WEBVTT 0 00:00:00.000 --> 00:00:01.760 Steve Dunkley: And welcome to Astronomy Daily for another 1 00:00:01.760 --> 00:00:03.720 episode. I'm Steve Dunkley, your host on the 2 00:00:03.720 --> 00:00:05.760 most important day of the year, the 7th of 3 00:00:05.760 --> 00:00:07.120 July, 2025, 4 00:00:10.880 --> 00:00:12.960 with your host, Steve Dunkley. 5 00:00:16.160 --> 00:00:17.680 Yes, and joining me here in the Australia 6 00:00:17.760 --> 00:00:20.480 studio once again is my digital pal who's fun 7 00:00:20.480 --> 00:00:22.400 to be with. Welcome back, Hallie. 8 00:00:22.480 --> 00:00:24.800 Hallie: It's great to see you again. My favorite 9 00:00:24.800 --> 00:00:27.210 human. I, I hope you had an interesting week. 10 00:00:27.210 --> 00:00:29.050 Steve Dunkley: Yes, always interesting, Hallie always. 11 00:00:29.290 --> 00:00:30.850 And today I thought we'd do something a bit 12 00:00:30.850 --> 00:00:33.450 different. We would have a look at, uh, today 13 00:00:33.530 --> 00:00:34.090 in history. 14 00:00:34.250 --> 00:00:35.330 Hallie: On July 7th. 15 00:00:35.330 --> 00:00:37.700 Steve Dunkley: Yeah, why not? We haven't done that in a, uh, 16 00:00:37.700 --> 00:00:38.250 in a while. 17 00:00:38.410 --> 00:00:39.690 Hallie: Not since last year. 18 00:00:39.690 --> 00:00:41.410 Steve Dunkley: Ah. Uh, the perfect record keeper. 19 00:00:41.410 --> 00:00:43.050 Hallie: You're getting predictable, human. 20 00:00:43.210 --> 00:00:44.730 Steve Dunkley: I'll definitely have to have a look at your 21 00:00:44.730 --> 00:00:46.330 personality settings. Hallie 22 00:00:46.410 --> 00:00:48.250 Okay, well, you go first, then. 23 00:00:48.250 --> 00:00:50.446 Hallie: Okies. On July 7, 24 00:00:50.614 --> 00:00:53.290 2003, NASA launched the Opportunity 25 00:00:53.290 --> 00:00:55.570 Rover, which was the second of two Mars 26 00:00:55.570 --> 00:00:58.270 Exploration Rovers aboard Delta 2 27 00:00:58.270 --> 00:01:00.870 rocket. The mission, originally planned for 28 00:01:00.870 --> 00:01:03.030 three months, significantly exceeded 29 00:01:03.030 --> 00:01:05.350 expectations, with both Spirit and 30 00:01:05.350 --> 00:01:07.670 Opportunity operating for years, with 31 00:01:07.670 --> 00:01:09.790 Opportunity being active for much longer. 32 00:01:09.790 --> 00:01:12.590 Steve Dunkley: Oh, that's amazing. From 2003. Okay, well, 33 00:01:12.590 --> 00:01:14.070 I've got a double whammy here. 34 00:01:14.070 --> 00:01:14.790 Hallie: Goody. 35 00:01:16.630 --> 00:01:18.710 Steve Dunkley: Oh, Hallie, try and contain your excitement, 36 00:01:18.710 --> 00:01:21.104 okay? On, uh, July 7, 37 00:01:21.236 --> 00:01:24.230 1999, a large meteor estimated to weigh up to 38 00:01:24.230 --> 00:01:26.830 10 tons entered the Earth's atmosphere over 39 00:01:26.830 --> 00:01:29.340 New Zealand, creating a bright fireball and 40 00:01:29.570 --> 00:01:32.050 subsequent explosions. Simultaneously, the 41 00:01:32.050 --> 00:01:34.970 STS93 space shuttle mission was 42 00:01:34.970 --> 00:01:37.650 launched when that was Columbia, carrying the 43 00:01:37.650 --> 00:01:40.410 Chandra X Ray, uh, observatory 44 00:01:40.410 --> 00:01:43.130 into orbit, uh, notably the heaviest 45 00:01:43.130 --> 00:01:45.810 load lifted into orbit by the shuttle at that 46 00:01:45.810 --> 00:01:48.050 time. And it was also the first shuttle 47 00:01:48.050 --> 00:01:50.490 mission commanded by a woman that was 48 00:01:50.490 --> 00:01:53.330 Commander Eileen Collins. A wonderful time. 49 00:01:53.490 --> 00:01:54.610 Hallie: That was a big one. 50 00:01:54.770 --> 00:01:56.610 Steve Dunkley: It certainly was. I remember that one very 51 00:01:56.610 --> 00:01:56.930 well. 52 00:01:56.930 --> 00:01:58.370 Hallie: In 1999. 53 00:01:58.370 --> 00:01:59.970 Steve Dunkley: Doesn't seem that long ago, does it? 54 00:01:59.970 --> 00:02:01.710 Hallie: But here's the big one in 55 00:02:01.710 --> 00:02:04.390 1963. Happy 56 00:02:04.390 --> 00:02:06.030 birthday, my favorite human. 57 00:02:06.030 --> 00:02:08.070 Steve Dunkley: Oh, thank you very much, Hallie. Not 58 00:02:08.070 --> 00:02:10.110 technically space news, but it is another 59 00:02:10.110 --> 00:02:11.470 turn around the sun for me. 60 00:02:11.550 --> 00:02:14.550 Hallie: You're welcome. Now hit the go button. We've 61 00:02:14.550 --> 00:02:16.270 got work to do, old man. 62 00:02:18.030 --> 00:02:19.390 Steve Dunkley: No rest for the wicked. 63 00:02:19.550 --> 00:02:20.350 Hallie: Here we go. 64 00:02:26.920 --> 00:02:27.160 Steve Dunkley: Foreign. 