1 00:00:04,160 --> 00:00:07,120 This is Geology Bytes with Oliver Strimple. 2 00:00:08,760 --> 00:00:12,560 The most volcanically active body in the solar system is IO, 3 00:00:13,000 --> 00:00:16,079 the innermost of Jupiter's Galilean moons. 4 00:00:16,800 --> 00:00:20,880 Since the 1970s, Jupiter and its moons have been visited by a 5 00:00:20,880 --> 00:00:25,000 number of space probes, including Pioneer, Voyager, 6 00:00:25,160 --> 00:00:29,600 Galileo and Juno. Each time one of these probes 7 00:00:29,600 --> 00:00:33,040 reached IO, and even between successive orbits of a 8 00:00:33,040 --> 00:00:36,600 particular probe, IO surface had changed. 9 00:00:37,560 --> 00:00:43,560 In December 2023 and February 2024, Juno flew by IO at a 10 00:00:43,560 --> 00:00:48,120 distance of 1500 kilometres, seeing, among other things, twin 11 00:00:48,120 --> 00:00:52,840 erupting plumes and lava lakes. What drives this intense 12 00:00:52,840 --> 00:00:57,160 volcanism, and what can Juno and its predecessors tell us about 13 00:00:57,160 --> 00:00:59,920 the structure of IO and how it interacts with Jupiter? 14 00:01:01,640 --> 00:01:06,000 Scott Bolton has a prolific research career that focuses on 15 00:01:06,000 --> 00:01:09,040 Jupiter and Saturn and the formation and evolution of the 16 00:01:09,040 --> 00:01:12,120 solar system. He has LED a number of science 17 00:01:12,120 --> 00:01:16,760 investigations on the Cassini, Galileo, Voyager and Magellan 18 00:01:16,760 --> 00:01:20,080 missions and is the principal investigator of the Juno 19 00:01:20,080 --> 00:01:22,880 mission. He's director of the space 20 00:01:22,880 --> 00:01:26,440 sciences department at Southwest Research Institute in San 21 00:01:26,440 --> 00:01:30,920 Antonio, TX Scott Bolton, welcome to GEOLOGY Bytes. 22 00:01:31,200 --> 00:01:33,320 Thanks for having me, happy to be here. 23 00:01:33,680 --> 00:01:36,560 Let's start with an overview of the Jovian system. 24 00:01:36,920 --> 00:01:41,360 Jupiter is the largest of all the planets in our solar system, 25 00:01:41,600 --> 00:01:44,440 and therefore a lot of scientists believe it must have 26 00:01:44,440 --> 00:01:47,680 formed first. Not only is it the largest 27 00:01:47,680 --> 00:01:50,600 planet, it's spinning around in 10 hours. 28 00:01:50,600 --> 00:01:53,920 So you have this planet that's 10 times the size of the Earth. 29 00:01:54,360 --> 00:01:58,600 1000 Earths fit inside of Jupiter and yet it's spinning 30 00:01:58,680 --> 00:02:01,640 faster than the Earth is. So it's it's moving around very, 31 00:02:01,640 --> 00:02:04,400 very quickly. And then it has the four 32 00:02:04,400 --> 00:02:07,160 Galilean moons that were discovered by Galileo, the 33 00:02:07,160 --> 00:02:10,680 astronomer back in Italian Renaissance when he pointed the 34 00:02:10,680 --> 00:02:13,360 first telescope up there. And the IO is one of those. 35 00:02:13,440 --> 00:02:17,680 And then you have Europa, Ganymede and Callisto, and 36 00:02:17,680 --> 00:02:20,160 they're moving around at different rates. 37 00:02:20,160 --> 00:02:22,760 IO goes around in a little less than a couple days. 38 00:02:23,720 --> 00:02:27,040 And the magnetosphere of Jupiter, which comes out of the 39 00:02:27,040 --> 00:02:30,320 magnetic field of the planet, come out of the poles. 40 00:02:30,320 --> 00:02:34,320 It's spinning very, very fast. It has a collection of charged 41 00:02:34,320 --> 00:02:38,640 particles and that is whipping around, banging into these moons 42 00:02:38,640 --> 00:02:41,240 because it's tied to Jupiter's spin rate. 43 00:02:41,240 --> 00:02:44,280 So it moves around in 10 hours, all of these charged particles. 44 00:02:44,560 --> 00:02:47,960 So they bang in and sputter these moons and knock off 45 00:02:47,960 --> 00:02:51,400 particles. Juno is the latest space probe 46 00:02:51,400 --> 00:02:54,760 to have approached Jupiter. Could you give us a summary of 47 00:02:54,760 --> 00:02:58,240 the Juno mission and how it compares with the prior missions 48 00:02:58,240 --> 00:03:02,680 that have reached Jupiter? Juno is somewhat unique for two 49 00:03:02,680 --> 00:03:05,200 reasons. One is it goes over the poles of 50 00:03:05,200 --> 00:03:07,360 Jupiter. Previously, the spacecraft have 51 00:03:07,360 --> 00:03:10,360 visited around the equator. And the other thing that's new 52 00:03:10,360 --> 00:03:13,400 about Juno is we go very, very close to Jupiter. 