1 00:00:00,000 --> 00:00:03,460 Imagine a moon, bigger than the planet Mercury, 2 00:00:04,400 --> 00:00:06,760 with a hidden ocean that might hold more water 3 00:00:06,760 --> 00:00:09,680 than all of Earth's oceans combined. 4 00:00:09,680 --> 00:00:10,880 That's amazing. 5 00:00:10,880 --> 00:00:13,840 That's Ganymede, Jupiter's enigmatic companion. 6 00:00:13,840 --> 00:00:14,660 I see. 7 00:00:14,660 --> 00:00:16,420 A world that pushes the boundaries 8 00:00:16,420 --> 00:00:18,280 of what we thought a moon could be. 9 00:00:18,280 --> 00:00:19,180 Yeah. 10 00:00:19,180 --> 00:00:22,920 Welcome to Cosmos in a Pod, Space and Astronomy series. 11 00:00:22,920 --> 00:00:23,760 Cool. 12 00:00:23,760 --> 00:00:25,800 Today we're taking a deep dive into Ganymede. 13 00:00:25,800 --> 00:00:26,620 Okay. 14 00:00:26,620 --> 00:00:29,680 A moon so extraordinary, 15 00:00:29,680 --> 00:00:33,080 it blurs the line between moon and planet. 16 00:00:33,080 --> 00:00:34,540 It's a celestial rebel. 17 00:00:34,540 --> 00:00:35,500 Right. That's for sure. 18 00:00:35,500 --> 00:00:36,340 Yeah. 19 00:00:36,340 --> 00:00:38,680 When you grasp the sheer scale of it. 20 00:00:38,680 --> 00:00:40,440 I know. Larger than Mercury. 21 00:00:40,440 --> 00:00:41,280 It's crazy. 22 00:00:41,280 --> 00:00:43,240 You begin to realize that Ganymede 23 00:00:43,240 --> 00:00:45,880 is something special in the cosmic landscape. 24 00:00:45,880 --> 00:00:46,720 You said it. 25 00:00:46,720 --> 00:00:48,040 Yeah. But here's what throws me. 26 00:00:48,040 --> 00:00:48,880 What's that? 27 00:00:48,880 --> 00:00:50,720 It's physically bigger than Mercury. 28 00:00:50,720 --> 00:00:51,560 Okay. 29 00:00:51,560 --> 00:00:54,040 But only about 45% is massive. 30 00:00:54,040 --> 00:00:56,200 It's like a giant fluffy marshmallow in space. 31 00:00:56,200 --> 00:00:57,040 Yeah. 32 00:00:57,040 --> 00:01:00,040 What does that tell us about what Ganymede is made of? 33 00:01:00,040 --> 00:01:01,840 That's a fantastic question. 34 00:01:01,840 --> 00:01:04,320 And it leads us right into 35 00:01:04,320 --> 00:01:06,600 one of Ganymede's biggest mysteries. 36 00:01:06,600 --> 00:01:09,840 That low density is a huge clue. 37 00:01:09,840 --> 00:01:10,680 Really? 38 00:01:10,680 --> 00:01:13,160 It tells us that Ganymede is made up mostly of ice. 39 00:01:13,160 --> 00:01:14,000 Ice! 40 00:01:14,000 --> 00:01:16,760 Not dense rock like Earth or even the moon. 41 00:01:16,760 --> 00:01:17,800 Wow. 42 00:01:17,800 --> 00:01:20,280 We're talking about a world dominated by ice. 43 00:01:20,280 --> 00:01:22,160 So not just like a little bit of ice? 44 00:01:22,160 --> 00:01:23,000 No. 45 00:01:23,000 --> 00:01:23,820 Like a lot of ice. 46 00:01:23,820 --> 00:01:24,660 Yeah. 47 00:01:24,660 --> 00:01:26,600 Okay. Now my mind is officially blown. 48 00:01:26,600 --> 00:01:28,080 A moon made mostly of ice. 49 00:01:28,080 --> 00:01:28,920 Right. 50 00:01:28,920 --> 00:01:31,240 And then there's this idea of a hidden ocean 51 00:01:31,240 --> 00:01:33,040 beneath that icy shell. 52 00:01:33,040 --> 00:01:33,880 Uh huh. 53 00:01:33,880 --> 00:01:35,400 An ocean that could hold more water 54 00:01:35,400 --> 00:01:37,680 than all the oceans on Earth combined. 55 00:01:37,680 --> 00:01:38,720 Why? 56 00:01:38,720 --> 00:01:39,920 It's almost too incredible to believe. 57 00:01:39,920 --> 00:01:41,800 It's one of the most exciting possibilities 58 00:01:41,800 --> 00:01:42,680 in our solar system. 59 00:01:42,680 --> 00:01:44,640 And it's not just speculation. 60 00:01:44,640 --> 00:01:45,600 Oh, there's evidence. 61 00:01:45,600 --> 00:01:47,480 We have several pieces of evidence 62 00:01:47,480 --> 00:01:50,600 that point towards the existence of this hidden ocean. 63 00:01:50,600 --> 00:01:51,440 Okay. 64 00:01:51,440 --> 00:01:54,200 One of the most intriguing is Ganymede's magnetic field. 65 00:01:54,200 --> 00:01:55,200 Wait, hold on. 66 00:01:55,200 --> 00:01:56,040 Yeah. 67 00:01:56,040 --> 00:01:58,480 A moon with its own magnetic field. 68 00:01:58,480 --> 00:01:59,760 Well, it's remarkable, isn't it? 69 00:01:59,760 --> 00:02:01,520 How is that even possible? 70 00:02:01,520 --> 00:02:04,240 Ganymede is the only moon in our solar system 71 00:02:04,240 --> 00:02:06,280 that we know of. 72 00:02:06,280 --> 00:02:08,640 That has its own intrinsic magnetic field. 73 00:02:08,640 --> 00:02:09,480 Okay. 74 00:02:09,480 --> 00:02:10,840 Think of it as a protective bubble. 75 00:02:10,840 --> 00:02:11,680 Right. 76 00:02:11,680 --> 00:02:12,840 Generated by the moon itself. 