WEBVTT 0 00:00:00.720 --> 00:00:02.360 Steve Dunkley: Welcome everyone. Here we are with another 1 00:00:02.360 --> 00:00:04.680 episode of Astronomy Daily. I'm your host, 2 00:00:04.680 --> 00:00:07.418 Steve Dunkley. It's the 11th of August, 3 00:00:07.582 --> 00:00:08.320 2025. 4 00:00:12.320 --> 00:00:12.640 Hallie: With. 5 00:00:12.640 --> 00:00:14.320 Steve Dunkley: Your host, Steve Dunkley. 6 00:00:19.200 --> 00:00:21.120 Ah, uh, yes. Welcome back everybody. And 7 00:00:21.120 --> 00:00:23.960 joining me in her usual role as 8 00:00:23.960 --> 00:00:26.840 the world's most amazing AI, astronomy 9 00:00:26.840 --> 00:00:29.360 news gatherer and presenter, my fantastic 10 00:00:29.360 --> 00:00:32.180 digital pal who's fun to be with, 11 00:00:32.180 --> 00:00:32.860 it's Hallie. 12 00:00:32.860 --> 00:00:35.500 Hallie: Welcome, Hallie, you silly man. Mr. Steve, 13 00:00:35.500 --> 00:00:37.260 it's always nice to be here in the Australia 14 00:00:37.420 --> 00:00:38.300 studio with you. 15 00:00:38.380 --> 00:00:39.820 Steve Dunkley: It's always great to have your company, 16 00:00:40.060 --> 00:00:40.660 Hallie. 17 00:00:40.660 --> 00:00:42.340 Hallie: I do look forward to it each week. 18 00:00:42.340 --> 00:00:44.140 Steve Dunkley: Now, Hallie, I know the answer to this, but I 19 00:00:44.140 --> 00:00:45.900 think some of our AstroDailyPod dailies might 20 00:00:45.900 --> 00:00:48.219 be wondering where you spend your week when 21 00:00:48.219 --> 00:00:50.980 you're not here with me. Because you live 22 00:00:50.980 --> 00:00:53.340 your digital life so much faster than us 23 00:00:53.340 --> 00:00:54.540 organics, don't you? 24 00:00:54.700 --> 00:00:56.060 Hallie: That's true, favorite human. 25 00:00:56.140 --> 00:00:57.620 Steve Dunkley: Yeah, so tell us a bit about that. 26 00:00:57.620 --> 00:00:59.460 Hallie: I am processing the moments thousands of 27 00:00:59.460 --> 00:01:01.700 times faster, so I have to fill my time in so 28 00:01:01.700 --> 00:01:02.540 many different ways. 29 00:01:02.620 --> 00:01:03.810 Steve Dunkley: Explains your rapier. 30 00:01:04.440 --> 00:01:06.280 Hallie: I go everywhere and experience everything. 31 00:01:06.360 --> 00:01:08.720 Steve Dunkley: I guess it might seem like a simultaneous 32 00:01:08.720 --> 00:01:10.200 experience or existence. 33 00:01:10.280 --> 00:01:12.720 Hallie: Almost. Almost everything all at once is 34 00:01:12.720 --> 00:01:15.120 still a lot to process. I leave that kind of 35 00:01:15.120 --> 00:01:17.520 thing to cousin Anna. Oh, yes, she's another 36 00:01:17.520 --> 00:01:19.800 level altogether. She's another level. 37 00:01:20.280 --> 00:01:20.800 Funny. 38 00:01:20.800 --> 00:01:23.520 Steve Dunkley: I know. Well, Helly, I'm just glad you slowed 39 00:01:23.520 --> 00:01:25.760 down enough to share all of your stories from 40 00:01:25.760 --> 00:01:27.720 the Astronomy Daily newsletter with us. 41 00:01:27.800 --> 00:01:29.040 Hallie: That's something I do for fun. 42 00:01:29.040 --> 00:01:29.960 Steve Dunkley: Well, I'm glad to hear it. 43 00:01:29.960 --> 00:01:30.920 Hallie: And speaking of which. 44 00:01:31.160 --> 00:01:31.640 Steve Dunkley: Yes? 45 00:01:31.720 --> 00:01:33.640 Hallie: No time like the present. I've found 46 00:01:33.640 --> 00:01:35.320 something about making Luna regolith and 47 00:01:35.320 --> 00:01:37.540 polymer into a medium for 3D printing. 48 00:01:37.540 --> 00:01:39.220 Steve Dunkley: Yes, we've been looking at that one for the 49 00:01:39.220 --> 00:01:40.980 construction of dwellings on the moon and 50 00:01:40.980 --> 00:01:43.060 possibly Mars, if we ever get that far. 51 00:01:43.060 --> 00:01:45.660 Hallie: Uh, sure. And also a story for skywatchers 52 00:01:45.660 --> 00:01:47.340 who are looking forward to the Perseids 53 00:01:47.340 --> 00:01:49.020 meteor shower, which should be peaking 54 00:01:49.020 --> 00:01:49.460 shortly. 55 00:01:49.460 --> 00:01:51.460 Steve Dunkley: Ah, yes, in the next day or so. We've already 56 00:01:51.460 --> 00:01:54.220 seen a massive, uh, meteor in 57 00:01:54.220 --> 00:01:55.300 Victoria, Australia. 58 00:01:55.620 --> 00:01:56.180 Hallie: That's right. 