53 00:03:13,400 --> 00:03:16,960 We're basically scraping just over the atmosphere as we fly 54 00:03:16,960 --> 00:03:19,760 over. And so we're getting a really 55 00:03:19,760 --> 00:03:23,960 close view of Jupiter and we're getting this global view. 56 00:03:23,960 --> 00:03:27,760 We basically can map the planet. Each orbit comes down over a 57 00:03:27,760 --> 00:03:33,080 different longitude. Voyager and Pioneer flew by, and 58 00:03:33,080 --> 00:03:35,760 Cassini even flew by on its way out to Saturn. 59 00:03:36,000 --> 00:03:39,000 And we got a view from the equator not that close to 60 00:03:39,000 --> 00:03:41,840 Jupiter. And Galileo orbited around 61 00:03:41,840 --> 00:03:45,800 Jupiter, but not as close as Juno and also confined to the 62 00:03:45,840 --> 00:03:49,920 Equatorial regions. When Juno first arrived at the 63 00:03:49,920 --> 00:03:55,760 Jovian system, you placed it in a 53 day highly eccentric orbit, 64 00:03:56,040 --> 00:04:00,440 coming as close as you said, really scraping the top 5000 65 00:04:00,440 --> 00:04:02,520 kilometres above the top of Jupiter's atmosphere. 66 00:04:03,120 --> 00:04:06,720 How did you then change the orbit to get it close to IO? 67 00:04:06,920 --> 00:04:09,200 Actually, Jupiter did that work for us. 68 00:04:09,600 --> 00:04:12,640 We were in an elliptical orbit. So when you get close to 69 00:04:12,640 --> 00:04:15,560 Jupiter, that's called Pera Jove, and when you're far away, 70 00:04:15,560 --> 00:04:18,000 it's called Apojov. And our Pera Jove originally was 71 00:04:18,000 --> 00:04:20,959 near the equator of Jupiter, and we were going over the poles. 72 00:04:21,440 --> 00:04:25,160 And Jupiter's gravity field is asymmetric, and it kind of 73 00:04:25,160 --> 00:04:29,600 twists the orbit of Juno and so that the aperage of moves more 74 00:04:29,600 --> 00:04:33,440 and more north with each orbit, almost 1° per orbit. 75 00:04:33,760 --> 00:04:38,040 And as we do that, when we're coming in toward the North Pole 76 00:04:38,240 --> 00:04:41,240 starts getting closer and closer to the planet. 77 00:04:41,280 --> 00:04:44,880 And as that moves closer to the planet, first you'll encounter 78 00:04:44,880 --> 00:04:49,000 Ganymede, then you get to Europa, and finally IO. 79 00:04:49,000 --> 00:04:51,760 And it's basically the orbit, what they call the line of 80 00:04:51,840 --> 00:04:53,680 absides that's being twisted around. 81 00:04:54,000 --> 00:04:57,720 And so we actually didn't have enough propellant to do do that. 82 00:04:58,000 --> 00:05:00,920 We're just mere mortals. But Jupiter, of course, with its 83 00:05:00,920 --> 00:05:03,680 giant gravity field, really controls the orbit. 84 00:05:04,320 --> 00:05:08,200 So as I said, you got as close as 1500 kilometers from the 85 00:05:08,200 --> 00:05:11,840 surface of IO. What instruments did you use to 86 00:05:11,840 --> 00:05:15,080 study it? We have a visible camera, we 87 00:05:15,080 --> 00:05:17,680 have an infrared camera and spectrometer. 88 00:05:17,960 --> 00:05:21,200 We also have a full set of fields and particles that look 89 00:05:21,200 --> 00:05:23,920 at the magnetosphere. So we have charged particle 90 00:05:23,920 --> 00:05:27,360 instruments like for plasma, energetic particles, plasma 91 00:05:27,360 --> 00:05:30,760 waves and radio emission. We have a microwave radiometer 92 00:05:30,760 --> 00:05:34,800 that we basically invented to look into Jupiter's atmosphere 93 00:05:34,800 --> 00:05:37,680 and to measure how much water and how the dynamics of the 94 00:05:37,680 --> 00:05:39,520 atmosphere work below the clouds. 95 00:05:39,840 --> 00:05:43,840 And we use that to look into the surface of IO. 96 00:05:44,280 --> 00:05:48,040 And we also have magnetometers, and we also have the gravity 97 00:05:48,040 --> 00:05:51,920 science, which looks at the interior structure and measures 98 00:05:51,920 --> 00:05:54,600 the gravity field. And we have an ultraviolet 99 00:05:54,680 --> 00:05:57,960 instrument. You have a microwave instrument. 100 00:05:58,640 --> 00:06:01,720 Are we looking at black body emissions or absorptions or 101 00:06:01,720 --> 00:06:04,080 reflections? How does that work to see the 102 00:06:04,080 --> 00:06:06,200 atmosphere and even below the surface? 103 00:06:07,120 --> 00:06:09,560 You see all of those that you just mentioned, you 104 00:06:09,560 --> 00:06:12,000 predominantly see black body emissions. 105 00:06:12,000 --> 00:06:14,960 So when you look at Jupiter, you have different wavelengths. 