1 00:00:00,000 --> 00:00:03,480 Imagine you're standing on Mars, like, billions of years ago, 2 00:00:03,480 --> 00:00:06,200 but not the Mars we see in pictures today. 3 00:00:06,200 --> 00:00:08,360 This Mars is, well, it's totally different. 4 00:00:08,360 --> 00:00:11,360 It has rivers and lakes and maybe even a whole ocean up 5 00:00:11,360 --> 00:00:12,040 north. 6 00:00:12,040 --> 00:00:13,360 Crazy, right? 7 00:00:13,360 --> 00:00:17,280 How did Mars go from that to a dry, dusty desert? 8 00:00:17,280 --> 00:00:18,800 It is a pretty crazy transformation 9 00:00:18,800 --> 00:00:19,720 when you think about it. 10 00:00:19,720 --> 00:00:20,220 Yeah. 11 00:00:20,220 --> 00:00:23,800 So in this deep dive, we're going to travel back in time 12 00:00:23,800 --> 00:00:26,760 and explore this ancient Mars, this planet that 13 00:00:26,760 --> 00:00:30,760 was once full of water, welcome to cosmos in a pod space 14 00:00:30,760 --> 00:00:31,760 and astronomy series. 15 00:00:31,760 --> 00:00:33,040 To understand the mystery, you've 16 00:00:33,040 --> 00:00:34,680 got to look at the atmosphere. 17 00:00:34,680 --> 00:00:38,120 See, billions of years ago, Mars had this thick atmosphere 18 00:00:38,120 --> 00:00:39,960 packed with carbon dioxide. 19 00:00:39,960 --> 00:00:42,440 And that acted like a giant blanket, trapping heat 20 00:00:42,440 --> 00:00:44,400 and letting liquid water flow. 21 00:00:44,400 --> 00:00:45,920 So like, how do we know all this? 22 00:00:45,920 --> 00:00:49,720 Is there like evidence of this watery past still on Mars today? 23 00:00:49,720 --> 00:00:50,520 Oh, absolutely. 24 00:00:50,520 --> 00:00:52,760 Martian surface, it's basically a history book, right? 25 00:00:52,760 --> 00:00:53,600 Full of clues. 26 00:00:53,600 --> 00:00:56,200 And one of the biggest clues is this massive canyon system 27 00:00:56,200 --> 00:00:57,440 called Valles Marineris. 28 00:00:57,440 --> 00:01:00,520 It's huge, way bigger than the Grand Canyon here on Earth. 29 00:01:00,520 --> 00:01:03,040 Like, it stretches over 4,500 kilometers. 30 00:01:03,040 --> 00:01:04,960 4,500 kilometers? 31 00:01:04,960 --> 00:01:05,520 Yeah. 32 00:01:05,520 --> 00:01:08,160 Wow, that's like the width of the US. 33 00:01:08,160 --> 00:01:08,660 Yeah. 34 00:01:08,660 --> 00:01:10,720 So how does a canyon tell us about water? 35 00:01:10,720 --> 00:01:11,560 Well, think about it. 36 00:01:11,560 --> 00:01:14,560 Something had to carve out something that massive 37 00:01:14,560 --> 00:01:16,720 and the most likely culprit. 38 00:01:16,720 --> 00:01:20,880 A ton of water flowing for millions and millions of years. 39 00:01:20,880 --> 00:01:23,840 OK, so a giant canyon hints at water. 40 00:01:23,840 --> 00:01:25,920 But are there any other features that back that up? 41 00:01:25,920 --> 00:01:28,500 There's this really cool spot inside Valles Marineris 42 00:01:28,500 --> 00:01:32,160 called Noctus labyrinthus, which means labyrinth of night. 43 00:01:32,160 --> 00:01:34,920 It's this maze of canyons and plateaus. 44 00:01:34,920 --> 00:01:36,880 And they also show signs of water erosion. 45 00:01:36,880 --> 00:01:40,480 It's almost like Mars is trying to tell us its story, 46 00:01:40,480 --> 00:01:42,240 you know, through these canyons and stuff. 47 00:01:42,240 --> 00:01:45,120 So if Mars had all this water, how did it all vanish? 48 00:01:45,120 --> 00:01:46,760 What happened to its atmosphere? 49 00:01:46,760 --> 00:01:49,280 Well, the main theory is that Mars' magnetic field, 50 00:01:49,280 --> 00:01:50,000 it's kind of weak. 51 00:01:50,000 --> 00:01:50,920 And that's a problem. 52 00:01:50,920 --> 00:01:54,080 See, unlike Earth, Mars doesn't have the strong magnetic shield 53 00:01:54,080 --> 00:01:55,800 to protect it from the solar wind. 54 00:01:55,800 --> 00:01:58,240 And the solar wind, well, it's this constant stream 55 00:01:58,240 --> 00:01:59,680 of charged particles from the sun 56 00:01:59,680 --> 00:02:02,120 that basically chipped away at Mars' atmosphere 57 00:02:02,120 --> 00:02:04,200 over like billions of years. 