WEBVTT 0 00:00:01.280 --> 00:00:04.000 Avery: Hello, and welcome to Astronomy Daily, the 1 00:00:04.000 --> 00:00:06.240 podcast that brings you the biggest news from 2 00:00:06.240 --> 00:00:08.400 across the cosmos. I'm Avery. 3 00:00:08.560 --> 00:00:11.440 Anna: And I'm Anna. It's great to have you with us 4 00:00:11.840 --> 00:00:13.960 today. We're marking our calendars for a 5 00:00:13.960 --> 00:00:16.560 celestial event that will be seen by billion. 6 00:00:17.200 --> 00:00:19.800 Avery: That's right. We'll also be diving into a 7 00:00:19.800 --> 00:00:22.320 major cosmic puzzle, the Hubble 8 00:00:22.320 --> 00:00:24.680 tension and how some brilliant astronomers 9 00:00:24.680 --> 00:00:25.760 are trying to solve it. 10 00:00:26.080 --> 00:00:28.600 Anna: Then we'll come back a little closer to home 11 00:00:28.600 --> 00:00:31.360 to talk about Canada's plans to send its very 12 00:00:31.360 --> 00:00:34.220 first RO over to the Moon. And finally, 13 00:00:34.380 --> 00:00:37.340 a truly inspiring story about how an 14 00:00:37.340 --> 00:00:40.220 amateur astronomer made a cosmic discovery 15 00:00:40.220 --> 00:00:41.660 from his own backyard. 16 00:00:41.980 --> 00:00:44.300 Avery: It's a packed show, so let's get started. 17 00:00:44.620 --> 00:00:47.180 First up, Anna, tell us about this massive 18 00:00:47.180 --> 00:00:49.260 event we should all be looking forward to. 19 00:00:49.500 --> 00:00:52.220 Anna: Certainly, everyone should circle 20 00:00:52.220 --> 00:00:55.100 September 7th and 8th, 2025, 21 00:00:55.100 --> 00:00:57.700 on their calendars. On those dates, we're 22 00:00:57.700 --> 00:01:00.460 going to be treated to a total lunar eclipse, 23 00:01:00.700 --> 00:01:02.620 also known as a Blood Moon. 24 00:01:03.170 --> 00:01:05.850 Avery: And this isn't just any eclipse. The 25 00:01:05.850 --> 00:01:08.290 visibility for this one is incredible. 26 00:01:08.530 --> 00:01:11.490 We're talking over 7 billion people 27 00:01:11.810 --> 00:01:14.370 across Australia, Asia, Africa 28 00:01:14.690 --> 00:01:17.330 and Europe will have a chance to see it. It's 29 00:01:17.330 --> 00:01:18.770 a, uh, truly global event. 30 00:01:19.170 --> 00:01:21.970 Anna: Exactly. For those who might be new to this, 31 00:01:22.130 --> 00:01:24.250 a, uh, total lunar eclipse happens when the 32 00:01:24.250 --> 00:01:27.050 Earth passes directly between the sun and 33 00:01:27.050 --> 00:01:29.650 the Moon, casting a shadow on the lunar 34 00:01:29.650 --> 00:01:30.130 surface. 35 00:01:30.730 --> 00:01:32.930 Avery: And the Blood Moon nickname comes from that 36 00:01:32.930 --> 00:01:35.210 amazing reddish colour the Moon takes on. 37 00:01:35.210 --> 00:01:37.850 Right. It always looks so dramatic. 38 00:01:38.010 --> 00:01:40.330 Anna: It does, and there's some beautiful physics 39 00:01:40.330 --> 00:01:43.090 behind it. As sunlight passes through Earth's 40 00:01:43.090 --> 00:01:45.850 atmosphere, the atmosphere scatters the blue 41 00:01:45.850 --> 00:01:48.330 light, but allows red light to pass through 42 00:01:48.330 --> 00:01:51.170 and reach the Moon. Essentially, the 43 00:01:51.170 --> 00:01:53.650 Moon is being illuminated by all of the 44 00:01:53.650 --> 00:01:56.210 sunrises and sunsets happening on Earth at 45 00:01:56.210 --> 00:01:56.890 that moment. 