106 00:06:14,960 --> 00:06:19,240 We have 6 channels and the short wavelengths or high frequency 107 00:06:19,480 --> 00:06:22,560 look at the top of the atmosphere and the longer 108 00:06:22,560 --> 00:06:26,080 wavelengths can see in and how far into the atmosphere is 109 00:06:26,080 --> 00:06:29,880 driven by the opacity of the atmosphere, which is driven by 110 00:06:29,880 --> 00:06:32,680 ammonia and water. Now when you look at IO with 111 00:06:32,680 --> 00:06:35,320 that, we weren't sure what we were going to see because no 112 00:06:35,320 --> 00:06:38,600 instrument like this has ever been used to really look at lava 113 00:06:38,600 --> 00:06:42,880 and rocky things like that. We actually think we're seeing 114 00:06:42,880 --> 00:06:48,040 into the lava a little bit because we see at the longest 115 00:06:48,040 --> 00:06:50,960 wavelength channels that the temperature is going up. 116 00:06:51,080 --> 00:06:53,760 That means that maybe you're seeing in where it's warmer. 117 00:06:54,080 --> 00:06:56,400 But of course, even though there's tons of volcanoes all 118 00:06:56,400 --> 00:06:59,360 over, it's not completely covered with volcanoes. 119 00:06:59,360 --> 00:07:02,960 So it's mixed with rock and sulfur dioxide ices and things 120 00:07:02,960 --> 00:07:05,400 like that. So it's a mixture of whatever we 121 00:07:05,400 --> 00:07:07,160 see. We're still trying to figure out 122 00:07:07,160 --> 00:07:10,040 exactly how to interpret it. Just fascinating. 123 00:07:10,040 --> 00:07:13,200 To follow up on a point you made, do microwaves actually 124 00:07:13,480 --> 00:07:16,480 penetrate the lava? Can you actually see a little 125 00:07:16,480 --> 00:07:20,280 bit below the surface? We're not sure we think so. 126 00:07:20,280 --> 00:07:23,280 We think that's what we're seeing, but we have no 127 00:07:23,320 --> 00:07:26,920 calibration of this type of measurement because there's no 128 00:07:26,920 --> 00:07:30,120 experience taking an instrument like this and looking at rock 129 00:07:30,120 --> 00:07:33,960 and lava very much. I think that we probably are 130 00:07:33,960 --> 00:07:37,920 seeing into the lava, but we definitely see the temperature 131 00:07:37,920 --> 00:07:42,040 going up, which means that you're probably seeing in to the 132 00:07:42,040 --> 00:07:45,040 surface where it's warmer. You mentioned that Juno's 133 00:07:45,040 --> 00:07:49,720 trajectory took us for the first time over the poles of Jupiter 134 00:07:49,720 --> 00:07:54,040 rather than the equator, and I wonder if its trajectory also 135 00:07:54,040 --> 00:07:58,000 gave us a view of parts of IO's surface that had not been 136 00:07:58,080 --> 00:08:01,520 visible to us before, and if so, whether you were able to map a 137 00:08:02,040 --> 00:08:05,880 distribution of the volcanism according to the latitude on IO. 138 00:08:06,680 --> 00:08:10,120 Yes, in fact we did. At the orbits approaching the 139 00:08:10,120 --> 00:08:13,480 first fly by, which was in the end of December this last year, 140 00:08:13,840 --> 00:08:18,960 we got the first real views of IO's North Pole, and so we made 141 00:08:18,960 --> 00:08:22,160 a map of the volcanoes around the North Pole. 142 00:08:22,400 --> 00:08:25,760 In the next few orbits, we'll get the first views of the South 143 00:08:25,760 --> 00:08:29,440 Pole, and so we're making maps of how the volcanoes are 144 00:08:29,440 --> 00:08:33,960 distributed at both poles and, of course, around the equator. 145 00:08:34,080 --> 00:08:37,919 I know it's early days yet as far as receiving all the data 146 00:08:37,919 --> 00:08:42,159 and processing it and so on, but so far, what kind of volcanic 147 00:08:42,159 --> 00:08:45,880 activity have we seen in the latest Juno imagery of IO? 148 00:08:46,720 --> 00:08:49,040 IO must be an amazing place to visit. 149 00:08:49,800 --> 00:08:53,600 It's covered with volcanoes that are going off all the time. 150 00:08:54,000 --> 00:08:56,720 And if you go to the poles, there's still volcanoes 151 00:08:56,720 --> 00:08:59,400 everywhere. So if you were a hiker and you 152 00:08:59,400 --> 00:09:03,160 were lucky enough to land on IO and you had the equipment or 153 00:09:03,160 --> 00:09:06,960 some sort of natural way to survive this because it must be 154 00:09:06,960 --> 00:09:10,440 really smelly there, like like Yellowstone. 155 00:09:10,680 --> 00:09:13,400 And no matter where you were, you would have a view of many 156 00:09:13,400 --> 00:09:15,920 volcanoes. And we also saw these incredible 157 00:09:15,920 --> 00:09:20,520 mountains because we got some imagery along the Terminator. 158 00:09:20,760 --> 00:09:24,600 And you can see these mountains are also all over IO that are 159 00:09:24,600 --> 00:09:26,800 coupled to the volcanoes, but they're not necessarily a 160 00:09:26,800 --> 00:09:29,200 volcanic. It has its own capability to 161 00:09:29,200 --> 00:09:30,800 make mountains. And some of them are quite 162 00:09:30,920 --> 00:09:33,000 sharp. They look like cliffs. 