58 00:02:04,200 --> 00:02:06,920 And eventually, well, most of the atmosphere was gone. 59 00:02:06,920 --> 00:02:10,760 Wow, so the sun basically blew away Mars' atmosphere. 60 00:02:10,760 --> 00:02:11,720 That's kind of sad. 61 00:02:11,720 --> 00:02:13,760 Did the water disappear with the atmosphere too? 62 00:02:13,760 --> 00:02:14,640 A lot of it did. 63 00:02:14,640 --> 00:02:17,080 As the atmosphere thinned, the water on the surface, 64 00:02:17,080 --> 00:02:18,760 well, it started to evaporate. 65 00:02:18,760 --> 00:02:19,840 And some of it broke down. 66 00:02:19,840 --> 00:02:21,560 The hydrogen escaped into space. 67 00:02:21,560 --> 00:02:25,320 But the oxygen, the oxygen reacted with iron in the soil. 68 00:02:25,320 --> 00:02:27,400 And that's how you get iron oxide. 69 00:02:27,400 --> 00:02:31,080 Or rust, that's what gives Mars its red color. 70 00:02:31,080 --> 00:02:33,200 So Mars is literally rusty. 71 00:02:33,200 --> 00:02:34,120 That's a fun fact. 72 00:02:34,120 --> 00:02:36,680 Is any of that ancient water still around today? 73 00:02:36,680 --> 00:02:37,560 Actually, yeah. 74 00:02:37,560 --> 00:02:39,240 Funny enough, Noctus labyrinthus, 75 00:02:39,240 --> 00:02:41,760 that place with the canyons, is one of the most humid places 76 00:02:41,760 --> 00:02:42,740 on Mars. 77 00:02:42,740 --> 00:02:45,960 At night, fog forms there because water vapor 78 00:02:45,960 --> 00:02:47,840 evaporates from the soil and freezes. 79 00:02:47,840 --> 00:02:48,680 Pretty cool, huh? 80 00:02:48,680 --> 00:02:51,640 It's like a little ghost of Mars' watery past. 81 00:02:51,640 --> 00:02:53,880 Let's talk about some specific places on Mars 82 00:02:53,880 --> 00:02:56,640 to give us even more clues about its watery history. 83 00:02:56,640 --> 00:02:59,880 Let's start with Copritis Chasma, this deep canyon that's 84 00:02:59,880 --> 00:03:02,400 tucked inside Valle Es Marineris. 85 00:03:02,400 --> 00:03:03,680 What's so special about it? 86 00:03:03,680 --> 00:03:05,640 Copritis Chasma, well, there's evidence 87 00:03:05,640 --> 00:03:07,640 there of a huge ancient lake. 88 00:03:07,640 --> 00:03:10,240 Some scientists think it might have been as big as the Black 89 00:03:10,240 --> 00:03:10,740 Sea. 90 00:03:10,740 --> 00:03:13,760 A lake the size of the Black Sea on Mars. 91 00:03:13,760 --> 00:03:14,600 Wow. 92 00:03:14,600 --> 00:03:16,920 That makes you wonder if anything lived in it. 93 00:03:16,920 --> 00:03:18,920 Do scientists think we might find signs of life 94 00:03:18,920 --> 00:03:20,040 in Copritis Chasma? 95 00:03:20,040 --> 00:03:21,540 It's definitely a good spot to look. 96 00:03:21,540 --> 00:03:22,680 I mean, the conditions back then 97 00:03:22,680 --> 00:03:25,640 might have been perfect for, say, microbial life to pop up. 98 00:03:25,640 --> 00:03:26,520 Mind blowing. 99 00:03:26,520 --> 00:03:28,020 Are there any other places on Mars 100 00:03:28,020 --> 00:03:30,560 that might hold clues about ancient Martian life? 101 00:03:30,560 --> 00:03:31,880 Oh, yeah, tons. 102 00:03:31,880 --> 00:03:33,600 Gale Crater, for example. 103 00:03:33,600 --> 00:03:35,880 That's where the Curiosity Rover landed. 104 00:03:35,880 --> 00:03:39,080 And it's this huge impact crater with this mountain 105 00:03:39,080 --> 00:03:42,120 of layered sediments right in the middle called Mount Sharp. 106 00:03:42,120 --> 00:03:45,080 And scientists think Gale Crater used to be a giant lake. 107 00:03:45,080 --> 00:03:47,560 And that Mount Sharp formed from all the sediment 108 00:03:47,560 --> 00:03:50,200 that settled at the bottom over millions of years. 109 00:03:50,200 --> 00:03:53,200 So Curiosity landed in an ancient lake bed. 110 00:03:53,200 --> 00:03:55,360 Talk about being in the right place. 111 00:03:55,360 --> 00:03:57,920 What has Curiosity found in Gale Crater so far? 112 00:03:57,920 --> 00:03:59,840 Well, it's found a bunch of cool stuff. 