77 00:02:12,840 --> 00:02:14,120 I see. 78 00:02:14,120 --> 00:02:16,980 The leading theory is that this magnetic field 79 00:02:16,980 --> 00:02:21,780 is created by a dynamo effect deep within Ganymede's core. 80 00:02:21,780 --> 00:02:22,620 Okay. 81 00:02:22,620 --> 00:02:26,120 It's capturing a giant molten dynamo 82 00:02:26,120 --> 00:02:28,920 churning away inside Ganymede. 83 00:02:28,920 --> 00:02:29,760 Uh-huh. 84 00:02:29,760 --> 00:02:32,720 But what exactly is this dynamo made of, 85 00:02:32,720 --> 00:02:34,280 and how does it work? 86 00:02:34,280 --> 00:02:36,320 We believe Ganymede's core is composed 87 00:02:36,320 --> 00:02:38,440 mainly of metallic iron. 88 00:02:38,440 --> 00:02:39,280 Okay. 89 00:02:39,280 --> 00:02:41,360 Perhaps with some iron sulfide mixed in. 90 00:02:41,360 --> 00:02:42,200 I see. 91 00:02:42,200 --> 00:02:45,480 This metallic core is constantly moving, churning, 92 00:02:45,480 --> 00:02:47,360 and generating electric currents. 93 00:02:47,360 --> 00:02:48,200 Right. 94 00:02:48,200 --> 00:02:50,320 These currents in turn create the magnetic field 95 00:02:50,320 --> 00:02:52,520 that surrounds Ganymede. 96 00:02:52,520 --> 00:02:55,040 This giant moon made mostly of ice. 97 00:02:55,040 --> 00:02:55,880 Yes. 98 00:02:55,880 --> 00:02:57,200 With a churning metallic heart 99 00:02:57,200 --> 00:02:59,040 generating its own magnetic field. 100 00:02:59,040 --> 00:02:59,880 Yeah. 101 00:02:59,880 --> 00:03:01,440 It already sounds more like a planet than a moon. 102 00:03:01,440 --> 00:03:02,280 Right. 103 00:03:02,280 --> 00:03:03,680 But how does this magnetic field connect 104 00:03:03,680 --> 00:03:06,040 to the possibility of a hidden ocean? 105 00:03:06,040 --> 00:03:08,080 Ah, that's where things get really interesting. 106 00:03:08,080 --> 00:03:08,920 Okay. 107 00:03:08,920 --> 00:03:10,320 This magnetic field isn't just sitting there. 108 00:03:10,320 --> 00:03:12,040 It's interacting with Jupiter's 109 00:03:12,040 --> 00:03:14,280 incredibly powerful magnetosphere. 110 00:03:14,280 --> 00:03:15,120 Okay. 111 00:03:15,120 --> 00:03:16,920 Imagine Jupiter's magnetosphere 112 00:03:16,920 --> 00:03:20,560 as a vast swirling ocean of charged particles. 113 00:03:20,560 --> 00:03:21,400 All right. 114 00:03:21,400 --> 00:03:22,760 And it's right in the middle of it. 115 00:03:22,760 --> 00:03:23,600 Yeah. 116 00:03:23,600 --> 00:03:24,840 With its own magnetic field 117 00:03:24,840 --> 00:03:27,120 pushing back against this cosmic current. 118 00:03:27,120 --> 00:03:29,000 So it's like a magnetic tug of war 119 00:03:29,000 --> 00:03:30,520 between Jupiter and Ganymede. 120 00:03:30,520 --> 00:03:31,360 Exactly. 121 00:03:31,360 --> 00:03:32,200 Wow. 122 00:03:32,200 --> 00:03:34,760 And this interaction creates some spectacular effects. 123 00:03:34,760 --> 00:03:35,720 Like what? 124 00:03:35,720 --> 00:03:38,320 We see auroras around Ganymede's poles. 125 00:03:38,320 --> 00:03:39,140 Oh, cool. 126 00:03:39,140 --> 00:03:40,760 Just like the Northern Lights on Earth. 127 00:03:40,760 --> 00:03:41,600 Okay. 128 00:03:41,600 --> 00:03:42,640 But here's the key. 129 00:03:42,640 --> 00:03:43,480 What is it? 130 00:03:43,480 --> 00:03:46,240 These auroras don't behave the way we'd expect 131 00:03:46,240 --> 00:03:49,120 if Ganymede were just a solid ball of ice. 132 00:03:49,120 --> 00:03:49,960 What do you mean? 133 00:03:49,960 --> 00:03:50,780 Yeah. 134 00:03:50,780 --> 00:03:51,620 Definitely. 135 00:03:51,620 --> 00:03:52,480 They wobble and shift 136 00:03:52,480 --> 00:03:55,440 in a way that suggests there's a salty, 137 00:03:55,440 --> 00:03:59,160 electrically conductive ocean beneath the ice. 138 00:03:59,160 --> 00:04:00,000 Oh, wow. 139 00:04:00,000 --> 00:04:01,320 Influencing the magnetic field. 140 00:04:01,320 --> 00:04:03,640 So the ocean is messing with the magnetic field. 141 00:04:03,640 --> 00:04:06,800 It's like the ocean is tugging on the magnetic field lines. 142 00:04:06,800 --> 00:04:07,640 Intruding. 143 00:04:07,640 --> 00:04:09,240 Making the auroras dance. 144 00:04:09,240 --> 00:04:10,840 So we have a giant moon, 145 00:04:10,840 --> 00:04:13,320 likely with a vast hidden ocean 146 00:04:13,320 --> 00:04:15,080 beneath a thick layer of ice. 147 00:04:15,080 --> 00:04:15,920 Right. 148 00:04:15,920 --> 00:04:18,320 And its own magnetic field interacting with Jupiter's 149 00:04:18,320 --> 00:04:20,040 in this incredible cosmic ballet. 150 00:04:20,040 --> 00:04:21,000 Exactly. 