that AI played a crucial role 199 00:08:18.060 --> 00:08:20.980 here. As Gagliano mentioned, their machine 200 00:08:20.980 --> 00:08:22.500 Learning system flagged 201 00:08:22.500 --> 00:08:25.500 SN2023SKD months 202 00:08:25.500 --> 00:08:28.500 before its most unusual behaviour, which gave 203 00:08:28.500 --> 00:08:30.700 them ample time to secure the critical 204 00:08:30.700 --> 00:08:33.340 observations needed to unravel this 205 00:08:33.340 --> 00:08:36.270 extraordinary explosion V. Ashley Villar, 206 00:08:36.270 --> 00:08:36.370 a. 207 00:08:36.370 --> 00:08:38.190 Avery: AH co author and assistant professor of 208 00:08:38.190 --> 00:08:41.150 astronomy at cfa, added that this event shows 209 00:08:41.150 --> 00:08:43.350 some of the clearest signs they've seen of a 210 00:08:43.350 --> 00:08:45.510 massive star interacting with the companion 211 00:08:45.510 --> 00:08:47.830 in the years before an explosion. They 212 00:08:47.830 --> 00:08:49.870 believe this might be part of a whole class 213 00:08:49.870 --> 00:08:52.270 of hidden explosions that AI will help them 214 00:08:52.270 --> 00:08:53.110 discover in the future. 215 00:08:53.510 --> 00:08:56.510 Anna: With new observatories like the veracy Rubin 216 00:08:56.510 --> 00:08:59.030 Observatory soon scanning the entire sky 217 00:08:59.030 --> 00:09:01.830 every few nights and projects like the Young 218 00:09:01.910 --> 00:09:04.550 Supernova Experiment continuing to identify 219 00:09:04.550 --> 00:09:07.250 new events quickly, astronomers expect expect 220 00:09:07.250 --> 00:09:09.450 to catch more of these rare and complex 221 00:09:09.450 --> 00:09:12.250 explosions in action. It's truly 222 00:09:12.250 --> 00:09:15.170 a new era for observing the most extreme 223 00:09:15.330 --> 00:09:18.330 cosmic events. That's an incredible story 224 00:09:18.330 --> 00:09:20.290 of cosmic violence and detection. 225 00:09:20.770 --> 00:09:23.570 Now let's shift gears a bit and delve into a 226 00:09:23.570 --> 00:09:26.410 long standing cosmic mystery. The case of 227 00:09:26.410 --> 00:09:28.690 the universe's missing sulphur. 228 00:09:28.770 --> 00:09:30.570 Avery: It sounds like something out of a detective 229 00:09:30.570 --> 00:09:32.810 novel. For years, scientists have been 230 00:09:32.810 --> 00:09:34.770 puzzled because there simply isn't as much 231 00:09:34.770 --> 00:09:37.370 sulphur floating around in deep space as they 232 00:09:37.370 --> 00:09:39.490 expected. This is quite an enigma, 233 00:09:39.490 --> 00:09:41.850 considering Sulphur is the 10th most abundant 234 00:09:41.850 --> 00:09:44.330 element in the universe and crucial for both 235 00:09:44.330 --> 00:09:45.410 planets and life. 236 00:09:45.730 --> 00:09:48.450 Anna: Exactly. But a, uh, new international study 237 00:09:48.690 --> 00:09:51.010 might have finally found its hiding place. 238 00:09:51.410 --> 00:09:53.090 Researchers from the University of 239 00:09:53.090 --> 00:09:55.810 Mississippi, the University of Hawaii at 240 00:09:55.810 --> 00:09:58.730 Manoa and Georgia State University teamed 241 00:09:58.730 --> 00:10:00.930 up to search for answers, publishing their 242 00:10:00.930 --> 00:10:02.690 findings in Nature Communication. 243 00:10:03.250 --> 00:10:06.010 Avery: So where has all the sulphur been? The team's 244 00:10:06.010 --> 00:10:07.610 results suggest that it's not actually 245 00:10:07.610 --> 00:10:10.310 missing at all. Instead, it's locked away in 246 00:10:10.310 --> 00:10:13.150 solid forms, bound within icy grains of 247 00:10:13.150 --> 00:10:14.150 interstellar dust. 248 00:10:14.310 --> 00:10:17.230 Anna: In these frigid environments, sulphur atoms 249 00:10:17.230 --> 00:10:19.270 can arrange themselves in two main 250 00:10:19.990 --> 00:10:22.030 neat eight atom rings called 251 00:10:22.030 --> 00:10:24.909 octasulfur