163 00:09:33,200 --> 00:09:36,240 It's just an amazing place. Giant lava lakes. 164 00:09:36,480 --> 00:09:40,000 Some of these are reflecting with specular reflections. 165 00:09:40,000 --> 00:09:43,280 So at least the lava lakes must have a very, very smooth 166 00:09:43,280 --> 00:09:45,520 surface. In fact, most of IO must be 167 00:09:45,520 --> 00:09:49,400 relatively smooth. We compare it to Europa and 168 00:09:49,400 --> 00:09:54,080 Ganymede, which we flew by years earlier, and that surface is 169 00:09:54,080 --> 00:09:56,480 much more rough. The ice is rough and the 170 00:09:56,560 --> 00:10:00,000 reflections is diffuse scattering, whereas in IO it's 171 00:10:00,000 --> 00:10:02,200 specular, almost like it's glass. 172 00:10:02,440 --> 00:10:07,000 So the frozen surface of the lava, you're saying that's shiny 173 00:10:07,040 --> 00:10:09,240 on Earth? Of course it gets very matte 174 00:10:09,240 --> 00:10:12,920 when we have cooled lava. It might be smooth, more like 175 00:10:12,920 --> 00:10:15,480 Obsidian. If you look sometimes near 176 00:10:15,480 --> 00:10:18,400 Earth's volcanic regions, you'd find Obsidian, which is a very 177 00:10:18,400 --> 00:10:21,400 smooth kind of glass. So whatever's forming there 178 00:10:21,400 --> 00:10:24,320 might be relatively pure and very smooth. 179 00:10:24,680 --> 00:10:26,880 And then a lot of lakes are cooling. 180 00:10:27,000 --> 00:10:30,640 Get a crust over them and then where the lava is coming up 181 00:10:30,640 --> 00:10:32,200 might make a ring around the lake. 182 00:10:32,440 --> 00:10:34,960 And sometimes there's protrusions out of that which 183 00:10:34,960 --> 00:10:38,760 represent natural terrain, elevation changes, the almost 184 00:10:38,760 --> 00:10:40,760 islands like. And then of course you have the 185 00:10:40,760 --> 00:10:43,680 volcano itself. Sometimes we see some of that. 186 00:10:43,920 --> 00:10:46,720 If you go to Hawaii or Iceland right now, you'll see this 187 00:10:46,720 --> 00:10:51,600 bubbling ring of lava and there's a cooled off lake and 188 00:10:51,600 --> 00:10:53,480 the material can get quite smooth. 189 00:10:53,520 --> 00:10:56,360 I don't think it's liquid because it's very cold on the 190 00:10:56,360 --> 00:10:59,600 surface of Isles, so the lava must be cooling very very 191 00:10:59,600 --> 00:11:02,200 quickly. So you said it would be smelly 192 00:11:02,200 --> 00:11:05,520 on the surface of IO. I presume you're referring to 193 00:11:05,960 --> 00:11:09,520 sulphur compounds like hydrogen sulphide or sulphur dioxide. 194 00:11:09,640 --> 00:11:14,280 But IO's very colourful surface has been likened to that of a 195 00:11:14,280 --> 00:11:17,840 well stocked pizza. So do we know what generates all 196 00:11:17,840 --> 00:11:22,800 those many Reds, yellows and the dark greens and greys and 197 00:11:22,800 --> 00:11:25,280 blacks? Sulphur compounds are certainly 198 00:11:25,280 --> 00:11:29,320 associated with the volcanoes as they erupt, and those are 199 00:11:29,480 --> 00:11:32,120 predominantly the thing that causing the yellows and the 200 00:11:32,120 --> 00:11:34,680 Reds. Now when the sulfur gas comes 201 00:11:34,680 --> 00:11:38,560 out of a volcano on IO, it instantly freezes, so it turns 202 00:11:38,560 --> 00:11:42,320 into snow and it's probably colored snow or dirty snow. 203 00:11:42,480 --> 00:11:46,440 So you get the yellow reddish gook that's being laid around. 204 00:11:46,880 --> 00:11:50,320 And the molten lava, as soon as it comes out, also starts 205 00:11:50,320 --> 00:11:53,040 cooling. So when that cools off, they 206 00:11:53,040 --> 00:11:55,120 produce a lot of the Grays and black. 207 00:11:56,440 --> 00:12:00,960 What drives all this intense volcanism on IO and makes it the 208 00:12:00,960 --> 00:12:03,640 most volcanically active body in the solar system? 209 00:12:04,160 --> 00:12:07,640 Iowa's volcanic activity is really driven by Jupiter. 210 00:12:07,680 --> 00:12:10,320 It's tidal forces. So the same thing that raises 211 00:12:10,320 --> 00:12:14,440 the ocean here on Earth. Our moon pulls and changes our 212 00:12:14,440 --> 00:12:17,240 tides. Jupiter is doing that on IO. 213 00:12:17,400 --> 00:12:21,520 It's relentlessly squeezing and literally torturing this poor 214 00:12:21,520 --> 00:12:25,480 moon as it orbits Jupiter. It's getting squeezed. 