1 00:00:00,000 --> 00:00:02,680 Our solar system, you know, it's home, right? 2 00:00:02,680 --> 00:00:06,380 It's familiar, but it's also just this tiny little speck 3 00:00:06,380 --> 00:00:08,680 in this huge cosmic ocean. 4 00:00:08,680 --> 00:00:09,840 What's out there? 5 00:00:09,840 --> 00:00:13,340 Beyond, you know, the usual planets in the sun. 6 00:00:13,340 --> 00:00:15,540 What mysteries and wonders are hiding out there 7 00:00:15,540 --> 00:00:17,020 in the darkness? 8 00:00:17,020 --> 00:00:20,120 Welcome to Cosmos in a Pod, Space, and Astronomy series. 9 00:00:20,120 --> 00:00:22,420 Today, we're taking a deep dive into the universe 10 00:00:22,420 --> 00:00:24,120 outside our solar system. 11 00:00:24,120 --> 00:00:26,060 And you sent us some amazing stuff, 12 00:00:26,060 --> 00:00:27,820 so let's explore it together. 13 00:00:27,820 --> 00:00:30,260 You know, it's amazing, even the space just outside 14 00:00:30,260 --> 00:00:33,200 our solar system, you know, the space we think of as empty, 15 00:00:33,200 --> 00:00:35,040 well, it's actually buzzing with activity. 16 00:00:35,040 --> 00:00:36,000 Oh, OK. 17 00:00:36,000 --> 00:00:38,560 So it's not just, like, completely isolated out there, 18 00:00:38,560 --> 00:00:39,280 then. 19 00:00:39,280 --> 00:00:41,000 What kind of buzz are we talking about here? 20 00:00:41,000 --> 00:00:42,680 Well, within just 15 light years, 21 00:00:42,680 --> 00:00:45,120 which is actually pretty close when you think about space, 22 00:00:45,120 --> 00:00:46,720 there are about 50 star systems. 23 00:00:46,720 --> 00:00:47,600 50? 24 00:00:47,600 --> 00:00:48,560 Whoa. 25 00:00:48,560 --> 00:00:51,160 That's a lot more neighbors than I would have thought. 26 00:00:51,160 --> 00:00:53,360 So what are these star systems like? 27 00:00:53,360 --> 00:00:55,080 I mean, are they kind of similar to ours, 28 00:00:55,080 --> 00:00:56,040 or are we talking about something 29 00:00:56,040 --> 00:00:57,200 completely different? 30 00:00:57,200 --> 00:00:58,560 Oh, there's a huge variety. 31 00:00:58,560 --> 00:01:01,560 Some are just single stars, like our sun, 32 00:01:01,560 --> 00:01:04,680 but others are binary systems with two stars orbiting 33 00:01:04,680 --> 00:01:05,480 each other. 34 00:01:05,480 --> 00:01:07,400 There's even some with multiple stars. 35 00:01:07,400 --> 00:01:09,720 And a lot of these systems, they have their own planets, 36 00:01:09,720 --> 00:01:10,920 just like ours. 37 00:01:10,920 --> 00:01:13,960 Some even have these things called protoplanetary disks. 38 00:01:13,960 --> 00:01:14,520 OK, hold on. 39 00:01:14,520 --> 00:01:17,120 You lost me with protoplanetary disks. 40 00:01:17,120 --> 00:01:17,800 What are those? 41 00:01:17,800 --> 00:01:19,400 Well, picture this. 42 00:01:19,400 --> 00:01:22,280 It's this swirling cloud of gas and dust, 43 00:01:22,280 --> 00:01:25,220 kind of like a cosmic pancake. 44 00:01:25,220 --> 00:01:28,160 And in these disks, that's where brand new planets are actually 45 00:01:28,160 --> 00:01:28,880 forming. 46 00:01:28,880 --> 00:01:31,320 It's like watching a solar system be born. 47 00:01:31,320 --> 00:01:32,360 Wow. 48 00:01:32,360 --> 00:01:33,000 That's amazing. 49 00:01:33,000 --> 00:01:35,080 So new worlds are coming into existence right now, 50 00:01:35,080 --> 00:01:37,720 like just a cosmic stone's throwaway. 51 00:01:37,720 --> 00:01:39,880 So are there any of these star systems 52 00:01:39,880 --> 00:01:41,540 that are particularly interesting 53 00:01:41,540 --> 00:01:42,320 in this neighborhood? 54 00:01:42,320 --> 00:01:43,000 Oh, tons. 55 00:01:43,000 --> 00:01:45,160 Let's start with one that's actually headed our way. 56 00:01:45,160 --> 00:01:46,280 It's called Barnard Star. 57 00:01:46,280 --> 00:01:48,720 It's a red dwarf just six light years away. 58 00:01:48,720 --> 00:01:49,920 And get this. 59 00:01:49,920 --> 00:01:53,160 It's zooming towards us at over 100 kilometers per second. 60 00:01:53,160 --> 00:01:53,760 Hold on. 61 00:01:53,760 --> 00:01:54,040 Hold on. 62 00:01:54,040 --> 00:01:54,360 Hold on. 63 00:01:54,360 --> 00:01:55,240 It's coming towards us. 64 00:01:55,240 --> 00:01:56,600 Should we be worried about that? 65 00:01:56,600 --> 00:01:58,520 No, no, not at all. 66 00:01:58,520 --> 00:02:00,720 It'll become our closest stellar neighbor, 67 00:02:00,720 --> 00:02:02,720 but not for about 10,000 years. 68 00:02:02,720 --> 00:02:05,000 And well, 10,000 years might sound soon, 69 00:02:05,000 --> 00:02:08,080 but that's like forever in space terms. 70 00:02:08,080 --> 00:02:09,800 What makes Barnard Star so interesting, 71 00:02:09,800 --> 00:02:13,520 though, is that it has a planet, GJ 699b. 72 00:02:13,520 --> 00:02:14,760 It's a super earth. 73 00:02:14,760 --> 00:02:17,320 So that means it's much bigger and heavier than our earth. 74 00:02:17,320 --> 00:02:17,920 Super earth. 75 00:02:17,920 --> 00:02:19,560 That sounds impressive. 76 00:02:19,560 --> 00:02:21,080 But is it anything like our planet? 77 00:02:21,080 --> 00:02:23,280 Could there be life there? 78 00:02:23,280 --> 00:02:25,240 Well, that's where things get really interesting. 79 00:02:25,240 --> 00:02:28,440 GJ 699b is a lot colder than Earth. 80 00:02:28,440 --> 00:02:31,600 The surface temperature is around a negative 168 Celsius. 81 00:02:31,600 --> 00:02:33,440 That's way colder than Antarctica. 82 00:02:33,440 --> 00:02:36,720 But there's a chance it might have a subsurface ocean heated 83 00:02:36,720 --> 00:02:38,720 by tidal forces from its star. 84 00:02:38,720 --> 00:02:40,160 Whoa. 85 00:02:40,160 --> 00:02:42,000 A hidden ocean under a frozen surface. 86 00:02:42,000 --> 00:02:42,520 That's cool. 87 00:02:42,520 --> 00:02:45,960 Imagine life huddled around these geothermal vents 88 00:02:45,960 --> 00:02:48,360 in this secret ocean completely alien to us. 89 00:02:48,360 --> 00:02:48,880 Exactly. 