1 00:00:00,766 --> 00:00:02,833 ♪ ♪ 2 00:00:06,100 --> 00:00:09,000 NARRATOR: A total solar eclipse. 3 00:00:09,000 --> 00:00:10,666 (people talking in background) 4 00:00:10,666 --> 00:00:13,200 NARRATOR: It's a rare and astonishing natural phenomenon. 5 00:00:13,200 --> 00:00:16,933 ♪ ♪ 6 00:00:16,933 --> 00:00:18,233 HAKEEM OLUSEYI: Seeing a total solar eclipse 7 00:00:18,233 --> 00:00:20,266 is, like, "What?!" 8 00:00:20,266 --> 00:00:22,200 You know, you just never forget it. 9 00:00:22,200 --> 00:00:23,866 ♪ ♪ 10 00:00:23,866 --> 00:00:28,000 NARRATOR: Solar eclipses have filled people with wonder 11 00:00:28,000 --> 00:00:29,700 since the earliest times. 12 00:00:29,700 --> 00:00:31,300 It connects us with the past, 13 00:00:31,300 --> 00:00:32,766 our predecessors. 14 00:00:32,766 --> 00:00:34,233 They observed the same thing we see today 15 00:00:34,233 --> 00:00:36,100 whenever we look at an eclipse. 16 00:00:36,100 --> 00:00:37,500 (cheers) 17 00:00:37,500 --> 00:00:39,466 AMIR CASPI: You feel a connection. 18 00:00:39,466 --> 00:00:42,500 I am a part of the universe, I am a part of the solar system, 19 00:00:42,500 --> 00:00:44,866 I am a part of this celestial event. 20 00:00:45,900 --> 00:00:49,133 NARRATOR: Can scientists seize these precious moments of darkness 21 00:00:49,133 --> 00:00:53,266 to explore a region of the sun normally invisible... 22 00:00:54,900 --> 00:00:58,733 ...its outer atmosphere, the solar corona? 23 00:00:58,733 --> 00:01:01,400 GRANT TREMBLAY: The solar corona is one of the great keyholes 24 00:01:01,400 --> 00:01:03,600 to peer into, to truly understand 25 00:01:03,600 --> 00:01:05,766 the behavior of the sun. 26 00:01:05,766 --> 00:01:09,666 NARRATOR: Behaviors like violent eruptions from the corona 27 00:01:09,666 --> 00:01:11,933 can cause huge solar storms. 28 00:01:11,933 --> 00:01:13,633 MICHAEL WONG: The largest solar storms 29 00:01:13,633 --> 00:01:18,000 could really destabilize most of the world's technology. 30 00:01:18,000 --> 00:01:20,933 NARRATOR: Plunging cities into darkness. 31 00:01:20,933 --> 00:01:23,900 With the help of eclipses, 32 00:01:23,900 --> 00:01:27,533 can researchers decode these dangerous blasts 33 00:01:27,533 --> 00:01:30,566 and, one day, learn to predict them? 34 00:01:31,933 --> 00:01:34,600 ANJALI TRIPATHI: It's completely extraordinary 35 00:01:34,600 --> 00:01:36,966 that nature gives us this opportunity 36 00:01:36,966 --> 00:01:38,700 to turn off the lights. 37 00:01:38,700 --> 00:01:41,233 NARRATOR: While millions will enjoy the spectacle, 38 00:01:41,233 --> 00:01:45,400 scientists are among the most avid eclipse chasers, 39 00:01:45,400 --> 00:01:48,733 studying the sun on the ground, 40 00:01:48,733 --> 00:01:50,266 in the air, 41 00:01:50,266 --> 00:01:53,133 and touching the corona itself. 42 00:01:53,133 --> 00:01:54,766 Their goal: 43 00:01:54,766 --> 00:01:56,066 to better understand 44 00:01:56,066 --> 00:01:59,400 our most important celestial neighbor. 45 00:01:59,400 --> 00:02:02,600 "Great American Eclipse." 46 00:02:02,600 --> 00:02:05,200 Right now, on "NOVA." 47 00:02:05,200 --> 00:02:14,066 ♪ ♪ 48 00:02:31,500 --> 00:02:36,166 NARRATOR: It's one of nature's greatest spectacles. 49 00:02:39,100 --> 00:02:41,000 OLUSEYI: A total solar eclipse 50 00:02:41,000 --> 00:02:43,633 is like the universe just walked up to your door 51 00:02:43,633 --> 00:02:45,466 and said, "Hey! Here I am! 52 00:02:45,466 --> 00:02:47,533 I'm dynamic, and I'm doing stuff!" 53 00:02:47,533 --> 00:02:49,533 ♪ ♪ 54 00:02:49,533 --> 00:02:52,100 NARRATOR: And on April 8, 2024, 55 00:02:52,100 --> 00:02:54,466 everybody in the lower 48 states 56 00:02:54,466 --> 00:02:58,466 can experience at least a partial solar eclipse-- 57 00:02:58,466 --> 00:02:59,733 weather permitting. 58 00:02:59,733 --> 00:03:05,033 ♪ ♪ 59 00:03:05,033 --> 00:03:08,500 For the 31.5 million people 60 00:03:08,500 --> 00:03:11,000 who live in the path of totality, 61 00:03:11,000 --> 00:03:16,200 the disc of the sun will completely disappear. 62 00:03:19,066 --> 00:03:20,766 TRIPATHI: It's very emotional. 63 00:03:20,766 --> 00:03:23,300 The world stops for a moment, 64 00:03:23,300 --> 00:03:25,300 and you are surrounded 65 00:03:25,300 --> 00:03:29,466 by a completely different universe. 66 00:03:29,466 --> 00:03:33,566 ♪ ♪ 67 00:03:36,333 --> 00:03:39,366 ♪ ♪ 68 00:03:39,366 --> 00:03:42,733 NARRATOR: A total solar eclipse only happens 69 00:03:42,733 --> 00:03:46,366 because of an astonishing coincidence. 70 00:03:46,366 --> 00:03:50,233 ♪ ♪ 71 00:03:50,233 --> 00:03:55,066 The Earth, moon, and sun must perfectly align, 72 00:03:55,066 --> 00:03:58,100 so the moon blocks the sun's light. 73 00:03:58,100 --> 00:04:00,166 ♪ ♪ 74 00:04:00,166 --> 00:04:03,800 The diameter of the moon is around 400 times smaller 75 00:04:03,800 --> 00:04:05,900 than that of the sun. 76 00:04:05,900 --> 00:04:08,933 But the moon also just so happens to be 77 00:04:08,933 --> 00:04:12,733 roughly 400 times closer to the Earth, 78 00:04:12,733 --> 00:04:16,400 so it appears the same size in the sky as the sun. 79 00:04:18,166 --> 00:04:20,733 When it passes in front of the sun, 80 00:04:20,733 --> 00:04:22,666 it blocks the sun's light, 81 00:04:22,666 --> 00:04:24,766 casting a shadow on the Earth 82 00:04:24,766 --> 00:04:28,900 that plunges everywhere it passes into darkness. 83 00:04:31,766 --> 00:04:34,100 CASPI: That experience is surreal. 84 00:04:34,100 --> 00:04:37,100 It is not like any other experience 85 00:04:37,100 --> 00:04:39,366 that a human being can have. 86 00:04:40,500 --> 00:04:44,966 NARRATOR: At 11:07 a.m. local time on Monday, April 8, 87 00:04:44,966 --> 00:04:46,966 the darkest part of the moon's shadow 88 00:04:46,966 --> 00:04:49,233 hits Mexico's Pacific Coast. 89 00:04:49,233 --> 00:04:52,400 Traveling at more than 1,500 miles an hour, 90 00:04:52,400 --> 00:04:55,500 the shadow is over 100 miles wide, 91 00:04:55,500 --> 00:04:58,633 passing over Dallas at 1:40 p.m., 92 00:04:58,633 --> 00:05:02,233 through Arkansas and Illinois, 93 00:05:02,233 --> 00:05:06,133 over Indianapolis at 3:06 p.m. 94 00:05:06,133 --> 00:05:10,066 and Buffalo at 3:18 p.m. local time. 95 00:05:10,066 --> 00:05:13,300 This shadow will exit continental North America 96 00:05:13,300 --> 00:05:18,300 at 4:38 p.m., after touching 15 U.S. states. 97 00:05:24,500 --> 00:05:27,733 TRIPATHI: It's a completely 98 00:05:27,733 --> 00:05:29,166 extraordinary coincidence 99 00:05:29,166 --> 00:05:32,233 that we get the angles just right to make this work. 100 00:05:32,233 --> 00:05:35,066 If we were anywhere else in the solar system, 101 00:05:35,066 --> 00:05:38,933 we would not have this perfect alignment. 102 00:05:40,733 --> 00:05:44,133 NARRATOR: And if the moon were any closer to Earth or any larger, 103 00:05:44,133 --> 00:05:46,600 it would completely obscure 104 00:05:46,600 --> 00:05:49,000 the object the scientists are trying to study... 105 00:05:50,833 --> 00:05:53,700 ...the sun's outer atmosphere. 106 00:05:53,700 --> 00:05:56,866 It's called the corona. 107 00:05:56,866 --> 00:05:59,500 (people talking in background) 108 00:05:59,500 --> 00:06:01,266 NARRATOR: During a total eclipse, 109 00:06:01,266 --> 00:06:03,200 the corona comes into view 110 00:06:03,200 --> 00:06:08,433 as the moon passes in front of the sun. 111 00:06:08,433 --> 00:06:10,633 So the moon has just made contact 112 00:06:10,633 --> 00:06:12,533 and started covering the sun's disc, 113 00:06:12,533 --> 00:06:15,633 and we call that first contact. 114 00:06:15,633 --> 00:06:17,166 And then, 115 00:06:17,166 --> 00:06:19,400 the disc of the moon slides down 116 00:06:19,400 --> 00:06:21,966 and covers the disc of the sun. 117 00:06:23,566 --> 00:06:26,300 And we call that second contact. 118 00:06:30,433 --> 00:06:32,033 This is the magic moment, 119 00:06:32,033 --> 00:06:33,800 this is what we're all waiting for 120 00:06:33,800 --> 00:06:35,166 in a total solar eclipse. 121 00:06:35,166 --> 00:06:37,500 This is totality. 122 00:06:37,500 --> 00:06:39,800 The entire disc of the sun is covered, 123 00:06:39,800 --> 00:06:42,666 and that allows the sun's atmosphere 124 00:06:42,666 --> 00:06:43,933 that we call the corona 125 00:06:43,933 --> 00:06:45,866 to emerge and be visible. 126 00:06:45,866 --> 00:06:48,300 It just... (makes sound effect) 127 00:06:48,300 --> 00:06:49,433 ...pops out, and you're just, like... 128 00:06:49,433 --> 00:06:51,200 (gasps): Wow! 129 00:06:51,200 --> 00:06:55,500 ♪ ♪ 130 00:06:55,500 --> 00:06:57,100 NARRATOR: But scientists on the ground 131 00:06:57,100 --> 00:06:59,766 only get a chance to study the corona 132 00:06:59,766 --> 00:07:02,400 if they're in the right spot 133 00:07:02,400 --> 00:07:05,466 and if the weather cooperates. 