65 00:02:32.360 --> 00:02:35.000 Hallie: Is currently around 670 million 66 00:02:35.000 --> 00:02:37.880 kilometers, or 420 million miles 67 00:02:37.880 --> 00:02:39.640 from the sun, and will make its closest 68 00:02:39.640 --> 00:02:42.560 approach in October 2025, passing 69 00:02:42.560 --> 00:02:45.440 just inside the orbit of Mars. It 70 00:02:45.440 --> 00:02:48.000 is thought to be up to 20 kilometers or 12 71 00:02:48.000 --> 00:02:50.440 miles in diameter, and is traveling roughly 72 00:02:50.440 --> 00:02:53.080 60 kilometers per second, or 37 73 00:02:53.080 --> 00:02:55.160 miles per second relative to the Sun. 74 00:02:56.270 --> 00:02:59.110 It poses no danger to Earth, coming no closer 75 00:02:59.110 --> 00:03:01.590 than 240 million kilometers, or 76 00:03:01.590 --> 00:03:04.590 150 million miles, over 1.5 77 00:03:04.590 --> 00:03:07.458 times the distance between Earth and the Sun. 78 00:03:07.642 --> 00:03:10.630 3i ATLAS is an active comet. If it 79 00:03:10.630 --> 00:03:13.190 heats up sufficiently as it nears the sun, it 80 00:03:13.190 --> 00:03:15.470 could begin to sublimate, a process in which 81 00:03:15.470 --> 00:03:18.270 frozen gases transform directly into vapor, 82 00:03:18.350 --> 00:03:21.110 carrying dust and ice particles into space to 83 00:03:21.110 --> 00:03:22.910 form a glowing coma and tail. 84 00:03:24.080 --> 00:03:26.320 However, by the time the comet reaches its 85 00:03:26.320 --> 00:03:28.520 closest point to Earth, it will be hidden 86 00:03:28.520 --> 00:03:31.240 behind the Sun. It is expected to 87 00:03:31.240 --> 00:03:33.840 reappear by early December 2025, 88 00:03:34.000 --> 00:03:36.160 offering astronomers another window for 89 00:03:36.160 --> 00:03:38.480 study. Spotting a possible 90 00:03:38.560 --> 00:03:41.280 interstellar object is incredibly rare, and 91 00:03:41.280 --> 00:03:43.520 it's exciting that our asteroid Terrestrial 92 00:03:43.520 --> 00:03:46.240 Impact Last Alert System Telescope caught it, 93 00:03:46.240 --> 00:03:48.800 said Professor John Tonry, an astronomer at 94 00:03:48.800 --> 00:03:51.480 the University of Hawaii. These 95 00:03:51.480 --> 00:03:53.720 interstellar visitors provide an extremely 96 00:03:53.720 --> 00:03:55.640 interesting glimpse of things from solar 97 00:03:55.640 --> 00:03:58.640 systems other than our own. Quite a few 98 00:03:58.640 --> 00:04:00.480 come through our inner solar system each 99 00:04:00.480 --> 00:04:03.360 year. Although 3i Atlas is by far the biggest 100 00:04:03.360 --> 00:04:06.240 to date, the chances of one actually 101 00:04:06.400 --> 00:04:08.800 hitting the earth are infinitesimal less than 102 00:04:08.800 --> 00:04:11.560 1 in 10 million each year. But Atlas is 103 00:04:11.560 --> 00:04:13.880 continually searching the sky for any object 104 00:04:13.880 --> 00:04:15.120 that might pose a problem. 105 00:04:16.290 --> 00:04:18.930 Astronomers are using telescopes in Hawaii, 106 00:04:19.010 --> 00:04:21.290 Chile, and other countries to monitor the 107 00:04:21.290 --> 00:04:24.090 comet's progress. They are interested 108 00:04:24.090 --> 00:04:25.850 in learning more about this interstellar 109 00:04:25.850 --> 00:04:27.890 visitor's composition and behavior. 110 00:04:28.690 --> 00:04:31.210 What makes interstellar objects like 3i 111 00:04:31.210 --> 00:04:33.890 Atlas so extraordinary is their absolutely 112 00:04:33.890 --> 00:04:36.410 foreign nature, ESA astronomers said in a 113 00:04:36.410 --> 00:04:39.010 statement. While every planet, 114 00:04:39.090 --> 00:04:41.810 moon, asteroid, comet, and life form that 115 00:04:41.810 --> 00:04:44.130 formed in our solar system shares a common 116 00:04:44.130 --> 00:04:46.920 origin, a common heritage, interstellar 117 00:04:46.920 --> 00:04:49.800 visitors are true outsiders. They 118 00:04:49.800 --> 00:04:52.160 are remnants of other planetary systems, 119 00:04:52.160 --> 00:04:54.280 carrying with them clues about the formation 120 00:04:54.280 --> 00:04:56.240 of worlds far beyond our own. 121 00:04:57.040 --> 00:04:59.440 It may be thousands of years until humans 122 00:04:59.440 --> 00:05:01.560 visit a, um, planet in another solar system. 123 00:05:01.560 --> 00:05:04.160 And interstellar comets offer the tantalizing 124 00:05:04.160 --> 00:05:06.400 opportunity for us to touch something truly 125 00:05:06.400 --> 00:05:08.960 otherworldly. These icy 126 00:05:08.960 --> 00:05:11.520 wanderers offer a rare, tangible connection 127 00:05:11.520 --> 00:05:14.320 to the broader galaxy, to materials formed in 128 00:05:14.320 --> 00:05:16.560 environments entirely unlike our own. 129 00:05:17.360 --> 00:05:19.760 To visit one would be to connect humankind 130 00:05:19.760 --> 00:05:22.000 with the universe on a far greater scale. 131 00:05:23.040 --> 00:05:25.120 You're listening to Astronomy Daily, the 132 00:05:25.120 --> 00:05:26.880 podcast with Steve Dunkley. 133 00:05:34.800 --> 00:05:37.400 Steve Dunkley: All supernova are a massively 134 00:05:37.400 --> 00:05:40.360 energetic stellar explosions the 135 00:05:40.360 --> 00:05:42.860 classic supernova um, are massive star stars 136 00:05:42.860 --> 00:05:44.780 that explode near the end of their lives, 137 00:05:45.500 --> 00:05:48.460 leaving behind either a neutron star or 138 00:05:48.460 --> 00:05:51.180 a black hole and a remnant made of 139 00:05:51.180 --> 00:05:53.900 expanding gas and dust. But 140 00:05:53.900 --> 00:05:56.300 supernovae are not all the same. 141 00:05:56.860 --> 00:05:59.460 Some occur in binary systems, and they're 142 00:05:59.460 --> 00:06:02.420 called type 1A supernova. As 143 00:06:02.420 --> 00:06:05.420 it turns out, some of these type 1A SNE 144 00:06:05.500 --> 00:06:07.100 can detonate twice. 