113 00:03:59,840 --> 00:04:03,020 Clear signs of water erosion, mineral-rich soil 114 00:04:03,020 --> 00:04:06,440 that could have supported life, and even organic molecules, 115 00:04:06,440 --> 00:04:09,080 which are like the building blocks of life. 116 00:04:09,080 --> 00:04:10,760 It's like Curiosity is telling us 117 00:04:10,760 --> 00:04:14,200 a story bit by bit about what Mars used to be like. 118 00:04:14,200 --> 00:04:17,200 So we've got canyons and craters that were once lakes. 119 00:04:17,200 --> 00:04:19,520 Any other cool features from Mars's water world? 120 00:04:19,520 --> 00:04:21,080 Well, there's Hellas Planitia. 121 00:04:21,080 --> 00:04:22,960 That's a massive impact crater, one 122 00:04:22,960 --> 00:04:24,880 of the biggest in the whole solar system. 123 00:04:24,880 --> 00:04:28,520 It's massive, like 2,300 kilometers across. 124 00:04:28,520 --> 00:04:32,400 It probably formed when a giant asteroid hit Mars billions 125 00:04:32,400 --> 00:04:33,400 of years ago. 126 00:04:33,400 --> 00:04:36,840 The impact was so powerful that it created this huge basin. 127 00:04:36,840 --> 00:04:39,560 And a lot of scientists think that basin filled with water 128 00:04:39,560 --> 00:04:41,160 and became a giant lake. 129 00:04:41,160 --> 00:04:44,080 A lake that big must have been an amazing sight. 130 00:04:44,080 --> 00:04:46,200 What does Hellas Planitia look like today? 131 00:04:46,200 --> 00:04:48,120 Today, it's known for its weird weather. 132 00:04:48,120 --> 00:04:49,600 Sometimes it gets really hazy. 133 00:04:49,600 --> 00:04:51,680 And in the Martian winter, it gets covered in frost. 134 00:04:51,680 --> 00:04:53,480 You can actually see it from Earth, 135 00:04:53,480 --> 00:04:55,160 this big white spot on Mars. 136 00:04:55,160 --> 00:04:56,040 It's pretty cool. 137 00:04:56,040 --> 00:05:00,320 From canyons to lakes to a giant frost covered basin, 138 00:05:00,320 --> 00:05:03,200 Mars really was a different world. 139 00:05:03,200 --> 00:05:05,720 Let's talk about another crater, Jezero Crater. 140 00:05:05,720 --> 00:05:07,760 That's where the Perseverance Rover is now. 141 00:05:07,760 --> 00:05:09,680 What's so special about Jezero Crater? 142 00:05:09,680 --> 00:05:14,160 Oh, Jezero Crater has evidence of an ancient river delta. 143 00:05:14,160 --> 00:05:18,160 Imagine a river flowing into a lake and dropping off sediment. 144 00:05:18,160 --> 00:05:20,720 Over time, that sediment builds up and creates 145 00:05:20,720 --> 00:05:22,680 this fan-shaped delta. 146 00:05:22,680 --> 00:05:24,280 And that's what we see at Jezero Crater. 147 00:05:24,280 --> 00:05:26,040 It's like a snapshot of the past. 148 00:05:26,040 --> 00:05:29,760 So Perseverance landed right in this ancient river delta. 149 00:05:29,760 --> 00:05:31,120 That sounds like the perfect spot 150 00:05:31,120 --> 00:05:32,920 to hunt for signs of past life. 151 00:05:32,920 --> 00:05:33,640 It really is. 152 00:05:33,640 --> 00:05:36,400 Perseverance has sent back some incredible images 153 00:05:36,400 --> 00:05:38,680 of sediment layers and rocks that were definitely 154 00:05:38,680 --> 00:05:40,920 shaped by water billions of years ago. 155 00:05:40,920 --> 00:05:43,800 Perseverance is doing more than just taking pictures, right? 156 00:05:43,800 --> 00:05:45,520 I mean, it's got all this high-tech gear, 157 00:05:45,520 --> 00:05:48,640 and it's doing experiments that could pave the way for humans 158 00:05:48,640 --> 00:05:49,680 to go to Mars someday. 159 00:05:49,680 --> 00:05:50,680 Exactly. 160 00:05:50,680 --> 00:05:52,120 One of the coolest things it's done 161 00:05:52,120 --> 00:05:55,080 is generate oxygen from the Martian atmosphere. 162 00:05:55,080 --> 00:05:57,080 That technology could be a game changer 163 00:05:57,080 --> 00:05:59,000 for future human missions. 