151 00:04:21,000 --> 00:04:23,600 It really does make you rethink what a moon can be. 152 00:04:23,600 --> 00:04:24,440 Absolutely. 153 00:04:24,440 --> 00:04:26,960 But what about Ganymede's surface? 154 00:04:26,960 --> 00:04:27,800 Yeah. 155 00:04:27,800 --> 00:04:29,920 What can we see from the outside looking in? 156 00:04:29,920 --> 00:04:31,440 The surface is fascinating. 157 00:04:31,440 --> 00:04:32,280 Okay. 158 00:04:32,280 --> 00:04:35,600 A tapestry of ancient and more recent features. 159 00:04:35,600 --> 00:04:39,040 There are two main types of terrain on Ganymede. 160 00:04:39,040 --> 00:04:39,880 Okay. 161 00:04:39,880 --> 00:04:41,720 You have these bright, grooved terrains, 162 00:04:41,720 --> 00:04:44,440 almost like giant scratch marks on the surface. 163 00:04:44,440 --> 00:04:45,260 I see. 164 00:04:45,260 --> 00:04:46,920 These areas are relatively young. 165 00:04:46,920 --> 00:04:47,760 Okay. 166 00:04:47,760 --> 00:04:50,800 They appear to have been formed by tectonic activity. 167 00:04:50,800 --> 00:04:52,240 So like the surface is moving around? 168 00:04:52,240 --> 00:04:54,200 The ice stretching and pulling apart. 169 00:04:54,200 --> 00:04:55,040 Ah. 170 00:04:55,040 --> 00:04:58,400 Then you have the darker, more heavily cratered regions. 171 00:04:58,400 --> 00:04:59,240 Okay. 172 00:04:59,240 --> 00:05:03,200 Ancient landscapes scarred by billions of years of impacts 173 00:05:03,200 --> 00:05:05,240 from asteroids and comets. 174 00:05:05,240 --> 00:05:07,800 It sounds like a world caught between these two forces. 175 00:05:07,800 --> 00:05:08,640 Yeah. 176 00:05:08,640 --> 00:05:10,960 The dynamism of internal processes shaping the surface. 177 00:05:10,960 --> 00:05:11,800 Right. 178 00:05:11,800 --> 00:05:14,360 And the constant bombardment from space. 179 00:05:14,360 --> 00:05:17,240 It's almost like looking at a snapshot 180 00:05:17,240 --> 00:05:18,760 of Ganymede's entire history. 181 00:05:18,760 --> 00:05:19,600 Yeah. 182 00:05:19,600 --> 00:05:21,000 Frozen in its surface features. 183 00:05:21,000 --> 00:05:22,600 That's a beautiful way to put it. 184 00:05:22,600 --> 00:05:23,440 Thanks. 185 00:05:23,440 --> 00:05:26,120 Those contrasting landscapes provide a glimpse 186 00:05:26,120 --> 00:05:29,320 into Ganymede's long and complex evolution. 187 00:05:29,320 --> 00:05:30,160 Wow. 188 00:05:30,160 --> 00:05:31,760 And that's just the beginning. 189 00:05:31,760 --> 00:05:32,600 For real. 190 00:05:32,600 --> 00:05:35,160 What lies beneath those icy plains. 191 00:05:35,160 --> 00:05:36,000 Yeah. 192 00:05:36,000 --> 00:05:37,480 Let's delve into Ganymede's interior 193 00:05:37,480 --> 00:05:39,120 to see what secrets it holds. 194 00:05:39,120 --> 00:05:39,960 Lead the way. 195 00:05:39,960 --> 00:05:40,800 Okay. 196 00:05:40,800 --> 00:05:42,600 I'm ready for the next layer of this cosmic onion. 197 00:05:42,600 --> 00:05:43,440 All right. 198 00:05:43,440 --> 00:05:46,480 Beneath those icy plains, Ganymede holds a secret 199 00:05:46,480 --> 00:05:49,600 that has tantalized scientists for decades. 200 00:05:49,600 --> 00:05:50,440 Oh really? 201 00:05:50,440 --> 00:05:53,360 The possibility of a vast hidden ocean. 202 00:05:54,240 --> 00:05:56,880 Imagine an ocean perhaps miles deep 203 00:05:56,880 --> 00:05:59,040 tucked away beneath the shell of ice. 204 00:05:59,040 --> 00:05:59,880 That's wild. 205 00:05:59,880 --> 00:06:01,800 A world untouched by sunlight 206 00:06:01,800 --> 00:06:04,000 yet potentially teeming with life. 207 00:06:04,000 --> 00:06:05,880 It's like something straight out of a science fiction novel. 208 00:06:05,880 --> 00:06:06,760 I know, right? 209 00:06:06,760 --> 00:06:08,400 But what makes this hidden ocean 210 00:06:08,400 --> 00:06:10,520 such a compelling place to search for life? 211 00:06:10,520 --> 00:06:11,360 Well. 212 00:06:11,360 --> 00:06:12,320 What are the ingredients that make it 213 00:06:12,320 --> 00:06:15,160 a possible cradle for alien ecosystems? 214 00:06:15,160 --> 00:06:17,120 First and foremost, you need water. 215 00:06:17,120 --> 00:06:17,960 Of course. 216 00:06:17,960 --> 00:06:18,800 Lots of it. 217 00:06:18,800 --> 00:06:19,640 Yeah. 218 00:06:19,640 --> 00:06:21,880 And Ganymede seems to have that in spades. 219 00:06:21,880 --> 00:06:24,320 This ocean isn't just a thin layer. 220 00:06:24,320 --> 00:06:25,680 So like a real ocean. 221 00:06:25,680 --> 00:06:26,960 It could be more extensive 222 00:06:26,960 --> 00:06:29,040 than all the oceans on earth combined. 223 00:06:29,040 --> 00:06:30,480 Wow, that's a lot of water. 