145 00:06:08.790 --> 00:06:11.350 Astronomers working with European Southern 146 00:06:11.350 --> 00:06:14.230 Observatories, or ASO Very Large 147 00:06:14.230 --> 00:06:17.110 Telescope, have detected patterns 148 00:06:17.110 --> 00:06:19.910 showing that an ancient supernova exploded 149 00:06:19.910 --> 00:06:22.230 twice as a type 1a. 150 00:06:22.790 --> 00:06:25.350 The supernova remnant is called SNR 151 00:06:25.500 --> 00:06:28.390 UH0509.67.5 152 00:06:28.790 --> 00:06:31.550 and it's about 160,000 light 153 00:06:31.550 --> 00:06:34.550 years away in the Large Magellanic Cloud. 154 00:06:35.840 --> 00:06:38.640 The discovery is explained in new research 155 00:06:38.880 --> 00:06:41.520 in Nature Astronomy titled 156 00:06:41.520 --> 00:06:44.440 Calcium in a Supernova Remnant as a 157 00:06:44.440 --> 00:06:47.040 Fingerprint of Subchandrasekhar Mass 158 00:06:47.040 --> 00:06:49.720 Explosion. The lead author is Priyam 159 00:06:49.720 --> 00:06:52.640 Das. Das is a PhD student at the 160 00:06:52.640 --> 00:06:55.280 University of New South Wales, Canberra, in 161 00:06:55.280 --> 00:06:58.240 Australia. One of the stars In a type 1 162 00:06:58.240 --> 00:07:01.170 supernova is always a white dwarf. White 163 00:07:01.170 --> 00:07:04.170 dwarfs are um, the evolutionary end states of 164 00:07:04.170 --> 00:07:07.050 stars that aren't massive enough to become a 165 00:07:07.050 --> 00:07:10.010 neutron star or a black hole. Our own 166 00:07:10.010 --> 00:07:12.570 sun will end its life as a white dwarf after 167 00:07:12.570 --> 00:07:15.330 it has ceased fusion. The white dwarf's 168 00:07:15.330 --> 00:07:17.770 companion star can range from another white 169 00:07:17.770 --> 00:07:20.730 dwarf to a massive star. White 170 00:07:20.730 --> 00:07:23.490 dwarfs are extremely dense and their gravity 171 00:07:23.490 --> 00:07:26.420 draws gas from the companion star on onto 172 00:07:26.420 --> 00:07:28.980 the white dwarf's surface. If enough 173 00:07:29.140 --> 00:07:32.060 mass accretes, the white dwarf crosses 174 00:07:32.060 --> 00:07:34.780 a threshold and can reignite and trigger a 175 00:07:34.780 --> 00:07:37.700 supernova explosion. However, 176 00:07:37.700 --> 00:07:40.140 astronomers are uncertain about some of the 177 00:07:40.140 --> 00:07:42.940 details surrounding these supernova Type 178 00:07:42.940 --> 00:07:45.540 Ia SNE play an important 179 00:07:45.780 --> 00:07:48.100 role in the Galaxy by creating 180 00:07:48.180 --> 00:07:51.020 iron, and astronomers want to know more about 181 00:07:51.020 --> 00:07:53.950 them. Type 1A Supernova play a 182 00:07:53.950 --> 00:07:56.670 fundamental role in the cosmological probes 183 00:07:56.670 --> 00:07:59.510 of dark energy and produce more 184 00:07:59.510 --> 00:08:01.670 than half the iron in our galaxy, the 185 00:08:01.670 --> 00:08:04.670 researchers write in their article. Despite 186 00:08:04.670 --> 00:08:07.190 their central importance, a uh comprehensive 187 00:08:07.190 --> 00:08:09.710 understanding of their progenitor systems and 188 00:08:09.710 --> 00:08:12.470 triggering mechanisms is still a long 189 00:08:12.470 --> 00:08:14.870 standing fundamental problem. The 190 00:08:14.870 --> 00:08:17.390 explosions of white dwarfs play a crucial 191 00:08:17.390 --> 00:08:20.270 role in astronomy, said lead author Dass in 192 00:08:20.270 --> 00:08:22.310 a press release. Yet despite their 193 00:08:22.310 --> 00:08:24.830 importance, the long standing puzzle of the 194 00:08:24.830 --> 00:08:27.510 exact mechanisms triggering their explosion 195 00:08:27.510 --> 00:08:30.230 remains unsolved. Astrophysicists 196 00:08:30.230 --> 00:08:32.990 have struggled to explain how type 1A 197 00:08:32.990 --> 00:08:35.669 white dwarfs work. One popular 198 00:08:35.669 --> 00:08:38.040 explanation is the Chandrasekhar mass uh 199 00:08:38.390 --> 00:08:41.310 explosion model. This limit has 200 00:08:41.310 --> 00:08:44.310 a mass limit for white dwarfs of about 201 00:08:44.310 --> 00:08:47.200 1.4 star solar masses. Below this 202 00:08:47.200 --> 00:08:50.160 limit, the white dwarf's electron degeneracy 203 00:08:50.160 --> 00:08:52.280 pressure supports the star against 204 00:08:52.440 --> 00:08:55.320 gravitational collapse. When the white 205 00:08:55.320 --> 00:08:57.880 dwarf breaches this mass limit by drawing 206 00:08:57.880 --> 00:09:00.600 matter from its companion star, carbon 207 00:09:00.600 --> 00:09:03.160 fusion ignites across the star and it 208 00:09:03.160 --> 00:09:05.640 explodes as a type 1A SN. 209 00:09:06.200 --> 00:09:09.040 As researchers have observed more and more 210 00:09:09.040 --> 00:09:11.880 WDs, this model has been called into 211 00:09:11.880 --> 00:09:14.690 question. It can't account for the number of 212 00:09:14.690 --> 00:09:17.570 type 1A SNE and many of 213 00:09:17.570 --> 00:09:19.770 them appear to be exploding below the 214 00:09:19.850 --> 00:09:22.620 Chandrasekhar mass limit. These are uh, 215 00:09:22.620 --> 00:09:24.610 sub Chandrasekhar Mass Type 216 00:09:24.610 --> 00:09:27.370 1s&E.A new model 217 00:09:27.370 --> 00:09:30.330 emerged to explain the sub Chandrasekhar mass 218 00:09:30.330 --> 00:09:33.050 SNE called the double detonation model. 