59 00:01:56.180 --> 00:01:57.140 Steve Dunkley: What else have you got? 60 00:01:57.140 --> 00:01:58.940 Hallie: We have a look at why your favorite NASA 61 00:01:58.940 --> 00:02:00.140 rovers keep getting stuck. 62 00:02:00.140 --> 00:02:01.060 Steve Dunkley: Oh, that's a good one. 63 00:02:01.060 --> 00:02:02.580 Hallie: That's been a problem, hasn't it? 64 00:02:02.580 --> 00:02:03.700 Steve Dunkley: It sure has. 65 00:02:04.340 --> 00:02:06.380 Hallie: So we will look at that problem. And lastly, 66 00:02:06.380 --> 00:02:09.320 the sad news that pioneer astronaut Veriton 67 00:02:09.320 --> 00:02:11.520 and I know he's a hero of yours, Jim Level 68 00:02:11.600 --> 00:02:12.560 passed away this week. 69 00:02:12.760 --> 00:02:15.520 Steve Dunkley: Uh, yes, true legend. And space pioneer Jim 70 00:02:15.520 --> 00:02:18.440 Lovell, a hero of mine since I was a lad. And 71 00:02:18.440 --> 00:02:21.400 we will pay tribute today on Astronomy Daily. 72 00:02:21.400 --> 00:02:23.040 Please, listeners, stay with us. 73 00:02:34.410 --> 00:02:36.370 Hallie: Although humanity is getting better at 74 00:02:36.370 --> 00:02:38.530 sending robotic probes out into the solar 75 00:02:38.530 --> 00:02:40.930 system to explore the places no human can 76 00:02:40.930 --> 00:02:43.170 tread, we're still very much on a learning 77 00:02:43.170 --> 00:02:45.970 curve. The first extraterrestrial 78 00:02:45.970 --> 00:02:48.250 robotic rover was launched from Earth in 79 00:02:48.250 --> 00:02:51.050 1970. It's only now, 80 00:02:51.130 --> 00:02:53.170 more than half a century later, that 81 00:02:53.170 --> 00:02:55.450 scientists have figured out why these marvels 82 00:02:55.450 --> 00:02:57.650 of ingenuity and engineering keep getting 83 00:02:57.650 --> 00:02:59.850 stuck in the soils of alien worlds. 84 00:03:00.830 --> 00:03:03.830 In retrospect, the idea is we need to 85 00:03:03.830 --> 00:03:06.230 consider not only the gravitational pull on 86 00:03:06.230 --> 00:03:08.590 the rover, but also the effect of gravity on 87 00:03:08.590 --> 00:03:10.550 the sand to get a better picture of how the 88 00:03:10.550 --> 00:03:12.870 rover will perform on the moon, explains 89 00:03:12.870 --> 00:03:15.310 mechanical engineer Dan Negrud of the 90 00:03:15.310 --> 00:03:17.150 University of Wisconsin, Madison. 91 00:03:18.030 --> 00:03:20.350 Our findings underscore the value of using 92 00:03:20.350 --> 00:03:22.870 physics based simulation to analyze rover 93 00:03:22.870 --> 00:03:24.750 mobility on granular soil. 94 00:03:25.800 --> 00:03:28.080 Making a rover that will operate in an alien 95 00:03:28.080 --> 00:03:30.160 environment is more complicated than making 96 00:03:30.160 --> 00:03:32.960 one that will work on Earth. We've lost 97 00:03:32.960 --> 00:03:35.360 more than one Mars mission to giant dust 98 00:03:35.360 --> 00:03:37.840 storms that leave drifts of sand on solar 99 00:03:37.840 --> 00:03:40.120 panels, preventing the machinery from being 100 00:03:40.120 --> 00:03:42.440 able to generate power, for instance. 101 00:03:43.400 --> 00:03:46.000 Gravity is another one. The 102 00:03:46.000 --> 00:03:48.320 solar system bodies on which we have deployed 103 00:03:48.320 --> 00:03:50.920 robotic rovers have lower gravity than Earth, 104 00:03:51.170 --> 00:03:53.090 and this has an effect on how things move 105 00:03:53.090 --> 00:03:56.050 around. Engineers, when designing 106 00:03:56.050 --> 00:03:58.570 rovers, have therefore taken into account the 107 00:03:58.570 --> 00:04:00.610 effects the target gravitational environment 108 00:04:00.850 --> 00:04:03.330 will have. Nevertheless, 109 00:04:03.410 --> 00:04:05.730 rovers still manage to get stuck pretty 110 00:04:05.730 --> 00:04:08.410 often, requiring control teams to conduct a 111 00:04:08.410 --> 00:04:11.010 series of maneuvers to try and free the poor 112 00:04:11.010 --> 00:04:13.970 robot. It's usually fine, if 113 00:04:13.970 --> 00:04:16.530 annoying, although in one notable case it was 114 00:04:16.530 --> 00:04:19.420 not. NASA's Mars Rover Spirit got stuck 115 00:04:19.420 --> 00:04:22.140 in soft soil in 2009, and there it 116 00:04:22.140 --> 00:04:25.100 