134 00:07:05,466 --> 00:07:08,866 The bane of every eclipse chaser is clouds and other weather 135 00:07:08,866 --> 00:07:10,200 that keep them from seeing totality. 136 00:07:10,200 --> 00:07:14,166 ♪ ♪ 137 00:07:14,166 --> 00:07:17,633 NARRATOR: Statistically, Mexico should have the clearest skies 138 00:07:17,633 --> 00:07:20,100 along the path of totality during April, 139 00:07:20,100 --> 00:07:23,700 with Texas a runner-up. 140 00:07:23,700 --> 00:07:25,800 But most places north of Missouri 141 00:07:25,800 --> 00:07:30,933 have less than 50% chance of clear skies. 142 00:07:30,933 --> 00:07:33,833 Standing on the center-line of the moon's shadow 143 00:07:33,833 --> 00:07:36,666 gives you the most time to view the corona. 144 00:07:41,500 --> 00:07:44,633 The last total solar eclipse to pass across the U.S. 145 00:07:44,633 --> 00:07:48,166 was in 2017. 146 00:07:48,166 --> 00:07:49,933 It was an unforgettable spectacle, 147 00:07:49,933 --> 00:07:54,933 witnessed by an estimated 215 million people. 148 00:07:54,933 --> 00:07:58,333 But the maximum duration of totality 149 00:07:58,333 --> 00:08:00,766 was just two minutes and 42 seconds. 150 00:08:00,766 --> 00:08:02,533 (crowd cheering) 151 00:08:02,533 --> 00:08:06,033 NARRATOR: In 2024, the maximum duration 152 00:08:06,033 --> 00:08:07,633 is almost twice as long, 153 00:08:07,633 --> 00:08:10,933 lasting four minutes and 28 seconds. 154 00:08:10,933 --> 00:08:15,133 ♪ ♪ 155 00:08:15,133 --> 00:08:16,633 During the eclipse, that gives you 156 00:08:16,633 --> 00:08:19,100 a really unique opportunity to suddenly see this corona 157 00:08:19,100 --> 00:08:22,800 and to study it scientifically. 158 00:08:22,800 --> 00:08:25,866 The corona is less bright-- quite a lot less bright-- 159 00:08:25,866 --> 00:08:27,700 than the main part of the sun, 160 00:08:27,700 --> 00:08:28,866 so, normally, 161 00:08:28,866 --> 00:08:30,233 when you observe the sun, 162 00:08:30,233 --> 00:08:33,633 you're not able to see that corona. 163 00:08:33,633 --> 00:08:37,133 ♪ ♪ 164 00:08:37,133 --> 00:08:40,866 NARRATOR: The sun is so bright that until the moon 165 00:08:40,866 --> 00:08:42,666 completely covers it, the only way 166 00:08:42,666 --> 00:08:46,733 to view it safely is to use certified solar filters 167 00:08:46,733 --> 00:08:49,333 or eclipse-viewing glasses. 168 00:08:49,333 --> 00:08:52,066 (crowd cheering and clapping) 169 00:08:52,066 --> 00:08:55,033 TRIPATHI: It's really exciting to watch. 170 00:08:55,033 --> 00:08:58,033 But there is this real danger of blinding yourself, 171 00:08:58,033 --> 00:09:01,533 or causing significant eye damage. 172 00:09:01,533 --> 00:09:04,633 WONG: You've got to get these special eclipse glasses, 173 00:09:04,633 --> 00:09:06,800 this special eyewear, that block out 174 00:09:06,800 --> 00:09:11,533 99.999% of the sunlight 175 00:09:11,533 --> 00:09:13,366 and virtually all of the U.V. light 176 00:09:13,366 --> 00:09:15,333 that would really damage your eyes. 177 00:09:15,333 --> 00:09:17,133 ♪ ♪ 178 00:09:17,133 --> 00:09:19,900 NARRATOR: The human eye has a lens. 179 00:09:19,900 --> 00:09:22,766 It helps focus light onto the retina, 180 00:09:22,766 --> 00:09:27,333 which contains over 100 million light-sensitive receptor cells. 181 00:09:29,133 --> 00:09:32,300 These cells translate light into electrical signals 182 00:09:32,300 --> 00:09:34,533 that the brain can read as images. 183 00:09:36,133 --> 00:09:38,433 Staring directly at the sun, 184 00:09:38,433 --> 00:09:42,666 the focused beam from the lens becomes so intense, 185 00:09:42,666 --> 00:09:46,600 it can easily burn the cells in the retina, 186 00:09:46,600 --> 00:09:50,100 leaving a permanent blind spot. 187 00:09:50,100 --> 00:09:52,800 ♪ ♪ 188 00:09:52,800 --> 00:09:56,166 Eclipse glasses will prevent this. 189 00:09:56,166 --> 00:09:59,066 But the magnifying effect of telescopes and binoculars 190 00:09:59,066 --> 00:10:01,933 can still destroy your eye. 191 00:10:03,033 --> 00:10:07,700 So, you see what that light did to these viewing glasses? 192 00:10:07,700 --> 00:10:09,500 It would do the same thing to your eye. 193 00:10:09,500 --> 00:10:12,366 You'd blind yourself instantly. 194 00:10:12,366 --> 00:10:13,766 Even if you're wearing 195 00:10:13,766 --> 00:10:16,033 certified solar viewing glasses, 196 00:10:16,033 --> 00:10:18,700 you cannot look through a telescope with them 197 00:10:18,700 --> 00:10:23,033 unless there is a telescopic solar filter 198 00:10:23,033 --> 00:10:26,200 on the telescope itself. 199 00:10:26,200 --> 00:10:30,066 ♪ ♪ 200 00:10:30,066 --> 00:10:32,533 TRIPATHI: During totality, that total darkness, 201 00:10:32,533 --> 00:10:34,800 you can actually take off your solar glasses 202 00:10:34,800 --> 00:10:37,333 and stare at the sun for just a brief moment 203 00:10:37,333 --> 00:10:39,300 and appreciate that darkness, 204 00:10:39,300 --> 00:10:41,466 with that coronal light around it, 205 00:10:41,466 --> 00:10:43,333 which is one of these amazing moments 206 00:10:43,333 --> 00:10:45,066 that you can only experience 207 00:10:45,066 --> 00:10:48,133 if you're actually witnessing total solar eclipse. 208 00:10:48,133 --> 00:10:49,666 ♪ ♪ 209 00:10:49,666 --> 00:10:51,733 NARRATOR: But on April 8, 210 00:10:51,733 --> 00:10:54,366 what about the people who are not lucky enough 211 00:10:54,366 --> 00:10:58,333 to live within or travel to the path of totality? 212 00:10:58,333 --> 00:11:02,033 What can they see? 213 00:11:02,033 --> 00:11:04,133 The good news is that nearly everyone 214 00:11:04,133 --> 00:11:07,200 in the U.S. lower 48 has a chance to experience 215 00:11:07,200 --> 00:11:10,166 at least a partial eclipse. 216 00:11:10,166 --> 00:11:13,633 ♪ ♪ 217 00:11:13,633 --> 00:11:16,366 You see roughly ten percent more of the sun 218 00:11:16,366 --> 00:11:20,633 with every 200 miles of distance from the path of totality. 219 00:11:23,433 --> 00:11:25,900 For example, 220 00:11:25,900 --> 00:11:28,100 in Atlanta, Georgia, the moon covers 221 00:11:28,100 --> 00:11:31,366 just over 80% of the sun's disc. 222 00:11:31,366 --> 00:11:33,633 In Los Angeles, California, 223 00:11:33,633 --> 00:11:37,100 around 50%. 224 00:11:37,100 --> 00:11:38,800 While in Portland, Oregon, 225 00:11:38,800 --> 00:11:41,766 just over 20% of the sun is blocked. 226 00:11:41,766 --> 00:11:44,200 ♪ ♪ 227 00:11:44,200 --> 00:11:47,833 Imagine looking up at the sky-- with proper eye protection-- 228 00:11:47,833 --> 00:11:50,600 and noticing that part of the sun has gone missing. 229 00:11:50,600 --> 00:11:54,433 That is the joy and wonder of a partial solar eclipse. 230 00:11:54,433 --> 00:11:57,900 So even if you don't experience total darkness, 231 00:11:57,900 --> 00:12:00,766 you are still experiencing this wondrous phenomenon. 232 00:12:02,866 --> 00:12:04,666 ♪ ♪ 233 00:12:04,666 --> 00:12:07,400 NARRATOR: But only the darkness of a total eclipse 234 00:12:07,400 --> 00:12:11,200 allows us to see the sun's outer atmosphere, 235 00:12:11,200 --> 00:12:13,233 the corona. 236 00:12:15,233 --> 00:12:18,600 The corona's elusive, pearly-white cloud is made 237 00:12:18,600 --> 00:12:21,600 from a state of matter rarely found on Earth 238 00:12:21,600 --> 00:12:24,100 called plasma. 239 00:12:25,933 --> 00:12:28,966 OLUSEYI: Sometimes we call plasma the fourth state of matter. 240 00:12:28,966 --> 00:12:30,900 There are many different states of matter, 241 00:12:30,900 --> 00:12:34,266 but the ones we're accustomed to here on Earth are four: 242 00:12:34,266 --> 00:12:38,466 solids, liquids, gases, and plasmas. 243 00:12:38,466 --> 00:12:41,800 NARRATOR: If you heat a gas to a high enough temperature, 244 00:12:41,800 --> 00:12:45,800 some of the electrons in its atoms fly off, 245 00:12:45,800 --> 00:12:49,066 leaving positively charged ions. 246 00:12:49,066 --> 00:12:52,466 This super-hot mixture of ions and electrons 247 00:12:52,466 --> 00:12:56,900 is known as a plasma. 248 00:12:56,900 --> 00:12:59,566 We don't see plasmas very often on Earth. 249 00:12:59,566 --> 00:13:01,100 Very briefly, 250 00:13:01,100 --> 00:13:02,800 as part of a lightning bolt, there'll be a plasma. 251 00:13:02,800 --> 00:13:05,000 (lightning crashing, thunder booming) 252 00:13:05,000 --> 00:13:08,266 But the sun, especially its corona, 253 00:13:08,266 --> 00:13:11,266 is this incredible plasma. 254 00:13:11,266 --> 00:13:13,533 ♪ ♪ 255 00:13:13,533 --> 00:13:16,333 NARRATOR: Although rare on Earth, 256 00:13:16,333 --> 00:13:17,866 plasma is a common state of matter 257 00:13:17,866 --> 00:13:20,333 in the visible universe. 258 00:13:20,333 --> 00:13:22,933 The stars we see in the sky are made from it, 259 00:13:22,933 --> 00:13:26,566 including our sun. 260 00:13:28,300 --> 00:13:31,966 With 1.3 million times more volume than Earth, 261 00:13:31,966 --> 00:13:35,200 our sun is a dense ball of plasma, 262 00:13:35,200 --> 00:13:37,333 made from hydrogen, helium, 263 00:13:37,333 --> 00:13:41,966 and smaller amounts of other elements. 