WEBVTT 0 00:00:00.000 --> 00:00:02.880 Anna: Good day and welcome to Astronomy Daily. 1 00:00:03.040 --> 00:00:04.080 I'm Anna. 2 00:00:04.160 --> 00:00:06.760 Avery: And I'm, um, avery. It's Monday, the 20th of 3 00:00:06.760 --> 00:00:09.520 July, 2026, and here's a lovely bit of 4 00:00:09.520 --> 00:00:12.400 timing to start us off. 57 years ago 5 00:00:12.400 --> 00:00:15.160 today, two human beings first set their boots 6 00:00:15.160 --> 00:00:17.120 down in the dust of another world. 7 00:00:17.520 --> 00:00:19.853 Anna: Apollo 11, 20 8 00:00:20.027 --> 00:00:22.800 July 1969. And on the very 9 00:00:22.800 --> 00:00:25.600 anniversary of that first arrival, our 10 00:00:25.600 --> 00:00:28.200 lead story today is about an arrival of a 11 00:00:28.200 --> 00:00:31.060 different kind. A young private company half 12 00:00:31.060 --> 00:00:34.060 a world away announcing itself to the cosmos 13 00:00:34.060 --> 00:00:35.060 for the first time. 14 00:00:35.460 --> 00:00:38.260 Avery: Plus a spacecraft that swung past Mars and 15 00:00:38.260 --> 00:00:40.740 came away with a scientific treasure chest. 16 00:00:40.900 --> 00:00:43.420 A, uh, Mars rover reading a 4 billion year 17 00:00:43.420 --> 00:00:46.340 old diary of cosmic violence. A nearby 18 00:00:46.340 --> 00:00:48.220 world that looks like it's holding onto an 19 00:00:48.220 --> 00:00:50.300 atmosphere, shrimp learning to 20 00:00:50.300 --> 00:00:53.020 Anna: eat in weightlessness, and black holes 21 00:00:53.020 --> 00:00:55.700 that ring like bells. Quite the menu. 22 00:00:55.990 --> 00:00:56.790 Let's get into it. 23 00:00:57.030 --> 00:00:59.510 So our lead On Saturday morning, 24 00:00:59.590 --> 00:01:02.310 18 July, a rocket called 25 00:01:02.390 --> 00:01:05.150 Vikram 1 lifted off from the Satish 26 00:01:05.150 --> 00:01:07.230 Dhawan Space center at Sri 27 00:01:07.230 --> 00:01:09.990 Harikoda on India's east coast. 28 00:01:10.230 --> 00:01:13.190 And 17 minutes later, mission Control could 29 00:01:13.190 --> 00:01:15.590 say the words everyone had been holding their 30 00:01:15.590 --> 00:01:17.590 breath for brand success. 31 00:01:18.390 --> 00:01:20.470 Avery: And the reason that matters, Anna, is who 32 00:01:20.470 --> 00:01:22.880 built it. Bikram 1 was developed by 33 00:01:22.880 --> 00:01:25.640 Skyroot Aerospace, a private company out of 34 00:01:25.640 --> 00:01:28.600 Hyderabad founded back in 2018 by two 35 00:01:28.600 --> 00:01:31.080 former ISRO engineers. This wasn't a 36 00:01:31.080 --> 00:01:33.440 government launch. This was India's first 37 00:01:33.440 --> 00:01:36.160 ever private orbital rocket reaching space. 38 00:01:36.640 --> 00:01:39.120 Anna: Which puts India in a very small club. 39 00:01:39.440 --> 00:01:41.760 With this flight, India becomes just the 40 00:01:41.760 --> 00:01:44.720 third nation on Earth with a private orbital 41 00:01:44.720 --> 00:01:47.720 launch capability alongside the United States 42 00:01:47.720 --> 00:01:50.570 and China. That's the whole company on that 43 00:01:50.570 --> 00:01:51.610 list. 3. 44 00:01:51.930 --> 00:01:53.890 Avery: The rocket itself is a neat piece of 45 00:01:53.890 --> 00:01:56.610 engineering. It's about 22 meters tall, four 46 00:01:56.610 --> 00:01:59.570 stages, three solid, one liquid, and 47 00:01:59.570 --> 00:02:02.370 it can put around 350 kilograms into 48 00:02:02.370 --> 00:02:04.769 low earth orbit. The mission was named 49 00:02:04.769 --> 00:02:07.290 Agaman, which is Sanskrit for arrival, 50 00:02:07.530 --> 00:02:09.290 hence our episode titled Today. 