164 00:05:59,000 --> 00:06:01,840 We could make breathable air and even rocket fuel 165 00:06:01,840 --> 00:06:03,120 right there on Mars. 166 00:06:03,120 --> 00:06:05,360 Talk about making Mars feel a bit more like home. 167 00:06:05,360 --> 00:06:06,880 Speaking of breakthroughs, let's talk 168 00:06:06,880 --> 00:06:09,880 about the robots that have made all these discoveries possible. 169 00:06:09,880 --> 00:06:11,200 These rovers are amazing. 170 00:06:11,200 --> 00:06:12,000 They really are. 171 00:06:12,000 --> 00:06:14,520 We wouldn't know nearly as much about Mars without them. 172 00:06:14,520 --> 00:06:17,360 Curiosity, for example, has been roaming around Mars 173 00:06:17,360 --> 00:06:18,600 for over a decade. 174 00:06:18,600 --> 00:06:20,040 How far has it traveled? 175 00:06:20,040 --> 00:06:21,120 Almost 30 kilometers. 176 00:06:21,120 --> 00:06:23,440 That's pretty impressive for a robot on another planet. 177 00:06:23,440 --> 00:06:25,960 It's amazing what humans can build, isn't it? 178 00:06:25,960 --> 00:06:28,280 What are some of the most important things curiosity 179 00:06:28,280 --> 00:06:29,680 has taught us about Mars? 180 00:06:29,680 --> 00:06:31,000 Oh, so much. 181 00:06:31,000 --> 00:06:35,400 It's found evidence of ancient streams, lakes, even groundwater. 182 00:06:35,400 --> 00:06:38,460 It's confirmed that there were organic molecules on Mars, 183 00:06:38,460 --> 00:06:40,800 meaning the ingredients for life were there. 184 00:06:40,800 --> 00:06:43,200 And it's also helped us understand how Mars' climate 185 00:06:43,200 --> 00:06:45,840 changed over time, how it went from being potentially 186 00:06:45,840 --> 00:06:48,200 habitable to the dry planet we see now. 187 00:06:48,200 --> 00:06:49,600 Wow, that's incredible. 188 00:06:49,600 --> 00:06:53,440 What about perseverance and ingenuity, the helicopter? 189 00:06:53,440 --> 00:06:55,520 What makes them different from the other rovers? 190 00:06:55,520 --> 00:06:58,080 Perseverance is collecting rock and soil samples 191 00:06:58,080 --> 00:07:00,000 that will eventually be brought back to Earth. 192 00:07:00,000 --> 00:07:01,560 Wow, that would be amazing. 193 00:07:01,560 --> 00:07:03,960 Imagine holding a piece of Mars in your hand. 194 00:07:03,960 --> 00:07:05,600 What else is perseverance doing? 195 00:07:05,600 --> 00:07:07,680 Well, besides making oxygen, it's 196 00:07:07,680 --> 00:07:10,040 testing out how to navigate autonomously, 197 00:07:10,040 --> 00:07:13,000 which is important for future human explorers. 198 00:07:13,000 --> 00:07:16,520 It even has radar that can look for underground water ice. 199 00:07:16,520 --> 00:07:19,880 It sounds like perseverance is really paving the way 200 00:07:19,880 --> 00:07:21,680 for humans to go to Mars. 201 00:07:21,680 --> 00:07:24,080 And ingenuity, the helicopter, it's 202 00:07:24,080 --> 00:07:26,640 crazy that we can fly something on another planet. 203 00:07:26,640 --> 00:07:28,100 I know, right? 204 00:07:28,100 --> 00:07:31,200 Ingenuity proved that powered flight is possible on Mars, 205 00:07:31,200 --> 00:07:33,240 even with that thin atmosphere. 206 00:07:33,240 --> 00:07:35,480 That opens up so many possibilities 207 00:07:35,480 --> 00:07:36,600 for future missions. 208 00:07:36,600 --> 00:07:38,800 Imagine drones scouting ahead of rovers 209 00:07:38,800 --> 00:07:40,400 or carrying stuff around. 210 00:07:40,400 --> 00:07:42,520 That would be incredible. 211 00:07:42,520 --> 00:07:44,200 OK, we've talked about Mars' past, 212 00:07:44,200 --> 00:07:46,280 but there's one more thing we need to discuss. 213 00:07:46,280 --> 00:07:51,080 Mars' two tiny moons, Phocos and Deimos. 214 00:07:51,080 --> 00:07:52,440 What can you tell us about them? 215 00:07:52,440 --> 00:07:55,520 Phocos and Deimos are a bit of a mystery. 216 00:07:55,520 --> 00:07:58,000 They're both pretty small compared to our moon, 217 00:07:58,000 --> 00:08:00,040 and they're kind of lumpy and potato shaped. 218 00:08:00,040 --> 00:08:02,560 That makes scientists think they might be captured asteroids. 219 00:08:02,560 --> 00:08:03,360 Captured asteroids. 