264 00:13:43,300 --> 00:13:45,700 The heat that creates this plasma 265 00:13:45,700 --> 00:13:48,733 is generated in the sun's core. 266 00:13:51,266 --> 00:13:53,266 Here, the extreme heat and pressure 267 00:13:53,266 --> 00:13:57,566 force the hydrogen nuclei to fuse together, 268 00:13:57,566 --> 00:13:59,900 creating helium 269 00:13:59,900 --> 00:14:02,300 and releasing vast amounts of energy 270 00:14:02,300 --> 00:14:06,366 as photons. 271 00:14:06,366 --> 00:14:09,333 This nuclear fusion heats the core 272 00:14:09,333 --> 00:14:14,000 to 27 million degrees Fahrenheit. 273 00:14:14,000 --> 00:14:15,900 From here, the photons 274 00:14:15,900 --> 00:14:19,200 pass through the dense inner layer of the sun. 275 00:14:19,200 --> 00:14:21,833 ♪ ♪ 276 00:14:21,833 --> 00:14:24,766 The temperature of the plasma gradually drops, 277 00:14:24,766 --> 00:14:28,033 as the photons reach the sun's visible surface, 278 00:14:28,033 --> 00:14:31,033 known as the photosphere. 279 00:14:31,033 --> 00:14:34,700 ♪ ♪ 280 00:14:34,700 --> 00:14:37,400 Here, rising and sinking plasma 281 00:14:37,400 --> 00:14:42,900 forms a seething surface of light and dark areas. 282 00:14:42,900 --> 00:14:46,133 Around the photosphere is the corona, 283 00:14:46,133 --> 00:14:50,066 the sun's outer atmosphere of extremely diffuse plasma, 284 00:14:50,066 --> 00:14:52,566 extending far into space. 285 00:14:54,700 --> 00:14:56,533 WONG: The corona is called the corona 286 00:14:56,533 --> 00:14:59,233 because it sort of has this crown-like shape, 287 00:14:59,233 --> 00:15:01,966 and "corona" in Latin is the word for crown. 288 00:15:03,300 --> 00:15:05,500 It's thin and wispy, and hence very dim 289 00:15:05,500 --> 00:15:08,200 compared to the actual surface of the sun, 290 00:15:08,200 --> 00:15:10,200 so we need that surface to be blocked 291 00:15:10,200 --> 00:15:11,900 in order to see the corona. 292 00:15:11,900 --> 00:15:14,766 ♪ ♪ 293 00:15:14,766 --> 00:15:17,266 NARRATOR: But what more could science discover 294 00:15:17,266 --> 00:15:21,600 if we could get closer? 295 00:15:21,600 --> 00:15:25,400 (machine whirring loudly) 296 00:15:25,400 --> 00:15:27,333 In 2018, 297 00:15:27,333 --> 00:15:31,000 NASA launches a pioneering space probe 298 00:15:31,000 --> 00:15:33,100 to do exactly that. 299 00:15:33,100 --> 00:15:37,066 It's called the Parker Solar Probe. 300 00:15:37,066 --> 00:15:38,566 Onboard are instruments that will change 301 00:15:38,566 --> 00:15:40,233 our understanding of the sun 302 00:15:40,233 --> 00:15:42,133 and study its extreme behavior. 303 00:15:42,133 --> 00:15:45,133 (people talking in background) 304 00:15:45,133 --> 00:15:48,466 KELLY KORRECK: Parker Solar Probe was conceived in 1958. 305 00:15:48,466 --> 00:15:51,166 There was a big, long wait 306 00:15:51,166 --> 00:15:52,533 because our technology 307 00:15:52,533 --> 00:15:54,166 was trying to catch up with our dreams. 308 00:15:54,166 --> 00:15:55,666 MAN: Go Delta. 309 00:15:55,666 --> 00:15:58,166 MAN 2: Go PSP. 310 00:15:58,166 --> 00:16:00,900 ♪ ♪ 311 00:16:00,900 --> 00:16:04,000 (inaudible) look good and in full thrust mode. 312 00:16:04,000 --> 00:16:07,366 ♪ ♪ 313 00:16:07,366 --> 00:16:09,966 KORRECK: Solar flares are large magnetic eruptions 314 00:16:09,966 --> 00:16:11,433 which can cause particles 315 00:16:11,433 --> 00:16:14,066 to come streaming towards the Earth. 316 00:16:14,066 --> 00:16:16,466 We also have coronal mass ejections, 317 00:16:16,466 --> 00:16:17,966 which are billions of tons of material, 318 00:16:17,966 --> 00:16:20,466 equivalent to 80 million school buses, 319 00:16:20,466 --> 00:16:23,000 racing towards us at millions of miles an hour 320 00:16:23,000 --> 00:16:26,733 that can do things like interfere with satellites 321 00:16:26,733 --> 00:16:30,300 or affect our power grid. 322 00:16:30,300 --> 00:16:32,400 NARRATOR: But even when the sun is quiet, 323 00:16:32,400 --> 00:16:35,266 a lower-intensity, steady outflow 324 00:16:35,266 --> 00:16:37,100 of charged solar particles 325 00:16:37,100 --> 00:16:40,533 forms what's called solar wind. 326 00:16:40,533 --> 00:16:42,766 ♪ ♪ 327 00:16:42,766 --> 00:16:45,400 KORRECK: It has been a mystery as to why that wind 328 00:16:45,400 --> 00:16:50,000 is accelerating constantly off the solar surface. 329 00:16:50,000 --> 00:16:54,400 (engine roaring) 330 00:16:54,400 --> 00:16:56,433 Parker Solar Probe is named for Eugene Parker, 331 00:16:56,433 --> 00:16:59,833 a very dear man who had a theory 332 00:16:59,833 --> 00:17:02,733 about the origins of the solar wind. 333 00:17:02,733 --> 00:17:04,966 That paper 334 00:17:04,966 --> 00:17:06,500 laid the groundwork for the study 335 00:17:06,500 --> 00:17:09,800 of the solar wind that we know today. 336 00:17:09,800 --> 00:17:12,833 ♪ ♪ 337 00:17:12,833 --> 00:17:16,166 Parker is the fastest human-made object. 338 00:17:16,166 --> 00:17:21,200 It'll reach speeds of 430,000 miles per hour. 339 00:17:21,200 --> 00:17:24,900 NARRATOR: A four-and-a-half-inch-thick heat shield 340 00:17:24,900 --> 00:17:27,500 made from a carbon composite, 341 00:17:27,500 --> 00:17:29,966 painted with heat-reflecting ceramic paint, 342 00:17:29,966 --> 00:17:32,300 protects the probe. 343 00:17:32,300 --> 00:17:34,200 KORRECK: The top heat shield is going to 344 00:17:34,200 --> 00:17:37,100 experience 1,300 degrees Celsius, 345 00:17:37,100 --> 00:17:40,833 and in the back, it's going to be room temperature. 346 00:17:40,833 --> 00:17:43,466 It's important to have this huge temperature difference. 347 00:17:43,466 --> 00:17:45,833 Those instruments in the back need to operate 348 00:17:45,833 --> 00:17:47,766 in about room temperature. 349 00:17:49,166 --> 00:17:52,533 NARRATOR: Since 2018, the probe's elongated orbit 350 00:17:52,533 --> 00:17:55,533 takes it progressively closer and closer to the sun. 351 00:17:55,533 --> 00:18:00,400 ♪ ♪ 352 00:18:00,400 --> 00:18:02,800 And in December 2021, 353 00:18:02,800 --> 00:18:05,700 the team announces a major breakthrough. 354 00:18:05,700 --> 00:18:09,800 ♪ ♪ 355 00:18:09,800 --> 00:18:13,433 KORRECK: Parker Solar Probe had touched the sun. 356 00:18:13,433 --> 00:18:16,466 This is definitely a first. 357 00:18:16,466 --> 00:18:18,766 This is the monumental achievement 358 00:18:18,766 --> 00:18:20,933 of being able to say that we were inside 359 00:18:20,933 --> 00:18:22,566 the atmosphere of a star. 360 00:18:22,566 --> 00:18:24,833 ♪ ♪ 361 00:18:24,833 --> 00:18:27,700 NARRATOR: Some scientists assumed the sun's atmosphere 362 00:18:27,700 --> 00:18:30,433 was smooth, like a ball. 363 00:18:30,433 --> 00:18:33,200 This is the boundary where the solar wind escapes 364 00:18:33,200 --> 00:18:36,533 the sun's gravity and magnetic pull, 365 00:18:36,533 --> 00:18:40,500 and spills out into space. 366 00:18:40,500 --> 00:18:43,000 But Parker's data shows it is undulating, 367 00:18:43,000 --> 00:18:46,900 complex, and dynamic. 368 00:18:46,900 --> 00:18:49,833 As the probe barrels through the sun's atmosphere, 369 00:18:49,833 --> 00:18:52,766 it runs into huge magnetic structures 370 00:18:52,766 --> 00:18:54,600 rising from the surface, 371 00:18:54,600 --> 00:18:58,200 called coronal pseudo-streamers. 372 00:18:58,200 --> 00:19:00,433 These could be responsible 373 00:19:00,433 --> 00:19:02,266 for the rugged edge of the sun's atmosphere. 374 00:19:05,700 --> 00:19:09,833 KORRECK: The particles of the solar wind are a plasma. 375 00:19:09,833 --> 00:19:12,533 We are just beginning to learn more and more 376 00:19:12,533 --> 00:19:14,000 about how they're thrown out of the sun. 377 00:19:15,400 --> 00:19:17,400 Knowing the shape of that surface 378 00:19:17,400 --> 00:19:20,200 is really important to understand the formation 379 00:19:20,200 --> 00:19:22,700 and acceleration of the solar wind towards us. 380 00:19:22,700 --> 00:19:27,133 ♪ ♪ 381 00:19:27,133 --> 00:19:29,400 NARRATOR: The strength of the solar wind 382 00:19:29,400 --> 00:19:32,666 depends on the behavior of the sun's magnetic field, 383 00:19:32,666 --> 00:19:35,566 which varies according to an 11-year cycle 384 00:19:35,566 --> 00:19:39,366 called the solar cycle. 385 00:19:39,366 --> 00:19:44,800 And according to that pattern, the expected activity in 2024 386 00:19:44,800 --> 00:19:47,233 could make the April eclipse 387 00:19:47,233 --> 00:19:50,900 particularly interesting for scientists. 388 00:19:50,900 --> 00:19:54,333 KORRECK: In 2017, the sun was at a minimum. 389 00:19:54,333 --> 00:19:57,066 In 2024, the difference is going to be 390 00:19:57,066 --> 00:19:58,533 that the sun will be very active. 