crowns and chains of 252 00:10:24.909 --> 00:10:27.670 sulphur atoms connected by hydrogen, known 253 00:10:27.670 --> 00:10:30.470 as polysulfons. These structures 254 00:10:30.630 --> 00:10:33.190 literally stick to icy dust grains, 255 00:10:33.190 --> 00:10:35.510 essentially freezing the sulphur out of view. 256 00:10:35.990 --> 00:10:37.830 Avery: It's fascinating how a common element on 257 00:10:37.830 --> 00:10:40.550 Earth found in volcanoes and power plants 258 00:10:40.630 --> 00:10:43.310 can be so elusive in space. Ralph 259 00:10:43.310 --> 00:10:45.110 Kaiser, one of the lead researchers, 260 00:10:45.190 --> 00:10:47.230 explained that the observed amount of sulphur 261 00:10:47.230 --> 00:10:50.230 in dense molecular clouds is three orders of 262 00:10:50.230 --> 00:10:52.750 magnitude less than predicted gas phase 263 00:10:52.750 --> 00:10:55.110 abundances. That's a huge difference. 264 00:10:55.350 --> 00:10:58.150 Anna: Astronomers typically identify elements in 265 00:10:58.150 --> 00:11:00.790 space by detecting the unique patterns of 266 00:11:00.790 --> 00:11:03.670 light they emit or absorb. While tools 267 00:11:03.670 --> 00:11:06.610 like James Webb Space Telescope can easily 268 00:11:06.610 --> 00:11:09.170 pick out oxygen, carbon and nitrogen, 269 00:11:09.330 --> 00:11:11.610 sulphur just doesn't follow the rules in the 270 00:11:11.610 --> 00:11:14.170 same way. As researcher uh, Ryan Fortenberry 271 00:11:14.170 --> 00:11:16.890 noted, when you do that for sulphur, it's out 272 00:11:16.890 --> 00:11:17.410 of whack. 273 00:11:17.570 --> 00:11:20.130 Avery: Another challenge is sulfur's shape. Shifting 274 00:11:20.130 --> 00:11:23.010 nature. Fortenberry likened it to a virus 275 00:11:23.090 --> 00:11:25.890 always changing shape as it moves, making it 276 00:11:25.890 --> 00:11:28.490 incredibly difficult to track. But this new 277 00:11:28.490 --> 00:11:30.810 research points to stable molecular forms 278 00:11:30.810 --> 00:11:32.850 that astronomers can now specifically hunt 279 00:11:32.850 --> 00:11:35.330 for using advanced radio telescopes. 280 00:11:35.750 --> 00:11:38.470 Anna: By recreating the conditions of deep space in 281 00:11:38.470 --> 00:11:40.830 laboratory experiments, the researchers 282 00:11:40.830 --> 00:11:43.510 confirmed that these solid sulphur compounds 283 00:11:43.590 --> 00:11:46.150 could indeed form on icy surfaces. 284 00:11:46.470 --> 00:11:49.230 And here's the Once these icy grains are 285 00:11:49.230 --> 00:11:52.110 heated in young star systems, the sulphur can 286 00:11:52.110 --> 00:11:54.990 sublime, meaning it transforms directly from 287 00:11:54.990 --> 00:11:57.630 a solid to a gas, making it finally 288 00:11:57.630 --> 00:11:58.790 detectable from Earth. 289 00:11:59.030 --> 00:12:00.990 Avery: This work could finally help astronomers 290 00:12:00.990 --> 00:12:03.070 piece together sulfur's role in both the 291 00:12:03.070 --> 00:12:05.630 formation of planets and the very chemistry 292 00:12:05.630 --> 00:12:08.020 that supports life. If they can pinpoint 293 00:12:08.020 --> 00:12:10.300 exactly where sulphur is stored, it could 294 00:12:10.300 --> 00:12:12.300 deepen our understanding of how essential 295 00:12:12.300 --> 00:12:14.620 life building elements are distributed across 296 00:12:14.620 --> 00:12:17.220 the cosmos. And, um, even improve models of 297 00:12:17.220 --> 00:12:19.180 planetary atmospheres, especially for 298 00:12:19.180 --> 00:12:20.060 exoplanets. 299 00:12:20.140 --> 00:12:22.979 Anna: It's a perfect example of astrochemistry 300 00:12:22.979 --> 00:12:25.340 forcing hard questions and leading to 301 00:12:25.340 --> 00:12:28.220 creative solutions. As Fortenberry put it, 302 00:12:28.540 --> 00:12:31.060 this kind of foundational research has the 303 00:12:31.060 --> 00:12:34.060 potential for significant unintended positive 304 00:12:34.060 --> 00:12:36.860 consequences for our broader understanding of 305 00:12:36.860 --> 00:12:37.500 the universe. 