1 00:00:08,887 --> 00:00:11,082 I want to take you on a journey. 2 00:00:11,247 --> 00:00:15,160 It's a journey like no other. A journey out there... 3 00:00:21,767 --> 00:00:26,682 Look up at the night sky. What do you see? 4 00:00:26,847 --> 00:00:29,407 The planets, the stars, 5 00:00:29,567 --> 00:00:32,161 a million points of light... 6 00:00:32,327 --> 00:00:35,319 You're looking at your universe. 7 00:00:38,407 --> 00:00:41,365 This series will take you there. 8 00:00:44,807 --> 00:00:50,803 We'll experience first-hand the wonders of the universe, its power and its danger. 9 00:00:55,327 --> 00:00:59,605 And to take a CLOSER look, we'll even bring space down here to Earth. 10 00:01:05,607 --> 00:01:08,280 We'll seek out alien life. 11 00:01:12,927 --> 00:01:15,600 Witness the birth of new worlds. 12 00:01:18,727 --> 00:01:23,755 And we'll discover why what happens out there in space affects all of us here 13 00:01:23,927 --> 00:01:28,443 on the one small planet we call our home. 14 00:01:31,407 --> 00:01:34,365 We'll take you from the beginning of time... 15 00:01:37,487 --> 00:01:40,081 ..to the far future of humanity. 16 00:01:41,607 --> 00:01:46,397 This is the voyage of a lifetime. This is the voyage into space. 17 00:02:15,047 --> 00:02:19,757 We begin with the BIG question: where did we come from? 18 00:02:24,847 --> 00:02:27,122 Aliens. 19 00:02:27,287 --> 00:02:32,566 What would you think if I told you that you, me, everyone came from outer space? 20 00:02:33,927 --> 00:02:37,522 Weird though it sounds, it's true - we're all aliens. 21 00:02:37,687 --> 00:02:42,841 Once upon a time, every single thing that makes us what we are came from the stars. 22 00:02:47,607 --> 00:02:50,917 We live in a small corner of the universe. 23 00:02:51,087 --> 00:02:54,523 This is our neighbourhood - the solar system. 24 00:02:54,687 --> 00:02:57,599 At its centre, the sun. 25 00:02:58,887 --> 00:03:04,996 And just 150 million kilometres away is our home: the Earth. 26 00:03:11,607 --> 00:03:13,837 It's an astonishing planet. 27 00:03:14,007 --> 00:03:19,365 The only place we know of in the whole universe where conditions are right for life. 28 00:03:20,327 --> 00:03:22,477 The air we breathe... 29 00:03:24,247 --> 00:03:26,602 Rich seas and oceans... 30 00:03:28,127 --> 00:03:30,322 Our planet is alive! 31 00:03:38,207 --> 00:03:41,677 And what's remarkable is, it shouldn't be! 32 00:03:48,007 --> 00:03:51,283 Life on Earth shouldn't even exist. 33 00:03:52,567 --> 00:03:57,687 So where DID it all come from - me, you, the planet we live on, even our sun? 34 00:03:57,847 --> 00:04:00,964 It's a puzzle because at the beginning none of it was here. 35 00:04:03,647 --> 00:04:05,717 Let me show you what I mean. 36 00:04:07,047 --> 00:04:10,562 This is the moment it all started - the Big Bang. 37 00:04:10,727 --> 00:04:12,877 (EXPLOSION) 38 00:04:30,567 --> 00:04:33,764 And that was it. The Big Bang created the universe, 39 00:04:33,927 --> 00:04:37,761 but a universe containing only a vast cloud of hydrogen gas. 40 00:04:38,007 --> 00:04:43,684 So how did something so featureless create our world? And how did it create us? 41 00:04:46,447 --> 00:04:49,166 The journey from a cloud of hydrogen 42 00:04:49,327 --> 00:04:52,399 to the building blocks of life is extraordinary. 43 00:04:55,927 --> 00:05:01,047 The calcium in my bones, the oxygen we breathe, where did it come from? 44 00:05:04,447 --> 00:05:10,124 It all began at the time the universe gave birth to the stars. 45 00:05:13,447 --> 00:05:16,166 For millions of years, the entire universe 46 00:05:16,327 --> 00:05:21,685 was nothing but the single vast cloud of hydrogen gas created in the Big Bang. 47 00:05:26,487 --> 00:05:30,162 But within the cloud, something amazing was happening. 48 00:05:32,207 --> 00:05:35,916 Shock waves from the Big Bang were echoing through the cloud, 49 00:05:36,087 --> 00:05:38,601 making it billow and swirl. 50 00:05:42,327 --> 00:05:47,685 Huge whirlpools of hydrogen formed, sucking in the cloud that created them, 51 00:05:47,847 --> 00:05:52,637 spinning them tighter and faster to form huge balls of gas. 52 00:05:57,487 --> 00:06:02,481 And as they span, these enormous spheres got hotter and hotter 53 00:06:02,647 --> 00:06:06,606 until the moment came that changed the universe forever. 54 00:06:11,847 --> 00:06:14,680 The first-ever stars were born. 55 00:06:19,967 --> 00:06:23,755 But these stars alone are not enough to explain why WE'RE here. 56 00:06:23,927 --> 00:06:26,487 What turned stars into us? 57 00:06:31,087 --> 00:06:35,365 Beneath the deserts of Arizona is a device which may reveal the answer. 