90 00:02:48,880 --> 00:02:51,520 It's a place scientists are definitely keeping an eye on. 91 00:02:51,520 --> 00:02:53,440 But let's move on to a star you can actually 92 00:02:53,440 --> 00:02:54,760 see in the night sky. 93 00:02:54,760 --> 00:02:57,240 Have you heard of Sirius, the dog star? 94 00:02:57,240 --> 00:02:58,200 Oh, yeah. 95 00:02:58,200 --> 00:02:58,680 Sirius. 96 00:02:58,680 --> 00:02:59,760 It's always the brightest one. 97 00:02:59,760 --> 00:03:00,920 What's the deal with that one? 98 00:03:00,920 --> 00:03:03,480 Sirius is kind of famous in the night sky. 99 00:03:03,480 --> 00:03:06,160 It's actually a binary system, meaning it's 100 00:03:06,160 --> 00:03:08,360 two stars orbiting each other. 101 00:03:08,360 --> 00:03:11,560 About 8.6 light years away, Sirius A 102 00:03:11,560 --> 00:03:13,280 is the one we see shining so bright. 103 00:03:13,280 --> 00:03:16,120 It's a blue-white giant, twice the mass of our sun, 104 00:03:16,120 --> 00:03:18,280 and 25 times brighter. 105 00:03:18,280 --> 00:03:21,280 But its partner, Sirius B, is something else. 106 00:03:21,280 --> 00:03:22,880 It's what we call a white dwarf. 107 00:03:22,880 --> 00:03:23,600 OK, wait a minute. 108 00:03:23,600 --> 00:03:25,120 What exactly is a white dwarf? 109 00:03:25,120 --> 00:03:26,680 Think of it like the dying embers 110 00:03:26,680 --> 00:03:29,120 of a star that's used up all its fuel. 111 00:03:29,120 --> 00:03:32,400 Super dense and faint, just this little glowing 112 00:03:32,400 --> 00:03:35,440 leftover piece of what was once a huge star. 113 00:03:35,440 --> 00:03:37,800 The process of Sirius B becoming a white dwarf 114 00:03:37,800 --> 00:03:39,120 was probably pretty wild. 115 00:03:39,120 --> 00:03:40,960 And it might have actually stopped any planets 116 00:03:40,960 --> 00:03:42,280 from forming around it. 117 00:03:42,280 --> 00:03:44,200 So any planets around Sirius B would 118 00:03:44,200 --> 00:03:46,600 have been destroyed during its transformation. 119 00:03:46,600 --> 00:03:47,520 That's pretty dramatic. 120 00:03:47,520 --> 00:03:48,020 It is. 121 00:03:48,020 --> 00:03:50,160 Really shows the crazy power and chaos 122 00:03:50,160 --> 00:03:52,200 that can happen out there in the universe. 123 00:03:52,200 --> 00:03:55,280 But speaking of solar systems, how about one with not one, 124 00:03:55,280 --> 00:03:57,600 not two, but three rocky planets? 125 00:03:57,600 --> 00:03:58,040 Three. 126 00:03:58,040 --> 00:03:58,800 Now you're talking. 127 00:03:58,800 --> 00:04:00,040 Tell me more about this system. 128 00:04:00,040 --> 00:04:01,560 It's called Wolf 1061. 129 00:04:01,560 --> 00:04:04,400 It's a red dwarf system about 14 light years away. 130 00:04:04,400 --> 00:04:07,720 And each of these three planets has its own unique story. 131 00:04:07,720 --> 00:04:09,240 OK, I'm hooked. 132 00:04:09,240 --> 00:04:10,520 What are these planets like? 133 00:04:10,520 --> 00:04:14,200 All right, so the innermost planet, Wolf 1061b, 134 00:04:14,200 --> 00:04:16,480 is tidally locked to its star. 135 00:04:16,480 --> 00:04:17,560 Tidally log, meaning? 136 00:04:17,560 --> 00:04:19,200 It means the same side of the planet 137 00:04:19,200 --> 00:04:22,000 always faces the star, kind of like how we only ever 138 00:04:22,000 --> 00:04:23,280 see one side of the moon. 139 00:04:23,280 --> 00:04:26,440 So one side's constantly baking under the star's heat, 140 00:04:26,440 --> 00:04:27,480 making it super hot. 141 00:04:27,480 --> 00:04:29,920 Probably not a good place to live. 142 00:04:29,920 --> 00:04:32,880 Then there's Wolf 1061, the farthest one out. 143 00:04:32,880 --> 00:04:36,440 It's bigger and much colder, probably an ice giant. 144 00:04:36,440 --> 00:04:38,280 So we got a burning world and a frozen world. 145 00:04:38,280 --> 00:04:39,640 What about the one in the middle? 146 00:04:39,640 --> 00:04:40,920 Ah, that's Wolf 1061c. 147 00:04:40,920 --> 00:04:42,240 And this one's really interesting. 148 00:04:42,240 --> 00:04:45,240 It's a super earth, like the one around Barnard's star. 149 00:04:45,240 --> 00:04:47,520 And it sits right in the habitable zone. 150 00:04:47,520 --> 00:04:50,960 Habitable zone so it could have liquid water, maybe even life. 151 00:04:50,960 --> 00:04:51,960 It's possible. 152 00:04:51,960 --> 00:04:55,040 Wolf 1061c is a prime target for scientists looking 153 00:04:55,040 --> 00:04:56,680 for signs of life beyond Earth. 154 00:04:56,680 --> 00:04:57,560 Wow. 155 00:04:57,560 --> 00:04:59,680 Three completely different planets, 156 00:04:59,680 --> 00:05:01,680 all orbiting the same star. 157 00:05:01,680 --> 00:05:03,400 Makes you wonder how many different kinds 158 00:05:03,400 --> 00:05:05,280 of planetary systems are out there. 159 00:05:05,280 --> 00:05:06,040 For sure. 160 00:05:06,040 --> 00:05:08,440 It shows the huge variety of worlds out there, 161 00:05:08,440 --> 00:05:10,560 each with its own unique story. 162 00:05:10,560 --> 00:05:12,060 But let's switch gears for a second 163 00:05:12,060 --> 00:05:15,240 and talk about a planet that might be even more Earth-like. 164 00:05:15,240 --> 00:05:18,240 It's called Gliese 370b. 165 00:05:18,240 --> 00:05:23,000 OK, Gliese 370b, another super earth in the habitable zone. 166 00:05:23,000 --> 00:05:25,880 Yeah, but this one's just a little bit bigger than Earth 167 00:05:25,880 --> 00:05:27,360 and might have an average temperature 168 00:05:27,360 --> 00:05:29,800 around 25 degrees Celsius. 169 00:05:29,800 --> 00:05:32,280 Think a nice spring day all year round. 170 00:05:32,280 --> 00:05:33,600 Sounds pretty nice. 171 00:05:33,600 --> 00:05:36,320 A temperate world orbiting another star. 172 00:05:36,320 --> 00:05:38,560 I mean, it blows my mind to think about what 173 00:05:38,560 --> 00:05:39,880 that place might look like. 174 00:05:39,880 --> 00:05:42,880 Could there be oceans, mountains, forests? 175 00:05:42,880 --> 00:05:44,080 It's amazing to think about. 176 00:05:44,080 --> 00:05:45,960 Right, OK, now get ready for this. 177 00:05:45,960 --> 00:05:49,560 Imagine a sky with not one sun, but six. 178 00:05:49,560 --> 00:05:50,840 Wait, six suns? 179 00:05:50,840 --> 00:05:51,760 Are you serious? 