220 00:08:03,360 --> 00:08:04,860 So like they were just floating around, 221 00:08:04,860 --> 00:08:06,040 and Mars grabbing grabbed them. 222 00:08:06,040 --> 00:08:06,780 Yep, pretty much. 223 00:08:06,780 --> 00:08:08,800 And now they're stuck orbiting Mars, 224 00:08:08,800 --> 00:08:10,840 but their stories don't end there. 225 00:08:10,840 --> 00:08:12,600 Oh, what do you mean? 226 00:08:12,600 --> 00:08:14,440 So their destinies are kind of tied to Mars, 227 00:08:14,440 --> 00:08:15,680 but in different ways. 228 00:08:15,680 --> 00:08:17,240 Phobos, the bigger one, it's actually 229 00:08:17,240 --> 00:08:18,840 spiraling in towards Mars. 230 00:08:18,840 --> 00:08:20,560 Mars' gravity is pulling it closer. 231 00:08:20,560 --> 00:08:21,920 So it's going to crash into Mars. 232 00:08:21,920 --> 00:08:23,920 Not quite crash, no, but it's going 233 00:08:23,920 --> 00:08:27,360 to meet a pretty spectacular end. 234 00:08:27,360 --> 00:08:30,160 As Phobos gets closer, it'll cross this line 235 00:08:30,160 --> 00:08:31,400 called the Roche limit. 236 00:08:31,400 --> 00:08:32,360 The Roche limit. 237 00:08:32,360 --> 00:08:32,860 What's that? 238 00:08:32,860 --> 00:08:36,160 It's the point where basically Mars' gravity gets 239 00:08:36,160 --> 00:08:39,720 so strong that it overpowers the gravity holding Phobos 240 00:08:39,720 --> 00:08:40,240 together. 241 00:08:40,240 --> 00:08:42,400 Oh, so Phobos is going to get ripped apart. 242 00:08:42,400 --> 00:08:43,040 Exactly. 243 00:08:43,040 --> 00:08:45,960 And when that happens, it'll create this ring of debris 244 00:08:45,960 --> 00:08:49,120 around Mars, like a cosmic dust cloud. 245 00:08:49,120 --> 00:08:51,400 Whoa, a ring around Mars. 246 00:08:51,400 --> 00:08:52,300 That's pretty wild. 247 00:08:52,300 --> 00:08:53,120 What about Deimos? 248 00:08:53,120 --> 00:08:54,040 What happens to it? 249 00:08:54,040 --> 00:08:57,200 Deimos is actually moving away from Mars very slowly, 250 00:08:57,200 --> 00:08:58,600 but it's drifting further out. 251 00:08:58,600 --> 00:09:01,440 It might even escape Mars' gravity completely one day. 252 00:09:01,440 --> 00:09:05,200 So one moon gets shredded, and the other flies off into space. 253 00:09:05,200 --> 00:09:07,960 The Martian system is a pretty wild place. 254 00:09:07,960 --> 00:09:09,360 OK, we spent a lot of time talking 255 00:09:09,360 --> 00:09:11,440 about water on ancient Mars, but the big question 256 00:09:11,440 --> 00:09:13,400 is, was there ever life? 257 00:09:13,400 --> 00:09:15,040 Could those lakes and rivers have actually 258 00:09:15,040 --> 00:09:17,160 had living things in them? 259 00:09:17,160 --> 00:09:19,960 Well, we know Mars had water, organic molecules, 260 00:09:19,960 --> 00:09:21,200 and energy from the sun. 261 00:09:21,200 --> 00:09:21,440 Yeah. 262 00:09:21,440 --> 00:09:23,360 And those are basically the ingredients you 263 00:09:23,360 --> 00:09:24,600 need for life as we know it. 264 00:09:24,600 --> 00:09:26,680 So the potential was there, but have we 265 00:09:26,680 --> 00:09:29,160 found any actual proof of life on Mars? 266 00:09:29,160 --> 00:09:32,560 Not yet, but there have been some pretty interesting clues. 267 00:09:32,560 --> 00:09:35,600 For example, Curiosity found methane in the Martian 268 00:09:35,600 --> 00:09:36,200 atmosphere. 269 00:09:36,200 --> 00:09:38,840 Methane, like the stuff we use for stoves and stuff? 270 00:09:38,840 --> 00:09:40,080 Yeah, that's the one. 271 00:09:40,080 --> 00:09:42,720 Now, methane can come from geological stuff, 272 00:09:42,720 --> 00:09:44,480 but it can also be made by living things, 273 00:09:44,480 --> 00:09:46,120 specifically microbes. 274 00:09:46,120 --> 00:09:47,960 So the methane Curiosity found could 275 00:09:47,960 --> 00:09:52,280 be a sign of tiny Martian bugs. 276 00:09:52,280 --> 00:09:54,640 That's pretty exciting, but I guess 277 00:09:54,640 --> 00:09:56,720 it's hard to know for sure where the methane came from. 278 00:09:56,720 --> 00:09:58,720 It is, and that's one of the things Perseverance 279 00:09:58,720 --> 00:09:59,800 is trying to figure out. 280 00:09:59,800 --> 00:10:01,340 It's got instruments that can look 281 00:10:01,340 --> 00:10:05,680 for signs of past life in that old lake bed in Jezero Crater. 