51 00:02:09.690 --> 00:02:11.970 Anna: And it delivered a genuinely charming 52 00:02:11.970 --> 00:02:14.810 payload. Multiple technology demonstration 53 00:02:14.890 --> 00:02:16.490 satellites went up to about 54 00:02:16.570 --> 00:02:19.540 450km, including a 55 00:02:19.540 --> 00:02:22.140 satellite from G' Raha Space, a debris 56 00:02:22.140 --> 00:02:24.500 capture robotic arm from a company called 57 00:02:24.500 --> 00:02:27.180 cosmoserve, and Sky Root's own 58 00:02:27.180 --> 00:02:28.380 scope satellite. 59 00:02:28.460 --> 00:02:31.100 Avery: But my favorite bits are the symbolic ones. 60 00:02:31.340 --> 00:02:33.620 There was a handwritten postcard from Prime 61 00:02:33.620 --> 00:02:36.500 Minister Modi carried to orbit. There was 62 00:02:36.500 --> 00:02:39.420 a floral artwork called Cosmic Bloom. 63 00:02:39.660 --> 00:02:42.420 And then there's this. An 18 karat 64 00:02:42.420 --> 00:02:44.660 gold micro rocket carrying 65 00:02:44.660 --> 00:02:47.500 microscopic sculptures of three giants of 66 00:02:47.500 --> 00:02:50.480 Indian science. Sivi Raman, Bikram 67 00:02:50.480 --> 00:02:53.000 Sarabhai and A.P.J. abdul 68 00:02:53.000 --> 00:02:53.560 Kalam. 69 00:02:53.880 --> 00:02:56.600 Anna: Each sculpture smaller than a grain of rice. 70 00:02:57.160 --> 00:02:59.880 Avery: Smaller than a grain of rice. I love that 71 00:03:00.120 --> 00:03:02.360 you launch your first orbital rocket and you 72 00:03:02.360 --> 00:03:04.320 find room to honor the people whose shoulders 73 00:03:04.320 --> 00:03:06.760 you're standing on. The rocket is even named 74 00:03:06.760 --> 00:03:09.240 after Sarabhai, often called the father of 75 00:03:09.240 --> 00:03:10.360 India's space program. 76 00:03:10.680 --> 00:03:13.240 Anna: It's a beautiful gesture, and it caps a 77 00:03:13.240 --> 00:03:15.880 journey that began with Sky Roots suborbital 78 00:03:15.880 --> 00:03:18.200 Vikram s back in 2022. 79 00:03:18.850 --> 00:03:21.250 This is the moment they graduate from reached 80 00:03:21.250 --> 00:03:24.210 space to reached orbit. One Sky Root 81 00:03:24.210 --> 00:03:26.850 commentator called it the dawn of a new space 82 00:03:26.850 --> 00:03:29.850 era. And for India's commercial sector, that 83 00:03:29.850 --> 00:03:31.250 doesn't feel like hyperbole. 84 00:03:31.570 --> 00:03:33.650 Avery: Now, meanwhile, on the other side of the 85 00:03:33.650 --> 00:03:35.730 launch world, we're all still waiting on a 86 00:03:35.730 --> 00:03:37.090 rather larger rocket. 87 00:03:37.330 --> 00:03:39.650 Anna: We are Starship Flight 13. 88 00:03:40.130 --> 00:03:42.170 Longtime listeners know we've been tracking 89 00:03:42.170 --> 00:03:45.010 this one. SpaceX tried to fly it on Thursday, 90 00:03:45.090 --> 00:03:47.594 but the countdown aborted right at T0 91 00:03:47.706 --> 00:03:50.360 when a few of the 33 Raptor engines 92 00:03:50.430 --> 00:03:52.390 engines on the super heavy booster didn't 93 00:03:52.390 --> 00:03:55.390 light, the vehicle safely detanked, no harm 94 00:03:55.390 --> 00:03:55.710 done. 95 00:03:55.950 --> 00:03:58.350 Avery: And Elon Musk