306 00:12:38.070 --> 00:12:39.510 Avery: That's a great point, Anna. 307 00:12:39.670 --> 00:12:41.750 Speaking of profound insights into how 308 00:12:41.750 --> 00:12:44.230 celestial bodies form, our next story 309 00:12:44.310 --> 00:12:46.630 completely redefines what we thought we knew 310 00:12:46.630 --> 00:12:49.190 about Vesta, one of the largest objects in 311 00:12:49.190 --> 00:12:51.790 the asteroid belt. For years, astronomers 312 00:12:51.790 --> 00:12:54.390 viewed Vesta as almost a miniature version of 313 00:12:54.390 --> 00:12:56.950 Earth, something between a rock in space and 314 00:12:56.950 --> 00:12:59.470 a full fledged planet due to its rocky 315 00:12:59.470 --> 00:13:02.030 surface, distinct layers, and volcanic 316 00:13:02.030 --> 00:13:02.310 history. 317 00:13:02.950 --> 00:13:05.750 Anna: But new research is truly shaking up that 318 00:13:05.750 --> 00:13:08.310 view. Data collected from NASA's dawn 319 00:13:08.310 --> 00:13:11.080 spacecraft, reanalyzed years later, 320 00:13:11.240 --> 00:13:13.880 is rewriting our understanding of how early 321 00:13:13.960 --> 00:13:16.240 planets may have formed and what might have 322 00:13:16.240 --> 00:13:17.960 gone wrong in Vesta's case. 323 00:13:18.000 --> 00:13:20.560 Avery: M the Dante spacecraft orbited Vesta from 324 00:13:20.560 --> 00:13:23.400 2011 to 2012, meticulously 325 00:13:23.400 --> 00:13:25.360 mapping its surface and measuring its 326 00:13:25.360 --> 00:13:27.920 gravity. Initially, this data suggested 327 00:13:27.920 --> 00:13:30.000 Vesta had undergone planetary 328 00:13:30.000 --> 00:13:32.600 differentiation, the process where dense 329 00:13:32.600 --> 00:13:35.160 materials sink to form a core and 330 00:13:35.160 --> 00:13:37.880 lighter materials create a mantle and crust. 331 00:13:37.940 --> 00:13:40.930 The Just like Earth or Mars, Vesta's 332 00:13:40.930 --> 00:13:43.130 volcanic surface seemed to confirm this. 333 00:13:43.930 --> 00:13:46.850 Anna: However, a decade after Dawn's mission ended 334 00:13:46.850 --> 00:13:49.850 in 2018, researchers at NASA's Jet 335 00:13:49.850 --> 00:13:52.810 Propulsion Lab, or JPL, decided to take 336 00:13:52.810 --> 00:13:54.970 a fresh look at the data, using better 337 00:13:54.970 --> 00:13:57.770 calibration and updated processing tools. 338 00:13:58.010 --> 00:14:00.530 And what they found completely challenged 339 00:14:00.530 --> 00:14:03.410 that long held Vesta may not have 340 00:14:03.410 --> 00:14:04.490 a core at all. 341 00:14:05.040 --> 00:14:07.840 Avery: That's a huge revelation. Ryan Park, a 342 00:14:07.840 --> 00:14:09.800 senior research scientist and principal 343 00:14:09.800 --> 00:14:12.560 engineer at jpl, expressed excitement, 344 00:14:12.640 --> 00:14:14.840 saying they were thrilled to confirm the 345 00:14:14.840 --> 00:14:17.320 data's strength in revealing Vesta's deep 346 00:14:17.320 --> 00:14:20.280 interior. By reanalyzing the dawn data, 347 00:14:20.280 --> 00:14:22.930 the team made a more precise estimate of, uh, 348 00:14:22.930 --> 00:14:25.040 Vesta's moment of inertia. 349 00:14:25.520 --> 00:14:28.200 Anna: For those wondering, the moment of inertia is 350 00:14:28.200 --> 00:14:31.200 a physics concept that reveals how mass is 351 00:14:31.200 --> 00:14:33.360 distributed within a rotating body. 352 00:14:34.100 --> 00:14:36.660 Assistant Professor Seth Jacobson of Michigan 353 00:14:36.660 --> 00:14:39.300 State University explained it with a simple 354 00:14:40.340 --> 00:14:42.940 Think of a figure skater. When they pull 355 00:14:42.940 --> 00:14:45.580 their arms in, they spin faster. When they 356 00:14:45.580 --> 00:14:47.620 stretch their arms out, they slow down. 357 00:14:48.020 --> 00:14:50.900 Celestial bodies with dense cores behave like 358 00:14:50.900 --> 00:14:53.500 skaters with their arms in rotating 359 00:14:53.500 --> 00:14:54.100 differently. 