180 00:05:51,760 --> 00:05:52,980 How does that even work? 181 00:05:52,980 --> 00:05:55,920 It's this complicated dance of gravity and orbits. 182 00:05:55,920 --> 00:05:58,560 The system's called Castor, about 50 light years away. 183 00:05:58,560 --> 00:06:01,220 It's got two pairs of binary stars orbiting each other, 184 00:06:01,220 --> 00:06:03,640 and then another, farther out, pair of red dwarfs 185 00:06:03,640 --> 00:06:04,760 circling the whole thing. 186 00:06:04,760 --> 00:06:06,760 Whoa, my brain is trying to picture that. 187 00:06:06,760 --> 00:06:09,960 A sky with six suns, it'd be like constant daylight. 188 00:06:09,960 --> 00:06:10,840 What about gravity? 189 00:06:10,840 --> 00:06:12,400 Wouldn't a planet in that system get 190 00:06:12,400 --> 00:06:14,240 pulled in six different directions? 191 00:06:14,240 --> 00:06:17,080 Well, no planets have been found in Castor yet. 192 00:06:17,080 --> 00:06:18,960 But it makes you wonder, right? 193 00:06:18,960 --> 00:06:21,620 What would it be like to experience a day, 194 00:06:21,620 --> 00:06:25,880 or I guess no day at all, on a planet with six suns rising 195 00:06:25,880 --> 00:06:27,640 and setting all the time? 196 00:06:27,640 --> 00:06:30,120 It would be like nothing we can imagine. 197 00:06:30,120 --> 00:06:33,520 It really puts our own little solar system in perspective. 198 00:06:33,520 --> 00:06:35,360 But all these systems we've talked about, 199 00:06:35,360 --> 00:06:37,080 they're still pretty close to us, right? 200 00:06:37,080 --> 00:06:39,640 Like, in the grand scheme of the universe. 201 00:06:39,640 --> 00:06:40,280 That's right. 202 00:06:40,280 --> 00:06:42,320 We've been looking at our little corner of the galaxy, 203 00:06:42,320 --> 00:06:43,800 but to really get the big picture, 204 00:06:43,800 --> 00:06:46,440 we've got to zoom out and look at the bigger structures 205 00:06:46,440 --> 00:06:48,120 our solar system's part of. 206 00:06:48,120 --> 00:06:49,400 OK, let's zoom out then. 207 00:06:49,400 --> 00:06:52,080 What's this grand stage our solar system is on? 208 00:06:52,080 --> 00:06:55,000 Well, right now we're moving through what astronomers call 209 00:06:55,000 --> 00:06:56,120 the local bubble. 210 00:06:56,120 --> 00:06:57,360 The local bubble. 211 00:06:57,360 --> 00:06:58,400 Sounds kind of fragile. 212 00:06:58,400 --> 00:06:59,240 What's that exactly? 213 00:06:59,240 --> 00:07:03,880 It's this region of space filled with super thin, scorching hot 214 00:07:03,880 --> 00:07:06,880 gas, so spread out that you wouldn't even feel it. 215 00:07:06,880 --> 00:07:08,600 Think of it like a giant bubble created 216 00:07:08,600 --> 00:07:10,440 by old supernova explosions. 217 00:07:10,440 --> 00:07:13,200 So we're just sailing through a giant bubble of leftover 218 00:07:13,200 --> 00:07:14,080 supernova stuff. 219 00:07:14,080 --> 00:07:14,640 Ah. 220 00:07:14,640 --> 00:07:15,600 That's wild. 221 00:07:15,600 --> 00:07:17,200 What happens when we leave this bubble? 222 00:07:17,200 --> 00:07:20,480 Well, in about 2,000 years, our solar system 223 00:07:20,480 --> 00:07:23,120 will enter a different region called the G Cloud, 224 00:07:23,120 --> 00:07:27,000 another area full of this gas called ionized hydrogen. 225 00:07:27,000 --> 00:07:29,240 So it seems like our solar system is constantly 226 00:07:29,240 --> 00:07:31,480 moving through all these different environments. 227 00:07:31,480 --> 00:07:34,560 Really shows how dynamic and how much a galaxy 228 00:07:34,560 --> 00:07:35,720 is changing all the time. 229 00:07:35,720 --> 00:07:36,840 Exactly. 230 00:07:36,840 --> 00:07:39,400 And speaking of the Milky Way, let's talk about our galactic 231 00:07:39,400 --> 00:07:40,360 home for a minute. 232 00:07:40,360 --> 00:07:45,160 It's a huge spiral galaxy with over 200 billion stars 233 00:07:45,160 --> 00:07:47,120 and probably over a trillion planets. 234 00:07:47,120 --> 00:07:48,360 A trillion planets. 235 00:07:48,360 --> 00:07:49,480 That's insane. 236 00:07:49,480 --> 00:07:51,440 So where do we fit in in all of that? 237 00:07:51,440 --> 00:07:54,200 Well, we're located in one of the Milky Way's spiral arms 238 00:07:54,200 --> 00:07:55,520 called the Orion arm. 239 00:07:55,520 --> 00:07:58,360 But the whole galaxy is filled with amazing structures. 240 00:07:58,360 --> 00:07:58,840 Like what? 241 00:07:58,840 --> 00:08:00,320 Give me the galactic highlights. 242 00:08:00,320 --> 00:08:02,800 Well, there's Barnard's Loop, this massive nebula 243 00:08:02,800 --> 00:08:05,200 shaped like a giant ring, a beautiful sight, 244 00:08:05,200 --> 00:08:08,120 this giant glowing cloud of gas and dust, 245 00:08:08,120 --> 00:08:10,720 all created by powerful supernova explosions. 246 00:08:10,720 --> 00:08:11,920 A supernova remnant. 247 00:08:11,920 --> 00:08:13,800 Now that's something I'd love to see up close. 248 00:08:13,800 --> 00:08:14,560 What else? 249 00:08:14,560 --> 00:08:16,240 Then there's the galactic halo. 250 00:08:16,240 --> 00:08:20,400 It's this huge spherical area around the Milky Way's disk, 251 00:08:20,400 --> 00:08:22,920 home to some of the oldest stars in the galaxy, 252 00:08:22,920 --> 00:08:25,760 stars that were born when the universe was still young. 253 00:08:25,760 --> 00:08:26,800 Ancient stars. 254 00:08:26,800 --> 00:08:30,080 Imagine what they've seen over billions of years. 255 00:08:30,080 --> 00:08:31,320 It's mind boggling. 256 00:08:31,320 --> 00:08:32,520 It really is. 257 00:08:32,520 --> 00:08:35,120 We've gone from looking at our neighbor stars 258 00:08:35,120 --> 00:08:38,200 all the way out to the edge of the galactic halo. 259 00:08:38,200 --> 00:08:39,480 And we've only just started. 260 00:08:39,480 --> 00:08:41,360 There's so much more out there. 