391 00:19:58,533 --> 00:19:59,933 It will be at a maximum. 392 00:19:59,933 --> 00:20:03,500 And those maximums are where you get the show. 393 00:20:03,500 --> 00:20:08,200 There could be a lot of activity going on. 394 00:20:08,200 --> 00:20:09,400 My dream is that 395 00:20:09,400 --> 00:20:11,433 there is actually a coronal mass ejection 396 00:20:11,433 --> 00:20:12,800 or a flare going off that we could see. 397 00:20:12,800 --> 00:20:16,066 That would be exciting. 398 00:20:19,466 --> 00:20:23,666 ♪ ♪ 399 00:20:23,666 --> 00:20:26,700 NARRATOR: Solar eclipses have captivated communities 400 00:20:26,700 --> 00:20:29,700 in North America for centuries. 401 00:20:30,700 --> 00:20:34,133 Three hours northwest of what is now Albuquerque, 402 00:20:34,133 --> 00:20:37,966 this canyon was once home to the Chacoans, 403 00:20:37,966 --> 00:20:40,166 a Pueblo Native American people 404 00:20:40,166 --> 00:20:43,766 who farmed the land here until the 13th century. 405 00:20:43,766 --> 00:20:47,066 ♪ ♪ 406 00:20:48,133 --> 00:20:51,400 Jon Ghahate believes they were closely attuned 407 00:20:51,400 --> 00:20:56,000 to the sun's movements and rhythms. 408 00:20:56,000 --> 00:20:58,700 GHAHATE: What makes the Pueblo communities different from 409 00:20:58,700 --> 00:21:01,266 our neighbors throughout this entire region is that 410 00:21:01,266 --> 00:21:05,600 they were permanent agrarian societies. 411 00:21:05,600 --> 00:21:08,066 To be an agrarian society, 412 00:21:08,066 --> 00:21:11,800 that takes a great deal of planning and problem solving. 413 00:21:11,800 --> 00:21:14,166 If I plant too late, 414 00:21:14,166 --> 00:21:16,033 I may not get a bountiful harvest. 415 00:21:16,033 --> 00:21:19,733 If I plant too early, maybe I'll get a late frost. 416 00:21:19,733 --> 00:21:21,966 So by being able to 417 00:21:21,966 --> 00:21:24,200 have an understanding of what timing means, 418 00:21:24,200 --> 00:21:26,233 as it applies to the seasons, 419 00:21:26,233 --> 00:21:29,633 is essential for survival. 420 00:21:31,500 --> 00:21:34,066 NARRATOR: At the top of nearby Fajada Butte, 421 00:21:34,066 --> 00:21:39,266 the Chacoans tracked the sun to measure the seasons. 422 00:21:39,266 --> 00:21:43,366 GHAHATE: There were some slabs that project sunlight on a spiral. 423 00:21:44,366 --> 00:21:45,566 On the equinox, 424 00:21:45,566 --> 00:21:48,766 the light hits a certain point on that, 425 00:21:48,766 --> 00:21:51,333 and that's why it's called the Sun Dagger. 426 00:21:51,333 --> 00:21:54,733 NARRATOR: The equinoxes mark the moments in the year 427 00:21:54,733 --> 00:21:58,100 when day and night are of roughly equal length. 428 00:21:59,533 --> 00:22:01,366 Knowing when these happen 429 00:22:01,366 --> 00:22:03,533 is vital for deciding when to plant 430 00:22:03,533 --> 00:22:07,766 and when to harvest. 431 00:22:07,766 --> 00:22:09,866 ♪ ♪ 432 00:22:09,866 --> 00:22:12,900 But the Sun Dagger is not the only evidence 433 00:22:12,900 --> 00:22:17,266 the Chacoans watched the skies closely. 434 00:22:17,266 --> 00:22:21,233 There's also a mysterious petroglyph here 435 00:22:21,233 --> 00:22:23,133 that suggests people on this continent 436 00:22:23,133 --> 00:22:24,833 may have witnessed eclipses 437 00:22:24,833 --> 00:22:27,933 that have passed across North America over centuries. 438 00:22:30,900 --> 00:22:33,600 You see the circular symbol here? 439 00:22:33,600 --> 00:22:37,700 Perhaps that represents the sun in totality. 440 00:22:37,700 --> 00:22:39,100 Around the symbol, 441 00:22:39,100 --> 00:22:41,500 we see lines or curvatures, 442 00:22:41,500 --> 00:22:42,866 which perhaps we could interpret 443 00:22:42,866 --> 00:22:44,966 as maybe the corona of the sun 444 00:22:44,966 --> 00:22:46,266 or the flares of the sun 445 00:22:46,266 --> 00:22:49,300 that perhaps someone might see in a total eclipse. 446 00:22:52,933 --> 00:22:56,966 NARRATOR: Scientists today can calculate that in 1097, 447 00:22:56,966 --> 00:22:59,033 a total eclipse was visible here 448 00:22:59,033 --> 00:23:01,966 while the sun was nearing the peak of its solar cycle-- 449 00:23:01,966 --> 00:23:05,400 solar maximum, when vast plumes 450 00:23:05,400 --> 00:23:09,233 would have extended from the corona. 451 00:23:09,233 --> 00:23:11,366 GHAHATE: That's the tantalizing thing about it. 452 00:23:11,366 --> 00:23:13,400 Much like whenever we have an eclipse 453 00:23:13,400 --> 00:23:16,000 in our time and age, people stop work, 454 00:23:16,000 --> 00:23:17,033 people want to go outside 455 00:23:17,033 --> 00:23:19,166 to record this monumental event, 456 00:23:19,166 --> 00:23:22,000 because it's something unique and special. 457 00:23:22,000 --> 00:23:23,800 It connects us with the past. 458 00:23:23,800 --> 00:23:25,833 Those are the same celestial bodies 459 00:23:25,833 --> 00:23:27,900 that our predecessors saw. 460 00:23:27,900 --> 00:23:31,000 We're just really the same as they were. 461 00:23:31,000 --> 00:23:32,800 We just have different tools. 462 00:23:32,800 --> 00:23:35,833 ♪ ♪ 463 00:23:35,833 --> 00:23:37,700 NARRATOR: There are 574 464 00:23:37,700 --> 00:23:40,800 recognized Indigenous communities across the U.S., 465 00:23:40,800 --> 00:23:44,200 with varying perspectives on solar eclipses. 466 00:23:46,633 --> 00:23:49,900 The Navajo people consider an eclipse to be 467 00:23:49,900 --> 00:23:55,400 a moment of renewal that can be harmful if viewed. 468 00:23:55,400 --> 00:23:57,066 Cherokee tradition says 469 00:23:57,066 --> 00:24:00,500 a giant frog is swallowing the sun, 470 00:24:00,500 --> 00:24:03,866 and the frog must be scared away to bring back the daylight. 471 00:24:09,033 --> 00:24:11,200 (wind howling) 472 00:24:11,200 --> 00:24:12,933 For the casual observer, 473 00:24:12,933 --> 00:24:14,933 the timing and location of eclipses 474 00:24:14,933 --> 00:24:18,366 can appear random. 475 00:24:18,366 --> 00:24:23,366 After the April 2024 total solar eclipse, 476 00:24:23,366 --> 00:24:25,366 it will be 20 years until another is visible 477 00:24:25,366 --> 00:24:28,033 from the U.S. lower 48. 478 00:24:28,033 --> 00:24:29,666 (people talking in background) 479 00:24:29,666 --> 00:24:32,666 NARRATOR: However, the period of time between total eclipses 480 00:24:32,666 --> 00:24:35,133 can be much shorter. 481 00:24:35,133 --> 00:24:38,800 FILM NARRATOR: Nature cooperating with ballyhoo. 482 00:24:38,800 --> 00:24:41,666 Elaborate preparations were made. 483 00:24:41,666 --> 00:24:43,800 NARRATOR: In 1925, 484 00:24:43,800 --> 00:24:47,133 American astronomers watched a total eclipse 485 00:24:47,133 --> 00:24:49,100 as it passed from the middle of the country 486 00:24:49,100 --> 00:24:51,233 to the east coast. 487 00:24:51,233 --> 00:24:54,566 Some even flew in an airship to make observations. 488 00:24:54,566 --> 00:24:57,433 ♪ ♪ 489 00:24:57,433 --> 00:24:59,700 This fortunate generation had already seen 490 00:24:59,700 --> 00:25:03,133 two total solar eclipses in the previous seven years, 491 00:25:03,133 --> 00:25:06,966 and would see another only seven years later. 492 00:25:06,966 --> 00:25:10,000 ♪ ♪ 493 00:25:10,000 --> 00:25:11,766 (people talking in background) 494 00:25:12,900 --> 00:25:15,266 NARRATOR: Despite this apparent randomness, 495 00:25:15,266 --> 00:25:18,533 there is a complex pattern behind eclipses. 496 00:25:20,866 --> 00:25:22,933 And, astonishingly, 497 00:25:22,933 --> 00:25:26,733 it was discovered over 2,000 years ago. 498 00:25:31,400 --> 00:25:33,633 Ancient Babylon, 499 00:25:33,633 --> 00:25:36,733 situated in what is now modern Iraq. 500 00:25:38,766 --> 00:25:41,233 For centuries, astronomers here recorded 501 00:25:41,233 --> 00:25:43,966 every occasion an eclipse was reported. 502 00:25:45,966 --> 00:25:49,366 Eventually, around the seventh century BC, 503 00:25:49,366 --> 00:25:52,000 they spotted a pattern. 504 00:25:52,000 --> 00:25:54,800 ♪ ♪ 505 00:25:54,800 --> 00:25:58,166 OSSENDRIJVER: Some very clever Babylonian astronomers figured out 506 00:25:58,166 --> 00:26:01,366 that solar eclipses are governed by a cycle. 507 00:26:01,366 --> 00:26:03,166 This is the so-called saros cycle. 508 00:26:04,700 --> 00:26:07,600 NARRATOR: Today, we know that a total solar eclipse 509 00:26:07,600 --> 00:26:10,566 will take place somewhere on Earth 510 00:26:10,566 --> 00:26:13,133 about once every 18 months. 511 00:26:15,700 --> 00:26:17,966 But with centuries of data, 512 00:26:17,966 --> 00:26:21,166 the Babylonians realized there was a larger pattern. 513 00:26:21,166 --> 00:26:26,700 Every 18 years, the time between eclipses would repeat. 514 00:26:29,066 --> 00:26:30,833 OSSENDRIJVER: They could actually make an entire calendar 515 00:26:30,833 --> 00:26:32,333 of eclipse predictions 516 00:26:32,333 --> 00:26:35,633 simply by projecting these past eclipses into the future. 