282 00:10:05,680 --> 00:10:07,720 Fingers crossed it finds something. 283 00:10:07,720 --> 00:10:09,520 It sounds like the search for life on Mars 284 00:10:09,520 --> 00:10:11,760 is a really slow and careful process. 285 00:10:11,760 --> 00:10:15,320 It is, but each new discovery gets us closer to figuring out 286 00:10:15,320 --> 00:10:17,280 if we're alone in the universe or not. 287 00:10:17,280 --> 00:10:19,600 Speaking of pushing boundaries, let's talk about the future 288 00:10:19,600 --> 00:10:21,920 of Mars exploration. 289 00:10:21,920 --> 00:10:24,680 Do you think humans will ever actually go to Mars? 290 00:10:24,680 --> 00:10:26,160 I think it's just a matter of time. 291 00:10:26,160 --> 00:10:28,560 We're already sending robots that can drive around, 292 00:10:28,560 --> 00:10:30,800 collect samples, even make oxygen. 293 00:10:30,800 --> 00:10:32,720 Sending humans is the next step. 294 00:10:32,720 --> 00:10:36,000 It would be amazing, but I bet it would be super challenging. 295 00:10:36,000 --> 00:10:38,920 What are some of the biggest hurdles to getting humans 296 00:10:38,920 --> 00:10:39,720 to Mars? 297 00:10:39,720 --> 00:10:41,400 Well, first, there's the trip itself. 298 00:10:41,400 --> 00:10:43,920 It takes like six to eight months to get to Mars, 299 00:10:43,920 --> 00:10:45,520 and that's just one way. 300 00:10:45,520 --> 00:10:49,840 Astronauts would have to deal with radiation, zero gravity, 301 00:10:49,840 --> 00:10:52,520 and being stuck in a small spacecraft for a long time. 302 00:10:52,520 --> 00:10:53,440 That sounds rough. 303 00:10:53,440 --> 00:10:54,980 And what about once they get to Mars? 304 00:10:54,980 --> 00:10:56,920 What kind of dangers would they face there? 305 00:10:56,920 --> 00:10:58,440 Mars is pretty harsh. 306 00:10:58,440 --> 00:11:01,120 The atmosphere is super thin, so you'd need a spacesuit 307 00:11:01,120 --> 00:11:02,360 to go outside. 308 00:11:02,360 --> 00:11:06,280 The temperature swings wildly, too, like 70 degrees Fahrenheit 309 00:11:06,280 --> 00:11:08,520 during the day and then negative 200 at night. 310 00:11:08,520 --> 00:11:09,960 Bruh, that's cold. 311 00:11:09,960 --> 00:11:11,360 I can only imagine what you'd need 312 00:11:11,360 --> 00:11:12,480 to pack for a trip like that. 313 00:11:12,480 --> 00:11:15,080 And there's no air to breathe on Mars, right? 314 00:11:15,080 --> 00:11:16,920 And the radiation is a problem, too, I guess. 315 00:11:16,920 --> 00:11:18,600 Yeah, and there's also the dust. 316 00:11:18,600 --> 00:11:20,720 It's really fine and gets everywhere. 317 00:11:20,720 --> 00:11:23,520 It could mess with equipment and even be bad for your health. 318 00:11:23,520 --> 00:11:26,600 So getting humans to Mars is a huge challenge, 319 00:11:26,600 --> 00:11:28,960 but it sounds like it would be worth it. 320 00:11:28,960 --> 00:11:31,280 Why are we so obsessed with going to this planet? 321 00:11:31,280 --> 00:11:34,880 For one thing, Mars can teach us about the early solar system. 322 00:11:34,880 --> 00:11:37,720 Studying it might help us understand how planets form, 323 00:11:37,720 --> 00:11:40,520 how they change, maybe even how life started. 324 00:11:40,520 --> 00:11:42,760 It's like a window into the past. 325 00:11:42,760 --> 00:11:44,320 So learning about our own origins 326 00:11:44,320 --> 00:11:46,400 is one reason to go to Mars. 327 00:11:46,400 --> 00:11:47,080 What else? 328 00:11:47,080 --> 00:11:48,760 Humans are explorers. 329 00:11:48,760 --> 00:11:49,720 It's in our nature. 330 00:11:49,720 --> 00:11:52,600 Mars is like the next big frontier, a challenge that 331 00:11:52,600 --> 00:11:54,120 makes us want to push our limits. 