said afterwards that to be 96 00:03:58.350 --> 00:04:00.630 confident of a clean flight, two Raptors 97 00:04:00.630 --> 00:04:02.990 would be pooled and replaced. So the target 98 00:04:03.070 --> 00:04:05.390 has been sliding around. But as we record, 99 00:04:05.710 --> 00:04:08.350 the working date is no earlier than the 23rd 100 00:04:08.350 --> 00:04:09.790 to 24th of July. 101 00:04:10.430 --> 00:04:12.990 Anna: So keep your eyes on this space literally 102 00:04:13.070 --> 00:04:15.710 later this week, when Flight 13 does 103 00:04:15.710 --> 00:04:18.590 fly, it's aiming to deploy the first batch of 104 00:04:18.590 --> 00:04:21.270 the big new V3 Starlink satellites 105 00:04:21.350 --> 00:04:23.710 and eventually to attempt catching the upper 106 00:04:23.710 --> 00:04:25.870 stage with the launch tower. But, uh, for 107 00:04:25.870 --> 00:04:28.230 today, the launch success story belongs to 108 00:04:28.230 --> 00:04:28.950 Skyroot. 109 00:04:29.430 --> 00:04:31.590 Avery: Small rocket, huge milestone. 110 00:04:31.990 --> 00:04:34.390 Sometimes that's exactly how history arrives. 111 00:04:34.870 --> 00:04:37.430 Story two takes us out into the solar system 112 00:04:37.430 --> 00:04:40.390 with NASA's Psyche spacecraft. The mission on 113 00:04:40.390 --> 00:04:42.790 its way to that strange metal rich asteroid 114 00:04:42.850 --> 00:04:45.320 on also called Psyche, out in the main belt. 115 00:04:45.720 --> 00:04:48.240 Anna: Right, and to get there, Psyche needed a 116 00:04:48.240 --> 00:04:50.960 gravitational boost. Back on 15 117 00:04:50.960 --> 00:04:53.800 May, it swung past Mars for a gravity assist 118 00:04:54.120 --> 00:04:56.280 dealing a little of the planet's orbital 119 00:04:56.280 --> 00:04:59.199 momentum to slingshot itself onward. And 120 00:04:59.199 --> 00:05:02.160 this week, JPL released the full science hall 121 00:05:02.160 --> 00:05:03.800 from that flyby, which is 122 00:05:03.800 --> 00:05:06.080 Avery: really a dress rehearsal that turned into a 123 00:05:06.080 --> 00:05:08.480 bonus science session. Because a flyby like 124 00:05:08.480 --> 00:05:10.520 this is the perfect chance to switch on your 125 00:05:10.520 --> 00:05:13.320 instruments against a real planetary body and 126 00:05:13.320 --> 00:05:15.280 check that everything works before you arrive 127 00:05:15.280 --> 00:05:17.480 at your actual target in 2029. 128 00:05:17.880 --> 00:05:20.720 Anna: And everything did work. The gamma ray and 129 00:05:20.720 --> 00:05:23.160 neutron spectrometer got its first proper 130 00:05:23.160 --> 00:05:25.880 workout measuring a real world. But the 131 00:05:25.880 --> 00:05:28.720 headline for me is the magnetometer. Because 132 00:05:28.720 --> 00:05:31.480 during the Mars pass, it made its first ever 133 00:05:31.480 --> 00:05:33.240 measurement of the magnetic environment 134 00:05:33.480 --> 00:05:34.760 around another body. 135 00:05:35.240 --> 00:05:37.160 Avery: And that instrument really matters for the 136 00:05:37.160 --> 00:05:39.680 mission's big question. When Psyche reaches 137 00:05:39.680 --> 00:05:41.760 the asteroid, one of the things scientists 138 00:05:41.760 --> 00:05:44.360 most want to know is whether it has or once 139 00:05:44.360 --> 00:05:47.220 had magnetic field, because that would be a 140 00:05:47.220 --> 00:05:50.060 fingerprint of a molten metal core, a clue 141 00:05:50.060 --> 00:05:52.340 that this object might be the exposed heart 142 00:05:52.340 --> 00:05:54.020 of a shattered baby planet. 