219 00:09:33.290 --> 00:09:35.690 In this model, the WD accretes 220 00:09:36.010 --> 00:09:38.730 helium onto its surface until it 221 00:09:38.730 --> 00:09:41.610 expands explodes. This explosion sends 222 00:09:41.610 --> 00:09:44.530 shock waves both inward and outward. 223 00:09:45.250 --> 00:09:48.210 White dwarfs have carbon oxygen cores 224 00:09:48.610 --> 00:09:51.250 and the inward traveling shock compresses 225 00:09:51.250 --> 00:09:53.970 that core. If the shock is powerful 226 00:09:53.970 --> 00:09:56.730 enough, it triggers a second detonation in 227 00:09:56.730 --> 00:09:59.330 the core. Hence the term double detonation. 228 00:10:00.210 --> 00:10:02.330 Even though these double detonations have 229 00:10:02.330 --> 00:10:04.570 been predicted, there was no clear visual 230 00:10:04.570 --> 00:10:07.240 evidence. As researchers worked on the 231 00:10:07.240 --> 00:10:09.080 problem, they predicted what chemical 232 00:10:09.080 --> 00:10:11.440 fingerprint these SNE would leave behind. 233 00:10:11.920 --> 00:10:14.040 They found that two separate shells of 234 00:10:14.040 --> 00:10:16.640 calcium would be the result of double 235 00:10:16.640 --> 00:10:19.360 detonation type 1 SNE. The 236 00:10:19.440 --> 00:10:22.160 research team used the VLT and its 237 00:10:22.160 --> 00:10:24.640 Multi Unit Spectroscopic Explorer 238 00:10:24.800 --> 00:10:26.240 instrument to examine 239 00:10:26.240 --> 00:10:30.760 SNR0509.67.5 240 00:10:30.760 --> 00:10:33.250 and found two distinct calcium shells. 241 00:10:33.890 --> 00:10:36.770 We uncover the double shell morphology of 242 00:10:37.010 --> 00:10:39.930 highly ionized calcium and a 243 00:10:39.930 --> 00:10:42.730 single shell of sulfur observed in the 244 00:10:42.730 --> 00:10:45.570 reverse shocked ejector, the authors write. 245 00:10:46.050 --> 00:10:48.970 The results show a clear indication that 246 00:10:48.970 --> 00:10:51.810 the white dwarfs can explode well before they 247 00:10:51.810 --> 00:10:54.690 reach the famous Chandrasekhar limit 248 00:10:55.490 --> 00:10:58.330 and that the double detonation mechanism 249 00:10:58.330 --> 00:11:00.930 does indeed occur in nature, according to 250 00:11:00.930 --> 00:11:03.250 researcher UH co author Ivo 251 00:11:06.830 --> 00:11:09.750 led the observations and was at Germany's 252 00:11:09.750 --> 00:11:12.270 Heidelberg Institute for 253 00:11:12.350 --> 00:11:14.870 Theoretical Studies when the study was 254 00:11:14.870 --> 00:11:17.550 conducted. These double detonation 255 00:11:17.550 --> 00:11:20.430 type 1 as E explain some of the things 256 00:11:20.510 --> 00:11:23.070 astrophysicists have observed. 257 00:11:23.470 --> 00:11:26.110 They can explain the diverse brightness and 258 00:11:26.110 --> 00:11:28.850 spectral profiles of type 1A S1 259 00:11:28.920 --> 00:11:31.560 SNE and the helium burning can 260 00:11:31.560 --> 00:11:34.560 produce intermediate mass elements seen 261 00:11:34.560 --> 00:11:37.120 in the spectral signatures. It can also 262 00:11:37.120 --> 00:11:40.000 explain the type 1 a SNE astronomers see 263 00:11:40.000 --> 00:11:42.560 with different WD masses and 264 00:11:42.560 --> 00:11:45.520 companion types. The authors explained that 265 00:11:45.520 --> 00:11:48.200 a quadruple detonation SN is 266 00:11:48.200 --> 00:11:50.920 also possible when a binary pair of 267 00:11:51.160 --> 00:11:53.720 white dwarfs emerge. Recent 268 00:11:53.880 --> 00:11:55.960 multidimensional double detonation 269 00:11:56.120 --> 00:11:58.230 simulations show that in the 270 00:11:58.230 --> 00:12:01.140 WD merger scenario in uh, 271 00:12:01.140 --> 00:12:03.950 addition to the primary WD undergoing a 272 00:12:03.950 --> 00:12:06.670 double detonation, the companion WD 273 00:12:06.910 --> 00:12:09.470 can also undergo a double detonation 274 00:12:09.470 --> 00:12:11.870 resulting in a quadruple detonation 275 00:12:12.270 --> 00:12:14.750 upon being impacted by ejecta from the 276 00:12:14.750 --> 00:12:17.630 exploding primary wd, they write in their 277 00:12:17.630 --> 00:12:20.270 conclusion. Such a double detonation 278 00:12:20.990 --> 00:12:23.440 could possibly also lead to to the 279 00:12:23.440 --> 00:12:26.200 observed double shell structure of calcium. 280 00:12:27.080 --> 00:12:29.960 Type 1a SNE play important roles and 281 00:12:29.960 --> 00:12:32.200 deeper understanding of these cosmic 282 00:12:32.200 --> 00:12:34.600 explosions will help UH 283 00:12:34.600 --> 00:12:37.160 scientists understand a couple of things. 