261 00:08:41,360 --> 00:08:43,560 I can't wait to see what we find next. 262 00:08:43,560 --> 00:08:45,320 This has been an incredible journey already, 263 00:08:45,320 --> 00:08:48,440 from our closest neighbors to the structure of the Milky Way. 264 00:08:48,440 --> 00:08:49,880 I'm hooked on this deep dive. 265 00:08:49,880 --> 00:08:50,560 Me too. 266 00:08:50,560 --> 00:08:53,320 And it's about to get even more interesting, 267 00:08:53,320 --> 00:08:56,040 ready to jump into the search for life beyond Earth. 268 00:08:56,040 --> 00:08:56,920 Absolutely. 269 00:08:56,920 --> 00:08:58,280 But let's save that for next time. 270 00:08:58,280 --> 00:09:00,560 We've covered so much already, I need a minute 271 00:09:00,560 --> 00:09:01,600 to let it all sink in. 272 00:09:01,600 --> 00:09:02,120 I agree. 273 00:09:02,120 --> 00:09:04,080 It's been a whirlwind tour of the cosmos. 274 00:09:04,080 --> 00:09:06,200 All right, folks, we're going to take a short break here. 275 00:09:06,200 --> 00:09:08,480 But we'll be back soon to keep exploring the universe 276 00:09:08,480 --> 00:09:09,960 beyond our solar system. 277 00:09:09,960 --> 00:09:11,560 So don't go anywhere. 278 00:09:11,560 --> 00:09:14,920 We're back and ready for more cosmic exploration. 279 00:09:14,920 --> 00:09:16,080 I'm ready to dive back in. 280 00:09:16,080 --> 00:09:18,120 Last time we were talking about the galactic halo 281 00:09:18,120 --> 00:09:20,200 and those ancient stars, the ones that 282 00:09:20,200 --> 00:09:22,920 have been around since the beginning of the universe. 283 00:09:22,920 --> 00:09:25,640 It's like having a time machine, isn't it? 284 00:09:25,640 --> 00:09:29,080 What else can you tell me about these cosmic elders? 285 00:09:29,080 --> 00:09:31,360 You know what's fascinating about these halo stars? 286 00:09:31,360 --> 00:09:33,320 They're actually pretty different from the stars 287 00:09:33,320 --> 00:09:36,080 that we see in the Milky Way's disk where our sun is. 288 00:09:36,080 --> 00:09:37,560 Different how? 289 00:09:37,560 --> 00:09:40,320 Are they like, I don't know, the grandparent stars? 290 00:09:40,320 --> 00:09:42,760 Older, smaller, maybe a little redder? 291 00:09:42,760 --> 00:09:44,040 You're on the right track. 292 00:09:44,040 --> 00:09:47,440 They are older, formed when the galaxy was much younger. 293 00:09:47,440 --> 00:09:49,720 And because of that, they don't have as many heavy elements. 294 00:09:49,720 --> 00:09:53,680 Heavy elements, so like stuff like iron, carbon, oxygen, 295 00:09:53,680 --> 00:09:56,720 all the things that make up planets and, well, us. 296 00:09:56,720 --> 00:09:57,840 Exactly. 297 00:09:57,840 --> 00:10:01,080 These halo stars formed before those heavier elements 298 00:10:01,080 --> 00:10:02,560 were really common in the universe. 299 00:10:02,560 --> 00:10:05,320 It's like a snapshot of what the early universe was made of, 300 00:10:05,320 --> 00:10:06,600 like cosmic fossils. 301 00:10:06,600 --> 00:10:07,560 That's so cool. 302 00:10:07,560 --> 00:10:10,680 By studying them, we can learn about how galaxies formed 303 00:10:10,680 --> 00:10:12,920 and even how the elements that make up everything we know 304 00:10:12,920 --> 00:10:13,960 came to be. 305 00:10:13,960 --> 00:10:16,120 It's like a cosmic family tree. 306 00:10:16,120 --> 00:10:18,400 But speaking of ancient history, are there 307 00:10:18,400 --> 00:10:22,600 any other unique stars out there with stories to tell? 308 00:10:22,600 --> 00:10:23,680 Oh, definitely. 309 00:10:23,680 --> 00:10:26,640 Did you know there are stars out there moving so fast 310 00:10:26,640 --> 00:10:28,760 that they're actually escaping the Milky Way, 311 00:10:28,760 --> 00:10:31,000 like they're breaking free from the galaxy's gravity? 312 00:10:31,000 --> 00:10:33,400 Like, they're actually, like, weight escaping the galaxy, 313 00:10:33,400 --> 00:10:35,320 like running away from home? 314 00:10:35,320 --> 00:10:36,120 That's crazy. 315 00:10:36,120 --> 00:10:37,120 How does that even happen? 316 00:10:37,120 --> 00:10:39,000 These are called runaway stars, and they're 317 00:10:39,000 --> 00:10:40,720 thought to get flung out of the galaxy 318 00:10:40,720 --> 00:10:44,320 because of some pretty intense gravitational interactions. 319 00:10:44,320 --> 00:10:45,080 Like what? 320 00:10:45,080 --> 00:10:47,280 Do they get too close to a black hole or something? 321 00:10:47,280 --> 00:10:49,080 That's one possibility. 322 00:10:49,080 --> 00:10:54,120 There's the star, HE 0437 5439. 323 00:10:54,120 --> 00:10:58,520 It's traveling at, get this, 722 kilometers per second. 324 00:10:58,520 --> 00:11:00,960 That's fast enough to escape the Milky Way's pole. 325 00:11:00,960 --> 00:11:02,520 We might have had a close encounter 326 00:11:02,520 --> 00:11:05,200 with the supermassive black hole at the center of our galaxy 327 00:11:05,200 --> 00:11:07,200 like millions of years ago. 328 00:11:07,200 --> 00:11:10,040 That interaction basically acted like a giant slingshot 329 00:11:10,040 --> 00:11:11,680 flinging it out into space. 330 00:11:11,680 --> 00:11:13,920 Wow, that's a rough breakup. 331 00:11:13,920 --> 00:11:16,400 So this star is basically on a solo trip 332 00:11:16,400 --> 00:11:17,800 through the universe now. 333 00:11:17,800 --> 00:11:19,320 Yeah, pretty much. 334 00:11:19,320 --> 00:11:23,080 A lone traveler on a one-way ticket through the cosmos. 335 00:11:23,080 --> 00:11:25,800 It makes you wonder how many other runaway stars are out 336 00:11:25,800 --> 00:11:29,200 there, just cruising through space with their own stories. 337 00:11:29,200 --> 00:11:29,720 Yeah. 338 00:11:29,720 --> 00:11:31,600 Thinking about all the things we still don't 339 00:11:31,600 --> 00:11:33,120 know about what's out there. 340 00:11:33,120 --> 00:11:33,920 Absolutely. 341 00:11:33,920 --> 00:11:36,760 And every new discovery just leads to more questions. 342 00:11:36,760 --> 00:11:39,200 That's part of what makes astronomy so exciting. 343 00:11:39,200 --> 00:11:42,000 It's not just stars that can exist outside of solar systems. 344 00:11:42,000 --> 00:11:45,200 There are also planets that don't orbit any star at all. 345 00:11:45,200 --> 00:11:45,920 Hold on. 346 00:11:45,920 --> 00:11:47,600 Planets without stars. 