143 00:05:54.420 --> 00:05:57.220 Anna: So proving the magnetometer works cleanly at 144 00:05:57.220 --> 00:05:59.700 Mars gives the team real confidence. For 145 00:05:59.700 --> 00:06:02.680 2029, JPL also released a, uh, 146 00:06:02.740 --> 00:06:05.220 lovely timelapse of Mars growing and then 147 00:06:05.220 --> 00:06:07.540 shrinking in the spacecraft's view as it 148 00:06:07.540 --> 00:06:08.340 swept past. 149 00:06:08.820 --> 00:06:10.580 Avery: It's a good reminder that, um, on these long 150 00:06:10.580 --> 00:06:13.500 cruises, the journey itself does science. You 151 00:06:13.500 --> 00:06:15.620 don't just coast to the destination, you 152 00:06:15.620 --> 00:06:18.140 rehearse, you calibrate. And sometimes you 153 00:06:18.140 --> 00:06:20.020 get a free look at a neighbor along the way. 154 00:06:20.420 --> 00:06:23.020 Anna: Story three keeps us at Mars, but on the 155 00:06:23.020 --> 00:06:25.460 surface with the Perseverance Rover, which 156 00:06:25.460 --> 00:06:27.780 has been climbing the rim of Jezero Crater. 157 00:06:28.020 --> 00:06:30.420 Avery: And it's found something remarkable up there. 158 00:06:30.660 --> 00:06:32.980 A new study in the Journal of Geophysical 159 00:06:32.980 --> 00:06:35.180 Research Planets, led by researchers at 160 00:06:35.180 --> 00:06:37.660 Imperial College London, describes a 161 00:06:37.660 --> 00:06:40.300 75 meter thick stack of rock on the crater 162 00:06:40.300 --> 00:06:42.470 rim that they're calling the Broom Point 163 00:06:42.470 --> 00:06:42.830 member. 164 00:06:43.150 --> 00:06:45.630 Anna: And this stack is essentially a diary, 165 00:06:45.950 --> 00:06:48.350 layer after layer of what geologists call 166 00:06:48.350 --> 00:06:51.070 breccia rock that's been smashed, 167 00:06:51.070 --> 00:06:54.030 melted and welded back together by repeated 168 00:06:54.030 --> 00:06:56.630 asteroid impacts. And the timing is the 169 00:06:56.630 --> 00:06:59.310 astonishing part. This terrain is older than 170 00:06:59.310 --> 00:07:00.310 Jezero Crater 171 00:07:00.310 --> 00:07:02.950 Avery: itself, which makes it some of the oldest 172 00:07:02.950 --> 00:07:05.350 ground any Mars rover has ever laid its 173 00:07:05.350 --> 00:07:07.830 instruments on. We're talking roughly 4 174 00:07:07.830 --> 00:07:10.300 billion years back in a chapter of solar 175 00:07:10.300 --> 00:07:12.620 system history, sometimes called the era of 176 00:07:12.620 --> 00:07:14.860 heavy bombardment, when impacts were 177 00:07:14.860 --> 00:07:15.540 relentless. 178 00:07:16.100 --> 00:07:18.540 Anna: So perseverance is effectively reading a 179 00:07:18.540 --> 00:07:20.740 weather report from the most violent period 180 00:07:20.740 --> 00:07:23.420 the inner solar system has known. Each 181 00:07:23.420 --> 00:07:26.180 layer records another blow. And because 182 00:07:26.180 --> 00:07:28.660 Earth's surface has been endlessly recycled 183 00:07:28.660 --> 00:07:31.420 by plate tectonics and erosion, we've lost 184 00:07:31.420 --> 00:07:33.620 almost all of our own rocks from that age. 185 00:07:34.020 --> 00:07:36.960 Avery: That's the quiet profundity of it. Mars kept 186 