517 00:26:35,633 --> 00:26:38,533 NARRATOR: Astonishingly, 518 00:26:38,533 --> 00:26:40,400 the Babylonian predictions were accurate 519 00:26:40,400 --> 00:26:44,166 to within an average of four hours. 520 00:26:44,166 --> 00:26:46,933 But they couldn't tell where in the world 521 00:26:46,933 --> 00:26:49,366 the eclipse would take place. 522 00:26:52,800 --> 00:26:55,566 ♪ ♪ 523 00:26:58,000 --> 00:27:00,533 It would be another 2,000 years 524 00:27:00,533 --> 00:27:03,633 before astronomers figured out how to do that. 525 00:27:07,566 --> 00:27:09,000 TYLER NORDGREN: In 1715, 526 00:27:09,000 --> 00:27:11,066 the British astronomer Edmond Halley 527 00:27:11,066 --> 00:27:13,366 became the first person to correctly predict 528 00:27:13,366 --> 00:27:14,900 a total solar eclipse 529 00:27:14,900 --> 00:27:16,100 by using the mathematics 530 00:27:16,100 --> 00:27:18,066 of his good friend Isaac Newton 531 00:27:18,066 --> 00:27:19,166 to calculate the orbit of the moon 532 00:27:19,166 --> 00:27:21,100 around the Earth, 533 00:27:21,100 --> 00:27:23,366 and therefore, where its shadow would fall 534 00:27:23,366 --> 00:27:24,866 across the countryside. 535 00:27:26,333 --> 00:27:30,333 NARRATOR: In April 1715, Halley published this map, 536 00:27:30,333 --> 00:27:33,166 forecasting that two weeks later, 537 00:27:33,166 --> 00:27:36,666 an eclipse would pass over Great Britain. 538 00:27:36,666 --> 00:27:40,666 Halley had studied records of past eclipses, 539 00:27:40,666 --> 00:27:45,400 and rediscovered the saros cycle, lost since ancient times. 540 00:27:47,633 --> 00:27:50,600 This told him an eclipse was due. 541 00:27:50,600 --> 00:27:53,933 He then used new, accurate observations 542 00:27:53,933 --> 00:27:55,733 of the moon's orbit to calculate its path. 543 00:28:01,900 --> 00:28:04,700 Among the things he had to take into account 544 00:28:04,700 --> 00:28:07,166 was the unusual orbit of the moon... 545 00:28:08,666 --> 00:28:11,500 ...which is tilted by five degrees. 546 00:28:13,366 --> 00:28:16,666 So most of the time, the moon's shadow misses our planet, 547 00:28:16,666 --> 00:28:20,800 which makes eclipses rare. 548 00:28:22,600 --> 00:28:25,700 He also had to factor in the gravitational effect 549 00:28:25,700 --> 00:28:27,833 of the Earth and the sun, 550 00:28:27,833 --> 00:28:30,566 which subtly alters the moon's position. 551 00:28:32,066 --> 00:28:34,566 Just 28 years earlier, 552 00:28:34,566 --> 00:28:37,800 Newton had proposed his new theory of gravity, 553 00:28:37,800 --> 00:28:40,300 which allowed Halley to accurately calculate 554 00:28:40,300 --> 00:28:42,633 the path of the eclipse. 555 00:28:44,966 --> 00:28:47,533 NORDGREN: From comparing the maps that Edmond Halley made 556 00:28:47,533 --> 00:28:51,533 of the 1715 eclipse, both before and after, 557 00:28:51,533 --> 00:28:54,333 based on the observations by the public, 558 00:28:54,333 --> 00:28:56,700 we find that he was actually within about 20 miles. 559 00:28:56,700 --> 00:28:58,466 Amazingly precise. 560 00:28:58,466 --> 00:29:02,100 NARRATOR: And Halley's estimate of the time of the eclipse 561 00:29:02,100 --> 00:29:06,800 was off by just four minutes. 562 00:29:06,800 --> 00:29:09,400 ♪ ♪ 563 00:29:09,400 --> 00:29:11,733 Today, with more accurate observations 564 00:29:11,733 --> 00:29:14,100 of the moon's orbit, astronomers can predict 565 00:29:14,100 --> 00:29:16,166 exactly where an eclipse will occur 566 00:29:16,166 --> 00:29:18,166 to the nearest hundred feet, 567 00:29:18,166 --> 00:29:21,366 and when to the nearest tenth of a second. 568 00:29:24,000 --> 00:29:26,733 This is how they know the precise path 569 00:29:26,733 --> 00:29:31,033 of the 2024 total eclipse years ahead of time. 570 00:29:36,266 --> 00:29:41,600 The dance between Earth, moon, and sun is predictable. 571 00:29:41,600 --> 00:29:47,900 But the sun itself-- and its corona-- are chaotic. 572 00:29:47,900 --> 00:29:52,433 Coronal mass ejections can disrupt our power supplies 573 00:29:52,433 --> 00:29:56,100 and destroy our communications technologies. 574 00:29:56,100 --> 00:30:00,733 So learning how to predict coronal mass ejections 575 00:30:00,733 --> 00:30:03,166 is the Holy Grail of solar physics. 576 00:30:06,866 --> 00:30:10,366 The sun is not some static, unchanging ball of gas, right? 577 00:30:10,366 --> 00:30:14,000 It is ejecting parts of itself into the solar system. 578 00:30:15,400 --> 00:30:18,400 The solar corona is this dynamic and ever-changing 579 00:30:18,400 --> 00:30:22,066 and incredibly beautiful halo of plasma around the sun. 580 00:30:22,066 --> 00:30:24,366 It's so important in so many ways. 581 00:30:26,400 --> 00:30:29,800 NARRATOR: The lines of plasma in the sun's corona are vast. 582 00:30:31,466 --> 00:30:34,500 They would dwarf the Earth. 583 00:30:35,900 --> 00:30:39,066 The force that drives their shape and motion... 584 00:30:41,100 --> 00:30:44,033 ...is the sun's magnetic field. 585 00:30:45,500 --> 00:30:49,566 Earth also has a magnetic field. 586 00:30:49,566 --> 00:30:54,033 It's formed by our planet's spinning liquid metal core 587 00:30:54,033 --> 00:30:58,933 and gives us our magnetic north and south poles. 588 00:31:01,733 --> 00:31:05,300 But the sun has even stronger magnetic fields, 589 00:31:05,300 --> 00:31:08,633 created by the movement of electrically charged particles 590 00:31:08,633 --> 00:31:11,166 churning beneath the surface. 591 00:31:15,666 --> 00:31:18,866 Because the plasma is moving faster in some regions, 592 00:31:18,866 --> 00:31:21,966 these fields bend and twist... 593 00:31:25,066 --> 00:31:28,000 ...until some break through the sun's photosphere 594 00:31:28,000 --> 00:31:30,633 into the corona, 595 00:31:30,633 --> 00:31:35,666 where they form giant arches called coronal loops. 596 00:31:38,133 --> 00:31:40,833 Because these magnetic fields trap 597 00:31:40,833 --> 00:31:44,333 electrically charged particles, they show up as the bright lines 598 00:31:44,333 --> 00:31:47,933 and loops of plasma we see in the corona. 599 00:31:49,566 --> 00:31:52,800 But these field lines can snap. 600 00:31:56,500 --> 00:31:58,866 TREMBLAY: The plasma is now free of its chains, 601 00:31:58,866 --> 00:32:00,533 its anchors from the sun, 602 00:32:00,533 --> 00:32:02,200 and it's free to blast off into space. 603 00:32:03,766 --> 00:32:05,833 NARRATOR: In a coronal mass ejection, 604 00:32:05,833 --> 00:32:10,400 the corona can throw a billion tons of plasma out into space... 605 00:32:12,500 --> 00:32:15,200 ...at speeds of almost 2,000 miles per second. 606 00:32:17,366 --> 00:32:20,800 When a coronal mass ejection heads our way, 607 00:32:20,800 --> 00:32:23,833 Earth's own magnetic field normally deflects it, 608 00:32:23,833 --> 00:32:28,266 protecting the planet. 609 00:32:28,266 --> 00:32:31,733 But a large coronal mass ejection 610 00:32:31,733 --> 00:32:33,733 can overwhelm our magnetic defenses 611 00:32:33,733 --> 00:32:36,266 with devastating consequences. 612 00:32:38,033 --> 00:32:41,400 OLUSEYI: A coronal mass ejection can stream toward the Earth 613 00:32:41,400 --> 00:32:43,766 and disrupt our technologies, 614 00:32:43,766 --> 00:32:47,366 burn out power stations, damage sensors on satellites, 615 00:32:47,366 --> 00:32:50,833 wreaking havoc, so, we really need to be able 616 00:32:50,833 --> 00:32:52,933 to predict these things. 617 00:32:52,933 --> 00:32:55,800 ♪ ♪ 618 00:32:57,933 --> 00:32:59,666 NARRATOR: In June 2023, 619 00:32:59,666 --> 00:33:02,200 the Parker Solar Probe makes a giant leap 620 00:33:02,200 --> 00:33:04,166 towards understanding the mechanisms 621 00:33:04,166 --> 00:33:07,300 that project solar material towards us. 622 00:33:09,066 --> 00:33:12,000 The probe flies close enough to the surface of the sun 623 00:33:12,000 --> 00:33:16,033 to examine the origins of the solar wind. 624 00:33:16,033 --> 00:33:20,433 ♪ ♪ 625 00:33:20,433 --> 00:33:23,833 The sun's surface is a superheated honeycomb 626 00:33:23,833 --> 00:33:29,100 of churning plasma cells, each the size of Texas. 627 00:33:29,100 --> 00:33:32,000 Here, magnetic plasma loops 628 00:33:32,000 --> 00:33:35,366 get dragged around and collide, 629 00:33:35,366 --> 00:33:38,933 triggering explosions that release vast amounts of energy 630 00:33:38,933 --> 00:33:42,566 and catapult streams of plasma away from the sun. 631 00:33:45,100 --> 00:33:48,100 Scientists have calculated there are thousands 632 00:33:48,100 --> 00:33:50,833 of these "jetlets" all over the sun's surface-- 633 00:33:50,833 --> 00:33:54,766 proof that they can give birth to the solar wind. 634 00:33:56,866 --> 00:33:59,133 This was a theory as to how some of the solar wind was formed. 