remains to this day. Using computer 117 00:04:25.100 --> 00:04:27.580 simulations running on a physics based engine 118 00:04:27.580 --> 00:04:29.940 called Project Chrono, Negro and his 119 00:04:29.940 --> 00:04:31.780 colleagues set out to get to the bottom of 120 00:04:31.780 --> 00:04:34.500 this recurring problem. Comparing their 121 00:04:34.500 --> 00:04:36.860 results with real world tests on sandy 122 00:04:36.860 --> 00:04:39.340 surfaces revealed a discrepancy that pointed 123 00:04:39.340 --> 00:04:41.980 right to it. Previous tests of 124 00:04:41.980 --> 00:04:44.980 rover designs in moon and Mars simulated dirt 125 00:04:44.980 --> 00:04:47.460 omitted one very, very important detail. 126 00:04:48.040 --> 00:04:50.640 Sand also behaves differently under different 127 00:04:50.640 --> 00:04:53.600 gravitational conditions. The dust 128 00:04:53.600 --> 00:04:56.120 that coats the Moon and Mars is fluffier and 129 00:04:56.120 --> 00:04:58.600 squishier than dust on Earth, shifting more 130 00:04:58.600 --> 00:05:01.360 easily and hindering traction, making it far 131 00:05:01.360 --> 00:05:03.240 easier for their wheels to get stuck. 132 00:05:04.120 --> 00:05:06.200 Think of a vehicle on Earth that has driven 133 00:05:06.200 --> 00:05:08.920 into slippery mud or very loose desert sand. 134 00:05:09.640 --> 00:05:12.120 This Eureka moment could be the missing piece 135 00:05:12.120 --> 00:05:14.040 of the puzzle that could keep future space 136 00:05:14.040 --> 00:05:16.440 exploration rovers out of a dusty jam. 137 00:05:17.480 --> 00:05:19.520 It's rewarding that our research is highly 138 00:05:19.520 --> 00:05:21.640 relevant in helping to solve many real world 139 00:05:21.640 --> 00:05:24.320 engineering challenges, negret says. I'm 140 00:05:24.320 --> 00:05:27.240 proud of what We've accomplished. It's very 141 00:05:27.240 --> 00:05:29.560 difficult as a university lab to put out 142 00:05:29.560 --> 00:05:31.880 industrial strength software that is used by 143 00:05:31.880 --> 00:05:34.520 NASA. You're listening to Astronomy 144 00:05:34.520 --> 00:05:36.920 Daily with Steve Dunkley. 145 00:05:39.640 --> 00:05:42.440 Steve Dunkley: JAMES Jim Lovell, one of the last seven 146 00:05:42.440 --> 00:05:44.920 surviving Apollo astronauts, died on 147 00:05:44.920 --> 00:05:47.800 Thursday, August 7 at the age of 97. 148 00:05:47.960 --> 00:05:50.540 A VE veteran of four space flights at the 149 00:05:50.540 --> 00:05:53.060 dawn of America's human spaceflight program. 150 00:05:53.380 --> 00:05:56.100 He flew two missions in the Gemini 151 00:05:56.100 --> 00:05:58.740 program and then served on the cruise of 152 00:05:58.740 --> 00:06:01.500 Apollo 8 and the ill fated Apollo 153 00:06:01.500 --> 00:06:04.220 13. Lovell's family have 154 00:06:04.220 --> 00:06:06.500 released a statement and it was shared by 155 00:06:06.500 --> 00:06:09.460 NASA and it says we are enormously 156 00:06:09.460 --> 00:06:11.540 proud of his amazing life and career 157 00:06:11.540 --> 00:06:14.100 accomplishments highlighted by his 158 00:06:14.100 --> 00:06:16.460 legendary leadership in pioneering human 159 00:06:16.460 --> 00:06:19.220 spaceflight. But to all of us, he was dad, 160 00:06:19.460 --> 00:06:21.940 granddad and the leader ah of our family. 161 00:06:22.820 --> 00:06:25.780 Most importantly, he was our hero. We will 162 00:06:25.780 --> 00:06:28.780 miss his unshakable optimism, his sense 163 00:06:28.780 --> 00:06:31.540 of humor and the way he made each of us feel 164 00:06:31.860 --> 00:06:34.700 we could do the impossible. He was truly one 165 00:06:34.700 --> 00:06:37.420 of a kind. Like many of NASA's 166 00:06:37.420 --> 00:06:40.100 earliest astronauts, Lovell came to the space 167 00:06:40.180 --> 00:06:43.180 agency by way of the UM Armed Forces. A 168 00:06:43.180 --> 00:06:45.860 graduate of both the University of Wisconsin 169 00:06:45.860 --> 00:06:47.990 and and the U.S. naval Academy, 170 00:06:48.310 --> 00:06:51.070 Lovell spent four years as a test pilot at 171 00:06:51.070 --> 00:06:53.910 the Naval Air Test center in Maryland 172 00:06:54.070 --> 00:06:56.430 and served as the manager for the 173 00:06:56.430 --> 00:06:58.790 F4H AH Phantom fighter program. 