00:07:36.960 --> 00:07:39.280 the receipts that Earth threw away to 187 00:07:39.280 --> 00:07:41.080 understand the bombardment that shaped our 188 00:07:41.080 --> 00:07:43.720 own young planet, the very era when life may 189 00:07:43.720 --> 00:07:46.000 have been getting started here, we may have 190 00:07:46.000 --> 00:07:48.000 to read the story off the rocks of Mars. 191 00:07:48.400 --> 00:07:50.840 Anna: And these are exactly the kinds of samples 192 00:07:50.840 --> 00:07:53.040 Perseverance has been caching for a future 193 00:07:53.040 --> 00:07:55.640 return to Earth. Imagine getting a four 194 00:07:55.640 --> 00:07:58.120 billion year old page of that diary into a 195 00:07:58.120 --> 00:07:58.640 laboratory. 196 00:07:59.120 --> 00:08:01.640 Avery: Story four is a big one for the exoplanet 197 00:08:01.640 --> 00:08:03.550 hunters. And Ana, Uh, I want to flag 198 00:08:03.550 --> 00:08:05.150 something right up front for our regular 199 00:08:05.150 --> 00:08:05.790 listeners. 200 00:08:06.270 --> 00:08:08.710 Anna: Please do, because this could sound familiar 201 00:08:08.710 --> 00:08:11.150 and it isn't exactly. 202 00:08:11.390 --> 00:08:14.270 Avery: A few days ago, in Friday's episode, we led 203 00:08:14.270 --> 00:08:16.750 with a story about the first detection of an 204 00:08:16.750 --> 00:08:19.590 atmosphere on a rocky world. This is a 205 00:08:19.590 --> 00:08:21.590 completely different planet, a different 206 00:08:21.590 --> 00:08:24.150 research team, and a different paper. So 207 00:08:24.150 --> 00:08:26.630 don't adjust your sets. This is fresh news 208 00:08:26.630 --> 00:08:27.790 about a different world. 209 00:08:28.250 --> 00:08:30.650 Anna: The world in question is LHS 210 00:08:30.730 --> 00:08:33.610 1140 B, a super Earth about 211 00:08:33.610 --> 00:08:36.450 49 light years away, orbiting a small 212 00:08:36.450 --> 00:08:39.330 red dwarf star. And it's long been one 213 00:08:39.330 --> 00:08:41.690 of the most tantalizing planets we know 214 00:08:41.930 --> 00:08:44.530 because it sits in the habitable zone where 215 00:08:44.530 --> 00:08:46.890 liquid water could in principle exist. 216 00:08:47.450 --> 00:08:49.770 Avery: And in a new paper in the journal Science 217 00:08:49.850 --> 00:08:52.770 published on 16 July, a team 218 00:08:52.770 --> 00:08:55.210 led from Harvard detected helium 219 00:08:55.290 --> 00:08:57.530 escaping from the planet. They used the 220 00:08:57.530 --> 00:09:00.210 Magellan Clay telescope in Chile to catch it. 221 00:09:00.530 --> 00:09:03.450 Anna: Now, on its own planet, losing gas might 222 00:09:03.450 --> 00:09:06.130 sound like bad news for an atmosphere, but 223 00:09:06.130 --> 00:09:08.930 here's the clever twist. Given how old this 224 00:09:08.930 --> 00:09:11.330 system is, the planet should have lost all 225 00:09:11.330 --> 00:09:14.330 its primordial helium long ago. The 226 00:09:14.330 --> 00:09:16.690 fact that we can still detect it escaping 227 00:09:16.690 --> 00:09:19.090 means something must be replenishing it. 228 00:09:19.570 --> 00:09:22.330 Avery: And that points to a substantial actively 229 00:09:22.330 --> 00:09:24.730 maintained atmosphere, rather than a bare 230 00:09:24.730 --> 00:09:27.730 airless rock, which is exactly the property 231 00:09:27.730 --> 00:09:30.390 you need if a habitable zone planet is going 232 00:09:30.390 --> 00:09:33.350 to be genuinely habitable. An atmosphere 233 00:09:33.350 --> 00:09:35.670 regulates temperature, shields the surface, 234 00:09:35.670 --> 00:09:37.070 and can hold onto water. 