635 00:34:00,900 --> 00:34:03,933 As Parker got closer, it showed that this theory 636 00:34:03,933 --> 00:34:06,366 is actually at work. 637 00:34:07,833 --> 00:34:10,600 When Eugene Parker proposed these theories, 638 00:34:10,600 --> 00:34:12,833 they seemed like science fiction, 639 00:34:12,833 --> 00:34:15,100 and now they're becoming science fact. 640 00:34:18,633 --> 00:34:21,266 NARRATOR: Soon, a new NASA mission, 641 00:34:21,266 --> 00:34:23,133 called PUNCH, will launch four cameras 642 00:34:23,133 --> 00:34:25,800 that will orbit Earth to continuously map 643 00:34:25,800 --> 00:34:28,000 not only how the solar wind flows towards 644 00:34:28,000 --> 00:34:29,833 and around our planet, 645 00:34:29,833 --> 00:34:32,800 but also across the entire solar system. 646 00:34:32,800 --> 00:34:33,966 So that's from space... 647 00:34:33,966 --> 00:34:36,433 NARRATOR: Craig DeForest leads the team. 648 00:34:36,433 --> 00:34:37,633 But it doesn't rule out... 649 00:34:37,633 --> 00:34:40,000 DEFOREST: The four cameras separate out 650 00:34:40,000 --> 00:34:41,233 all the way around the world, 651 00:34:41,233 --> 00:34:44,033 looking out in different directions. 652 00:34:44,033 --> 00:34:46,866 We synchronize them, so they're snapping pictures 653 00:34:46,866 --> 00:34:48,366 at the exact same time 654 00:34:48,366 --> 00:34:51,766 to image those clouds of material in all directions, 655 00:34:51,766 --> 00:34:56,533 in three dimensions, as they streak across the solar system, 656 00:34:56,533 --> 00:35:00,266 sweeping out and past us. 657 00:35:00,266 --> 00:35:01,833 With a system like PUNCH, 658 00:35:01,833 --> 00:35:04,566 we would be able to track the events 659 00:35:04,566 --> 00:35:06,133 all the way across the solar system. 660 00:35:06,133 --> 00:35:08,100 This is revolutionary. 661 00:35:08,100 --> 00:35:11,733 We expect to be able to greatly improve 662 00:35:11,733 --> 00:35:14,533 forecasting of space weather. 663 00:35:17,666 --> 00:35:20,633 ♪ ♪ 664 00:35:20,633 --> 00:35:23,033 NARRATOR: Back on Earth, 665 00:35:23,033 --> 00:35:26,000 in October 2023, Craig gears up 666 00:35:26,000 --> 00:35:28,966 to test a new version of an old instrument 667 00:35:28,966 --> 00:35:31,933 that, for the first time, could make the sun's 668 00:35:31,933 --> 00:35:34,400 elusive and violent corona visible 669 00:35:34,400 --> 00:35:37,400 to any of us at any time. 670 00:35:37,400 --> 00:35:41,700 It's called a coronagraph. 671 00:35:41,700 --> 00:35:46,100 DEFOREST: What a coronagraph does is interpose a manmade object 672 00:35:46,100 --> 00:35:49,733 in front of a telescope so that we can block out the sun, 673 00:35:49,733 --> 00:35:52,133 just like the moon would do, 674 00:35:52,133 --> 00:35:54,566 and see the corona around it. 675 00:35:56,233 --> 00:35:59,933 NARRATOR: But coronagraphs have limitations. 676 00:36:01,033 --> 00:36:03,966 It's almost impossible to block enough of the sun's light 677 00:36:03,966 --> 00:36:05,866 to see the corona, 678 00:36:05,866 --> 00:36:09,633 unless they are either incredibly precise and expensive 679 00:36:09,633 --> 00:36:12,166 or they are deployed in space, 680 00:36:12,166 --> 00:36:16,100 above the Earth's light-scattering atmosphere. 681 00:36:16,100 --> 00:36:18,866 It allows the camera to see a perfectly uniform field of view. 682 00:36:18,866 --> 00:36:20,833 NARRATOR: The team hopes to produce 683 00:36:20,833 --> 00:36:23,800 the first-ever coronagraph that anyone can download, 684 00:36:23,800 --> 00:36:26,300 3D-print, and fit onto a telescope at home. 685 00:36:26,300 --> 00:36:28,033 No, there you go-- that's it. 686 00:36:28,033 --> 00:36:29,666 Oh, there it is, perfect. 687 00:36:29,666 --> 00:36:32,266 We expect to refine the design and be able to publish 688 00:36:32,266 --> 00:36:34,833 a design that will access the corona 689 00:36:34,833 --> 00:36:37,800 on any sunny day. 690 00:36:37,800 --> 00:36:39,533 NARRATOR: To help them test this device, 691 00:36:39,533 --> 00:36:41,966 the team has chosen a special day. 692 00:36:41,966 --> 00:36:46,066 Over Albuquerque, New Mexico, today, there will be 693 00:36:46,066 --> 00:36:48,966 an annular solar eclipse. 694 00:36:48,966 --> 00:36:53,400 ♪ ♪ 695 00:36:53,400 --> 00:36:56,100 The moon's orbit is not a perfect circle. 696 00:36:56,100 --> 00:37:00,100 It's very slightly elliptical. 697 00:37:00,100 --> 00:37:03,000 So, when the moon is farther from the Earth, 698 00:37:03,000 --> 00:37:05,100 it appears smaller, 699 00:37:05,100 --> 00:37:08,233 and doesn't completely cover the sun, 700 00:37:08,233 --> 00:37:11,133 creating an annular eclipse, 701 00:37:11,133 --> 00:37:14,666 also known as a "ring of fire" eclipse. 702 00:37:18,166 --> 00:37:20,366 We have a special case, where the moon 703 00:37:20,366 --> 00:37:22,100 does 90% of the work. 704 00:37:22,100 --> 00:37:25,333 The sky is much darker. 705 00:37:25,333 --> 00:37:28,633 (people talking in background) 706 00:37:28,633 --> 00:37:30,433 NARRATOR: By complete chance, 707 00:37:30,433 --> 00:37:32,366 the annular eclipse coincides 708 00:37:32,366 --> 00:37:36,766 with the Albuquerque International Balloon Fiesta-- 709 00:37:36,766 --> 00:37:39,800 the world's largest gathering of balloonists. 710 00:37:42,633 --> 00:37:46,000 Today, we have 550 balloons in this beautiful Albuquerque sky. 711 00:37:46,000 --> 00:37:50,466 We'll have somewhere between 800,000 and one million 712 00:37:50,466 --> 00:37:52,500 come through our gates. 713 00:37:52,500 --> 00:37:54,833 We just got really lucky when we saw 714 00:37:54,833 --> 00:37:57,166 that the eclipse was going to coincide with our event. 715 00:37:57,166 --> 00:37:58,533 We couldn't be happier. 716 00:38:00,333 --> 00:38:02,433 JUDITH NAKAMURA: I think the crowd is going to be in awe 717 00:38:02,433 --> 00:38:05,066 of getting to witness this once-in-a-lifetime event, 718 00:38:05,066 --> 00:38:06,400 because it's not happened here before. 719 00:38:06,400 --> 00:38:08,700 We just have to thank Mother Nature 720 00:38:08,700 --> 00:38:11,466 and the calendar lining up together. 721 00:38:11,466 --> 00:38:14,866 So we are about to have first contact. 722 00:38:14,866 --> 00:38:18,400 Three, two, one-- oh, yeah, you see it. 723 00:38:18,400 --> 00:38:19,400 Right on the top. 724 00:38:19,400 --> 00:38:20,866 WOMAN: Ooh, and there's a bite! 725 00:38:20,866 --> 00:38:23,933 ♪ ♪ 726 00:38:23,933 --> 00:38:26,233 NARRATOR: As the moon begins to line up with the sun, 727 00:38:26,233 --> 00:38:30,200 everything starts to get... weird. 728 00:38:31,500 --> 00:38:34,400 WOMAN: Because the sun is turning into a crescent sun, 729 00:38:34,400 --> 00:38:36,400 the shadows change shape. 730 00:38:36,400 --> 00:38:38,866 So it's one of the most eerie things about an eclipse, 731 00:38:38,866 --> 00:38:41,100 is the shadows changing shape. 732 00:38:44,100 --> 00:38:47,700 ♪ ♪ 733 00:38:52,866 --> 00:38:54,800 All right, we have annularity. 734 00:38:54,800 --> 00:38:59,266 (crowd cheers and applauds) 735 00:38:59,266 --> 00:39:01,133 MAN: All right. 736 00:39:01,133 --> 00:39:02,766 (people talking, exclaiming in background) So cool! 737 00:39:02,766 --> 00:39:04,566 CHILD: This is so beautiful! 738 00:39:04,566 --> 00:39:06,066 (people talking in background) 739 00:39:06,066 --> 00:39:08,033 CHILD 1: Lookit! CHILD 2: It's a perfect circle! 740 00:39:11,066 --> 00:39:15,100 NAKAMURA: What a spectacular, awesome sight. 741 00:39:15,100 --> 00:39:16,933 Thank you, Mother Nature. 742 00:39:16,933 --> 00:39:19,033 Thank you, Mother Nature, and thank you, Balloon Fiesta. 743 00:39:20,600 --> 00:39:22,933 DEFOREST: This is phenomenal! 744 00:39:23,900 --> 00:39:27,000 The visceral reactions that you feel during 745 00:39:27,000 --> 00:39:30,600 the approach and during the annularity itself are, 746 00:39:30,600 --> 00:39:32,833 it's very hard to describe. 747 00:39:32,833 --> 00:39:33,866 It's, it's very moving. 748 00:39:33,866 --> 00:39:35,733 (mouths) 749 00:39:36,966 --> 00:39:39,333 DEFOREST: Annular eclipses are phenomenal. 750 00:39:39,333 --> 00:39:42,000 If you can ever get to the path of a total solar eclipse, 751 00:39:42,000 --> 00:39:44,366 it is incredible and life-changing. 752 00:39:46,166 --> 00:39:47,666 We won't know 753 00:39:47,666 --> 00:39:49,800 until we analyze the data that we got today 754 00:39:49,800 --> 00:39:51,900 just how much of the corona we saw. 755 00:39:51,900 --> 00:39:53,900 So if you look, 756 00:39:53,900 --> 00:39:56,133 if I turn this thing on and off... 757 00:39:56,133 --> 00:40:00,400 (murmurs) So this is our coronagraph. 758 00:40:00,400 --> 00:40:02,333 Look at that-- they seem to line up. Perfect. 759 00:40:02,333 --> 00:40:04,600 So I think we've seen the corona. 760 00:40:04,600 --> 00:40:05,733 Yeah, I mean, I think 761 00:40:05,733 --> 00:40:06,933 that there's a really good possibility. 