224 00:06:30,480 --> 00:06:32,200 But water alone isn't enough. 225 00:06:32,200 --> 00:06:33,040 Okay. 226 00:06:33,040 --> 00:06:36,200 You need the right chemical building blocks for life. 227 00:06:36,200 --> 00:06:37,040 Like what? 228 00:06:37,040 --> 00:06:40,120 Things like carbon, hydrogen, nitrogen, and oxygen. 229 00:06:40,120 --> 00:06:42,320 So where would those building blocks come from? 230 00:06:42,320 --> 00:06:43,160 Right. 231 00:06:43,160 --> 00:06:44,080 Is there a way for them to get 232 00:06:44,080 --> 00:06:47,920 into this hidden ocean if it's trapped beneath all that ice? 233 00:06:47,920 --> 00:06:50,840 That's where Ganymede's rocky mantle comes into play. 234 00:06:50,840 --> 00:06:51,840 The mantle. 235 00:06:51,840 --> 00:06:55,240 We believe that Ganymede's ocean is in direct contact 236 00:06:55,240 --> 00:06:56,760 with the rocky layer beneath it. 237 00:06:56,760 --> 00:06:57,600 I see. 238 00:06:57,600 --> 00:07:00,040 This contact is crucial because it allows 239 00:07:00,040 --> 00:07:02,040 for the exchange of minerals and chemicals 240 00:07:02,040 --> 00:07:03,640 between the rock and the water. 241 00:07:03,640 --> 00:07:06,720 So it's like a giant cosmic chemistry experiment 242 00:07:06,720 --> 00:07:08,520 happening deep beneath the ice. 243 00:07:08,520 --> 00:07:09,760 That's a great way to put it. 244 00:07:09,760 --> 00:07:11,120 What kind of chemicals are we talking about 245 00:07:11,120 --> 00:07:13,840 and how would they contribute to the possibility of life? 246 00:07:13,840 --> 00:07:14,920 Think of it like this. 247 00:07:14,920 --> 00:07:15,760 Okay. 248 00:07:15,760 --> 00:07:18,640 The rocky mantle provides the raw ingredients, 249 00:07:18,640 --> 00:07:21,320 the basic elements needed for life, 250 00:07:21,320 --> 00:07:23,880 and the water acts as a solvent. 251 00:07:23,880 --> 00:07:24,720 Okay. 252 00:07:24,720 --> 00:07:27,280 A medium where those elements can mix and interact. 253 00:07:27,280 --> 00:07:28,120 Right. 254 00:07:28,120 --> 00:07:29,840 Potentially forming more complex molecules 255 00:07:29,840 --> 00:07:30,680 like amino acids. 256 00:07:30,680 --> 00:07:31,520 The sun presents. 257 00:07:31,520 --> 00:07:32,840 The building blocks of proteins. 258 00:07:32,840 --> 00:07:35,720 So we have the water, the building blocks, 259 00:07:35,720 --> 00:07:38,280 but Ganymede is still an incredibly harsh environment. 260 00:07:38,280 --> 00:07:39,120 Right. 261 00:07:39,120 --> 00:07:42,160 It's far from the sun, incredibly cold, 262 00:07:42,160 --> 00:07:45,240 and bombarded by radiation from Jupiter. 263 00:07:45,240 --> 00:07:47,560 How could anything possibly survive down there? 264 00:07:47,560 --> 00:07:48,400 You're right. 265 00:07:48,400 --> 00:07:50,400 It's a challenging environment to say the least. 266 00:07:50,400 --> 00:07:51,240 For sure. 267 00:07:51,240 --> 00:07:52,680 But Ganymede has a secret weapon. 268 00:07:52,680 --> 00:07:53,520 What's that? 269 00:07:53,520 --> 00:07:54,520 It's magnetic field. 270 00:07:54,520 --> 00:07:55,360 Oh yeah. 271 00:07:55,360 --> 00:07:57,360 Remember that protective bubble we talked about? 272 00:07:57,360 --> 00:07:58,200 Yeah. 273 00:07:58,200 --> 00:08:00,000 That magnetic field shields the moon 274 00:08:00,000 --> 00:08:02,680 from much of Jupiter's harsh radiation. 275 00:08:02,680 --> 00:08:03,520 Interesting. 276 00:08:03,520 --> 00:08:06,640 Creating a more protected zone within the subsurface ocean. 277 00:08:06,640 --> 00:08:09,640 So the magnetic field acts like a cosmic umbrella. 278 00:08:09,640 --> 00:08:10,480 Exactly. 279 00:08:10,480 --> 00:08:12,960 Shielding potential life from the worst 280 00:08:12,960 --> 00:08:14,760 of Jupiter's radiation storms. 281 00:08:14,760 --> 00:08:17,840 And while it's still incredibly cold, 282 00:08:17,840 --> 00:08:22,080 the tidal forces from Jupiter, those gravitational tugs 283 00:08:22,080 --> 00:08:24,440 that stretch and squeeze Ganymede's interior, 284 00:08:24,440 --> 00:08:25,520 generate heat. 285 00:08:25,520 --> 00:08:26,360 Heat. 286 00:08:26,360 --> 00:08:29,080 This heat, combined with the heat from radioactive decay 287 00:08:29,080 --> 00:08:31,640 within Ganymede's core and mantle, 288 00:08:31,640 --> 00:08:34,240 could keep the ocean liquid. 289 00:08:34,240 --> 00:08:35,960 So there could be liquid water down there. 290 00:08:35,960 --> 00:08:36,960 It's possible. 