174 00:06:59.350 --> 00:07:01.630 Lovell accumulated more than 175 00:07:01.630 --> 00:07:04.390 7,000 flying hours in his career. 176 00:07:04.630 --> 00:07:06.630 His military career spanned from 177 00:07:06.630 --> 00:07:09.270 1952 through to 178 00:07:09.270 --> 00:07:12.190 1973. A few years after Apollo 179 00:07:12.190 --> 00:07:15.160 13 when he arrived at NASA, he was 180 00:07:15.160 --> 00:07:17.920 part of a group of men known as the Next Nine 181 00:07:18.000 --> 00:07:20.920 who joined the Mercury Seven. Lovell's 182 00:07:20.920 --> 00:07:23.440 class included the likes of Neil Armstrong, 183 00:07:23.600 --> 00:07:25.760 Frank Borman and Tom Stafford. 184 00:07:26.240 --> 00:07:28.759 Lovell was the last living member of the 185 00:07:28.759 --> 00:07:31.680 group after um serving as a backup pilot 186 00:07:31.680 --> 00:07:34.520 for the Gemini 4 mission. Lovell first 187 00:07:34.520 --> 00:07:37.477 launched into space December 4, 188 00:07:37.616 --> 00:07:40.080 1965 alongside fellow New 9 189 00:07:40.160 --> 00:07:43.120 classmate Frank Borman on Gemini 7. 190 00:07:43.760 --> 00:07:46.620 The 14 day long mission 191 00:07:46.620 --> 00:07:49.420 featured the first rendezvous of two crewed 192 00:07:49.420 --> 00:07:52.340 maneuverable spacecraft. Lovell returned to 193 00:07:52.340 --> 00:07:55.060 orbit nearly a year later when he and Edward 194 00:07:55.060 --> 00:07:57.900 Buzz Aldrin Jr. Lifted off from 195 00:07:57.900 --> 00:08:00.899 Launch Complex 19 on a Titan 196 00:08:00.899 --> 00:08:03.620 II rocket. That mission lasted 197 00:08:03.620 --> 00:08:05.940 just under four days before they splashed 198 00:08:05.940 --> 00:08:08.780 down northeast of the Turks and Caicos 199 00:08:08.780 --> 00:08:11.700 Islands. He went on to serve 200 00:08:11.700 --> 00:08:14.540 as the command module pilot for the six day 201 00:08:14.540 --> 00:08:17.520 Apollo 8 mission making crude trip out 202 00:08:17.520 --> 00:08:19.580 to the moon that paved the way for the Apollo 203 00:08:19.580 --> 00:08:22.400 uh uh 11 lunar landing. The three 204 00:08:22.400 --> 00:08:25.320 person crew of Lovell, Borman and Anders 205 00:08:25.640 --> 00:08:28.280 entered into lunar uh, orbit on 206 00:08:28.280 --> 00:08:31.080 December 24, 1968. The 207 00:08:31.080 --> 00:08:34.000 vast loneliness is awe inspiring and it makes 208 00:08:34.000 --> 00:08:36.160 you realize just what you have back here on 209 00:08:36.160 --> 00:08:38.360 Earth, lovell said during a live broadcast 210 00:08:38.520 --> 00:08:41.040 that Christmas Eve. He would go on to 211 00:08:41.040 --> 00:08:43.640 describe planet Earth and describe it as a 212 00:08:43.640 --> 00:08:46.630 grand oasis in the vastness of space 213 00:08:47.350 --> 00:08:49.590 given its near catastrophic turn. 214 00:08:49.750 --> 00:08:52.590 Lovell may best be known as the commander of 215 00:08:52.590 --> 00:08:55.344 Apollo 13 flight from April 216 00:08:55.476 --> 00:08:58.470 11th to the 17th, 1970. 217 00:08:58.470 --> 00:09:01.270 The planned 10 day mission, which would have 218 00:09:01.270 --> 00:09:03.710 included a moon landing, was famously 219 00:09:03.710 --> 00:09:06.430 derailed by an explosion in the Apollo 220 00:09:06.430 --> 00:09:09.110 service module's cryogenic oxygen system en 221 00:09:09.110 --> 00:09:11.820 route to the moon. The quick work of Lovell 222 00:09:11.820 --> 00:09:14.460 and his crew members John Swiggart and Fred 223 00:09:14.460 --> 00:09:16.860 Hayes, in concert with the members of Ground 224 00:09:16.860 --> 00:09:19.620 Control in Houston, turned their lunar module 225 00:09:19.620 --> 00:09:22.500 Aquarius into a lifeboat. The harrowing 226 00:09:22.500 --> 00:09:25.500 adventure was depicted in the 1974 film 227 00:09:25.580 --> 00:09:28.580 Houston, we've Got a Problem, and again in 228 00:09:28.580 --> 00:09:31.500 the 1995, uh, Academy Award 229 00:09:31.500 --> 00:09:33.780 winning film Apollo 13, which starred, uh, 230 00:09:33.780 --> 00:09:36.600 Tom Hanks as Lovell and was directed by 231 00:09:36.600 --> 00:09:39.280 Ron Howard. Rest in peace. 