360 00:14:54.340 --> 00:14:56.580 Avery: And Vesta's behaviour simply didn't match 361 00:14:56.580 --> 00:14:59.140 what scientists expected from a core bearing 362 00:14:59.140 --> 00:15:02.080 body. Its moment of inertia and calculated 363 00:15:02.080 --> 00:15:04.920 at only 6.6% lower than a 364 00:15:04.920 --> 00:15:07.800 perfectly uniform structure suggests its 365 00:15:07.800 --> 00:15:10.120 internal structure is. Surprisingly, even 366 00:15:10.680 --> 00:15:13.320 this value points to only a mild difference 367 00:15:13.320 --> 00:15:16.000 in density beneath its crust, not the 368 00:15:16.000 --> 00:15:18.840 deep layering we see in fully differentiated 369 00:15:18.840 --> 00:15:19.320 planets. 370 00:15:20.040 --> 00:15:22.760 Anna: This new perspective has forced scientists to 371 00:15:22.760 --> 00:15:24.680 rethink everything they thought they knew 372 00:15:24.680 --> 00:15:26.920 about Vesta's formation. They're now 373 00:15:26.920 --> 00:15:29.690 exploring two main ideas. The first 374 00:15:29.690 --> 00:15:32.490 is that Vesta began to differentiate. Its 375 00:15:32.490 --> 00:15:34.770 insides started to melt and separate into 376 00:15:34.770 --> 00:15:37.250 layers. But something interrupted the 377 00:15:37.250 --> 00:15:39.970 process. This could have been a late start in 378 00:15:39.970 --> 00:15:42.770 forming or limited exposure to heat producing 379 00:15:42.770 --> 00:15:45.049 elements like radioactive aluminium. 380 00:15:45.049 --> 00:15:47.890 Avery: 26 the second theory is even more 381 00:15:47.890 --> 00:15:50.690 dramatic. It suggests Vesta might be the 382 00:15:50.690 --> 00:15:52.930 shattered remnants of a much larger 383 00:15:52.930 --> 00:15:55.740 differentiated planet. That body could have 384 00:15:55.740 --> 00:15:57.980 been destroyed in a massive collision during 385 00:15:57.980 --> 00:16:00.580 the solar system's early years. And Vesta 386 00:16:00.580 --> 00:16:02.420 would then be just one of the reassembled 387 00:16:02.420 --> 00:16:05.340 pieces, essentially chunky space debris of, 388 00:16:05.340 --> 00:16:08.100 uh, a growing world that never quite made 389 00:16:08.100 --> 00:16:10.660 it. Seth Jacobson, who initially 390 00:16:10.660 --> 00:16:13.020 considered this idea a stretch years ago, 391 00:16:13.500 --> 00:16:14.940 now takes it seriously. 392 00:16:15.580 --> 00:16:18.180 Anna: The mystery deepens when you consider Vesta's 393 00:16:18.180 --> 00:16:20.620 meteorites. Researchers have collected 394 00:16:20.620 --> 00:16:23.180 thousands of space rocks on Earth believed to 395 00:16:23.180 --> 00:16:25.700 have come from Vesta. And these meteorites 396 00:16:25.700 --> 00:16:27.860 look like they formed in a molten environment 397 00:16:28.260 --> 00:16:31.220 showing signs of volcanic activity. However, 398 00:16:31.540 --> 00:16:34.340 they don't obviously suggest incomplete 399 00:16:34.340 --> 00:16:37.180 differentiation, which creates a problem for 400 00:16:37.180 --> 00:16:39.460 the first hypothesis of partial melting. 401 00:16:39.700 --> 00:16:42.620 Avery: That's quite the conundrum. The second idea, 402 00:16:42.620 --> 00:16:45.300 where Vesta is a remnant of a larger 403 00:16:45.300 --> 00:16:48.220 destroyed planet, might better explain the 404 00:16:48.220 --> 00:16:51.060 rocks by. But it also raises new questions 405 00:16:51.060 --> 00:16:53.220 about how such a colossal collision would 406 00:16:53.220 --> 00:16:56.060 occur. Jacobson's lab is actively 407 00:16:56.060 --> 00:16:58.180 modelling what those collisions m might have 408 00:16:58.180 --> 00:17:00.660 looked like and how debris like Vesta might 409 00:17:00.660 --> 00:17:01.340 have formed. 