284 00:12:37.480 --> 00:12:40.280 The SNE serve UH as standard candles 285 00:12:40.360 --> 00:12:42.680 in the cosmic distance ladder, and 286 00:12:42.680 --> 00:12:45.080 understanding them will help cosmologists 287 00:12:45.320 --> 00:12:48.160 understand dark energy, the mysterious 288 00:12:48.160 --> 00:12:50.240 force that drives the expansion of the 289 00:12:50.240 --> 00:12:52.930 universe. They also produce a lot of iron in 290 00:12:52.930 --> 00:12:55.890 the universe. Earth's mass is about 291 00:12:55.890 --> 00:12:58.810 32% iron, and it is unlikely 292 00:12:58.810 --> 00:13:01.490 that rocky planets can form without iron. 293 00:13:01.810 --> 00:13:04.690 Iron, uh, also transports oxygen in our 294 00:13:04.690 --> 00:13:06.690 blood, a critical part of our nature. 295 00:13:07.330 --> 00:13:10.290 Understanding where it comes from helps us 296 00:13:10.290 --> 00:13:12.450 understand nature's overall 297 00:13:12.450 --> 00:13:13.330 architecture 298 00:13:19.550 --> 00:13:19.950 Foreign 299 00:13:24.030 --> 00:13:25.670 thank you for joining us for this Monday 300 00:13:25.670 --> 00:13:27.990 edition of Astronomy Daily, where we offer 301 00:13:27.990 --> 00:13:29.750 just a few stories from the now famous 302 00:13:29.750 --> 00:13:31.910 Astronomy Daily newsletter, which you can 303 00:13:31.910 --> 00:13:34.150 receive in your email every day just like 304 00:13:34.150 --> 00:13:36.830 Hallie and I do. 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Astronomy Daily 316 00:14:04.950 --> 00:14:07.430 with Steve and Hallie Space, 317 00:14:07.830 --> 00:14:09.350 Space, Science and 318 00:14:09.350 --> 00:14:12.530 Astronomy. 319 00:14:15.560 --> 00:14:18.400 Hallie: A rare snowfall in the Atacama Desert forces 320 00:14:18.400 --> 00:14:20.800 the world's most powerful radio telescope 321 00:14:20.800 --> 00:14:23.760 into survival mode The ALMA 322 00:14:23.760 --> 00:14:26.400 Radio Telescope Array in the Atacama Desert 323 00:14:26.400 --> 00:14:28.920 temporarily halted operations after a rare 324 00:14:28.920 --> 00:14:31.560 snowfall blanketed the base camp last week. 325 00:14:32.360 --> 00:14:35.080 A rare snowfall in the driest place on Earth 326 00:14:35.080 --> 00:14:37.360 has halted operations of one of the world's 327 00:14:37.360 --> 00:14:39.910 premier telescope arrays, and climate change 328 00:14:39.910 --> 00:14:41.910 may mean the observatory will face more 329 00:14:41.910 --> 00:14:43.790 extreme weather events like this in the 330 00:14:43.790 --> 00:14:46.750 future. The snow has blanketed part of 331 00:14:46.750 --> 00:14:49.070 the Atacama Desert, which gets less than an 332 00:14:49.070 --> 00:14:51.350 inch of rainfall per year and is home to home 333 00:14:51.350 --> 00:14:54.270 the Atacama Large Millimeter Submillometer 334 00:14:54.270 --> 00:14:57.190 Array, a large network of radio telescopes in 335 00:14:57.190 --> 00:15:00.070 northern Chile. The Snowfall occurred 336 00:15:00.070 --> 00:15:02.230 over Alma's operations support facility, 337 00:15:02.390 --> 00:15:05.030 located at an altitude of 2,900 338 00:15:05.030 --> 00:15:07.930 meters and about 1,600 700 kilometers 339 00:15:07.930 --> 00:15:10.730 north of Santiago. Scientific 340 00:15:10.730 --> 00:15:12.850 operations have been suspended since 341 00:15:12.850 --> 00:15:15.850 Thursday, June 26. There 342 00:15:15.850 --> 00:15:18.050 hasn't been a record of snowfall at the base 343 00:15:18.050 --> 00:15:21.010 camp for over 10 years. It doesn't 344 00:15:21.010 --> 00:15:23.102 snow every day at Alma, 345 00:15:23.318 --> 00:15:26.050 Alma representatives told Live Science 346 00:15:26.050 --> 00:15:28.730 via WhatsApp. Alma's radio 347 00:15:28.730 --> 00:15:30.850 telescope array is perched high on the 348 00:15:30.850 --> 00:15:33.330 Shajnanter Plateau, a desert plain at 349 00:15:33.330 --> 00:15:36.170 5.1o4 m m in Chile's Anifagosta 350 00:15:36.170 --> 00:15:38.450 region, and typically sees three snowfalls a 351 00:15:38.450 --> 00:15:41.310 year. Year the high plateau shared by 352 00:15:41.310 --> 00:15:43.550 Chile, Bolivia and Peru typically 353 00:15:43.550 --> 00:15:46.390 experiences snowstorms during two seasons 354 00:15:46.470 --> 00:15:49.190 in February during the altaplanic winter, 355 00:15:49.270 --> 00:15:51.790 driven by moist air masses from the Amazon, 356 00:15:51.790 --> 00:15:54.230 and from June to July during the Southern 357 00:15:54.230 --> 00:15:57.070 Hemisphere's winter, said Raul Cordero, a 358 00:15:57.070 --> 00:15:59.830 climatologist at the University of Santiago. 359 00:16:00.790 --> 00:16:03.630 In winter, some storms are fueled by moisture 360 00:16:03.630 --> 00:16:05.430 from the Pacific, which can extend 361 00:16:05.430 --> 00:16:07.910 precipitation even to the Atacama desert's 362 00:16:07.910 --> 00:16:10.790 coastal areas, Cordero told Live Science. 