347 00:11:47,600 --> 00:11:49,200 How is that even possible? 348 00:11:49,200 --> 00:11:51,080 Don't planets need a star's gravity 349 00:11:51,080 --> 00:11:53,760 to form and stay in orbit? 350 00:11:53,760 --> 00:11:55,120 That's what we used to think. 351 00:11:55,120 --> 00:11:58,080 But then we discovered these things called rogue planets 352 00:11:58,080 --> 00:12:00,360 or sometimes free-floating planets. 353 00:12:00,360 --> 00:12:02,000 They might have formed in the star system 354 00:12:02,000 --> 00:12:04,360 and then gotten kicked out maybe because of other planets 355 00:12:04,360 --> 00:12:06,400 or even a passing star. 356 00:12:06,400 --> 00:12:08,560 Or it's possible they formed on their own 357 00:12:08,560 --> 00:12:10,800 from collapsing gas and dust without ever being 358 00:12:10,800 --> 00:12:12,080 part of a solar system. 359 00:12:12,080 --> 00:12:15,840 So they're like cosmic orphans just wandering the galaxy alone. 360 00:12:15,840 --> 00:12:18,840 That's kind of sad, but also super cool. 361 00:12:18,840 --> 00:12:21,040 I wonder what it would be like on a rogue planet, just 362 00:12:21,040 --> 00:12:22,640 constant darkness and cold. 363 00:12:22,640 --> 00:12:25,120 It would be a very different environment than we're used to, 364 00:12:25,120 --> 00:12:26,200 that's for sure. 365 00:12:26,200 --> 00:12:27,640 Speaking of strange environments, 366 00:12:27,640 --> 00:12:31,120 have you heard about the planet where it rains molten iron? 367 00:12:31,120 --> 00:12:32,400 Molten iron rain. 368 00:12:32,400 --> 00:12:34,760 OK, that is officially the most metal thing I've ever heard. 369 00:12:34,760 --> 00:12:36,640 Tell me everything about this planet. 370 00:12:36,640 --> 00:12:41,520 It's called West P-76b, a gas giant about 390 light years 371 00:12:41,520 --> 00:12:42,520 away. 372 00:12:42,520 --> 00:12:45,800 It orbits its star so closely that one side is always 373 00:12:45,800 --> 00:12:47,600 blasted with intense heat. 374 00:12:47,600 --> 00:12:50,600 Ah, so it's tidally locked like some of those other planets 375 00:12:50,600 --> 00:12:51,480 we were talking about? 376 00:12:51,480 --> 00:12:53,680 One side always facing the star. 377 00:12:53,680 --> 00:12:54,720 Exactly. 378 00:12:54,720 --> 00:12:57,160 And on that day side, temperatures can get over 2,400 379 00:12:57,160 --> 00:12:58,240 degrees Celsius. 380 00:12:58,240 --> 00:13:00,360 That's hot enough to vaporize iron. 381 00:13:00,360 --> 00:13:02,680 The planet's strong winds then carry that iron vapor 382 00:13:02,680 --> 00:13:05,840 over to the cooler night side, where it condenses and falls 383 00:13:05,840 --> 00:13:07,240 as molten iron rain. 384 00:13:07,240 --> 00:13:09,920 Wow, that's a rainstorm I would definitely want to avoid. 385 00:13:09,920 --> 00:13:12,000 It's like something straight out of a sci-fi movie. 386 00:13:12,000 --> 00:13:15,360 It really shows the crazy range of conditions 387 00:13:15,360 --> 00:13:17,160 that are out there in the universe. 388 00:13:17,160 --> 00:13:22,440 And West P-76b isn't the only exoplanet with extreme weather. 389 00:13:22,440 --> 00:13:23,640 Want to hear about some more? 390 00:13:23,640 --> 00:13:24,520 Absolutely. 391 00:13:24,520 --> 00:13:25,520 The weirder, the better. 392 00:13:25,520 --> 00:13:27,360 Let me with more crazy exoplanet weather. 393 00:13:27,360 --> 00:13:30,800 OK, how about a planet where it rains glass sideways? 394 00:13:30,800 --> 00:13:32,400 Glass rain sideways. 395 00:13:32,400 --> 00:13:33,600 OK, now I have to hear about this. 396 00:13:33,600 --> 00:13:34,320 Tell me more. 397 00:13:34,320 --> 00:13:38,280 This one's called HD 189733b. 398 00:13:38,280 --> 00:13:39,760 And its atmosphere is thought to be 399 00:13:39,760 --> 00:13:41,600 full of these tiny silicate particles, 400 00:13:41,600 --> 00:13:43,320 the stuff that makes up glass. 401 00:13:43,320 --> 00:13:46,680 The winds on this planet can get up to over 7,000 kilometers 402 00:13:46,680 --> 00:13:47,320 per hour. 403 00:13:47,320 --> 00:13:50,080 So imagine shards of glass whipping through the air 404 00:13:50,080 --> 00:13:51,160 at supersonic speeds. 405 00:13:51,160 --> 00:13:51,920 That's insane. 406 00:13:51,920 --> 00:13:53,440 What other wild weather is out there? 407 00:13:53,440 --> 00:13:55,400 Well, we've talked about scorching hot planets 408 00:13:55,400 --> 00:13:56,120 and frozen ones. 409 00:13:56,120 --> 00:13:58,200 But how about a planet that's completely 410 00:13:58,200 --> 00:14:01,560 covered in a global ocean hundreds of kilometers deep? 411 00:14:01,560 --> 00:14:02,960 A water world. 412 00:14:02,960 --> 00:14:04,960 Now, that's something I could get behind. 413 00:14:04,960 --> 00:14:07,200 Imagine the kind of life that could exist in an ocean 414 00:14:07,200 --> 00:14:08,160 that fast. 415 00:14:08,160 --> 00:14:09,560 It's a fascinating thought. 416 00:14:09,560 --> 00:14:13,120 This planet is called GJ 1214b. 417 00:14:13,120 --> 00:14:14,920 And scientists think it's a super Earth 418 00:14:14,920 --> 00:14:17,400 with this incredibly deep ocean. 419 00:14:17,400 --> 00:14:20,920 But those depths would be under unbelievable pressure. 420 00:14:20,920 --> 00:14:22,960 Who knows what might be lurking down there? 421 00:14:22,960 --> 00:14:25,080 That's both exciting and terrifying. 422 00:14:25,080 --> 00:14:26,720 It makes you realize how little we know 423 00:14:26,720 --> 00:14:28,360 about what's possible out there. 424 00:14:28,360 --> 00:14:30,640 What other weird planets are hiding in the universe? 425 00:14:30,640 --> 00:14:33,280 Well, how about a planet made mostly of carbon? 426 00:14:33,280 --> 00:14:35,440 Scientists believe that the intense pressure 427 00:14:35,440 --> 00:14:38,680 inside this planet, called 55 Cancri e, 428 00:14:38,680 --> 00:14:40,520 could have formed massive diamonds. 429 00:14:40,520 --> 00:14:41,640 A diamond planet. 430 00:14:41,640 --> 00:14:43,120 Now, that's some serious bling. 