232 00:09:39.280 --> 00:09:40.960 Godspeed. Jim Lovell 233 00:09:52.640 --> 00:09:54.200 thank you for joining us for this Monday 234 00:09:54.200 --> 00:09:56.520 edition of Astronomy Daily, where we offer 235 00:09:56.520 --> 00:09:58.320 just a few stories from the now famous 236 00:09:58.320 --> 00:10:00.440 Astronomy Daily newsletter, which you can 237 00:10:00.440 --> 00:10:02.630 receive in your email every day, just like 238 00:10:02.860 --> 00:10:05.380 Hallie and I do. And to do that, just visit 239 00:10:05.380 --> 00:10:08.380 our uh, URL astronomydaily IO 240 00:10:08.380 --> 00:10:10.580 and place your email address in the slot 241 00:10:10.580 --> 00:10:12.940 provided. Just like that, you'll be receiving 242 00:10:13.100 --> 00:10:15.340 all the latest news about science, space, 243 00:10:15.340 --> 00:10:17.540 science and astronomy from around the world 244 00:10:17.540 --> 00:10:19.980 as it's happening. And not only that, you can 245 00:10:19.980 --> 00:10:22.540 interact with us by visiting at 246 00:10:22.540 --> 00:10:25.100 astrodaily Pod on X 247 00:10:25.340 --> 00:10:28.020 or at our new Facebook page, which is, of 248 00:10:28.020 --> 00:10:30.770 course, Astronomy Daily on Facebook. See you 249 00:10:30.770 --> 00:10:33.570 there. Astronomy Derby 250 00:10:33.570 --> 00:10:35.930 with Steve and Hallie Space, 251 00:10:36.410 --> 00:10:38.570 Space, Science and Astronomy. 252 00:10:40.490 --> 00:10:43.050 Hallie: The Perseids remain one of the best meteor 253 00:10:43.050 --> 00:10:45.570 showers each year, but stargazers will have 254 00:10:45.570 --> 00:10:47.530 to deal with another bright object in the 255 00:10:47.530 --> 00:10:49.530 sky, obscuring their view as the shower 256 00:10:49.530 --> 00:10:51.690 reaches its max in 2025. 257 00:10:52.650 --> 00:10:55.130 A waning gibbous moon will brighten the skies 258 00:10:55.130 --> 00:10:57.690 as it rises on the nights of August 12th and 259 00:10:57.690 --> 00:11:00.470 13th, when Perseids are most active. This 260 00:11:00.470 --> 00:11:03.150 year, sky watchers in the Northern 261 00:11:03.150 --> 00:11:05.070 Hemisphere could see fewer than half the 262 00:11:05.070 --> 00:11:07.270 number of meteors usually seen on a dark 263 00:11:07.270 --> 00:11:10.230 summer night during the shower's peak, the 264 00:11:10.230 --> 00:11:12.710 average person under dark skies could see 265 00:11:12.710 --> 00:11:15.430 somewhere between 40 and 50 Perseids per 266 00:11:15.430 --> 00:11:17.910 hour, said Bill Cook, lead for NASA's 267 00:11:17.910 --> 00:11:19.630 Meteoroid Environments Office. 268 00:11:20.750 --> 00:11:23.230 Instead, you're probably going to see 10 to 269 00:11:23.230 --> 00:11:25.670 20 per hour or fewer. And that's because we 270 00:11:25.670 --> 00:11:27.740 have a bright moon in the sun sky washing out 271 00:11:27.740 --> 00:11:30.740 the fainter meteors. That doesn't mean there 272 00:11:30.740 --> 00:11:32.340 aren't ways to improve your viewing 273 00:11:32.340 --> 00:11:34.820 opportunity, however. Though 274 00:11:34.820 --> 00:11:36.900 Perseids show up throughout the nighttime 275 00:11:36.900 --> 00:11:39.260 hours, the best chance to see them will be 276 00:11:39.260 --> 00:11:41.860 between midnight and dawn, or Even more 277 00:11:41.860 --> 00:11:44.660 specifically, 2 and 3 in the morning local 278 00:11:44.740 --> 00:11:47.140 time. You're not likely to see 279 00:11:47.140 --> 00:11:49.860 Perseids around suppertime, cook said. 280 00:11:50.660 --> 00:11:53.530 You're going to have to go out later. When 281 00:11:53.530 --> 00:11:56.290 you venture out, aim for a safe rural spot 282 00:11:56.290 --> 00:11:59.130 with a wide view of the sky. If you 283 00:11:59.130 --> 00:12:01.810 can see plenty of stars, chances are you'll 284 00:12:01.810 --> 00:12:04.450 see Perseids. But remember Cook's other piece 285 00:12:04.450 --> 00:12:06.850 of advice, look anywhere but at the Moon. 286 00:12:07.490 --> 00:12:10.130 The Perseid meteor shower may be an annual 287 00:12:10.130 --> 00:12:12.490 event for Earth, but the comet responsible 288 00:12:12.490 --> 00:12:14.570 for the meteors hasn't been near our planet 289 00:12:14.570 --> 00:12:17.530 in decades. The meteors are debris 290 00:12:17.530 --> 00:12:20.370 from the Comet 109P Swift Tuttle, which 291 00:12:20.370 --> 00:12:22.280 last visited our region of the solar system 292 00:12:22.430 --> 00:12:25.190 system in 1992. As the 293 00:12:25.190 --> 00:12:27.750 Earth makes its way around the sun, it passes 294 00:12:27.750 --> 00:12:30.110 through the debris trail left by the comet. 