291 00:08:36,960 --> 00:08:37,920 Wow. 292 00:08:37,920 --> 00:08:41,240 It's incredible to think that even in this cold, distant 293 00:08:41,240 --> 00:08:45,160 world, there could be a warm, habitable oasis hidden 294 00:08:45,160 --> 00:08:46,240 beneath the ice. 295 00:08:46,240 --> 00:08:49,640 It's one of the things that makes Ganymede so fascinating. 296 00:08:49,640 --> 00:08:52,160 But how do we go from speculation to confirmation? 297 00:08:52,160 --> 00:08:52,880 Yeah. 298 00:08:52,880 --> 00:08:55,920 How do we actually find out if there's life on Ganymede? 299 00:08:55,920 --> 00:08:57,760 That's the million dollar question, isn't it? 300 00:08:57,760 --> 00:08:58,600 I guess so. 301 00:08:58,600 --> 00:09:02,120 To get definitive proof, we need to send spacecraft 302 00:09:02,120 --> 00:09:05,080 that can study Ganymede up close and personal. 303 00:09:05,080 --> 00:09:05,840 OK. 304 00:09:05,840 --> 00:09:08,080 We've already had some tantalizing glimpses 305 00:09:08,080 --> 00:09:10,320 from missions like Voyager and Galileo. 306 00:09:10,320 --> 00:09:12,880 Those missions gave us those incredible images 307 00:09:12,880 --> 00:09:14,000 of Ganymede's surface. 308 00:09:14,000 --> 00:09:14,320 Yes. 309 00:09:14,320 --> 00:09:15,960 And helped us confirm the existence 310 00:09:15,960 --> 00:09:17,160 of its magnetic field, right? 311 00:09:17,160 --> 00:09:18,160 Exactly. 312 00:09:18,160 --> 00:09:21,440 But those missions were just flybys, quick snapshots. 313 00:09:21,440 --> 00:09:24,880 To truly understand Ganymede's potential for life, 314 00:09:24,880 --> 00:09:26,760 we need a dedicated mission. 315 00:09:26,760 --> 00:09:28,400 Like a mission just to Ganymede. 316 00:09:28,400 --> 00:09:30,200 Something that can orbit the moon, 317 00:09:30,200 --> 00:09:33,320 study its ocean in detail, and search 318 00:09:33,320 --> 00:09:35,520 for signs of biological activity. 319 00:09:35,520 --> 00:09:36,200 Wow. 320 00:09:36,200 --> 00:09:37,560 And luckily, there is one. 321 00:09:37,560 --> 00:09:39,720 We have just the mission on the horizon. 322 00:09:39,720 --> 00:09:40,920 You're talking about JE. 323 00:09:40,920 --> 00:09:41,560 Yes. 324 00:09:41,560 --> 00:09:43,720 The Jupiter Icy Moons Explorer. 325 00:09:43,720 --> 00:09:44,480 That's the one. 326 00:09:44,480 --> 00:09:45,960 Set to launch in 2024. 327 00:09:45,960 --> 00:09:48,200 JUCE is going to be a game changer. 328 00:09:48,200 --> 00:09:48,800 How so? 329 00:09:48,800 --> 00:09:51,280 It's specifically designed to explore 330 00:09:51,280 --> 00:09:55,560 the icy moons of Jupiter, with a particular focus on Ganymede, 331 00:09:55,560 --> 00:09:57,360 Europa, and Callisto. 332 00:09:57,360 --> 00:10:01,440 So what kind of tools will JE have in its arsenal 333 00:10:01,440 --> 00:10:03,240 to unlock Ganymede's secrets? 334 00:10:03,240 --> 00:10:04,840 What kind of data will it collect? 335 00:10:04,840 --> 00:10:08,760 JE is equipped with a suite of cutting edge instruments. 336 00:10:08,760 --> 00:10:09,280 OK. 337 00:10:09,280 --> 00:10:11,640 It has radar that can penetrate the ice 338 00:10:11,640 --> 00:10:13,920 and map the subsurface ocean in detail. 339 00:10:13,920 --> 00:10:14,440 Wow. 340 00:10:14,440 --> 00:10:17,160 Giving us a 3D view of its structure and depth. 341 00:10:17,160 --> 00:10:18,640 So we can actually see the ocean. 342 00:10:18,640 --> 00:10:20,520 It has instruments that can analyze 343 00:10:20,520 --> 00:10:23,200 the composition of the ice and search for organic molecules. 344 00:10:23,200 --> 00:10:25,760 And it even has a magnetometer that 345 00:10:25,760 --> 00:10:27,640 can measure the subtle variations 346 00:10:27,640 --> 00:10:29,560 in Ganymede's magnetic field. 347 00:10:29,560 --> 00:10:30,080 OK. 348 00:10:30,080 --> 00:10:32,960 Which could provide more clues about the ocean's salinity 349 00:10:32,960 --> 00:10:33,520 and depth. 350 00:10:33,520 --> 00:10:37,720 It sounds like G-U-C-E will be our eyes and ears on Ganymede. 351 00:10:37,720 --> 00:10:38,200 Yeah. 352 00:10:38,200 --> 00:10:40,640 Giving us an unprecedented look at this hidden world. 353 00:10:40,640 --> 00:10:41,280 Exactly. 354 00:10:41,280 --> 00:10:42,640 Well, let's step back for a moment 355 00:10:42,640 --> 00:10:44,440 and put Ganymede into context. 356 00:10:44,440 --> 00:10:44,920 All right. 357 00:10:44,920 --> 00:10:48,360 We keep hearing about other intriguing Jovian moons, 358 00:10:48,360 --> 00:10:50,200 like Europa and Callisto. 359 00:10:50,200 --> 00:10:51,200 Right? 360 00:10:51,200 --> 00:10:54,360 How does Ganymede compare to its cosmic siblings? 361 00:10:54,360 --> 00:10:55,920 That's a great question. 362 00:10:55,920 --> 00:10:56,520 Thanks. 