46 00:01:57.280 --> 00:01:59.280 Avery: That's such a poetic way to think about it. 47 00:01:59.760 --> 00:02:02.160 So how long will we get to enjoy this 48 00:02:02.160 --> 00:02:02.720 spectacle? 49 00:02:02.880 --> 00:02:05.360 Anna: The entire event, from the moment the Earth's 50 00:02:05.360 --> 00:02:07.680 shadow first touches the Moon until it 51 00:02:07.680 --> 00:02:10.360 leaves, will last about five and a half 52 00:02:10.360 --> 00:02:13.040 hours. The most spectacular part, the 53 00:02:13.040 --> 00:02:15.920 totality when the Moon is fully in shadow, 54 00:02:16.000 --> 00:02:18.560 will last for an impressive 1 hour and 55 00:02:18.560 --> 00:02:19.520 22 minutes. 56 00:02:20.080 --> 00:02:22.040 Avery: Plenty of time to get outside and take a 57 00:02:22.040 --> 00:02:24.720 look. And as if that wasn't enough, there's 58 00:02:24.720 --> 00:02:26.680 another eclipse, uh, happening right after 59 00:02:26.680 --> 00:02:27.600 this, isn't there? 60 00:02:28.050 --> 00:02:30.170 Anna: Yes. Just a couple of weeks later, on 61 00:02:30.170 --> 00:02:33.170 September 21, 2025. This 62 00:02:33.170 --> 00:02:35.890 time, it's a partial solar eclipse, where the 63 00:02:35.890 --> 00:02:37.970 Moon will pass in front of the sun but won't 64 00:02:37.970 --> 00:02:40.650 cover it completely. This one will be visible 65 00:02:40.650 --> 00:02:43.210 from New Zealand, Antarctica and parts of 66 00:02:43.210 --> 00:02:45.810 Australia. So it's a busy month for sky 67 00:02:45.810 --> 00:02:47.250 watchers in the Southern Hemisphere. 68 00:02:47.570 --> 00:02:48.530 Avery: Fantastic. 69 00:02:48.770 --> 00:02:51.010 Well, from one cosmic measurement to another, 70 00:02:51.250 --> 00:02:53.850 let's talk about the expansion of the 71 00:02:53.850 --> 00:02:56.170 universe. This has been a source of some 72 00:02:56.170 --> 00:02:58.450 major debate in astronomy, right, Anna? 73 00:02:58.690 --> 00:03:01.490 Anna: A huge debate. It's a problem known as 74 00:03:01.490 --> 00:03:04.210 the Hubble tension. Put simply, different 75 00:03:04.290 --> 00:03:06.890 methods for measuring how fast the universe 76 00:03:06.890 --> 00:03:09.650 is expanding are giving us different answers. 77 00:03:09.730 --> 00:03:12.090 And the difference is significant enough that 78 00:03:12.090 --> 00:03:13.890 it can't be easily dismissed. 79 00:03:14.130 --> 00:03:16.570 Avery: So you have one group measuring the expansion 80 00:03:16.570 --> 00:03:19.250 based on the early universe, like the cosmic 81 00:03:19.250 --> 00:03:21.410 microwave background, and another group 82 00:03:21.410 --> 00:03:23.770 measuring it based on objects in the more 83 00:03:23.770 --> 00:03:26.410 modern universe, like supernovae. And their 84 00:03:26.410 --> 00:03:29.010 numbers don't measure match precisely. 85 00:03:29.330 --> 00:03:31.730 Anna: This discrepancy could mean one of two 86 00:03:31.730 --> 00:03:34.370 things. Either our measurements are wrong, 87 00:03:34.530 --> 00:03:37.330 or our fundamental understanding of physics 88 00:03:37.330 --> 00:03:40.050 is incomplete. Now, a team of 89 00:03:40.050 --> 00:03:42.930 Indian astronomers led by Professor Anupam 90 00:03:42.930 --> 00:03:45.930 Bhardija has introduced a new method that 91 00:03:45.930 --> 00:03:47.410 could help settle the debate. 