431 00:14:43,120 --> 00:14:45,120 I wonder how much a diamond the size of a planet 432 00:14:45,120 --> 00:14:45,840 would be worth. 433 00:14:45,840 --> 00:14:47,840 That's a question for the economists, I think. 434 00:14:47,840 --> 00:14:50,240 But it really shows you the amazing diversity 435 00:14:50,240 --> 00:14:51,360 of planets out there. 436 00:14:51,360 --> 00:14:52,120 No kidding. 437 00:14:52,120 --> 00:14:55,040 We've got molten iron rain, glass storms, water worlds, 438 00:14:55,040 --> 00:14:56,240 diamond planets. 439 00:14:56,240 --> 00:14:58,360 The universe is so much stranger and more awesome 440 00:14:58,360 --> 00:14:59,520 than I ever imagined. 441 00:14:59,520 --> 00:15:00,440 It really is. 442 00:15:00,440 --> 00:15:02,320 And with all this talk of diverse planets 443 00:15:02,320 --> 00:15:04,400 and extreme environments, it leads us 444 00:15:04,400 --> 00:15:06,920 to one of the biggest questions of all. 445 00:15:06,920 --> 00:15:10,200 Are we alone in this vast and crazy universe? 446 00:15:10,200 --> 00:15:12,600 The age-old question. 447 00:15:12,600 --> 00:15:15,680 It's something humans have been wondering about forever. 448 00:15:15,680 --> 00:15:19,800 Where do we stand in the search for life beyond Earth? 449 00:15:19,800 --> 00:15:21,680 I think the first thing to consider is just 450 00:15:21,680 --> 00:15:23,600 how massive the universe is. 451 00:15:23,600 --> 00:15:26,880 I mean, trillions of stars in our galaxy alone, 452 00:15:26,880 --> 00:15:29,720 and billions and billions of galaxies out there, 453 00:15:29,720 --> 00:15:32,000 it seems pretty unlikely that we're the only planet 454 00:15:32,000 --> 00:15:33,440 where life exists. 455 00:15:33,440 --> 00:15:34,760 That's what I've always thought. 456 00:15:34,760 --> 00:15:37,840 The odds just seem way too high against us being totally alone. 457 00:15:37,840 --> 00:15:39,800 But we haven't actually found any real proof 458 00:15:39,800 --> 00:15:41,720 of alien life yet, have we? 459 00:15:41,720 --> 00:15:42,520 Not yet. 460 00:15:42,520 --> 00:15:44,560 But that doesn't mean it's not out there. 461 00:15:44,560 --> 00:15:46,240 There are a lot of promising places 462 00:15:46,240 --> 00:15:48,640 where scientists are searching for signs of life. 463 00:15:48,640 --> 00:15:50,260 One of the most interesting is actually 464 00:15:50,260 --> 00:15:52,920 right here in our own solar system, Europa, one 465 00:15:52,920 --> 00:15:53,840 of Jupiter's moons. 466 00:15:53,840 --> 00:15:54,520 Europa. 467 00:15:54,520 --> 00:15:56,480 But isn't that just a giant ball of ice? 468 00:15:56,480 --> 00:15:58,040 On the surface, yeah. 469 00:15:58,040 --> 00:16:01,200 But scientists believe there's a huge salty ocean hidden 470 00:16:01,200 --> 00:16:02,120 under that ice. 471 00:16:02,120 --> 00:16:03,560 A hidden ocean. 472 00:16:03,560 --> 00:16:05,720 That sounds like a perfect place for life, 473 00:16:05,720 --> 00:16:09,200 protected from the highness of space by a layer of ice. 474 00:16:09,200 --> 00:16:10,880 What an amazing thought. 475 00:16:10,880 --> 00:16:13,600 Are there any other places like that in our solar system? 476 00:16:13,600 --> 00:16:14,560 There is. 477 00:16:14,560 --> 00:16:18,680 Saturn's moon Enceladus also has a subsurface ocean. 478 00:16:18,680 --> 00:16:20,600 And it's even more exciting because we've actually 479 00:16:20,600 --> 00:16:23,200 seen plumes of water vapor shooting out 480 00:16:23,200 --> 00:16:25,520 from cracks in the ice. 481 00:16:25,520 --> 00:16:30,040 So those plumes are like direct evidence of a hidden ocean. 482 00:16:30,040 --> 00:16:31,040 Incredible. 483 00:16:31,040 --> 00:16:34,080 Do you think those plumes could contain signs of life? 484 00:16:34,080 --> 00:16:36,280 Maybe even tiny microbes or something. 485 00:16:36,280 --> 00:16:37,600 It's definitely possible. 486 00:16:37,600 --> 00:16:39,880 Scientists are really eager to send missions 487 00:16:39,880 --> 00:16:42,860 to both Europa and Enceladus to study those plumes 488 00:16:42,860 --> 00:16:45,480 and look for anything that might suggest life. 489 00:16:45,480 --> 00:16:47,440 But it's not just moons that are promising 490 00:16:47,440 --> 00:16:49,120 in the search for alien life. 491 00:16:49,120 --> 00:16:51,360 We're also looking at exoplanets pretty closely. 492 00:16:51,360 --> 00:16:52,800 Like those potentially habitable ones 493 00:16:52,800 --> 00:16:56,680 we talked about earlier, Wolf 1061c and Gliese 370b. 494 00:16:56,680 --> 00:16:57,400 Exactly. 495 00:16:57,400 --> 00:16:59,240 Those planets are in the habitable zones 496 00:16:59,240 --> 00:17:01,200 of their stars, which means the temperatures are right 497 00:17:01,200 --> 00:17:03,480 for liquid water to exist on their surfaces. 498 00:17:03,480 --> 00:17:05,800 OK, so we've got these potentially habitable moons 499 00:17:05,800 --> 00:17:07,000 and planets. 500 00:17:07,000 --> 00:17:09,720 But how do we actually look for life on these worlds? 501 00:17:09,720 --> 00:17:12,280 We can't just like fly over there and take some samples. 502 00:17:12,280 --> 00:17:14,760 Not yet, at least not with our current technology. 503 00:17:14,760 --> 00:17:17,200 But we can study the atmospheres of these exoplanets 504 00:17:17,200 --> 00:17:19,000 using powerful telescopes. 505 00:17:19,000 --> 00:17:19,640 I see. 506 00:17:19,640 --> 00:17:21,520 So we're looking for clues in the air they breathe. 507 00:17:21,520 --> 00:17:22,640 What kind of clues are we talking about? 508 00:17:22,640 --> 00:17:26,000 Well, if we find certain gases in an exoplanet's atmosphere, 509 00:17:26,000 --> 00:17:30,040 like oxygen, methane, or even more complex molecules, 510 00:17:30,040 --> 00:17:32,240 it could mean there's something biological going on. 511 00:17:32,240 --> 00:17:34,240 So it's like we're looking for the chemical fingerprints 512 00:17:34,240 --> 00:17:35,280 of life. 513 00:17:35,280 --> 00:17:36,520 That's so cool. 514 00:17:36,520 --> 00:17:39,520 Are there any telescopes powerful enough to do that now? 515 00:17:39,520 --> 00:17:41,160 There are some that are getting close, 516 00:17:41,160 --> 00:17:43,280 but the next generation of telescopes 517 00:17:43,280 --> 00:17:45,200 will be even more powerful. 