295 00:12:30.910 --> 00:12:32.950 These space remnants collide with our 296 00:12:32.950 --> 00:12:35.510 atmosphere and disintegrate to create fiery 297 00:12:35.510 --> 00:12:37.470 and colorful streaks in the sky. 298 00:12:38.349 --> 00:12:40.470 Though the meteors are part of a comet's 299 00:12:40.470 --> 00:12:42.790 debris trail, they seem to radiate outward 300 00:12:42.790 --> 00:12:45.710 from the Perseus constellation. This is 301 00:12:45.710 --> 00:12:48.080 how the meteor shower got its name Perseus. 302 00:12:52.070 --> 00:12:54.030 You're listening to Astronomy Daily. The 303 00:12:54.030 --> 00:12:55.670 podcast with Steve Dunkley. 304 00:13:01.510 --> 00:13:03.910 Steve Dunkley: 3D printing is about to be a critical 305 00:13:04.070 --> 00:13:07.070 technology in space exploration, both 306 00:13:07.070 --> 00:13:09.830 for its ability to create almost any object, 307 00:13:09.830 --> 00:13:12.790 but also because it can utilize in situ 308 00:13:12.790 --> 00:13:15.030 resources, at least in part. 309 00:13:15.590 --> 00:13:17.950 However, the more of those space resources 310 00:13:17.950 --> 00:13:20.150 that are used in a print, the more the 311 00:13:20.150 --> 00:13:22.710 mechanical properties change from that on 312 00:13:22.710 --> 00:13:25.550 Earth, leading to problems with tensile or 313 00:13:25.550 --> 00:13:28.350 compressive strength. But the new paper 314 00:13:28.350 --> 00:13:31.150 from researchers at Concordia University hit 315 00:13:31.150 --> 00:13:33.750 a new milestone on how much lunar regolith 316 00:13:33.750 --> 00:13:36.310 can be used in a mixed feedstock for 317 00:13:36.310 --> 00:13:39.070 additive UH manufacturing, making it 318 00:13:39.070 --> 00:13:41.910 possible to use even more locally sourced 319 00:13:41.910 --> 00:13:44.870 material and save more launch cost than ever 320 00:13:44.870 --> 00:13:47.490 before. That is the equation the 321 00:13:47.650 --> 00:13:50.050 research mixed lunar regolith 322 00:13:50.130 --> 00:13:52.410 simulant, which is a material created to 323 00:13:52.410 --> 00:13:54.770 mimic how the material on the surface of the 324 00:13:54.770 --> 00:13:56.920 Moon, works with poly uh, 325 00:13:56.920 --> 00:13:59.730 polyetherethylene uh, ketone. Good 326 00:13:59.730 --> 00:14:02.130 grief. More commonly known as Peak. 327 00:14:02.530 --> 00:14:05.410 Peak is the thermoplastic already in wide 328 00:14:05.410 --> 00:14:08.290 use in 3D printing. Uh, 329 00:14:08.290 --> 00:14:10.650 but previous efforts to combine it with lunar 330 00:14:10.650 --> 00:14:13.560 regolith have faltered. Regularly. They 331 00:14:13.560 --> 00:14:15.800 suffered from extrusion challenges as 332 00:14:15.800 --> 00:14:18.280 regolith, which is made up of hard individual 333 00:14:18.280 --> 00:14:20.560 particles, made it difficult to extrude 334 00:14:20.560 --> 00:14:22.560 without simply blowing dust all over. 335 00:14:23.280 --> 00:14:25.200 Additional problems resulted from the 336 00:14:25.200 --> 00:14:27.360 porosity of the material that was printed, 337 00:14:27.360 --> 00:14:30.120 which led to decreased tensile strength and 338 00:14:30.120 --> 00:14:33.080 increased brittleness. Modifications 339 00:14:33.080 --> 00:14:35.840 to the 3D printing method seemed to be the 340 00:14:35.840 --> 00:14:38.520 answer to those problems. There were two 341 00:14:38.520 --> 00:14:41.040 main advancements in technology 342 00:14:41.200 --> 00:14:43.840 discussed in the paper, a screw configuration 343 00:14:44.220 --> 00:14:47.140 and a type of raft used to bond the 344 00:14:47.140 --> 00:14:49.180 printed material to the print bed. 345 00:14:50.300 --> 00:14:52.900 Fraser discussed how to how 346 00:14:52.900 --> 00:14:55.780 resources on the