332 00:11:54,120 --> 00:11:55,600 Yeah, I get that. 333 00:11:55,600 --> 00:11:57,640 There's something really exciting about exploring 334 00:11:57,640 --> 00:11:59,800 the unknown, but are there any practical reasons 335 00:11:59,800 --> 00:12:00,920 to go to Mars? 336 00:12:00,920 --> 00:12:03,440 Could it benefit humanity in a real way? 337 00:12:03,440 --> 00:12:04,640 Maybe. 338 00:12:04,640 --> 00:12:08,000 Some people think Mars could be a backup plan for humanity, 339 00:12:08,000 --> 00:12:09,920 if something really bad happened to Earth. 340 00:12:09,920 --> 00:12:11,320 That's a scary thought. 341 00:12:11,320 --> 00:12:13,440 And some people even talk about terraforming Mars, 342 00:12:13,440 --> 00:12:15,560 making it more like Earth so we could live there. 343 00:12:15,560 --> 00:12:16,920 Yeah, terraforming. 344 00:12:16,920 --> 00:12:20,480 That would mean changing Mars' atmosphere, warming it up, 345 00:12:20,480 --> 00:12:22,040 getting water flowing again. 346 00:12:22,040 --> 00:12:24,720 It sounds like science fiction, but is it really possible? 347 00:12:24,720 --> 00:12:27,240 It would be incredibly hard, but some scientists 348 00:12:27,240 --> 00:12:28,880 think it could be done eventually. 349 00:12:28,880 --> 00:12:32,760 Imagine a green Mars, a second home for humans. 350 00:12:32,760 --> 00:12:34,680 That would be amazing. 351 00:12:34,680 --> 00:12:38,080 But right now, Mars is still pre-dry and dusty. 352 00:12:38,080 --> 00:12:40,640 It is, but it wasn't always that way. 353 00:12:40,640 --> 00:12:42,720 And who knows what other secrets we'll discover 354 00:12:42,720 --> 00:12:43,880 as we keep exploring? 355 00:12:43,880 --> 00:12:45,960 Well, this deep dive has definitely made me even more 356 00:12:45,960 --> 00:12:47,480 curious about Mars. 357 00:12:47,480 --> 00:12:50,960 We've learned about its watery past, the possibility of life, 358 00:12:50,960 --> 00:12:53,920 the robots exploring it, and even the idea of humans 359 00:12:53,920 --> 00:12:54,960 going there someday. 360 00:12:54,960 --> 00:12:56,560 We've only just scratched the surface. 361 00:12:56,560 --> 00:12:57,920 There's so much more to learn. 362 00:12:57,920 --> 00:12:59,040 Absolutely. 363 00:12:59,040 --> 00:13:01,240 I bet there are tons of surprises waiting for us 364 00:13:01,240 --> 00:13:02,080 on Mars. 365 00:13:02,080 --> 00:13:03,840 But for now, let's take a break and think 366 00:13:03,840 --> 00:13:07,480 about everything we've learned about Mars' ancient past. 367 00:13:07,480 --> 00:13:09,320 We'll be back in a bit to wrap things up 368 00:13:09,320 --> 00:13:13,200 and talk about what the future holds for Mars exploration. 369 00:13:13,200 --> 00:13:15,720 OK, so we've covered a lot about ancient Mars, 370 00:13:15,720 --> 00:13:18,320 its watery past, the hints of life, 371 00:13:18,320 --> 00:13:21,340 the rovers exploring it now, and the idea of humans 372 00:13:21,340 --> 00:13:22,720 going there one day. 373 00:13:22,720 --> 00:13:25,160 But we haven't talked about Mars' moons yet, 374 00:13:25,160 --> 00:13:26,640 Phobos and Dimos. 375 00:13:26,640 --> 00:13:28,280 Oh, yeah, those two. 376 00:13:28,280 --> 00:13:30,040 They're pretty interesting in their own way. 377 00:13:30,040 --> 00:13:31,200 They're not like our moon, are they? 378 00:13:31,200 --> 00:13:33,000 I mean, they're much smaller, and they kind of 379 00:13:33,000 --> 00:13:35,560 look like potatoes just tumbling around Mars. 380 00:13:35,560 --> 00:13:38,960 Yeah, their shape is a big clue about where they came from. 381 00:13:38,960 --> 00:13:40,840 Scientists think they're captured asteroids, 382 00:13:40,840 --> 00:13:44,160 not moons that formed along with Mars, like our moon did. 383 00:13:44,160 --> 00:13:45,120 Captured asteroids. 384 00:13:45,120 --> 00:13:48,480 So Mars just like snagged them with its gravity. 385 00:13:48,480 --> 00:13:49,320 Yep, basically. 