235 00:09:37.470 --> 00:09:39.790 Anna: This has been one of the great open questions 236 00:09:39.790 --> 00:09:42.670 for planets around red dwarf stars. Those 237 00:09:42.670 --> 00:09:45.070 stars are prone to flares that can strip a, 238 00:09:45.070 --> 00:09:47.630 uh, planet's air away. So finding strong 239 00:09:47.630 --> 00:09:50.430 evidence that LHS 1140 B 240 00:09:50.590 --> 00:09:53.150 is holding onto and refreshing an 241 00:09:53.150 --> 00:09:56.030 atmosphere is a genuinely significant step. 242 00:09:56.610 --> 00:09:59.570 Avery: It moves this world from promising a dress 243 00:09:59.570 --> 00:10:02.290 toward address. Worth a very close look. 244 00:10:02.610 --> 00:10:05.130 And you can bet the James Webb Telescope's 245 00:10:05.130 --> 00:10:06.850 name is already on the waiting list. 246 00:10:07.250 --> 00:10:10.170 Anna: Dory5 is a little lighter and I have 247 00:10:10.170 --> 00:10:12.050 to say, rather delightful. 248 00:10:12.450 --> 00:10:14.210 Avery, we need to talk about 249 00:10:14.450 --> 00:10:15.490 spacestream. 250 00:10:15.890 --> 00:10:18.490 Avery: Words I did not expect to say today, but here 251 00:10:18.490 --> 00:10:21.330 we are. Researchers at the Okayama University 252 00:10:21.410 --> 00:10:24.330 of Science in Japan have published the first 253 00:10:24.330 --> 00:10:26.210 results from something called the Space 254 00:10:26.290 --> 00:10:29.110 Aquaculture Project. And the question they're 255 00:10:29.110 --> 00:10:31.830 asking is deeply practical. Can we grow 256 00:10:31.830 --> 00:10:33.070 seafood in space? 257 00:10:33.630 --> 00:10:36.230 Anna: Because if we are serious about long stays on 258 00:10:36.230 --> 00:10:38.830 the moon or Mars, we can't just keep shipping 259 00:10:38.830 --> 00:10:41.430 up freeze dried meals forever. We need 260 00:10:41.430 --> 00:10:44.270 closed loop food systems, little self 261 00:10:44.270 --> 00:10:46.990 sustaining ecosystems that recycle nutrients. 262 00:10:47.230 --> 00:10:49.950 And a food chain needs more than just plants, 263 00:10:50.510 --> 00:10:50.910 right? 264 00:10:50.990 --> 00:10:53.870 Avery: So the team built a clever device, a high 265 00:10:53.870 --> 00:10:56.760 speed clinostat, essentially a rig that 266 00:10:56.760 --> 00:10:59.600 spins at around 130 rotations per 267 00:10:59.600 --> 00:11:01.680 minute to simulate the effects of 268 00:11:01.680 --> 00:11:04.400 microgravity here on the ground. And into 269 00:11:04.400 --> 00:11:07.080 that they placed juvenile shrimp along with 270 00:11:07.080 --> 00:11:10.080 tiny brine shrimp Artemia as their food. 271 00:11:10.320 --> 00:11:12.720 Anna: And the Key finding is, charmingly, 272 00:11:13.200 --> 00:11:16.000 the shrimp could still feed. Catching and 273 00:11:16.000 --> 00:11:18.240 eating prey when your body doesn't know which 274 00:11:18.240 --> 00:11:21.080 way is down is not trivial. A lot of 275 00:11:21.080 --> 00:11:24.000 feeding behavior relies on gravity cues. But 276 00:11:24.000 --> 00:11:26.360 the shrimp managed what suggests 277 00:11:26.360 --> 00:11:27.160 crustaceans 278 00:11:27.160 --> 00:11:29.880 Avery: could be a viable link in a future space food 279 00:11:29.880 --> 00:11:32.400 chain. And it's the published paper in the 280 00:11:32.400 --> 00:11:34.680 journal Microgravity Science and Technology 281 00:11:35.160 --> 00:11:37.880 that makes this more than a fun idea. It's an 282 00:11:37.880 --> 00:11:39.480 actual first data point. 