215 00:12:25,480 --> 00:12:29,080 The gravity field is so strong, it's basically changing its 216 00:12:29,080 --> 00:12:32,920 shape and it feels a stronger gravity on one side versus the 217 00:12:32,920 --> 00:12:36,760 other, and that is churning inside and producing all of the 218 00:12:36,960 --> 00:12:40,000 volcanic activity. Do we know anything about the 219 00:12:40,000 --> 00:12:44,520 mechanism by which this heating leads to the many volcanoes that 220 00:12:44,520 --> 00:12:47,800 pepper IO surface? To that, you have to look inside 221 00:12:47,800 --> 00:12:50,480 of IO. And the question is, is whether 222 00:12:50,480 --> 00:12:56,760 there's a global magma ocean or pockets of lava that just 223 00:12:56,760 --> 00:13:00,600 produce local volcanoes. In other words, if I go down 224 00:13:00,600 --> 00:13:04,400 deep into IO, is there a layer that's all lava? 225 00:13:04,800 --> 00:13:08,320 And in fact, we chose to do 2 flybys in order to get the 226 00:13:08,320 --> 00:13:12,640 gravity field very, very precisely to distinguish a 227 00:13:12,640 --> 00:13:15,880 global magma ocean from one that is not global. 228 00:13:16,120 --> 00:13:19,400 I think that in the next few months we will probably resolve 229 00:13:19,400 --> 00:13:23,800 that question and put very good constraints on how IO works 230 00:13:23,800 --> 00:13:28,240 inside and how it produces all of the volcanoes that we see. 231 00:13:28,960 --> 00:13:33,200 We see volcanism on other bodies apart from the Earth, such as 232 00:13:33,240 --> 00:13:37,600 our own moon. So not all volcanism is caused 233 00:13:37,600 --> 00:13:39,600 by tidal heating then? Not all of it. 234 00:13:39,720 --> 00:13:42,920 Tidal forces are much smaller here because the moon can only 235 00:13:42,920 --> 00:13:46,280 do so much to us. Venus is also volcanic. 236 00:13:46,480 --> 00:13:48,360 Mars you can see all the volcanoes. 237 00:13:48,360 --> 00:13:52,200 So tidal forces play a role. Some of them have small moons 238 00:13:52,200 --> 00:13:54,720 going around them. Or in case of Venus, it's closer 239 00:13:54,720 --> 00:13:58,160 to the sun so it gets some tidal forces, but a lot of it is 240 00:13:58,160 --> 00:14:01,600 geothermal as well. There's material deep down in 241 00:14:01,600 --> 00:14:03,280 the planet that's keeping it warm. 242 00:14:03,280 --> 00:14:06,120 Radioactive material that rayogenic heating. 243 00:14:06,360 --> 00:14:09,800 People see it on Enceladus. We see crowd vents where water 244 00:14:09,800 --> 00:14:13,400 is spewing out of the ice, so something cracks the ice. 245 00:14:13,640 --> 00:14:17,120 People think that maybe Europa that might have blooms of water 246 00:14:17,400 --> 00:14:20,320 coming out of it, the ice might be cracking as well. 247 00:14:20,320 --> 00:14:24,720 It must be feeling some tidal forces from Jupiter as well, 248 00:14:24,720 --> 00:14:26,880 even though it's further away than IO. 249 00:14:27,600 --> 00:14:29,920 IO is the one that's really getting tortured because it's 250 00:14:29,920 --> 00:14:33,640 really close. Juno has a magnetometer on 251 00:14:33,640 --> 00:14:37,960 board, you said. How does IO affect Jupiter's 252 00:14:37,960 --> 00:14:42,320 magnetic field, and what can we learn from that interaction? 253 00:14:42,760 --> 00:14:45,840 Juno has a very, very sensitive magnetometer. 254 00:14:45,840 --> 00:14:50,280 It's very powerful tool to investigate the interior of 255 00:14:50,280 --> 00:14:53,640 Jupiter and actually see how the magnetic fields are produced and 256 00:14:53,640 --> 00:14:55,560 map out the magnetic field of Jupiter. 257 00:14:56,040 --> 00:14:57,920 Now, Jupiter's magnetic field is enormous. 258 00:14:57,920 --> 00:15:00,760 In fact, it's the largest structure in the solar system. 259 00:15:00,760 --> 00:15:02,960 It makes what's called a magnetosphere, which is filled 260 00:15:02,960 --> 00:15:06,360 with charged particles. So the magnetometers on Juno 261 00:15:06,360 --> 00:15:10,000 were designed to measure Jupiter's magnetic field and map 262 00:15:10,000 --> 00:15:12,240 it. IO's impact on Jupiter's 263 00:15:12,240 --> 00:15:15,680 magnetic field and magnetosphere is the fact that it's filling 264 00:15:16,080 --> 00:15:19,760 the space with charged particles, material that comes 265 00:15:19,800 --> 00:15:23,600 out of the volcanoes. It gets ionized through sunlight 266 00:15:23,600 --> 00:15:27,800 or collisions and then starts whipping around and becomes part 267 00:15:27,800 --> 00:15:32,240 of Jupiter's magnetosphere. That also feeds the Aurora. 268 00:15:32,320 --> 00:15:34,960 So when they get caught up on these magnetic field lines, it's 269 00:15:34,960 --> 00:15:37,960 almost like an umbilical cord between IO and Jupiter. 