518 00:17:45,200 --> 00:17:48,000 They'll be able to analyze the atmospheres of distant worlds 519 00:17:48,000 --> 00:17:49,720 in way more detail. 520 00:17:49,720 --> 00:17:51,920 It's a very exciting time for the search 521 00:17:51,920 --> 00:17:53,800 for life beyond Earth. 522 00:17:53,800 --> 00:17:55,200 I can't wait to see what we find. 523 00:17:55,200 --> 00:17:58,920 It feels like we're on the edge of some major breakthroughs. 524 00:17:58,920 --> 00:18:01,400 But even if we don't find intelligent life, 525 00:18:01,400 --> 00:18:04,440 wouldn't finding any kind of life, even just microbes, 526 00:18:04,440 --> 00:18:05,600 be a huge discovery? 527 00:18:05,600 --> 00:18:06,360 Oh, absolutely. 528 00:18:06,360 --> 00:18:07,440 It would change everything. 529 00:18:07,440 --> 00:18:09,560 It would prove that life isn't unique to Earth 530 00:18:09,560 --> 00:18:11,640 and that it can arise in all sorts of different forms 531 00:18:11,640 --> 00:18:12,480 and environments. 532 00:18:12,480 --> 00:18:15,040 It would make us rethink our place in the universe 533 00:18:15,040 --> 00:18:17,080 and how we understand life itself. 534 00:18:17,080 --> 00:18:20,840 Imagine the implications for science, philosophy, religion, 535 00:18:20,840 --> 00:18:21,520 everything. 536 00:18:21,520 --> 00:18:24,080 It would be a total paradigm shift for humanity. 537 00:18:24,080 --> 00:18:26,680 It's both thrilling and a little scary to think about. 538 00:18:26,680 --> 00:18:27,760 I agree. 539 00:18:27,760 --> 00:18:30,480 But in the end, I think it would be a good thing. 540 00:18:30,480 --> 00:18:33,400 It would show us that we're not alone in this vast universe 541 00:18:33,400 --> 00:18:36,280 and that life is more common and more diverse than we ever 542 00:18:36,280 --> 00:18:37,440 thought possible. 543 00:18:37,440 --> 00:18:40,400 It would open up a whole new chapter in human history 544 00:18:40,400 --> 00:18:43,240 and our exploration of the cosmos. 545 00:18:43,240 --> 00:18:46,360 But speaking of exploring, we've covered so much ground 546 00:18:46,360 --> 00:18:47,800 in this episode. 547 00:18:47,800 --> 00:18:49,320 Where do we even go from here? 548 00:18:49,320 --> 00:18:51,760 Well, there's still so much more to discover. 549 00:18:51,760 --> 00:18:54,280 We could delve into the mysteries of black holes, 550 00:18:54,280 --> 00:18:56,720 explore the possibility of parallel universes, 551 00:18:56,720 --> 00:18:59,440 or even discuss the ultimate fate of the universe. 552 00:18:59,440 --> 00:19:01,880 Wow, those are some heavy topics. 553 00:19:01,880 --> 00:19:03,680 But I guess that's what this podcast is all about, 554 00:19:03,680 --> 00:19:05,320 diving deep into the big questions 555 00:19:05,320 --> 00:19:06,560 and mysteries of the universe. 556 00:19:06,560 --> 00:19:07,440 Exactly. 557 00:19:07,440 --> 00:19:09,920 And I can't wait to continue this journey with you. 558 00:19:09,920 --> 00:19:13,080 We're back for the final part of our cosmic journey, 559 00:19:13,080 --> 00:19:15,880 exploring the universe beyond our solar system. 560 00:19:15,880 --> 00:19:18,040 Yeah, it's been quite the adventure, hasn't it? 561 00:19:18,040 --> 00:19:21,320 From nearby stars to runaway planets, hidden oceans, 562 00:19:21,320 --> 00:19:24,080 and even a planet with molten iron rain. 563 00:19:24,080 --> 00:19:24,960 I know. 564 00:19:24,960 --> 00:19:26,880 My mind is still blown from all the amazing stuff 565 00:19:26,880 --> 00:19:28,240 we've talked about. 566 00:19:28,240 --> 00:19:32,600 But we left off last time with a pretty big cliffhanger, 567 00:19:32,600 --> 00:19:35,040 the search for extraterrestrial life. 568 00:19:35,040 --> 00:19:35,400 Right. 569 00:19:35,400 --> 00:19:37,720 It's something that everyone seems to be curious about. 570 00:19:37,720 --> 00:19:38,680 For sure. 571 00:19:38,680 --> 00:19:40,880 So where do we go from here? 572 00:19:40,880 --> 00:19:44,160 What are the most promising ways to search 573 00:19:44,160 --> 00:19:45,520 for life beyond Earth? 574 00:19:45,520 --> 00:19:49,240 I mean, we talked about those icy moons, Europa and Enceladus, 575 00:19:49,240 --> 00:19:51,720 and those potentially habitable exoplanets. 576 00:19:51,720 --> 00:19:54,960 But what are scientists actually doing to try and find proof? 577 00:19:54,960 --> 00:19:56,680 Well, a big part of it is looking for what 578 00:19:56,680 --> 00:19:58,320 we call biosignatures. 579 00:19:58,320 --> 00:19:59,440 OK, biosignatures. 580 00:19:59,440 --> 00:20:00,160 What are those? 581 00:20:00,160 --> 00:20:01,880 Basically, there are any signs that 582 00:20:01,880 --> 00:20:04,760 could mean life exists or existed in the past. 583 00:20:04,760 --> 00:20:07,960 It could be like chemicals in a planet's atmosphere, 584 00:20:07,960 --> 00:20:11,200 geological stuff that suggests there was biological activity, 585 00:20:11,200 --> 00:20:13,520 or even signals that seem like they're artificial. 586 00:20:13,520 --> 00:20:16,280 So like, clues that point to life, even if we don't actually 587 00:20:16,280 --> 00:20:17,800 see the life itself. 588 00:20:17,800 --> 00:20:19,880 What are some examples of these biosignatures? 589 00:20:19,880 --> 00:20:23,320 Well, in terms of atmospheres, one of the big ones is oxygen. 590 00:20:23,320 --> 00:20:24,880 You mean like the stuff we breathe? 591 00:20:24,880 --> 00:20:25,960 Exactly. 592 00:20:25,960 --> 00:20:28,200 On Earth, most of the oxygen in our atmosphere 593 00:20:28,200 --> 00:20:32,040 comes from photosynthesis, from plants and other organisms. 594 00:20:32,040 --> 00:20:35,840 So if we find a lot of oxygen in the atmosphere of an exoplanet, 595 00:20:35,840 --> 00:20:37,760 it could be a sign that something's producing it 596 00:20:37,760 --> 00:20:38,760 biologically. 