762 00:40:06,933 --> 00:40:08,433 ♪ ♪ 763 00:40:08,433 --> 00:40:11,466 DEFOREST: What we're looking at is the very first data, 764 00:40:11,466 --> 00:40:13,566 and what we found is, yes, 765 00:40:13,566 --> 00:40:16,166 it looks to me like it's the corona. 766 00:40:16,166 --> 00:40:19,500 We're not done yet-- we have more analysis to do. 767 00:40:19,500 --> 00:40:21,600 We've really just begun. 768 00:40:24,733 --> 00:40:26,433 ♪ ♪ 769 00:40:26,433 --> 00:40:30,233 NARRATOR: During the April 2024 total eclipse, 770 00:40:30,233 --> 00:40:32,766 amateur astronomers will work with scientists 771 00:40:32,766 --> 00:40:36,533 to study how the corona changes in real time. 772 00:40:36,533 --> 00:40:38,500 (people talking in background) 773 00:40:38,500 --> 00:40:42,266 CASPI: Citizen scientists, or community participants, 774 00:40:42,266 --> 00:40:44,466 they're going to get training and we're going to deploy them 775 00:40:44,466 --> 00:40:47,266 all along the eclipse path, from the very edge 776 00:40:47,266 --> 00:40:49,033 of the United States in Texas 777 00:40:49,033 --> 00:40:51,000 all the way to the other edge in Maine, 778 00:40:51,000 --> 00:40:53,100 where they will be able to observe 779 00:40:53,100 --> 00:40:55,966 the eclipse shadow passing over each one of them. 780 00:40:55,966 --> 00:40:57,366 And that way, we can put together 781 00:40:57,366 --> 00:40:58,933 all of their observations 782 00:40:58,933 --> 00:41:03,666 into one hourlong movie of totality. 783 00:41:03,666 --> 00:41:07,433 And so that gives us information about how the corona is evolving 784 00:41:07,433 --> 00:41:09,866 and changing over a period of one hour. 785 00:41:09,866 --> 00:41:11,500 ♪ ♪ 786 00:41:11,500 --> 00:41:14,466 NARRATOR: These citizen scientists may play a role 787 00:41:14,466 --> 00:41:16,566 in solving one of the most enduring 788 00:41:16,566 --> 00:41:18,633 mysteries of the corona. 789 00:41:20,833 --> 00:41:22,900 ♪ ♪ 790 00:41:27,666 --> 00:41:30,000 In the late 1800s, 791 00:41:30,000 --> 00:41:33,033 a team of astronomers studying the corona during an eclipse 792 00:41:33,033 --> 00:41:35,833 made a surprising discovery. 793 00:41:37,033 --> 00:41:38,433 In 1869, 794 00:41:38,433 --> 00:41:39,466 there was a total solar eclipse 795 00:41:39,466 --> 00:41:40,866 visible from the United States. 796 00:41:40,866 --> 00:41:44,466 Charles Young, an astronomer at Dartmouth College, 797 00:41:44,466 --> 00:41:46,533 led an expedition to Iowa in order to use 798 00:41:46,533 --> 00:41:49,166 the brand-new technology of spectroscopy. 799 00:41:49,166 --> 00:41:53,700 NARRATOR: A spectroscope uses a prism to divide white light 800 00:41:53,700 --> 00:41:55,066 into its constituent colors, 801 00:41:55,066 --> 00:41:57,400 or wavelengths. 802 00:41:58,900 --> 00:42:01,900 If you heat an element enough, 803 00:42:01,900 --> 00:42:06,233 its gas emits light in very specific wavelengths. 804 00:42:08,300 --> 00:42:10,466 Viewed through a spectroscope, 805 00:42:10,466 --> 00:42:14,300 each element has its own unique pattern of colored lines. 806 00:42:14,300 --> 00:42:19,333 ♪ ♪ 807 00:42:23,200 --> 00:42:26,633 By pointing a spectroscope at the corona during an eclipse, 808 00:42:26,633 --> 00:42:30,866 Young hoped to find the elements it contained. 809 00:42:32,866 --> 00:42:36,500 What he discovered was a mysterious spectral line 810 00:42:36,500 --> 00:42:40,500 no one had ever seen coming from any element on Earth. 811 00:42:43,400 --> 00:42:45,733 NORDGREN: He noticed there was a special green line-- 812 00:42:45,733 --> 00:42:48,700 green light emitted from the corona. 813 00:42:48,700 --> 00:42:51,266 And since it matched up with no known element, 814 00:42:51,266 --> 00:42:54,333 people naturally assumed that there must be some new element 815 00:42:54,333 --> 00:42:57,400 not existing here on the Earth that had been discovered. 816 00:42:57,400 --> 00:43:01,033 NARRATOR: Scientists gave this strange new element a name: 817 00:43:01,033 --> 00:43:03,266 coronium, 818 00:43:03,266 --> 00:43:05,333 because it had been discovered in the corona. 819 00:43:07,266 --> 00:43:08,866 NORDGREN: For the next 70 years, 820 00:43:08,866 --> 00:43:10,466 astronomers sought to identify 821 00:43:10,466 --> 00:43:12,166 what this mystery element might be. 822 00:43:12,166 --> 00:43:13,700 What they found, in fact, 823 00:43:13,700 --> 00:43:15,733 was that it was a known element: iron. 824 00:43:15,733 --> 00:43:17,633 Iron at such a high temperature, 825 00:43:17,633 --> 00:43:20,966 that 13 of its 26 electrons had been ripped away. 826 00:43:22,400 --> 00:43:25,366 NARRATOR: Astonishingly, the corona was so hot, 827 00:43:25,366 --> 00:43:28,333 it had turned the metal iron into a plasma 828 00:43:28,333 --> 00:43:30,700 with a spectral line completely different 829 00:43:30,700 --> 00:43:32,733 from iron found on Earth. 830 00:43:35,633 --> 00:43:38,266 NORDGREN: Only under extraordinarily high temperatures 831 00:43:38,266 --> 00:43:39,933 is this ever possible, 832 00:43:39,933 --> 00:43:43,166 so when you see a total solar eclipse, 833 00:43:43,166 --> 00:43:45,333 and you witness that amazing corona, 834 00:43:45,333 --> 00:43:46,766 you are seeing the hottest thing 835 00:43:46,766 --> 00:43:49,700 you will ever see with the human eye. 836 00:43:49,700 --> 00:43:53,400 NARRATOR: The corona is about two million degrees. 837 00:43:53,400 --> 00:43:55,566 And that's a problem. 838 00:43:55,566 --> 00:43:59,866 The surface of the sun is only about 10,000 degrees. 839 00:43:59,866 --> 00:44:02,333 How can the sun's outer atmosphere 840 00:44:02,333 --> 00:44:04,933 be hotter than its surface? 841 00:44:04,933 --> 00:44:09,033 It seems to defy basic laws of physics. 842 00:44:11,033 --> 00:44:13,266 ♪ ♪ 843 00:44:13,266 --> 00:44:16,000 Back in 2017, in search of answers, 844 00:44:16,000 --> 00:44:19,333 scientists came up with a plan 845 00:44:19,333 --> 00:44:22,200 to not only extend viewing time, but also avoid 846 00:44:22,200 --> 00:44:25,366 any clouds that might obscure the eclipse. 847 00:44:25,366 --> 00:44:29,866 Amir Caspi and his team fly two NASA jet aircraft 848 00:44:29,866 --> 00:44:32,100 fitted with telescopes above the clouds, 849 00:44:32,100 --> 00:44:34,766 and track the eclipse 850 00:44:34,766 --> 00:44:36,966 from an altitude of 50,000 feet. 851 00:44:36,966 --> 00:44:41,000 CASPI: By getting above 90% of the atmosphere, 852 00:44:41,000 --> 00:44:45,033 above 90% of the water vapor, we can access wavelengths 853 00:44:45,033 --> 00:44:47,733 that we normally wouldn't be able to on the ground. 854 00:44:47,733 --> 00:44:50,533 NARRATOR: They hoped their data might shed light on why the corona 855 00:44:50,533 --> 00:44:54,000 is so much hotter than the surface of the sun. 856 00:44:54,000 --> 00:44:55,366 CASPI: And the idea is 857 00:44:55,366 --> 00:44:56,733 that they pick up the track 858 00:44:56,733 --> 00:44:58,366 and follow the track straight through... 859 00:44:58,366 --> 00:45:01,666 NARRATOR: The jets could not keep up with the eclipse shadow 860 00:45:01,666 --> 00:45:04,500 traveling around 1,500 miles an hour, 861 00:45:04,500 --> 00:45:07,533 more than three times as fast as the planes. 862 00:45:07,533 --> 00:45:11,266 But by flying two jets along the path of the eclipse, 863 00:45:11,266 --> 00:45:16,433 Amir extended the viewing time to over seven minutes. 864 00:45:16,433 --> 00:45:18,633 The instruments aboard Amir's jets 865 00:45:18,633 --> 00:45:20,933 could image the infrared radiation 866 00:45:20,933 --> 00:45:24,266 emitted by the corona in high resolution. 867 00:45:26,566 --> 00:45:30,200 JENNA SAMRA: Infrared radiation is special because it allows us 868 00:45:30,200 --> 00:45:32,000 to probe the corona's magnetic field, 869 00:45:32,000 --> 00:45:33,766 and the corona's magnetic field 870 00:45:33,766 --> 00:45:36,533 is critically important for pretty much 871 00:45:36,533 --> 00:45:39,166 everything that happens in the solar corona. 872 00:45:41,433 --> 00:45:43,466 NARRATOR: The infrared images of magnetic structures 873 00:45:43,466 --> 00:45:47,566 in the corona collected by Amir and his team in 2017 874 00:45:47,566 --> 00:45:51,900 gave some unexpected results. 875 00:45:51,900 --> 00:45:54,133 One of the things that we noticed is that, 876 00:45:54,133 --> 00:45:56,333 structures called prominences. 877 00:45:56,333 --> 00:45:59,300 This is material from the solar chromosphere, 878 00:45:59,300 --> 00:46:01,033 the layer just above the surface. 879 00:46:01,033 --> 00:46:06,100 Its temperature is only 10,000, 20,000 degrees Celsius. 880 00:46:06,100 --> 00:46:09,600 Other structures, what we call active regions, 881 00:46:09,600 --> 00:46:12,566 those are at millions of degrees. 