270 00:15:38,240 --> 00:15:42,800 There's a spot in Jupiter's Aurora that actually tells you 271 00:15:42,800 --> 00:15:48,480 where IO is and connecting Jupiter width IO through its 272 00:15:48,480 --> 00:15:51,440 magnetic field. IO is so powerful in the fact 273 00:15:51,440 --> 00:15:54,160 that it's distributing all of these charged particles from the 274 00:15:54,160 --> 00:15:58,960 volcano that there's a ring around Jupiter that's called the 275 00:15:59,040 --> 00:16:02,600 IO Taurus and it's filled with charged particles. 276 00:16:02,600 --> 00:16:04,600 And we've known about this for a long time. 277 00:16:04,720 --> 00:16:06,400 A previous missions have studied this. 278 00:16:06,400 --> 00:16:09,320 You can study this from some telescopes, from the Earth even. 279 00:16:10,000 --> 00:16:13,560 And this torus of charged particles around IO is very, 280 00:16:13,560 --> 00:16:17,400 very high in radiation. It's very hazardous place to go 281 00:16:17,400 --> 00:16:20,920 for spacecraft. And that Taurus also makes a 282 00:16:20,920 --> 00:16:24,120 little bit of Aurora. So when you look at the Aurora 283 00:16:24,120 --> 00:16:28,080 of Jupiter, you can see sort of a tail coming out of IO that's 284 00:16:28,080 --> 00:16:30,120 coming from this Taurus ringing around. 285 00:16:30,400 --> 00:16:35,760 And you can also see this spot. You mentioned that you saw some 286 00:16:35,760 --> 00:16:40,920 topography on the surface of IO that was not volcanic in nature, 287 00:16:41,040 --> 00:16:44,240 cliffs and so on. Are we talking about tectonics 288 00:16:44,240 --> 00:16:47,400 on I or what do you think might cause non volcanic topography 289 00:16:47,400 --> 00:16:49,160 there? Yeah, you need some kind of 290 00:16:49,160 --> 00:16:53,200 mountain building capability, not necessarily plate tectonics, 291 00:16:53,200 --> 00:16:57,440 but so far we haven't really uncovered plate tectonics around 292 00:16:57,440 --> 00:17:01,840 another body other than Earth. But something is moving around 293 00:17:02,040 --> 00:17:04,920 and you're forming mountains, and we see mountain ranges 294 00:17:04,920 --> 00:17:07,560 formed in other places besides the Earth. 295 00:17:08,280 --> 00:17:12,400 What's next in the flight plan or science plan for the Juno 296 00:17:12,400 --> 00:17:15,560 mission? We will continue to go under IO 297 00:17:15,560 --> 00:17:18,640 for the next few orbits, relatively close 10s of 298 00:17:18,640 --> 00:17:21,880 thousands of kilometres away. So we're hoping to continue to 299 00:17:21,880 --> 00:17:25,960 monitor now the South Pole and the volcanoes and we're trying 300 00:17:25,960 --> 00:17:29,760 to tie the volcanic activity to activity that we see in the 301 00:17:29,760 --> 00:17:33,280 Aurora and the magnetosphere to really understand how IO is 302 00:17:33,280 --> 00:17:35,040 really driving this whole system. 303 00:17:35,320 --> 00:17:37,240 But also we're doing occultations. 304 00:17:37,240 --> 00:17:41,160 We actually go behind Jupiter. We're solar powered, so it's a 305 00:17:41,160 --> 00:17:44,840 little bit of a nail biting because when you go in behind 306 00:17:44,840 --> 00:17:47,920 Jupiter you don't have power going on to your solar arrays 307 00:17:47,920 --> 00:17:49,720 for a little while. But we're getting incredible 308 00:17:49,720 --> 00:17:52,680 measurements of the atmosphere by doing occultation. 309 00:17:52,680 --> 00:17:56,120 We pass the radio beam through the atmosphere and we watch it 310 00:17:56,120 --> 00:17:59,120 blink on and off. As you go into an occultation, 311 00:17:59,120 --> 00:18:02,360 you're going behind Jupiter and you can learn a lot about the 312 00:18:02,440 --> 00:18:05,480 density and the properties of the upper atmosphere. 313 00:18:05,480 --> 00:18:09,560 With that, we're also getting closer and closer to Jupiter's 314 00:18:09,560 --> 00:18:13,440 polar region. And so as the perigove of Juno 315 00:18:13,600 --> 00:18:17,520 moves further and further north, the altitude that we pass over 316 00:18:17,520 --> 00:18:20,960 the poles is dropping. And so we're studying these 317 00:18:20,960 --> 00:18:23,520 polar cyclones very, very closely. 