410 00:17:01.900 --> 00:17:04.900 Anna: Ultimately, Vesta's internal structure holds 411 00:17:04.900 --> 00:17:07.420 the key to understanding how planets grow 412 00:17:07.820 --> 00:17:10.300 or fail to. For a long time, 413 00:17:10.300 --> 00:17:12.380 Vesta seemed like a textbook 414 00:17:12.380 --> 00:17:15.260 protoplanet, an object that started forming 415 00:17:15.260 --> 00:17:17.870 but didn't quite make it. Now 416 00:17:18.110 --> 00:17:20.430 that picture has become much blurrier. 417 00:17:21.150 --> 00:17:24.150 Avery: Instead of being a failed planet, Vesta might 418 00:17:24.150 --> 00:17:26.870 be something even more intriguing. A, uh, 419 00:17:26.950 --> 00:17:29.870 survivor of cosmic violence. If it 420 00:17:29.870 --> 00:17:32.630 truly is a chunk of a planet destroyed in the 421 00:17:32.630 --> 00:17:34.830 early solar system, it could provide 422 00:17:34.910 --> 00:17:37.750 scientists with invaluable insights into the 423 00:17:37.750 --> 00:17:40.470 collisions and processes that shaped the 424 00:17:40.470 --> 00:17:41.390 worlds we see today. 425 00:17:42.420 --> 00:17:45.270 Anna: As Jacobsen puts it, no longer is the Vesta, 426 00:17:45.270 --> 00:17:48.100 um, meteorite collection a sample of a body 427 00:17:48.100 --> 00:17:50.820 in space that failed to make it as a planet. 428 00:17:51.300 --> 00:17:54.020 These could be pieces of an ancient planet 429 00:17:54.100 --> 00:17:57.100 before it grew to full completion. We just 430 00:17:57.100 --> 00:17:58.900 don't know which planet that is yet. 431 00:17:59.620 --> 00:18:02.620 Avery: This discovery is a powerful reminder that in 432 00:18:02.620 --> 00:18:05.340 science, answers often lead to more 433 00:18:05.340 --> 00:18:08.140 questions. This reanalysis of old 434 00:18:08.140 --> 00:18:10.740 data isn't just changing our understanding of 435 00:18:10.740 --> 00:18:13.300 one asteroid. It could reshape how 436 00:18:13.300 --> 00:18:15.500 researchers think about early planetary 437 00:18:15.500 --> 00:18:18.180 formation across the entire solar system. 438 00:18:18.900 --> 00:18:21.620 Anna: And that's it for this episode. What a 439 00:18:21.620 --> 00:18:24.180 journey we've had today. From the surprising 440 00:18:24.180 --> 00:18:27.180 seismic activity of our moon and the critical 441 00:18:27.180 --> 00:18:30.060 implications for future lunar bases, to the 442 00:18:30.060 --> 00:18:32.980 mind boggling explosion of a star trying to 443 00:18:32.980 --> 00:18:35.700 swallow a block whole, the universe 444 00:18:35.860 --> 00:18:37.540 certainly keeps us on our toes. 445 00:18:38.550 --> 00:18:40.790 Avery: Absolutely, Anna. Uh, and let's not forget 446 00:18:40.790 --> 00:18:43.190 the cosmic mystery of the missing sulphur, 447 00:18:43.350 --> 00:18:45.470 now believed to be hidden in icy dust, uh, 448 00:18:45.510 --> 00:18:48.470 grains. And the groundbreaking reanalysis of 449 00:18:48.470 --> 00:18:51.030 Vesta, which challenges its long held 450 00:18:51.030 --> 00:18:53.989 status as a protoplanet, suggesting it might 451 00:18:53.989 --> 00:18:56.070 be a fragment of a destroyed world. 452 00:18:56.710 --> 00:18:59.150 Anna: It's been a day packed with fascinating 453 00:18:59.150 --> 00:19:01.630 discoveries that push the boundaries of our 454 00:19:01.630 --> 00:19:02.230 understanding. 455 00:19:02.950 --> 00:19:05.750 Avery: Indeed. Thank you for joining us on Astronomy 456 00:19:05.750 --> 00:19:08.070 Daily. We hope you enjoyed diving into the 457 00:19:08.070 --> 00:19:09.470 latest space news with us. 458 00:19:10.030 --> 00:19:12.230 Anna: We look forward to having you back next time 459 00:19:12.230 --> 00:19:14.590 for more amazing insights from across the 460 00:19:14.590 --> 00:19:17.390 cosmos. Until then, keep looking up.