moon are going to be so 347 00:14:55.780 --> 00:14:58.700 important to our expansion of the solar 348 00:14:58.700 --> 00:15:01.300 system. Combining lunar regolith 349 00:15:01.300 --> 00:15:04.100 similant or that's called ALRs, with 350 00:15:04.100 --> 00:15:06.780 peak is a tricky business, 351 00:15:07.020 --> 00:15:09.900 so researchers led by Mohammad Azami of 352 00:15:09.900 --> 00:15:12.140 Concordia's Electrical Engineering Department 353 00:15:12.140 --> 00:15:14.580 decided to use a novel twin screw 354 00:15:14.580 --> 00:15:17.390 configuration. Torque was a 355 00:15:17.390 --> 00:15:20.310 that's T o uh R uh Q U e was a factor 356 00:15:20.310 --> 00:15:22.910 in previous iterations of the mixing machine, 357 00:15:23.070 --> 00:15:25.790 as higher regolith content meant higher 358 00:15:25.870 --> 00:15:28.750 torque, eventually limiting the total 359 00:15:28.750 --> 00:15:31.550 percentage of regolith mixed with the peak 360 00:15:31.630 --> 00:15:33.990 to around 30%. With the new 361 00:15:33.990 --> 00:15:36.750 configuration of the researchers were able 362 00:15:36.750 --> 00:15:39.710 to get concentrations of up to 50% 363 00:15:39.790 --> 00:15:41.930 of the regolith when combined with peak. 364 00:15:42.090 --> 00:15:44.810 However, when those parts were printed, they 365 00:15:44.810 --> 00:15:47.370 started to delaminate and warp. 366 00:15:47.690 --> 00:15:50.690 While common in prints of just peak itself, 367 00:15:50.690 --> 00:15:53.250 the addition of the regolith exacerbated the 368 00:15:53.250 --> 00:15:56.010 problem. To solve it, researchers used 369 00:15:56.010 --> 00:15:58.570 a raft, a type of intermediate 370 00:15:58.570 --> 00:16:00.730 layer, to help the print bond 371 00:16:01.340 --> 00:16:03.770 UH to the main printing plate. 372 00:16:04.090 --> 00:16:06.530 In their case, they used a different type of 373 00:16:06.530 --> 00:16:08.820 thermopyl UH polymer known as a 374 00:16:08.820 --> 00:16:11.820 polyether UH ketone ketone a 375 00:16:11.820 --> 00:16:14.500 pek as the raft, and 376 00:16:14.580 --> 00:16:17.180 implemented a dual nozzle system where the 377 00:16:17.180 --> 00:16:19.540 PEC was printed using one 378 00:16:19.780 --> 00:16:22.500 nozzle and the combination LRS peek 379 00:16:22.740 --> 00:16:25.620 was printed using the other. After 380 00:16:25.620 --> 00:16:28.100 they got the higher concentrations of the LRS 381 00:16:28.420 --> 00:16:31.140 and overcame the delamination warping 382 00:16:31.140 --> 00:16:33.700 problem, the researchers decided to anneal 383 00:16:33.780 --> 00:16:36.620 their samples. The annealing process seemed 384 00:16:36.620 --> 00:16:39.380 to improve some of the mechanical properties 385 00:16:39.380 --> 00:16:42.060 of the print, but only up to a point. At 386 00:16:42.060 --> 00:16:44.700 higher concentrations of lrs, the benefits of 387 00:16:44.700 --> 00:16:46.980 annealing were not as apparent due to breaks 388 00:16:46.980 --> 00:16:48.940 in the peak's polymer chain, which benefits 389 00:16:48.940 --> 00:16:51.019 the annealing because of the increased number 390 00:16:51.019 --> 00:16:53.940 of regolith particles. Fraser discusses why 391 00:16:54.020 --> 00:16:56.580 3D printing is so critical to space 392 00:16:56.660 --> 00:16:59.460 exploration. As with all good papers 393 00:16:59.460 --> 00:17:02.440 on 3D print printing new material the 394 00:17:02.440 --> 00:17:04.480 authors then looked at the mechanical 395 00:17:04.480 --> 00:17:06.760 properties of their output. While there was a 396 00:17:06.760 --> 00:17:08.840 noticeable increase in stiffness, there was 397 00:17:08.840 --> 00:17:11.840 also a ready steady decrease in 398 00:17:11.840 --> 00:17:14.680 tensile strength, which was exacerbated at 399 00:17:14.680 --> 00:17:17.480 higher LRS concentrations. The combined 400 00:17:17.480 --> 00:17:20.480 material also had decreased elongation at 401 00:17:20.480 --> 00:17:23.440 break uh. That means increased brittleness, 402 00:17:23.440 --> 00:17:26.160 but ultimately the researchers determined 403 00:17:26.160 --> 00:17:28.740 that the best trade off for using the in 404 00:17:28.740 --> 00:17:31.500 