363 00:10:56,520 --> 00:11:01,160 All three of these moons, Ganymede, Europa, and Callisto, 364 00:11:01,160 --> 00:11:03,800 are thought to have subsurface oceans. 365 00:11:03,800 --> 00:11:05,000 So they all have oceans. 366 00:11:05,000 --> 00:11:07,040 They're like a family of ocean worlds. 367 00:11:07,040 --> 00:11:07,560 That's cool. 368 00:11:07,560 --> 00:11:09,400 Each with its own unique characteristics 369 00:11:09,400 --> 00:11:11,200 and potential for life. 370 00:11:11,200 --> 00:11:14,160 Europa, for example, is slightly smaller than Ganymede. 371 00:11:14,160 --> 00:11:14,640 OK. 372 00:11:14,640 --> 00:11:16,600 And has a much thinner ice shell. 373 00:11:16,600 --> 00:11:17,240 Interesting. 374 00:11:17,240 --> 00:11:19,520 Some scientists believe that this thinner ice 375 00:11:19,520 --> 00:11:22,960 shell could make Europa even more habitable than Ganymede. 376 00:11:22,960 --> 00:11:23,480 Really? 377 00:11:23,480 --> 00:11:23,980 Yeah. 378 00:11:23,980 --> 00:11:25,720 So Europa might be even more promising 379 00:11:25,720 --> 00:11:27,240 in the search for life. 380 00:11:27,240 --> 00:11:28,160 It's possible. 381 00:11:28,160 --> 00:11:29,120 Why is that? 382 00:11:29,120 --> 00:11:31,000 Well, a thinner ice shell means that there's 383 00:11:31,000 --> 00:11:33,600 potentially more interaction between the ocean 384 00:11:33,600 --> 00:11:34,360 and the surface. 385 00:11:34,360 --> 00:11:34,960 I see. 386 00:11:34,960 --> 00:11:37,120 It also means that it might be easier for us 387 00:11:37,120 --> 00:11:40,800 to send probes or even landers to Europa's ocean 388 00:11:40,800 --> 00:11:41,520 in the future. 389 00:11:41,520 --> 00:11:42,120 Oh, wow. 390 00:11:42,120 --> 00:11:45,680 Plus, Europa has a higher tidal heating rate than Ganymede. 391 00:11:45,680 --> 00:11:46,200 OK. 392 00:11:46,200 --> 00:11:50,280 Meaning its interior is likely more geologically active. 393 00:11:50,280 --> 00:11:52,800 Imagine volcanoes erupting on the ocean floor. 394 00:11:52,800 --> 00:11:53,520 Whoa. 395 00:11:53,520 --> 00:11:57,120 Hydrothermal vents spearing out hot mineral-rich water. 396 00:11:57,120 --> 00:11:58,040 That's amazing. 397 00:11:58,040 --> 00:12:01,280 It could be a very dynamic and potentially life-friendly 398 00:12:01,280 --> 00:12:02,120 environment. 399 00:12:02,120 --> 00:12:04,160 It sounds like Europa is giving Ganymede 400 00:12:04,160 --> 00:12:07,800 a run for its money in the most likely to harbor life category. 401 00:12:07,800 --> 00:12:08,760 What about Callisto? 402 00:12:08,760 --> 00:12:10,320 How does it fit into this picture? 403 00:12:10,320 --> 00:12:13,120 Callisto is the outlier in the family. 404 00:12:13,120 --> 00:12:15,840 It's the most heavily cratered object in our solar system. 405 00:12:15,840 --> 00:12:16,400 Seriously? 406 00:12:16,400 --> 00:12:18,560 A testament to its long and violent history. 407 00:12:18,560 --> 00:12:19,040 Wow. 408 00:12:19,040 --> 00:12:21,680 It's thought to be the oldest of the Galilean moons. 409 00:12:21,680 --> 00:12:22,180 OK. 410 00:12:22,180 --> 00:12:25,080 And has a more ancient, less active surface. 411 00:12:25,080 --> 00:12:26,440 So not as much going on. 412 00:12:26,440 --> 00:12:30,480 While it likely also harbors a subsurface ocean, 413 00:12:30,480 --> 00:12:33,440 it's thought to be deeper and potentially less hospitable 414 00:12:33,440 --> 00:12:36,200 than those of Ganymede or Europa. 415 00:12:36,200 --> 00:12:38,760 So each of these moons has its own story 416 00:12:38,760 --> 00:12:42,200 to tell, its own unique set of characteristics 417 00:12:42,200 --> 00:12:45,400 that make it a fascinating target in the search for life 418 00:12:45,400 --> 00:12:46,200 beyond Earth. 419 00:12:46,200 --> 00:12:47,160 Exactly. 420 00:12:47,160 --> 00:12:50,800 It's amazing to think that right here in our own solar system, 421 00:12:50,800 --> 00:12:53,520 we have this incredible diversity of worlds. 422 00:12:53,520 --> 00:12:54,520 It really is. 423 00:12:54,520 --> 00:12:57,480 Each with the potential to rewrite our understanding 424 00:12:57,480 --> 00:12:59,560 of life in the universe. 425 00:12:59,560 --> 00:13:01,360 It really is mind blowing, isn't it? 426 00:13:01,360 --> 00:13:01,920 Yeah. 427 00:13:01,920 --> 00:13:04,080 And we've only just scratched the surface. 428 00:13:04,080 --> 00:13:05,320 So much more to learn. 429 00:13:05,320 --> 00:13:08,640 With missions like Joe Icy on the horizon, 430 00:13:08,640 --> 00:13:11,040 we're on the verge of a new era of exploration. 431 00:13:11,040 --> 00:13:11,720 It's exciting. 