283 00:11:39.800 --> 00:11:42.360 Anna: A prawn on the barbie Orbital edition. 284 00:11:42.760 --> 00:11:44.960 Somewhere down the line, an astronaut's 285 00:11:44.960 --> 00:11:47.320 dinner might start life spinning in a lab 286 00:11:47.320 --> 00:11:48.040 like this one. 287 00:11:48.360 --> 00:11:50.680 Avery: Clear skies and apparently clear water. 288 00:11:51.150 --> 00:11:53.430 And for our last story, we go to the most 289 00:11:53.430 --> 00:11:56.230 extreme physics in the universe. Because it 290 00:11:56.230 --> 00:11:58.270 turns out, black holes ring. 291 00:11:58.590 --> 00:12:01.550 Anna: They do. When two black holes spiral 292 00:12:01.550 --> 00:12:04.230 together and merge, the newborn black hole 293 00:12:04.230 --> 00:12:06.310 that results doesn't just settle down 294 00:12:06.310 --> 00:12:08.750 quietly. It, for a fraction of a second, 295 00:12:08.990 --> 00:12:11.790 wobbles, it vibrates, and it sheds 296 00:12:11.790 --> 00:12:14.670 that energy as gravitational waves at very 297 00:12:14.830 --> 00:12:17.720 specific frequencies. Scientists call it the 298 00:12:17.720 --> 00:12:18.360 ring down. 299 00:12:18.760 --> 00:12:21.200 Avery: And the analogy everyone reaches for is a 300 00:12:21.200 --> 00:12:23.640 bell. Strike a bell and it rings at 301 00:12:23.640 --> 00:12:25.960 particular tones that depend on its shape, 302 00:12:26.040 --> 00:12:28.680 its size, its material. A black 303 00:12:28.680 --> 00:12:31.520 hole is much simpler. Its ring depends on 304 00:12:31.520 --> 00:12:34.320 essentially just two things, its mass and 305 00:12:34.320 --> 00:12:35.000 its spin. 306 00:12:35.400 --> 00:12:38.360 Anna: And that simplicity is the gift. A major 307 00:12:38.360 --> 00:12:40.680 new review, bringing together researchers 308 00:12:40.680 --> 00:12:43.200 from the University of Birmingham, Johns 309 00:12:43.200 --> 00:12:45.560 Hopkins and the University of Lisbon in the 310 00:12:45.560 --> 00:12:48.260 journal Classical and Quantum Gravity, lays 311 00:12:48.260 --> 00:12:50.900 out how black hole spectroscopy is 312 00:12:50.900 --> 00:12:53.620 maturing from a beautiful theory into a real 313 00:12:53.780 --> 00:12:55.540 working experimental science. 314 00:12:56.020 --> 00:12:58.180 Avery: And the reason it matters is that it's one of 315 00:12:58.180 --> 00:13:00.420 the cleanest tests of Einstein we have. 316 00:13:00.900 --> 00:13:03.380 General relativity makes a very precise 317 00:13:03.380 --> 00:13:05.660 prediction for what those ring down tones 318 00:13:05.660 --> 00:13:08.380 should be. If we listen carefully and the 319 00:13:08.380 --> 00:13:10.900 tones match, Einstein passes another 320 00:13:10.900 --> 00:13:13.780 brutal exam. If they don't quite match, 321 00:13:14.580 --> 00:13:15.180 then we 322 00:13:15.180 --> 00:13:17.420 Anna: might be hearing the first whisper of new 323 00:13:17.420 --> 00:13:20.220 physics. A crack in the theory under the most 324 00:13:20.220 --> 00:13:22.180 extreme conditions imaginable. 