92 00:03:47.570 --> 00:03:49.490 Avery: And what's their new secret weapon? 93 00:03:49.570 --> 00:03:52.090 Anna: They're using a specific type of star called 94 00:03:52.090 --> 00:03:54.370 Mira variables. These are old 95 00:03:54.530 --> 00:03:57.370 pulsating red giant stars that have a very 96 00:03:57.370 --> 00:03:59.400 predictable relationship between their 97 00:03:59.630 --> 00:04:02.070 pulsation period and their intrinsic 98 00:04:02.070 --> 00:04:04.470 brightness. By measuring how bright they 99 00:04:04.470 --> 00:04:06.830 appear from Earth, we can calculate their 100 00:04:06.830 --> 00:04:08.750 distance with great accuracy. 101 00:04:09.150 --> 00:04:11.350 Avery: So it's another standard candle, like the 102 00:04:11.350 --> 00:04:13.630 supernovae we use, but a totally different 103 00:04:13.630 --> 00:04:15.870 type of object. That's a great way to double 104 00:04:15.870 --> 00:04:18.030 check our results. And what did they find? 105 00:04:18.510 --> 00:04:21.470 Anna: Using data from the Gaia Space Telescope, 106 00:04:21.710 --> 00:04:23.870 they've managed to calculate the Hubble 107 00:04:23.870 --> 00:04:26.750 constant, that's the rate of expansion. With 108 00:04:26.750 --> 00:04:29.390 a precision of 3.7%. 109 00:04:30.230 --> 00:04:32.270 Their measurement aligns, uh, more closely 110 00:04:32.270 --> 00:04:34.750 with the values from other modern universe 111 00:04:34.750 --> 00:04:37.510 observations, like those using supernovae. 112 00:04:38.070 --> 00:04:39.870 Avery: So this strengthens the case that the 113 00:04:39.870 --> 00:04:42.230 discrepancy isn't just a measurement error. 114 00:04:42.310 --> 00:04:44.950 The Hubble tension might be real. And that 115 00:04:44.950 --> 00:04:46.149 means what? 116 00:04:46.390 --> 00:04:49.230 Anna: It could point to new physics, something 117 00:04:49.230 --> 00:04:51.670 we don't yet understand about the universe. 118 00:04:52.070 --> 00:04:54.870 It could affect our calculations for the age 119 00:04:55.030 --> 00:04:57.560 and size of the universe and 120 00:04:57.560 --> 00:05:00.560 deepen the mystery of dark energy. This 121 00:05:00.560 --> 00:05:03.320 discovery is a significant step in 122 00:05:03.320 --> 00:05:05.680 refining our cosmic yardstick. 123 00:05:06.240 --> 00:05:08.560 Avery: Incredible work from the edge of the 124 00:05:08.560 --> 00:05:09.040 universe. 125 00:05:09.200 --> 00:05:11.240 Let's bring it back to our own cosmic 126 00:05:11.240 --> 00:05:13.199 neighbourhood. We're heading back to the 127 00:05:13.199 --> 00:05:15.760 moon. And Canada is building the ride. 128 00:05:16.080 --> 00:05:18.440 Anna: That's right. As part of the Artemis 129 00:05:18.440 --> 00:05:21.280 programme, the company Canadensis Aerospace 130 00:05:21.440 --> 00:05:24.080 is developing Canada's very first 131 00:05:24.240 --> 00:05:26.960 lunar rover. It's a hugely 132 00:05:26.960 --> 00:05:29.620 exciting project, scheduled for launch in 133 00:05:29.620 --> 00:05:30.540 2029. 