432 00:13:11,720 --> 00:13:15,360 One that could reveal the secrets of these ocean worlds 433 00:13:15,360 --> 00:13:17,800 and perhaps even answer that age-old question. 434 00:13:17,800 --> 00:13:18,320 What's that? 435 00:13:18,320 --> 00:13:19,120 Are we alone? 436 00:13:19,120 --> 00:13:20,440 The big question. 437 00:13:20,440 --> 00:13:22,640 But even with all that we've learned, 438 00:13:22,640 --> 00:13:25,600 there are still so many mysteries surrounding Ganymede. 439 00:13:25,600 --> 00:13:28,120 So many unanswered questions that keep 440 00:13:28,120 --> 00:13:30,000 us reaching for the stars. 441 00:13:30,000 --> 00:13:32,160 You certainly sparked my curiosity. 442 00:13:32,160 --> 00:13:33,360 That's good to hear. 443 00:13:33,360 --> 00:13:35,760 What are some of those lingering mysteries? 444 00:13:35,760 --> 00:13:37,960 What are the questions that keep you up at night? 445 00:13:37,960 --> 00:13:40,920 So we have these three fascinating moons, 446 00:13:40,920 --> 00:13:45,720 Ganymede, Europa, and Callista, each with its own unique set 447 00:13:45,720 --> 00:13:48,880 of characteristics and potential for harboring life. 448 00:13:48,880 --> 00:13:49,480 Incredible. 449 00:13:49,480 --> 00:13:52,280 It's like a cosmic choose your own adventure story. 450 00:13:52,280 --> 00:13:52,800 Yeah. 451 00:13:52,800 --> 00:13:55,440 But instead of choosing different paths, 452 00:13:55,440 --> 00:13:56,720 we get to explore them all. 453 00:13:56,720 --> 00:13:57,360 Exactly. 454 00:13:57,360 --> 00:14:00,840 And that's what makes exploring the Jovian system so captivating. 455 00:14:00,840 --> 00:14:01,600 Absolutely. 456 00:14:01,600 --> 00:14:04,080 It's like having a whole collection of alien worlds 457 00:14:04,080 --> 00:14:05,720 right in our cosmic backyard. 458 00:14:05,720 --> 00:14:07,240 Right here in our solar system. 459 00:14:07,240 --> 00:14:09,840 But even with all that we've discovered, 460 00:14:09,840 --> 00:14:13,160 there are still so many unanswered questions 461 00:14:13,160 --> 00:14:14,400 about Ganymede. 462 00:14:14,400 --> 00:14:17,000 Oh, for sure. 463 00:14:17,000 --> 00:14:18,800 Give us some of those lingering mysteries 464 00:14:18,800 --> 00:14:21,120 that keep scientists on the edge of their seats. 465 00:14:21,120 --> 00:14:22,600 Well, one of the biggest mysteries 466 00:14:22,600 --> 00:14:25,960 is the exact composition of Ganymede's ocean. 467 00:14:25,960 --> 00:14:28,040 We know it's likely salty. 468 00:14:28,040 --> 00:14:29,680 But how salty? 469 00:14:29,680 --> 00:14:32,280 Does it contain the right mix of chemicals and elements 470 00:14:32,280 --> 00:14:33,440 to support life? 471 00:14:33,440 --> 00:14:34,200 Yeah. 472 00:14:34,200 --> 00:14:35,640 Could it actually have life? 473 00:14:35,640 --> 00:14:38,880 And what about the dynamics of its core? 474 00:14:38,880 --> 00:14:41,400 What exactly drives that dynamo effect 475 00:14:41,400 --> 00:14:43,920 that generates its magnetic field? 476 00:14:43,920 --> 00:14:47,160 How does it interact with Jupiter's massive magnetic 477 00:14:47,160 --> 00:14:47,600 field? 478 00:14:47,600 --> 00:14:48,520 Yeah, that's a big one. 479 00:14:48,520 --> 00:14:49,800 These are all questions that we're still 480 00:14:49,800 --> 00:14:50,880 trying to piece together. 481 00:14:50,880 --> 00:14:52,720 And what about Ganymede's surface? 482 00:14:52,720 --> 00:14:53,240 Yeah. 483 00:14:53,240 --> 00:14:55,920 We've seen evidence of tectonic activity and impacts. 484 00:14:55,920 --> 00:14:56,600 Right. 485 00:14:56,600 --> 00:14:59,080 But how active is its surface today? 486 00:14:59,080 --> 00:15:00,040 That's a great question. 487 00:15:00,040 --> 00:15:02,480 Are there still processes shaping and reshaping 488 00:15:02,480 --> 00:15:03,440 its landscape? 489 00:15:03,440 --> 00:15:05,560 That's another area where we need more data. 490 00:15:05,560 --> 00:15:06,060 OK. 491 00:15:06,060 --> 00:15:08,120 We've seen hints of cryovolcanism. 492 00:15:08,120 --> 00:15:08,960 Cryovolcanism. 493 00:15:08,960 --> 00:15:12,480 Ice volcanoes that erupt with water and other volatiles 494 00:15:12,480 --> 00:15:14,160 instead of molten rock. 495 00:15:14,160 --> 00:15:14,960 Oh, wow. 496 00:15:14,960 --> 00:15:15,880 Ice volcanoes. 497 00:15:15,880 --> 00:15:18,360 But how frequent are these eruptions? 498 00:15:18,360 --> 00:15:21,240 And what role do they play in shaping Ganymede's surface 499 00:15:21,240 --> 00:15:23,640 and potentially replenishing its ocean? 500 00:15:23,640 --> 00:15:25,120 So they could be feeding the ocean. 