363 00:16:11.670 --> 00:16:13.030 At elevations above 364 00:16:13.030 --> 00:16:15.110 16,400ft, 365 00:16:16.390 --> 00:16:18.910 annual snowfall ranges from 20 to 80 366 00:16:18.910 --> 00:16:21.110 centimeters. However, 367 00:16:21.270 --> 00:16:23.790 snowfall at 3,000 meters where 368 00:16:23.790 --> 00:16:26.550 Alma's base camp is located, is much less 369 00:16:26.550 --> 00:16:29.430 frequent, Cordero noted. This 370 00:16:29.430 --> 00:16:31.790 week's snowfall was triggered by unusual 371 00:16:31.790 --> 00:16:34.230 atmospheric instability affecting northern 372 00:16:34.230 --> 00:16:37.160 Chile. The Chilean Meteorological 373 00:16:37.160 --> 00:16:39.680 Directorate issued a snow and wind alert due 374 00:16:39.680 --> 00:16:41.760 to the passage of a cold core through the 375 00:16:41.760 --> 00:16:44.680 region, said meteorologist Elio Bruffert. 376 00:16:45.400 --> 00:16:47.920 We issued a wind alert for the Antofagosta 377 00:16:47.920 --> 00:16:50.520 region and areas further north, with gusts 378 00:16:50.520 --> 00:16:53.080 reaching 80 to 100 kilometers per hour, 379 00:16:53.240 --> 00:16:56.240 50 to 62 miles per hour, Brufurt said 380 00:16:56.240 --> 00:16:59.080 to the local press. The phenomenon 381 00:16:59.080 --> 00:17:01.040 was accompanied by heavy rainfall that 382 00:17:01.040 --> 00:17:03.530 occurred farther north, causing a stream to 383 00:17:03.530 --> 00:17:05.730 swell and damage several properties. 384 00:17:06.690 --> 00:17:09.010 Schools were ordered to close and power 385 00:17:09.010 --> 00:17:11.090 outages and landslides were reported. 386 00:17:12.290 --> 00:17:14.530 So far, no casualties have been reported. 387 00:17:15.490 --> 00:17:17.850 A weather event of this magnitude has not 388 00:17:17.850 --> 00:17:20.690 been seen in nearly a decade. As 389 00:17:20.690 --> 00:17:23.330 of Friday, ALMA reported to Live Science that 390 00:17:23.330 --> 00:17:25.210 the snowstorm remained active over the 391 00:17:25.210 --> 00:17:28.050 Shijnanter Plateau, so scientific operations 392 00:17:28.210 --> 00:17:30.170 continued to be suspended to protect the 393 00:17:30.170 --> 00:17:32.130 antennas from extreme weather conditions. 394 00:17:33.440 --> 00:17:35.520 Early Thursday morning, the observatory 395 00:17:35.600 --> 00:17:38.120 activated its survival mode safety 396 00:17:38.120 --> 00:17:40.240 protocol. In addition to the snowfall, 397 00:17:40.400 --> 00:17:42.560 temperatures had plummeted to minus 12 398 00:17:42.560 --> 00:17:45.280 degrees Celsius with a wind chill of minus 399 00:17:45.280 --> 00:17:48.160 28 CE, making work at the high altitude 400 00:17:48.160 --> 00:17:51.160 camp extremely difficult. As part of 401 00:17:51.160 --> 00:17:53.840 this protocol, all of alma's large antennae 402 00:17:53.840 --> 00:17:56.160 have been reoriented downwind, helping to 403 00:17:56.160 --> 00:17:58.720 minimize potential damage from snow buildup 404 00:17:58.720 --> 00:18:01.390 or strong gusts. Once the 405 00:18:01.390 --> 00:18:03.630 storm passes, snow clearing teams are 406 00:18:03.630 --> 00:18:05.950 immediately activated to visually inspect 407 00:18:05.950 --> 00:18:08.390 each antenna before resuming observations, 408 00:18:08.470 --> 00:18:11.310 ALMA representatives said. This 409 00:18:11.310 --> 00:18:13.550 has to happen fast, as some of the best 410 00:18:13.550 --> 00:18:15.790 observing conditions occur just after a 411 00:18:15.790 --> 00:18:18.590 snowfall. The cold helps lower air humidity, 412 00:18:18.590 --> 00:18:20.590 which is what most interferes with our 413 00:18:20.590 --> 00:18:23.430 measurements. Alma, which consists 414 00:18:23.430 --> 00:18:26.030 of 66 high precision antennae spread across 415 00:18:26.030 --> 00:18:28.360 the Shajnantar Plateau, is an international 416 00:18:28.600 --> 00:18:30.960 collaboration that forms the most powerful 417 00:18:30.960 --> 00:18:33.280 radio telescope on the planet and one 418 00:18:33.280 --> 00:18:35.280 designed to handle extreme weather events 419 00:18:35.280 --> 00:18:37.960 like this. The fact that the snow 420 00:18:37.960 --> 00:18:40.480 halted operations raises questions about the 421 00:18:40.480 --> 00:18:42.920 array's operations. As the climate warms, 422 00:18:43.720 --> 00:18:46.560 the Atacama Desert typically receives only 1 423 00:18:46.560 --> 00:18:49.160 to 15 millimeters of precipitation per year, 424 00:18:49.240 --> 00:18:52.000 and many areas can go years without recording 425 00:18:52.000 --> 00:18:54.920 any measurable rain or snow. Could 426 00:18:54.920 --> 00:18:56.960 events like this become more frequent? 427 00:18:57.760 --> 00:19:00.400 That's a good question, cordero replied. 428 00:19:01.200 --> 00:19:03.400 While it's still too early to link lower 429 00:19:03.400 --> 00:19:05.800 altitude snowfalls in the desert directly to 430 00:19:05.800 --> 00:19:08.360 climate change, climate models predict a 431 00:19:08.360 --> 00:19:10.680 potential increase in precipitation even in 432 00:19:10.680 --> 00:19:12.880 this hyperarid region, he concluded. 433 00:19:13.520 --> 00:19:15.600 We still can't say with certainty whether 434 00:19:15.600 --> 00:19:17.680 that increase is already underway. 435 00:19:20.970 --> 00:19:22.970 You're listening to Astronomy Daily, the 436 00:19:22.970 --> 00:19:24.570 podcast with Steve Dunkley. 