134 00:05:31.100 --> 00:05:33.660 Avery: It's a compact little explorer, too, only 135 00:05:33.660 --> 00:05:36.540 about 35 kilogrammes. So what's its 136 00:05:36.540 --> 00:05:38.380 mission? What will it be looking for. 137 00:05:38.620 --> 00:05:41.100 Anna: The rover is headed to the moon's south 138 00:05:41.100 --> 00:05:43.940 polar region, which is a key area of 139 00:05:43.940 --> 00:05:46.780 interest for scientists. Its primary mission 140 00:05:46.780 --> 00:05:49.660 is to search for water ice. Finding 141 00:05:49.660 --> 00:05:52.660 accessible water ice is considered the holy 142 00:05:52.660 --> 00:05:54.780 grail for future lunar exploration. 143 00:05:55.530 --> 00:05:57.970 Avery: Because if you have water, you have drinking 144 00:05:57.970 --> 00:06:00.330 water. For astronauts, you can grow plants 145 00:06:00.490 --> 00:06:03.450 and you can even split the H2O into hydrogen 146 00:06:03.450 --> 00:06:06.130 and oxygen to make rocket fuel. It would be a 147 00:06:06.130 --> 00:06:08.370 total game changer for establishing a long 148 00:06:08.370 --> 00:06:09.770 term presence on the moon. 149 00:06:10.010 --> 00:06:12.810 Anna: Exactly. The rover also has a second 150 00:06:12.810 --> 00:06:15.530 objective to measure lunar radiation. 151 00:06:16.090 --> 00:06:18.890 Understanding the radiation environment is 152 00:06:18.970 --> 00:06:21.650 critical for ensuring the safety of future 153 00:06:21.650 --> 00:06:24.130 astronauts. But it's not going to be an easy 154 00:06:24.130 --> 00:06:26.810 job. The lunar surface is incredibly 155 00:06:27.110 --> 00:06:27.510 hostile. 156 00:06:27.670 --> 00:06:30.430 Avery: I'll say. The temperature swings are mind 157 00:06:30.430 --> 00:06:32.590 boggling. The rover has to be built to 158 00:06:32.590 --> 00:06:35.550 withstand everything from -200 degrees 159 00:06:35.550 --> 00:06:37.990 Celsius in the shadows to a boiling 160 00:06:37.990 --> 00:06:40.470 100 degrees Celsius in direct sunlight. 161 00:06:40.630 --> 00:06:43.470 Anna: And then there's the lunar regolith, that 162 00:06:43.470 --> 00:06:46.310 fine abrasive dust that gets into 163 00:06:46.310 --> 00:06:49.110 everything. Navigating through it is a 164 00:06:49.110 --> 00:06:52.030 major engineering challenge. It's a testament 165 00:06:52.030 --> 00:06:54.690 to the team at Canadensis that they're taking 166 00:06:54.690 --> 00:06:55.250 this on. 167 00:06:55.890 --> 00:06:58.130 Avery: Absolutely. We'll be cheering it on in 168 00:06:58.130 --> 00:06:58.930 2029. 169 00:06:59.490 --> 00:07:02.330 Now for our final story. We're celebrating a 170 00:07:02.330 --> 00:07:04.410 different kind of explorer. One without a 171 00:07:04.410 --> 00:07:06.770 billion dollar budget, but with just as much 172 00:07:06.770 --> 00:07:07.250 passion. 173 00:07:07.570 --> 00:07:10.170 Anna: This is a wonderful story that really 174 00:07:10.170 --> 00:07:12.850 highlights the incredible contributions of 175 00:07:13.090 --> 00:07:15.410 amateur astronomers. It comes from 176 00:07:15.410 --> 00:07:18.210 Switzerland, where an amateur named Joseph 177 00:07:18.210 --> 00:07:20.930 Kaiser has discovered a small moon 178 00:07:21.230 --> 00:07:22.430 orbiting an asteroid. 179 00:07:22.750 --> 00:07:25.430 Avery: That's amazing. How on Earth does an amateur 180 00:07:25.430 --> 00:07:27.230 astronomer spot something like that? 181 00:07:27.630 --> 00:07:30.230 Asteroids are tiny and a moon orbiting one 182 00:07:30.230 --> 00:07:31.390 would be even smaller. 