501 00:15:25,120 --> 00:15:26,920 There's still so much we don't know. 502 00:15:26,920 --> 00:15:28,920 It seems like every answer we find 503 00:15:28,920 --> 00:15:30,360 just leads to more questions. 504 00:15:30,360 --> 00:15:31,160 I know. 505 00:15:31,160 --> 00:15:32,400 It's amazing, isn't it? 506 00:15:32,400 --> 00:15:34,800 It's like peeling back the layers of a cosmic onion. 507 00:15:34,800 --> 00:15:35,300 Yeah. 508 00:15:35,300 --> 00:15:37,200 Only to find another onion underneath. 509 00:15:37,200 --> 00:15:39,120 That's the beauty of science, isn't it? 510 00:15:39,120 --> 00:15:40,000 I guess so. 511 00:15:40,000 --> 00:15:42,280 It's a constant process of discovery. 512 00:15:42,280 --> 00:15:42,800 Yeah. 513 00:15:42,800 --> 00:15:44,580 Of pushing the boundaries of what we know 514 00:15:44,580 --> 00:15:46,360 and venturing into the unknown. 515 00:15:46,360 --> 00:15:47,400 Always learning. 516 00:15:47,400 --> 00:15:50,360 And Ganymede is a prime example of that. 517 00:15:50,360 --> 00:15:54,320 It's a world that challenges our assumptions about what 518 00:15:54,320 --> 00:15:57,320 a moon can be and forces us to expand 519 00:15:57,320 --> 00:15:59,040 our understanding of the universe 520 00:15:59,040 --> 00:16:02,160 and the potential for life beyond Earth. 521 00:16:02,160 --> 00:16:04,200 Ganymede is a world of contrasts. 522 00:16:04,200 --> 00:16:04,960 It really is. 523 00:16:04,960 --> 00:16:06,040 Ice and rock. 524 00:16:06,040 --> 00:16:06,840 Yes. 525 00:16:06,840 --> 00:16:10,640 Ancient craters and youthful grooves, a hidden ocean, 526 00:16:10,640 --> 00:16:12,760 and a swirling magnetic field. 527 00:16:12,760 --> 00:16:14,100 It's a fascinating place. 528 00:16:14,100 --> 00:16:16,160 It's a moon that acts more like a planet. 529 00:16:16,160 --> 00:16:16,720 Right. 530 00:16:16,720 --> 00:16:18,840 A world that holds the keys to unlocking 531 00:16:18,840 --> 00:16:21,000 some of the biggest mysteries in our solar system. 532 00:16:21,000 --> 00:16:21,800 Absolutely. 533 00:16:21,800 --> 00:16:24,400 By studying Ganymede, we're not just learning 534 00:16:24,400 --> 00:16:26,280 about a single celestial body. 535 00:16:26,280 --> 00:16:27,080 No, we're not. 536 00:16:27,080 --> 00:16:30,120 We're gaining insights into the formation and evolution 537 00:16:30,120 --> 00:16:31,560 of planetary systems. 538 00:16:31,560 --> 00:16:32,200 That's right. 539 00:16:32,200 --> 00:16:34,000 The dynamics of icy worlds. 540 00:16:34,000 --> 00:16:34,500 Uh-huh. 541 00:16:34,500 --> 00:16:36,400 And the potential for life in the universe. 542 00:16:36,400 --> 00:16:39,280 It's a journey of exploration that's just beginning. 543 00:16:39,280 --> 00:16:39,800 Yeah. 544 00:16:39,800 --> 00:16:42,320 And the discoveries we make along the way 545 00:16:42,320 --> 00:16:44,580 are sure to rewrite our understanding 546 00:16:44,580 --> 00:16:46,480 of our place in the cosmos. 547 00:16:46,480 --> 00:16:48,440 Ganymede isn't just a moon. 548 00:16:48,440 --> 00:16:48,940 Right. 549 00:16:48,940 --> 00:16:52,240 It's a world of its own, challenging our understanding 550 00:16:52,240 --> 00:16:53,840 of what a moon can be. 551 00:16:53,840 --> 00:16:55,160 It really makes you think. 552 00:16:55,160 --> 00:16:57,920 As we continue to explore its mysteries, 553 00:16:57,920 --> 00:16:59,780 we're not only unraveling the secrets 554 00:16:59,780 --> 00:17:01,360 of this fascinating world. 555 00:17:01,360 --> 00:17:02,000 Absolutely. 556 00:17:02,000 --> 00:17:05,760 But also gaining insights into the potential for life 557 00:17:05,760 --> 00:17:08,260 beyond Earth and the vast diversity 558 00:17:08,260 --> 00:17:09,440 of our cosmic neighborhood. 559 00:17:09,440 --> 00:17:12,280 It's an incredible time to be studying these worlds. 560 00:17:12,280 --> 00:17:16,000 If life could exist on Ganymede in its hidden ocean, 561 00:17:16,000 --> 00:17:17,160 what might it look like? 562 00:17:17,160 --> 00:17:19,280 It's a question that sparks the imagination. 563 00:17:19,280 --> 00:17:22,320 How would it have adapted to such an extreme environment? 564 00:17:22,320 --> 00:17:23,080 Who knows? 565 00:17:23,080 --> 00:17:24,680 But it's exciting to think about. 566 00:17:24,680 --> 00:17:26,360 Don't forget to follow and subscribe 567 00:17:26,360 --> 00:17:30,240 to Cosmos in a Pod for more deep dives into the universe. 568 00:17:30,240 --> 00:17:32,920 And check out our YouTube channel for stunning visuals 569 00:17:32,920 --> 00:17:47,120 and more in-depth explorations.