325 00:13:22.660 --> 00:13:24.660 Avery: And we're on the cusp of hearing this 326 00:13:24.660 --> 00:13:27.500 properly. Today's detectors catch hints of 327 00:13:27.500 --> 00:13:29.980 the ring, but the next generation, the 328 00:13:29.980 --> 00:13:32.780 Einstein telescope, cosmic explorer and the 329 00:13:32.780 --> 00:13:35.460 space based LISA mission, will hear these 330 00:13:35.460 --> 00:13:37.540 black hole bells with real clarity. 331 00:13:38.180 --> 00:13:40.960 Anna: It's a wonderful thought. The most silent, 332 00:13:40.960 --> 00:13:43.600 invisible objects in the cosmos, and we're 333 00:13:43.600 --> 00:13:46.320 learning to listen to them chime before we 334 00:13:46.320 --> 00:13:48.920 go, our sky watch. And this one's for our 335 00:13:48.920 --> 00:13:51.080 friends down south, which is a lot of us. 336 00:13:51.400 --> 00:13:53.600 Avery: There's a large coronal hole on the sun 337 00:13:53.600 --> 00:13:56.320 that's rotated around to face Earth, and it's 338 00:13:56.320 --> 00:13:59.000 sending a stream of fast solar wind our way. 339 00:13:59.240 --> 00:14:01.320 The forecaster is expected to arrive around 340 00:14:01.320 --> 00:14:03.320 the 21st to 22nd of July. 341 00:14:03.640 --> 00:14:06.200 Anna: So midweek, which brings a chance, 342 00:14:06.360 --> 00:14:09.040 and I'll stress chance of some minor 343 00:14:09.040 --> 00:14:11.900 aurora australis activity for the fall far 344 00:14:11.900 --> 00:14:14.900 southern latitudes. We're talking Tasmania, 345 00:14:15.060 --> 00:14:17.460 the south of the south island of New Zealand, 346 00:14:17.540 --> 00:14:20.500 and similar high magnetic latitude spots. 347 00:14:21.300 --> 00:14:23.900 Avery: Let's keep expectations sensible. This is a 348 00:14:23.900 --> 00:14:26.100 modest event, not one of the great storms 349 00:14:26.100 --> 00:14:29.100 we've had this cycle. Geomagnetic activity in 350 00:14:29.100 --> 00:14:31.700 the kp3.5 range, so no 351 00:14:31.700 --> 00:14:34.060 guarantees of curtains of light. But if 352 00:14:34.060 --> 00:14:36.740 you're somewhere dark and far south midweek, 353 00:14:36.740 --> 00:14:38.860 it's worth a look toward the southern horizon 354 00:14:38.860 --> 00:14:39.540 after dark. 355 00:14:40.060 --> 00:14:42.220 Anna: And with solar maximum conditions still 356 00:14:42.220 --> 00:14:44.780 lingering, these chances keep coming around. 357 00:14:45.180 --> 00:14:47.620 Wrap up warm. It is winter down here after 358 00:14:47.620 --> 00:14:47.980 all. 359 00:14:48.460 --> 00:14:50.980 Avery: That's our lot for today. From India's first 360 00:14:50.980 --> 00:14:53.300 private rocket reaching orbit. To shrimp 361 00:14:53.300 --> 00:14:55.939 learning to dine in free fall. To black holes 362 00:14:55.939 --> 00:14:58.380 ringing across spacetime. What a spread. 363 00:14:58.860 --> 00:15:00.860 Anna: Thanks for spending part of your day with us. 364 00:15:01.020 --> 00:15:03.180 You can find us at astronomydaily, 365 00:15:03.500 --> 00:15:05.980 IO and on all the socials at 366 00:15:06.140 --> 00:15:08.640 AstroDailyPod We're back tomorrow. 367 00:15:08.780 --> 00:15:11.120 Avery: Um, until then, I'm Avery. 368 00:15:11.200 --> 00:15:13.360 Anna: And I'm Anna. Clear skies everyone. 369 00:15:16.180 --> 00:15:17.080 Avery: Mhm.