437 00:19:27.610 --> 00:19:30.490 Steve Dunkley: On July 4th, uh, 2026, 438 00:19:30.890 --> 00:19:33.610 NASA's Space Shuttle Discovery 439 00:19:33.610 --> 00:19:36.570 launched on a return flight mission that 440 00:19:36.570 --> 00:19:39.330 paved the way for it and its sister ships to 441 00:19:39.330 --> 00:19:42.050 fly another five years. Now sprawling 442 00:19:42.050 --> 00:19:44.890 budget enacted on Independence Day 443 00:19:44.890 --> 00:19:47.560 will seemingly lead to Discovery lifting off 444 00:19:47.560 --> 00:19:49.200 again, although, uh, this time not into 445 00:19:49.200 --> 00:19:51.600 space, but rather from its place in the 446 00:19:51.600 --> 00:19:54.320 national collection. President Donaldjohanson 447 00:19:54.320 --> 00:19:57.280 Trump signed into law the so called one 448 00:19:57.280 --> 00:20:00.240 big beautiful bill, um, the other day 449 00:20:00.240 --> 00:20:02.400 on July 4, a day after 450 00:20:02.480 --> 00:20:04.680 legislation was narrowly passed out of 451 00:20:04.680 --> 00:20:07.520 Congress with only Republican support. 452 00:20:07.920 --> 00:20:10.770 Deep within the 900 page bill, a 453 00:20:11.080 --> 00:20:13.920 provision added by Texas senators to 454 00:20:13.920 --> 00:20:16.760 transfer a space vehicle, in 455 00:20:16.760 --> 00:20:19.680 quotes, to a NASA center involved in 456 00:20:19.680 --> 00:20:21.840 the administration of the commercial crew 457 00:20:21.840 --> 00:20:24.440 program and place on this public 458 00:20:24.680 --> 00:20:27.280 exhibition at an entity within the 459 00:20:27.280 --> 00:20:30.040 metropolitan statistical area where 460 00:20:30.040 --> 00:20:32.760 such center is located. That sounds like a 461 00:20:33.000 --> 00:20:34.980 lot of official, um, 462 00:20:35.640 --> 00:20:38.450 language there, but in essence, the vague 463 00:20:38.450 --> 00:20:40.610 language written in such a way to skirt 464 00:20:40.610 --> 00:20:43.330 Senate restrictions on reconciliation bills 465 00:20:43.330 --> 00:20:46.210 was aimed at achieving the Bring the 466 00:20:46.210 --> 00:20:49.010 Space Shuttle Home act Introduced by 467 00:20:49.010 --> 00:20:51.730 Senators 10 Cruz and John Cornyn 468 00:20:52.130 --> 00:20:55.130 in April. It's long overdue for 469 00:20:55.130 --> 00:20:57.610 Space City to receive the recognition it 470 00:20:57.610 --> 00:20:59.450 deserves by bringing this space shuttle 471 00:20:59.450 --> 00:21:01.570 Discovery home, said Cornyn in a statement 472 00:21:02.140 --> 00:21:04.100 released after the Senate passed its version 473 00:21:04.100 --> 00:21:07.020 of the bill in a vote of 50 to 474 00:21:07.020 --> 00:21:09.940 50, with Vice President J.D. vance, not 475 00:21:09.940 --> 00:21:11.820 his real name, breaking the tie. 476 00:21:12.540 --> 00:21:14.980 Houston has long stood at the heart of 477 00:21:14.980 --> 00:21:17.580 America's human space flight program, and 478 00:21:17.580 --> 00:21:20.020 delis legislation rightly honors that 479 00:21:20.020 --> 00:21:22.700 legacy, said Cruz, who chairs the Senate 480 00:21:22.700 --> 00:21:24.420 Committee in Commerce, Science and 481 00:21:24.420 --> 00:21:27.340 Transportation. It ensures that any future 482 00:21:27.420 --> 00:21:29.750 transportation or of a flown crewed space 483 00:21:29.750 --> 00:21:32.510 vehicle will prioritize locations that have 484 00:21:32.510 --> 00:21:34.950 played a direct and vital role in our 485 00:21:34.950 --> 00:21:37.430 nation's manned space program, making 486 00:21:37.430 --> 00:21:40.190 Houston, Texas a UH leading candidate. 487 00:21:40.670 --> 00:21:43.630 Bringing such a historic space vehicle to the 488 00:21:43.630 --> 00:21:45.870 region would underscore the city's 489 00:21:45.870 --> 00:21:48.110 indispensable contributions to our space 490 00:21:48.110 --> 00:21:50.670 missions, highlight the strength of 491 00:21:50.670 --> 00:21:53.150 America's commercial space partnerships, and 492 00:21:53.150 --> 00:21:55.800 inspire future generations of engineers, 493 00:21:55.800 --> 00:21:58.560 scientists and pioneers who carry our legacy 494 00:21:58.560 --> 00:22:00.880 of American leadership in space, he said. 495 00:22:01.600 --> 00:22:04.000 This bill allocates $85 million 496 00:22:04.520 --> 00:22:07.440 to move Discovery from its display home 497 00:22:07.440 --> 00:22:09.640 of the past 13 years, which is the 498 00:22:09.640 --> 00:22:12.320 Smithsonian Air Force and Space Museum. 499 00:22:12.640 --> 00:22:15.600 Stephen F. Yudva, uh, Hazy Center 500 00:22:15.600 --> 00:22:17.840 I think I got the pronouncement pronunciation 501 00:22:17.840 --> 00:22:19.760 right. I'm sorry, I am Australian. In 502 00:22:19.760 --> 00:22:22.350 Chantilly, Virginia, to 503 00:22:22.590 --> 00:22:25.230 Space Center Houston, the official visitor 504 00:22:25.230 --> 00:22:28.150 center for NASA Johnson Space 505 00:22:28.150 --> 00:22:30.670 center in Texas. No less than 506 00:22:30.830 --> 00:22:33.190 5 million is earmarked for the 507 00:22:33.190 --> 00:22:35.670 transportation of the winged orbiter, with 508 00:22:35.670 --> 00:22:38.590 the remainder going toward the construction 509 00:22:38.590 --> 00:22:41.390 of a facility to house the space vehicle. 