318 00:18:23,520 --> 00:18:27,880 And we're able to see now with the microwave radiometer, the 319 00:18:27,880 --> 00:18:31,480 beam is getting to the point where we can resolve these polar 320 00:18:31,480 --> 00:18:34,160 cyclones. And so we're studying those with 321 00:18:34,160 --> 00:18:38,120 multiple wavelengths and looking at how they look in microwave 322 00:18:38,120 --> 00:18:39,520 eyes. At the same time. 323 00:18:39,520 --> 00:18:43,960 We're seeing them in infrared invisible light and really for 324 00:18:43,960 --> 00:18:46,560 the first time looking underneath those polar cyclones 325 00:18:46,560 --> 00:18:49,680 to see how they compare to each other, how deep the roots are, 326 00:18:49,920 --> 00:18:53,320 and compare those two other kinds of vortices that we see 327 00:18:53,680 --> 00:18:56,440 all over Jupiter. And of course, we're also 328 00:18:56,480 --> 00:19:00,120 continue to map out the magnetosphere and the Aurora. 329 00:19:00,400 --> 00:19:02,920 We're getting closer and closer to the North Pole. 330 00:19:02,920 --> 00:19:05,880 So we're really getting to the point where the auroral 331 00:19:05,880 --> 00:19:09,400 accelerations are happening. And so we're going to learn a 332 00:19:09,400 --> 00:19:12,360 lot about how the Aurora and Jupiter get created. 333 00:19:12,640 --> 00:19:15,080 And we're finally going to get to the point where we're 334 00:19:15,080 --> 00:19:18,560 crossing into the rings of Jupiter, which are very, very 335 00:19:18,560 --> 00:19:20,360 close to Jupiter. Very hazardous. 336 00:19:20,680 --> 00:19:22,800 These are very dangerous places to go. 337 00:19:23,000 --> 00:19:26,200 We're kind of an armored tank and our Shields are still 338 00:19:26,200 --> 00:19:29,480 holding, so we're getting closer and closer and we're going to 339 00:19:29,480 --> 00:19:31,720 study the rings of Jupiter as well. 340 00:19:32,240 --> 00:19:35,080 You're saying you're an arm attack, but if you get hit by a 341 00:19:35,080 --> 00:19:37,040 particle in the ring, can you survive that? 342 00:19:37,120 --> 00:19:40,960 We're hoping that we won't get hit, but it's not just the 343 00:19:40,960 --> 00:19:43,400 particles hitting you, it's also the radiation. 344 00:19:43,680 --> 00:19:46,600 We're getting more and more radiation with every orbit. 345 00:19:47,120 --> 00:19:49,840 What is the ultimate fate of Juno going to be? 346 00:19:50,120 --> 00:19:53,760 It either will run out of propellant, which will mean that 347 00:19:53,760 --> 00:19:57,240 we can't point the antenna down to the Earth to downlink our 348 00:19:57,240 --> 00:20:01,080 data. We use the propellant to steer 349 00:20:01,160 --> 00:20:04,080 the spacecraft a little bit and can change its orbit a little 350 00:20:04,080 --> 00:20:07,360 bit, but mostly to turn the spacecraft and point the solar 351 00:20:07,360 --> 00:20:09,160 arrays or the antenna at the Earth. 352 00:20:09,840 --> 00:20:13,400 Or we will have suffer so much radiation that some of the 353 00:20:13,400 --> 00:20:17,400 systems will stop working. And so the end of Juno will be 354 00:20:17,400 --> 00:20:20,720 defined probably by one of those at one point. 355 00:20:20,720 --> 00:20:22,320 We were designed so that we would. 356 00:20:22,680 --> 00:20:27,400 Purposely move Juno into Jupiter to dispose of it to make sure it 357 00:20:27,400 --> 00:20:31,400 didn't crash in to Europa. But now we're past that and we 358 00:20:31,400 --> 00:20:33,320 can't crash into it. Really. 359 00:20:33,480 --> 00:20:38,040 Jupiter's gravity field is too powerful, so we will just die 360 00:20:38,040 --> 00:20:41,800 naturally and eventually the orbit will cause it to fall into 361 00:20:41,800 --> 00:20:44,240 Jupiter, but we won't necessarily control that. 362 00:20:45,480 --> 00:20:51,240 Thinking about future missions, what kind of mission would best 363 00:20:51,240 --> 00:20:56,120 advance our knowledge of the interior of Jupiter's moons, Not 364 00:20:56,120 --> 00:20:59,320 just IO, but some of the other ones where we think there might 365 00:20:59,320 --> 00:21:04,080 be a subsurface ocean. And of course, we speculate that 366 00:21:04,080 --> 00:21:05,720 they might harbour life. Right. 367 00:21:05,720 --> 00:21:08,560 They may be habitable. So there's two missions, one 368 00:21:08,560 --> 00:21:11,640 that's already on its way out. That was the European Space 369 00:21:11,640 --> 00:21:15,800 Agency's mission called JUICE, and it's on its way out to study 370 00:21:15,800 --> 00:21:18,440 Europa and Ganymede and Callisto. 371 00:21:18,680 --> 00:21:19,960 And they'll get a little bit of IO. 372 00:21:19,960 --> 00:21:23,960 They don't get too close to it. Their target is mostly Ganymede. 373 00:21:23,960 --> 00:21:27,200 They'll eventually orbit Ganymede, and that will really 374 00:21:27,200 --> 00:21:29,600 tell us a lot about the interior of Ganymede. 