183 00:07:31.710 --> 00:07:34.510 Anna: He used a very clever technique called 184 00:07:34.590 --> 00:07:37.349 stellar occultation. This is when an 185 00:07:37.349 --> 00:07:40.190 object, in this case the asteroid, passes 186 00:07:40.190 --> 00:07:42.030 in front of a distant star, 187 00:07:42.510 --> 00:07:44.430 temporarily blocking its light. 188 00:07:44.990 --> 00:07:47.190 Avery: Right. So he was watching the star, expecting 189 00:07:47.190 --> 00:07:49.510 it to blink out for a moment as the main 190 00:07:49.510 --> 00:07:52.110 asteroid, named 2001 PE40 191 00:07:52.270 --> 00:07:52.830 passed. 192 00:07:53.450 --> 00:07:56.330 Anna: Exactly. But what he observed was 193 00:07:56.330 --> 00:07:59.250 something unexpected. After the main 194 00:07:59.250 --> 00:08:01.690 asteroid passed and the star's light 195 00:08:01.690 --> 00:08:04.570 returned, it disappeared a second time, 196 00:08:04.890 --> 00:08:07.610 very briefly. That second blink 197 00:08:07.930 --> 00:08:10.090 was caused by a smaller object 198 00:08:10.410 --> 00:08:13.210 trailing the asteroid. Its own tiny 199 00:08:13.210 --> 00:08:13.610 moon. 200 00:08:14.090 --> 00:08:16.450 Avery: That is brilliant. What a moment that must 201 00:08:16.450 --> 00:08:19.140 have been, realising what he'd seen. Do we 202 00:08:19.140 --> 00:08:21.060 know anything about the size of these 203 00:08:21.060 --> 00:08:21.620 objects? 204 00:08:21.940 --> 00:08:24.580 Anna: We do. The main asteroid is about 205 00:08:24.660 --> 00:08:27.060 12.6 kilometres long. 206 00:08:27.460 --> 00:08:29.700 Its newly discovered moon is about 207 00:08:29.780 --> 00:08:32.700 2.9 kilometres long and orbits at 208 00:08:32.700 --> 00:08:35.540 a distance of just under 24 kilometres. 209 00:08:35.860 --> 00:08:38.380 It's a significant find and a huge 210 00:08:38.380 --> 00:08:40.260 achievement for amateur astronomy. 211 00:08:40.500 --> 00:08:43.100 Avery: It really is. It goes to show that you don't 212 00:08:43.100 --> 00:08:44.820 need to be a professional with a giant 213 00:08:44.820 --> 00:08:46.940 observatory to make a real contribution to 214 00:08:46.940 --> 00:08:49.560 science. All you need is patience and skill 215 00:08:49.560 --> 00:08:50.880 and a clear night sky. 216 00:08:51.600 --> 00:08:53.360 Anna: A perfect story to end on. 217 00:08:53.600 --> 00:08:55.880 And that brings us to the close of another 218 00:08:55.880 --> 00:08:57.600 episode of Astronomy Daily. 219 00:08:58.000 --> 00:09:00.360 Avery: We covered a lot of ground today, from a 220 00:09:00.360 --> 00:09:02.840 future blood moon for billions to a new way 221 00:09:02.840 --> 00:09:04.999 of measuring our expanding universe, to 222 00:09:04.999 --> 00:09:07.440 Canada's future lunar rover. And a 223 00:09:07.440 --> 00:09:10.080 fantastic discovery by an amateur astronomer. 224 00:09:10.560 --> 00:09:13.000 Anna: Thank you so much for joining us. We hope 225 00:09:13.000 --> 00:09:15.160 you'll subscribe to the podcast so you don't 226 00:09:15.160 --> 00:09:17.520 miss an episode, and please visit our 227 00:09:17.520 --> 00:09:20.520 website@astronomydaily.IO for even more 228 00:09:20.520 --> 00:09:22.380 news and all our back episodes. 229 00:09:22.860 --> 00:09:25.300 Avery: Until next time, this has been Avery and 230 00:09:25.300 --> 00:09:25.900 Anna. 231 00:09:26.220 --> 00:09:27.500 Anna: Keep looking up. Uh.