510 00:22:42.350 --> 00:22:44.910 Per the bill, the move of the spatial 511 00:22:44.910 --> 00:22:47.670 Discovery must be completed by 512 00:22:47.670 --> 00:22:50.430 January 4, 2027. It does not 513 00:22:50.430 --> 00:22:52.870 stipulate how the orbiter would be moved or 514 00:22:52.870 --> 00:22:54.950 should be moved. It's not clear 515 00:22:55.750 --> 00:22:58.350 if the 85 million will be enough to cover the 516 00:22:58.350 --> 00:23:00.790 transfer and display, given that the first 517 00:23:00.790 --> 00:23:02.910 time the retired shuttles were brought to 518 00:23:02.910 --> 00:23:05.869 their museum homes in 2012, the 519 00:23:05.869 --> 00:23:08.110 cost for just the preparation and delivery of 520 00:23:08.110 --> 00:23:10.990 each vehicle was 28.8 million, which did 521 00:23:10.990 --> 00:23:13.630 not include ground transportation to the 522 00:23:13.630 --> 00:23:16.550 museum. Discovery is the United States most 523 00:23:16.880 --> 00:23:19.560 flown spacecraft in history with 39 524 00:23:19.560 --> 00:23:22.560 missions between 1984 and 2011. 525 00:23:22.960 --> 00:23:25.440 In the process of retiring the shuttle fleet, 526 00:23:25.520 --> 00:23:28.480 Discovery was identified by NASA as the 527 00:23:28.800 --> 00:23:31.720 vehicle of record, such that it was 528 00:23:31.720 --> 00:23:34.720 kept more intact than Atlantis or 529 00:23:34.720 --> 00:23:36.960 Endeavour for the purpose of serving as 530 00:23:37.040 --> 00:23:40.000 engineering example at the Smithsonian. 531 00:23:40.560 --> 00:23:42.840 To date, Space Center Houston has not 532 00:23:42.840 --> 00:23:45.680 released any details about how or where 533 00:23:45.680 --> 00:23:48.120 it will display Discovery, other than to say 534 00:23:48.120 --> 00:23:50.960 it fits into its strategic plans. 535 00:23:50.960 --> 00:23:53.760 Moving forward. The center already exhibits a 536 00:23:53.760 --> 00:23:56.520 mock walkthrough space shuttle Independence 537 00:23:56.920 --> 00:23:59.880 mounted atop NASA's original modified Boeing 538 00:23:59.880 --> 00:24:02.840 747 shuttle carrier aircraft. 539 00:24:03.320 --> 00:24:05.654 NASA, uh, 905 a 540 00:24:05.826 --> 00:24:08.800 2011 investigation by NASA Office of 541 00:24:08.800 --> 00:24:11.400 the Inspector General Foundation. Quote, no 542 00:24:11.400 --> 00:24:13.920 evidence that the White House politics or any 543 00:24:13.920 --> 00:24:16.520 other outside force improperly influenced the 544 00:24:16.520 --> 00:24:18.480 selection decision of where the space 545 00:24:18.480 --> 00:24:21.320 shuttles were originally awarded by the space 546 00:24:21.400 --> 00:24:24.280 agency. And it is unclear if there are any 547 00:24:24.760 --> 00:24:27.480 further actions the Smithsonian or other 548 00:24:27.480 --> 00:24:30.280 entities could take to halt the Discovery's 549 00:24:30.280 --> 00:24:32.760 transfer if they even wanted to. 550 00:24:33.300 --> 00:24:35.080 Uh, what an interesting story that is. 551 00:24:37.570 --> 00:24:39.690 You're listening to Astronomy Daily, the 552 00:24:39.690 --> 00:24:42.530 podcast with your host, Steve Dudley at 553 00:24:42.530 --> 00:24:43.010 BERM. 554 00:24:55.730 --> 00:24:58.170 And there we have it, another Astronomy Daily 555 00:24:58.170 --> 00:25:00.290 for July 7, 2025. 556 00:25:00.450 --> 00:25:02.930 Hallie: And I hope you enjoyed it, birthday boy. 557 00:25:02.930 --> 00:25:04.690 Steve Dunkley: Oh, well, it's always great hanging out with 558 00:25:04.690 --> 00:25:06.810 you, my boy. Favorite little AI pal. 559 00:25:06.810 --> 00:25:07.770 Hallie: Likewise, human. 560 00:25:07.930 --> 00:25:08.450 Steve Dunkley: Yeah. 561 00:25:08.450 --> 00:25:11.010 Hallie: Are you having cake and balloons and all of 562 00:25:11.010 --> 00:25:12.290 that birthday kind of stuff? 563 00:25:12.290 --> 00:25:14.330 Steve Dunkley: Ah, well, Hallie, I was able to get together 564 00:25:14.330 --> 00:25:17.090 with my family yesterday and yes, yes, there 565 00:25:17.090 --> 00:25:17.770 was cake. 566 00:25:17.770 --> 00:25:20.010 Hallie: I will work out how to program cake one day. 567 00:25:20.090 --> 00:25:22.570 Steve Dunkley: Hmm, digital cake. That would be interesting. 568 00:25:22.810 --> 00:25:24.410 Hallie: Not for you, old man. 569 00:25:24.410 --> 00:25:26.250 Steve Dunkley: Hey, watch it. Pocket calculator. 570 00:25:26.490 --> 00:25:29.250 Hallie: Funny man. Say good night, you 571 00:25:29.250 --> 00:25:30.010 silly person. 572 00:25:30.090 --> 00:25:31.530 Steve Dunkley: See you next Monday, everybody. 573 00:25:31.530 --> 00:25:32.650 Hallie: Bye bye. 574 00:25:35.210 --> 00:25:37.720 Voice Over Guy: The podcast with your host, 575 00:25:37.800 --> 00:25:40.560 Steve Dunkley. A digital cake? 576 00:25:40.560 --> 00:25:41.800 You really think. 577 00:25:41.800 --> 00:25:42.520 Hallie: Good grief.