882 00:46:12,566 --> 00:46:15,500 And we saw that prominences and active regions 883 00:46:15,500 --> 00:46:18,266 were glowing with approximately equal brightness 884 00:46:18,266 --> 00:46:21,500 in the infrared images. 885 00:46:21,500 --> 00:46:24,133 That's something that boggled our minds, 886 00:46:24,133 --> 00:46:27,600 because they are a hundred times different in temperatures, 887 00:46:27,600 --> 00:46:31,100 so how could they be glowing at the same intensity? 888 00:46:32,733 --> 00:46:35,100 NARRATOR: What are the physical mechanisms 889 00:46:35,100 --> 00:46:37,500 that cause these dramatically different regions 890 00:46:37,500 --> 00:46:40,966 to emit infrared equally? 891 00:46:40,966 --> 00:46:44,666 2024 gives us a new opportunity to study the corona 892 00:46:44,666 --> 00:46:47,733 and answer some of the questions that we opened in 2017. 893 00:46:50,000 --> 00:46:51,533 NARRATOR: In 2024, 894 00:46:51,533 --> 00:46:55,000 can new instruments making even more detailed measurements 895 00:46:55,000 --> 00:46:56,900 of infrared radiation 896 00:46:56,900 --> 00:47:01,466 help us explain these surprising observations? 897 00:47:01,466 --> 00:47:03,366 Here's your incoming vector, right? 898 00:47:03,366 --> 00:47:06,800 NARRATOR: Jenna Samra is looking for clues. 899 00:47:06,800 --> 00:47:10,166 She and her team have built their own spectroscope 900 00:47:10,166 --> 00:47:12,500 that also measures the exact brightness 901 00:47:12,500 --> 00:47:14,733 of the infrared light. 902 00:47:14,733 --> 00:47:17,233 And they'll install this sensitive equipment 903 00:47:17,233 --> 00:47:19,633 onboard a Gulfstream V jet 904 00:47:19,633 --> 00:47:22,666 to track the eclipse from the air. 905 00:47:24,166 --> 00:47:26,400 Models suggest there are infrared wavelengths 906 00:47:26,400 --> 00:47:29,266 where the corona emits light 907 00:47:29,266 --> 00:47:31,900 that we've not yet detected with instruments. 908 00:47:31,900 --> 00:47:34,433 These could eventually help us measure 909 00:47:34,433 --> 00:47:36,300 the corona's magnetic field, 910 00:47:36,300 --> 00:47:39,700 which stores the energy that heats the corona. 911 00:47:39,700 --> 00:47:42,566 SAMRA: Physicists have predicted a number 912 00:47:42,566 --> 00:47:45,500 of these bright wavelengths, called emission lines, 913 00:47:45,500 --> 00:47:49,800 and our spectrum should encompass about 20 of these, 914 00:47:49,800 --> 00:47:52,466 and about half of these have never been seen before. 915 00:47:53,933 --> 00:47:57,633 NARRATOR: Jenna wants to find those missing lines. 916 00:47:57,633 --> 00:47:59,566 But what if they aren't there? 917 00:47:59,566 --> 00:48:03,166 Would that mean the physicists' predictions are wrong? 918 00:48:03,166 --> 00:48:04,800 For now, 919 00:48:04,800 --> 00:48:08,333 they're just at the start of their investigation. 920 00:48:08,333 --> 00:48:10,500 Our instrument is going to be a stepping stone 921 00:48:10,500 --> 00:48:13,033 for understanding the, the physics of the corona, 922 00:48:13,033 --> 00:48:15,566 including predicting solar flares 923 00:48:15,566 --> 00:48:18,066 and coronal mass ejections. 924 00:48:18,066 --> 00:48:22,566 NARRATOR: But in a jet moving at over 500 miles per hour, 925 00:48:22,566 --> 00:48:25,566 how can you keep the eclipse perfectly centered 926 00:48:25,566 --> 00:48:29,633 so the spectroscope can take reliable measurements? 927 00:48:29,633 --> 00:48:32,833 SAMRA: The apparent position of the sun starts moving around. 928 00:48:32,833 --> 00:48:34,500 So this mirror actually tracks the sun. 929 00:48:34,500 --> 00:48:36,300 It's moving a thousand times a second 930 00:48:36,300 --> 00:48:40,166 to basically take out the turbulence of the airplane. 931 00:48:40,166 --> 00:48:41,600 The mirror is auto-correcting. 932 00:48:41,600 --> 00:48:42,933 It's getting a signal from the camera, it's saying, 933 00:48:42,933 --> 00:48:45,700 "Oh, the sun has moved off of center. 934 00:48:45,700 --> 00:48:48,366 Bring it back to center." 935 00:48:53,300 --> 00:48:55,733 NARRATOR: While Earth-bound scientists are limited 936 00:48:55,733 --> 00:48:59,566 to studying this eclipse from one angle, 937 00:48:59,566 --> 00:49:01,666 viewing from space will give scientists 938 00:49:01,666 --> 00:49:03,666 an entirely different perspective 939 00:49:03,666 --> 00:49:07,933 on how the sun's corona and its magnetic fields 940 00:49:07,933 --> 00:49:11,500 are shifting, heating, and cooling during the eclipse. 941 00:49:13,933 --> 00:49:16,833 The Parker Solar Probe will be looking at the sun 942 00:49:16,833 --> 00:49:19,266 from 90 degrees in relation to the rest of us 943 00:49:19,266 --> 00:49:21,500 here on Earth 944 00:49:21,500 --> 00:49:23,700 during the 2024 eclipse. 945 00:49:23,700 --> 00:49:26,433 This will give multiple perspectives on the corona 946 00:49:26,433 --> 00:49:29,300 and allow scientists to compare real-time data 947 00:49:29,300 --> 00:49:32,333 from different angles. 948 00:49:32,333 --> 00:49:36,066 KORRECK: I'm so excited for the 2024 eclipse. 949 00:49:36,066 --> 00:49:40,400 It's been a long time coming to really understand our star, 950 00:49:40,400 --> 00:49:42,866 the sun. 951 00:49:42,866 --> 00:49:46,733 NARRATOR: With clear weather, spectators under the path of the eclipse 952 00:49:46,733 --> 00:49:52,266 can enjoy totality for almost four-and-a-half minutes. 953 00:49:52,266 --> 00:49:54,966 But as the moon begins to reveal the sun, 954 00:49:54,966 --> 00:49:57,600 further cosmic treats await. 955 00:50:00,733 --> 00:50:01,966 Here's the thing about the moon-- 956 00:50:01,966 --> 00:50:03,733 it's not a smooth ball. 957 00:50:03,733 --> 00:50:06,433 There are mountains, there are valleys. 958 00:50:06,433 --> 00:50:08,600 So between those valleys and peaks, 959 00:50:08,600 --> 00:50:11,133 you get light of the sun peeking through, 960 00:50:11,133 --> 00:50:14,700 and those little bright dots look like a string of beads. 961 00:50:14,700 --> 00:50:16,500 We call that Baily's beads. 962 00:50:16,500 --> 00:50:20,833 So we can actually see the topography of the moon 963 00:50:20,833 --> 00:50:24,200 illustrated and amplified by the light from the sun. 964 00:50:25,200 --> 00:50:28,233 NARRATOR: As more sunlight creeps around the edge of the moon, 965 00:50:28,233 --> 00:50:31,300 there's one final, astonishing display. 966 00:50:33,966 --> 00:50:35,666 Then you have this big bright spot, 967 00:50:35,666 --> 00:50:38,233 and this is known as the diamond ring. 968 00:50:38,233 --> 00:50:41,300 It is stunning. 969 00:50:41,300 --> 00:50:44,133 It's beautiful, and you don't want to miss it. 970 00:50:46,366 --> 00:50:48,233 (crowd cheering and applauding) 971 00:50:48,233 --> 00:50:51,500 NARRATOR: The 2024 eclipse 972 00:50:51,500 --> 00:50:53,333 can teach us more than ever before 973 00:50:53,333 --> 00:50:55,366 about our nearest star 974 00:50:55,366 --> 00:50:57,133 that gives us life on Earth. 975 00:50:58,633 --> 00:51:00,533 Total solar eclipses are amazing celestial events 976 00:51:00,533 --> 00:51:03,366 to see, and it's just awe-inspiring 977 00:51:03,366 --> 00:51:06,433 to experience something so extraordinary. 978 00:51:06,433 --> 00:51:09,333 DEFOREST: We are in a golden age right now 979 00:51:09,333 --> 00:51:10,833 of solar physics. 980 00:51:10,833 --> 00:51:13,233 ♪ ♪ 981 00:51:13,233 --> 00:51:14,900 Our understanding of what the sun is doing 982 00:51:14,900 --> 00:51:16,666 is going to evolve dramatically. 983 00:51:18,133 --> 00:51:19,733 NARRATOR: Countless people around the world 984 00:51:19,733 --> 00:51:22,100 and across millennia have gazed 985 00:51:22,100 --> 00:51:27,166 with wonder and awe as the sun disappears. 986 00:51:27,166 --> 00:51:29,066 It's how we as human beings interpret this event 987 00:51:29,066 --> 00:51:30,900 that has been going on as long as 988 00:51:30,900 --> 00:51:33,366 human beings have been on this planet. 989 00:51:33,366 --> 00:51:34,700 TREMBLAY: Let me tell you, 990 00:51:34,700 --> 00:51:39,233 you have never seen a shadow this spectacular. 991 00:51:39,233 --> 00:51:42,500 It is a truly remarkable event, because you'd have to wait years 992 00:51:42,500 --> 00:51:46,266 for the next total eclipse to go over your head. 993 00:51:47,966 --> 00:51:53,033 NARRATOR: 31.5 million people live in the path of totality, 994 00:51:53,033 --> 00:51:59,000 a rare moment when the celestial dance comes home. 995 00:51:59,000 --> 00:52:01,766 You don't want to miss this opportunity to see the eclipse. 996 00:52:01,766 --> 00:52:03,833 Yeah, don't miss it! (laughs) 997 00:52:03,833 --> 00:52:06,633 ♪ ♪ 998 00:52:35,500 --> 00:52:43,033 ♪ ♪ 999 00:52:46,866 --> 00:52:54,400 ♪ ♪ 1000 00:52:56,033 --> 00:53:03,633 ♪ ♪ 1001 00:53:05,266 --> 00:53:12,800 ♪ ♪ 1002 00:53:18,533 --> 00:53:25,700 ♪ ♪