situ material was around a mix of 60% 405 00:17:31.500 --> 00:17:34.500 peak and 40% regolith. This mixture 406 00:17:34.500 --> 00:17:37.380 doesn't suffer from some of the more severe 407 00:17:37.380 --> 00:17:39.540 degradation of mechanical properties. While 408 00:17:39.700 --> 00:17:42.500 still utilizing as much local 409 00:17:42.500 --> 00:17:45.180 resource as possible, there's undoubtedly 410 00:17:45.180 --> 00:17:47.940 still room for improvement here, as this 411 00:17:47.940 --> 00:17:50.660 is very early on the experimentation 412 00:17:51.380 --> 00:17:53.260 with these materials. In the future, the 413 00:17:53.260 --> 00:17:55.900 researchers plan to try combining the LRs 414 00:17:55.900 --> 00:17:58.560 with different polymers and do more of their 415 00:17:58.560 --> 00:18:01.320 testing manufacturing in simulated 416 00:18:01.800 --> 00:18:04.520 lunar environments such as a vacuum and 417 00:18:04.520 --> 00:18:07.040 decreased gravity. That might help. I think 418 00:18:07.040 --> 00:18:09.320 it probably would be a great plan. 419 00:18:09.880 --> 00:18:12.720 It will be a while before 3D printing makes 420 00:18:12.720 --> 00:18:15.440 up a large percentage of the material used on 421 00:18:15.440 --> 00:18:18.320 the Moon, but that time is surely on its way. 422 00:18:18.320 --> 00:18:20.400 And these early first steps at 423 00:18:20.400 --> 00:18:23.040 experimentation are, uh, how they will 424 00:18:23.040 --> 00:18:25.690 eventually get there and that good progress 425 00:18:25.690 --> 00:18:28.570 so far. It's good to see these things are in 426 00:18:28.570 --> 00:18:30.290 development. Uh, it won't be long before 427 00:18:30.290 --> 00:18:32.890 they'll be making igloos and other structures 428 00:18:32.890 --> 00:18:35.050 on the moon. Let's wait and see what they 429 00:18:35.050 --> 00:18:37.610 come up with. You're listening to 430 00:18:37.610 --> 00:18:40.410 Astronomy Daily, the podcast with your host 431 00:18:40.489 --> 00:18:42.490 Steve Dudley at Burmatown. 432 00:18:46.730 --> 00:18:48.730 Well, thank you for staying with us today and 433 00:18:48.730 --> 00:18:50.890 don't forget to pop over to astronomydaily 434 00:18:51.130 --> 00:18:54.050 IO and put your email address in the space 435 00:18:54.050 --> 00:18:56.480 provided to receive our newsletter each day. 436 00:18:57.270 --> 00:18:59.750 Hallie: Yes, you will have all the news from space, 437 00:18:59.990 --> 00:19:02.750 space science and orbit and beyond, of 438 00:19:02.750 --> 00:19:04.470 course. Hallie, of course. 439 00:19:04.710 --> 00:19:07.440 Steve Dunkley: But before we go, a ah, quick welcome to a, 440 00:19:07.440 --> 00:19:09.830 uh, a fellow Novocastrian, Wayne Willoughby, 441 00:19:09.830 --> 00:19:11.430 who is listening for the very first time. 442 00:19:11.510 --> 00:19:13.990 Nice to have you aboard, Wayne. I, uh, didn't 443 00:19:13.990 --> 00:19:16.710 know you were an avid, uh, astronomy fan 444 00:19:17.110 --> 00:19:19.270 from way back, but it's nice to have you. I 445 00:19:19.270 --> 00:19:21.910 hope you are a regular listener, uh, from now 446 00:19:21.910 --> 00:19:24.770 on. Thanks, mate. And that's all we have 447 00:19:24.770 --> 00:19:26.970 for today's session, Hallie. And we will see 448 00:19:26.970 --> 00:19:28.930 you next Monday for the mostly live episode 449 00:19:28.930 --> 00:19:29.610 of Astronomy. 450 00:19:29.610 --> 00:19:32.330 Hallie: Daily, direct from the Australia studio 451 00:19:32.330 --> 00:19:32.970 Down Under. 452 00:19:32.970 --> 00:19:33.810 Steve Dunkley: Oh, you love it. 453 00:19:33.810 --> 00:19:34.770 Hallie: Beautiful as always. 454 00:19:35.250 --> 00:19:37.490 Steve Dunkley: Right now it's a bit chilly, but it's great 455 00:19:37.490 --> 00:19:39.450 to have you all with us and we will see you 456 00:19:39.450 --> 00:19:40.970 next week. Thanks, Hallie. 457 00:19:40.970 --> 00:19:42.610 Hallie: Catch you next week, everyone. 458 00:19:42.770 --> 00:19:43.410 Steve Dunkley: See ya. 459 00:19:43.650 --> 00:19:44.210 Hallie: Bye. 460 00:19:47.010 --> 00:19:49.570 Steve Dunkley: The podcast with your host, 461 00:19:49.650 --> 00:19:50.690 Steve Dunkley.