597 00:20:38,760 --> 00:20:40,040 That makes sense. 598 00:20:40,040 --> 00:20:41,920 What other atmospheric clues are there? 599 00:20:41,920 --> 00:20:43,720 Methane's another one. 600 00:20:43,720 --> 00:20:45,400 It can be made by biological stuff, 601 00:20:45,400 --> 00:20:48,000 but also by geological processes. 602 00:20:48,000 --> 00:20:50,400 So finding it along with other gases, 603 00:20:50,400 --> 00:20:52,520 like oxygen or carbon dioxide, could 604 00:20:52,520 --> 00:20:54,680 be a stronger sign of life. 605 00:20:54,680 --> 00:20:57,640 And then there are even more complex organic molecules, 606 00:20:57,640 --> 00:20:58,720 like amino acids. 607 00:20:58,720 --> 00:21:01,040 Those are the building blocks of proteins. 608 00:21:01,040 --> 00:21:03,320 Finding those in an exoplanet's atmosphere 609 00:21:03,320 --> 00:21:04,920 would be a really big deal. 610 00:21:04,920 --> 00:21:07,560 So it's kind of like a cosmic game of Clue. 611 00:21:07,560 --> 00:21:09,800 But instead of a candlestick in the library, 612 00:21:09,800 --> 00:21:13,160 we're looking for methane and oxygen on a distant planet. 613 00:21:13,160 --> 00:21:14,720 That's a great analogy. 614 00:21:14,720 --> 00:21:17,400 And just like in Clue, the Clues can be a bit tricky 615 00:21:17,400 --> 00:21:18,800 to understand sometimes. 616 00:21:18,800 --> 00:21:20,640 That's why we have to be really careful 617 00:21:20,640 --> 00:21:23,840 and consider all the possible explanations for what we see 618 00:21:23,840 --> 00:21:26,000 and not jump to conclusions too quickly. 619 00:21:26,000 --> 00:21:26,200 Right. 620 00:21:26,200 --> 00:21:27,560 We don't want to get excited about something 621 00:21:27,560 --> 00:21:28,760 that's not really there. 622 00:21:28,760 --> 00:21:30,560 So are there any biosignatures that 623 00:21:30,560 --> 00:21:35,640 would be more certain, like a smoking gun for life? 624 00:21:35,640 --> 00:21:39,480 Well, finding something like complex organic molecules 625 00:21:39,480 --> 00:21:42,120 that are definitely the product of biological processes, 626 00:21:42,120 --> 00:21:43,320 that would be huge. 627 00:21:43,320 --> 00:21:47,600 Or imagine finding structures or patterns on a planet surface 628 00:21:47,600 --> 00:21:50,280 that could only have been created by intelligent life. 629 00:21:50,280 --> 00:21:53,000 Like alien cities or giant crop circles. 630 00:21:53,000 --> 00:21:54,440 Now, that would be a discovery. 631 00:21:54,440 --> 00:21:55,320 Absolutely. 632 00:21:55,320 --> 00:21:57,960 But even if we don't find anything that dramatic, 633 00:21:57,960 --> 00:22:00,280 any sign of life beyond Earth would 634 00:22:00,280 --> 00:22:03,660 be a monumental discovery and would completely change 635 00:22:03,660 --> 00:22:05,440 how we understand the universe. 636 00:22:05,440 --> 00:22:07,640 It's amazing to think that we might be this close 637 00:22:07,640 --> 00:22:09,560 to such a huge discovery. 638 00:22:09,560 --> 00:22:12,200 It makes you wonder, what would happen to humanity 639 00:22:12,200 --> 00:22:15,440 if we did find undeniable proof of alien life? 640 00:22:15,440 --> 00:22:17,720 I think it'd be one of the biggest things to ever happen 641 00:22:17,720 --> 00:22:18,800 in human history. 642 00:22:18,800 --> 00:22:20,960 We'd have to rethink our place in the cosmos, 643 00:22:20,960 --> 00:22:23,760 our ideas about what life is, and maybe even our own beliefs. 644 00:22:23,760 --> 00:22:25,400 It's almost too much to take in. 645 00:22:25,400 --> 00:22:27,480 Do you think it would be a good thing or a bad thing 646 00:22:27,480 --> 00:22:28,480 for humanity? 647 00:22:28,480 --> 00:22:30,200 Hard to say for sure. 648 00:22:30,200 --> 00:22:32,120 It would be a huge change. 649 00:22:32,120 --> 00:22:34,600 And there would probably be a lot of fear and confusion 650 00:22:34,600 --> 00:22:35,800 at first. 651 00:22:35,800 --> 00:22:38,880 But in the end, I think it would be good. 652 00:22:38,880 --> 00:22:41,560 It would show that we're not alone, that life is more common 653 00:22:41,560 --> 00:22:43,520 and more diverse than we ever thought. 654 00:22:43,520 --> 00:22:46,880 And it would open up so many new possibilities for science, 655 00:22:46,880 --> 00:22:49,040 philosophy, everything. 656 00:22:49,040 --> 00:22:51,520 It would be a whole new chapter in the human story. 657 00:22:51,520 --> 00:22:52,600 Exactly. 658 00:22:52,600 --> 00:22:55,480 And who knows what we might learn from other life forms? 659 00:22:55,480 --> 00:22:58,640 What kind of knowledge, technologies, or perspectives 660 00:22:58,640 --> 00:23:00,200 might they have to share with us? 661 00:23:00,200 --> 00:23:02,520 It's mind blowing to think about. 662 00:23:02,520 --> 00:23:04,440 But as much as I'd love to keep talking 663 00:23:04,440 --> 00:23:06,440 about alien civilizations and all that, 664 00:23:06,440 --> 00:23:09,440 it looks like we've reached the end of our deep dive. 665 00:23:09,440 --> 00:23:11,640 It has been an incredible journey for sure. 666 00:23:11,640 --> 00:23:13,680 We've explored our galactic neighborhood, 667 00:23:13,680 --> 00:23:15,760 learned about all these bizarre planets, 668 00:23:15,760 --> 00:23:18,760 and thought about the big mysteries of the Milky Way. 669 00:23:18,760 --> 00:23:20,480 And really, we've just scratched the surface. 670 00:23:20,480 --> 00:23:21,320 Yeah, that's right. 671 00:23:21,320 --> 00:23:23,840 The universe is vast and full of wonders. 672 00:23:23,840 --> 00:23:25,600 There's still so much left to discover. 673 00:23:25,600 --> 00:23:28,520 So keep looking up at the stars, keep asking questions, 674 00:23:28,520 --> 00:23:30,080 and never stop exploring. 675 00:23:30,080 --> 00:23:32,360 And if you want more cosmic adventures, 676 00:23:32,360 --> 00:23:35,040 be sure to follow Cosmos in a pod and subscribe 677 00:23:35,040 --> 00:23:36,400 to our YouTube channel. 678 00:23:36,400 --> 00:24:03,160 Until next time, keep wondering and keep exploring.