375 00:21:30,160 --> 00:21:33,840 They'll get phenomenal data on the gravity field and the 376 00:21:33,840 --> 00:21:38,360 magnetic field of this body, as well as radar instruments to see 377 00:21:38,360 --> 00:21:40,960 into the ice. And then NASA has a mission that 378 00:21:40,960 --> 00:21:44,480 will launch later this year called Europa Clipper that will 379 00:21:44,480 --> 00:21:47,720 study Europa very closely. It doesn't go into orbit at 380 00:21:47,720 --> 00:21:51,200 Europa, but it gets many flybys of Europa and eventually 381 00:21:51,200 --> 00:21:54,600 Ganymede, and they'll be there together studying these two 382 00:21:54,600 --> 00:21:56,680 moons. And they were being designed 383 00:21:56,800 --> 00:22:00,840 around the same time as Juno, but they just got later starts. 384 00:22:01,040 --> 00:22:04,560 But they're follow ONS and much of the design of the spacecraft 385 00:22:04,560 --> 00:22:07,800 is similar to Juno. So we have a radiation vault. 386 00:22:07,920 --> 00:22:09,560 They both have something like that. 387 00:22:09,760 --> 00:22:12,280 They're both solar powered like Juno was. 388 00:22:12,520 --> 00:22:16,440 Neither of them get really close to IO, so some future mission to 389 00:22:16,440 --> 00:22:19,960 go to IO would be very interesting, either to orbit it, 390 00:22:19,960 --> 00:22:23,680 or even better to get maybe a sample of the plume and bring it 391 00:22:23,680 --> 00:22:25,640 back. What you'd really like is get a 392 00:22:25,640 --> 00:22:29,800 step further, like Osiris Rex got these material from an 393 00:22:29,800 --> 00:22:33,080 asteroid. It'd be great to get samples of 394 00:22:33,080 --> 00:22:38,200 the volcanic plumes or the ices and bring them back to Earth 395 00:22:38,200 --> 00:22:42,800 laboratories someday. Maybe you could land on Europa 396 00:22:42,920 --> 00:22:46,680 or Ganymede and even the ultimate would be go down in 397 00:22:46,680 --> 00:22:49,000 with something and actually sample the ocean. 398 00:22:49,360 --> 00:22:53,000 They're quite deep, probably kilometers deep, maybe many 399 00:22:53,000 --> 00:22:55,440 kilometers, so it's not so easy to do. 400 00:22:56,160 --> 00:23:00,360 If you could decide what a future space probe would be, 401 00:23:00,680 --> 00:23:02,240 where would you go and what would it look like? 402 00:23:02,840 --> 00:23:05,760 Well I'm kind of a greedy scientist so I would want more 403 00:23:05,760 --> 00:23:10,640 than one, but comparing the planets is really important. 404 00:23:10,760 --> 00:23:14,120 Juno uncovered real puzzles about how Jupiter formed and how 405 00:23:14,200 --> 00:23:17,440 its inside works. We didn't really know that and I 406 00:23:17,440 --> 00:23:20,920 think to fully understand that and interpret that we need to 407 00:23:20,920 --> 00:23:23,320 get other examples. So we need to do the same thing 408 00:23:23,320 --> 00:23:25,560 at the ice giants Uranus and Neptune. 409 00:23:25,960 --> 00:23:29,160 They have moons as well. May also be ocean worlds. 410 00:23:29,440 --> 00:23:31,360 You could do a Juno like mission. 411 00:23:31,680 --> 00:23:35,040 We've shown that you can study the body really close and at the 412 00:23:35,040 --> 00:23:37,200 same time get flybys of satellites. 413 00:23:37,360 --> 00:23:40,360 If you could do something like that at Uranus and Neptune, that 414 00:23:40,360 --> 00:23:43,240 would be phenomenal. Even going back to Saturn's 415 00:23:43,240 --> 00:23:48,160 system and studying Titan and Enceladus and Saturn would be 416 00:23:48,160 --> 00:23:51,360 beneficial. Enceladus may also be habitable, 417 00:23:51,760 --> 00:23:55,160 and it's sitting there sending its water plumes out, making it 418 00:23:55,160 --> 00:23:58,800 easy for us to sample them. And these giant planets, 419 00:23:58,880 --> 00:24:03,160 Jupiter, Saturn, Uranus and Neptune represent giant planets 420 00:24:03,160 --> 00:24:05,720 that we see in exoplanetary systems. 421 00:24:05,720 --> 00:24:08,840 And if we're going to understand these other planetary systems 422 00:24:08,840 --> 00:24:12,120 that we're discovering now, we really need to understand what's 423 00:24:12,120 --> 00:24:15,040 in our own backyard. Scott Bolton. 424 00:24:15,040 --> 00:24:16,960 Thank you very much. Thank you. 425 00:24:18,120 --> 00:24:20,840 To see pictures and illustrations that support this 426 00:24:20,840 --> 00:24:26,400 podcast, go to geologybytes.com, where you'll also find 427 00:24:26,400 --> 00:24:29,880 transcripts and a subject matter index of all the episodes. 428 00:24:30,560 --> 00:24:33,800 There you can also give me feedback which I welcome, as 429 00:24:33,800 --> 00:24:36,760 well as sign up to get my emails about new episodes.