386 00:13:49,320 --> 00:13:52,200 It's like a cosmic game of catch, and Mars won. 387 00:13:52,200 --> 00:13:54,560 But their story isn't over yet. 388 00:13:54,560 --> 00:13:56,000 Oh, what do you mean? 389 00:13:56,000 --> 00:13:59,600 Their fates are kind of tied to Mars, but in different ways. 390 00:13:59,600 --> 00:14:01,560 Phobos, the bigger one, is actually 391 00:14:01,560 --> 00:14:03,040 spiraling in towards Mars. 392 00:14:03,040 --> 00:14:05,680 It's getting closer and closer because of Mars' gravity. 393 00:14:05,680 --> 00:14:07,320 Wait, so it's going to crash into Mars? 394 00:14:07,320 --> 00:14:08,960 Not exactly crash, no. 395 00:14:08,960 --> 00:14:11,280 But it's going to get ripped apart. 396 00:14:11,280 --> 00:14:13,560 As it gets closer to Mars, it's going to cross this line 397 00:14:13,560 --> 00:14:15,200 called the Roche limit. 398 00:14:15,200 --> 00:14:15,920 Roche limit? 399 00:14:15,920 --> 00:14:16,520 What's that? 400 00:14:16,520 --> 00:14:19,440 It's the point where Mars' gravity gets so strong 401 00:14:19,440 --> 00:14:22,520 that it overpowers the gravity holding Phobos together. 402 00:14:22,520 --> 00:14:25,200 Oh, so Phobos is going to like explode. 403 00:14:25,200 --> 00:14:25,840 Kind of. 404 00:14:25,840 --> 00:14:28,240 It'll get torn to shreds by Mars' gravity 405 00:14:28,240 --> 00:14:30,680 and create this ring of debris around the planet, 406 00:14:30,680 --> 00:14:34,400 like Saturn's rings, but made of Phobos bits. 407 00:14:34,400 --> 00:14:37,000 Wow, a ring around Mars. 408 00:14:37,000 --> 00:14:38,360 That's a crazy thought. 409 00:14:38,360 --> 00:14:39,680 So what about Deimos? 410 00:14:39,680 --> 00:14:41,000 Does it get shredded too? 411 00:14:41,000 --> 00:14:41,480 Nope. 412 00:14:41,480 --> 00:14:44,920 Deimos is actually moving away from Mars slowly, 413 00:14:44,920 --> 00:14:46,440 but it's getting further away. 414 00:14:46,440 --> 00:14:49,280 It might even escape Mars' gravity entirely one day 415 00:14:49,280 --> 00:14:51,160 and just like float off into space. 416 00:14:51,160 --> 00:14:55,160 So one moon gets ripped apart and the other one escapes. 417 00:14:55,160 --> 00:14:58,120 The Martian system is a pretty wild place. 418 00:14:58,120 --> 00:15:00,320 Well, I think we've covered pretty much everything 419 00:15:00,320 --> 00:15:02,080 there is to know about ancient Mars. 420 00:15:02,080 --> 00:15:05,440 It's watery past, the hints of life, 421 00:15:05,440 --> 00:15:08,760 the rovers exploring it now, and the possibility 422 00:15:08,760 --> 00:15:10,560 of humans going there someday. 423 00:15:10,560 --> 00:15:11,920 It's been an incredible journey. 424 00:15:11,920 --> 00:15:13,360 It has been fascinating, hasn't it? 425 00:15:13,360 --> 00:15:14,760 And it's only the beginning. 426 00:15:14,760 --> 00:15:16,520 There's so much more to discover on Mars. 427 00:15:16,520 --> 00:15:18,280 Yeah, who knows what other secrets are 428 00:15:18,280 --> 00:15:19,640 waiting to be uncovered? 429 00:15:19,640 --> 00:15:21,960 Maybe we'll find proof that life existed there 430 00:15:21,960 --> 00:15:23,640 or even that it still exists today. 431 00:15:23,640 --> 00:15:24,760 That would be incredible. 432 00:15:24,760 --> 00:15:26,280 It's a big question, isn't it? 433 00:15:26,280 --> 00:15:27,880 Are we alone in the universe? 434 00:15:27,880 --> 00:15:31,240 It's a question that will keep driving us to explore Mars 435 00:15:31,240 --> 00:15:33,120 and the rest of the cosmos. 436 00:15:33,120 --> 00:15:34,960 Well, thanks for joining us on this deep dive. 437 00:15:34,960 --> 00:15:37,120 It's been a pleasure talking about Mars with you. 438 00:15:37,120 --> 00:15:38,640 The pleasure was all mine. 439 00:15:38,640 --> 00:15:40,520 And for all you space fans out there, 440 00:15:40,520 --> 00:15:43,000 don't forget to follow and subscribe to Cosmos 441 00:15:43,000 --> 00:15:46,200 in a Pod and our YouTube channel for more explorations 442 00:15:46,200 --> 00:15:47,320 of the universe. 443 00:15:47,320 --> 00:15:50,480 Keep looking up and keep wondering.