58 00:06:36,327 --> 00:06:41,242 Lawrence Krauss is a physicist, but this isn't a lab he's visiting. 59 00:06:41,407 --> 00:06:43,921 It's a weapons silo. 60 00:06:47,087 --> 00:06:50,716 The closest we've been able to come to that incredible release of energy 61 00:06:50,887 --> 00:06:56,484 associated with the violent birth of a star is with the hydrogen bomb, or the superbomb. 62 00:07:01,167 --> 00:07:04,876 Hidden in bunkers like this is the technology that allows us 63 00:07:05,047 --> 00:07:08,835 to understand what goes on in the heart of a star. 64 00:07:09,007 --> 00:07:11,646 (ALARM BELL) 65 00:07:11,807 --> 00:07:14,002 (SIREN) 66 00:07:14,847 --> 00:07:18,396 It's the most destructive weapon on our planet. 67 00:07:18,567 --> 00:07:21,001 (ALARM) 68 00:07:21,167 --> 00:07:23,601 (CONTINUOUS SIREN) 69 00:07:45,167 --> 00:07:48,318 This is the power of a hydrogen bomb. 70 00:07:48,487 --> 00:07:53,766 It's the same hydrogen that fuels the fire of every star in the universe. 71 00:08:00,687 --> 00:08:03,201 (KRAUSS) I'm standing on the gantry 72 00:08:03,367 --> 00:08:07,565 near the very top of a Titan intercontinental ballistic missile. 73 00:08:07,727 --> 00:08:11,003 A huge rocket designed to propel, at its very top, 74 00:08:11,167 --> 00:08:16,799 a small payload containing the most explosive device ever created by mankind. 75 00:08:20,407 --> 00:08:23,843 The amount of hydrogen gas in an H-bomb is tiny. 76 00:08:24,007 --> 00:08:26,965 It's barely enough to fill a party balloon. 77 00:08:27,127 --> 00:08:30,642 But the energy it can unleash is devastating. 78 00:08:36,607 --> 00:08:39,758 (EXPLOSION) 79 00:08:54,727 --> 00:08:58,481 This is the same energy which keeps the stars alight. 80 00:09:03,447 --> 00:09:07,725 All this is from a single balloonful of hydrogen. 81 00:09:13,447 --> 00:09:18,043 The ball of hydrogen that makes a star is a million kilometres across. 82 00:09:20,727 --> 00:09:25,198 A star releases the energy of millions of H-bombs every second. 83 00:09:25,367 --> 00:09:27,358 (EXPLOSION) 84 00:09:30,527 --> 00:09:35,157 But, far from being destructive, inside the nuclear furnace of every star 85 00:09:35,327 --> 00:09:38,603 there is an extraordinary process of creation. 86 00:09:46,647 --> 00:09:51,880 As I stand here in this silo and look up at the thermonuclear device 100 feet above... 87 00:09:52,047 --> 00:09:56,916 If it were to go off, I and everything in a ten-mile radius would be evaporated. 88 00:09:57,087 --> 00:10:01,956 But it's also likely that almost every element in the universe would be created. 89 00:10:02,127 --> 00:10:06,882 Just as inside stars hydrogen fuses to form helium, which fuses to form carbon, 90 00:10:07,047 --> 00:10:09,686 then nitrogen, then oxygen, silicon, iron... 91 00:10:09,847 --> 00:10:13,806 As I look around me, everything I see was once the inside of a star. 92 00:10:13,967 --> 00:10:16,606 Every atom came from inside of a star. 93 00:10:23,247 --> 00:10:26,000 The universe began with hydrogen. 94 00:10:32,247 --> 00:10:34,966 And hydrogen created the stars. 95 00:10:38,047 --> 00:10:41,756 And the stars created the elements we need for life: 96 00:10:41,927 --> 00:10:46,079 oxygen in the air, calcium in our bones. 97 00:10:52,167 --> 00:10:55,796 It all came from the stars, but how? 98 00:10:56,567 --> 00:11:01,038 If it was created THERE, how did it make our world? 99 00:11:05,647 --> 00:11:09,845 It's astonishing to think all the ingredients to make the Earth and every living thing 100 00:11:10,007 --> 00:11:12,805 were created inside stars. 101 00:11:17,887 --> 00:11:23,245 Every star is an immense factory churning out billions of tons of chemicals. 102 00:11:23,407 --> 00:11:27,002 But the chemicals aren't much use to anybody while they're in there. 103 00:11:27,167 --> 00:11:30,000 Luckily for us, stars don't last forever. 104 00:11:30,167 --> 00:11:33,125 Just occasionally, they explode. 105 00:11:38,327 --> 00:11:43,321 Amazing but true. Entire stars can blow themselves apart. 106 00:11:43,487 --> 00:11:46,126 To understand WHY, 107 00:11:46,287 --> 00:11:50,280 let me take you back to the very last few moments of a star's life, 108 00:11:50,447 --> 00:11:53,644 just as it teeters on the point of destruction. 109 00:12:02,727 --> 00:12:06,037 This is a star that died billions of years ago. 110 00:12:10,007 --> 00:12:14,478 It's huge. Its life has been violent and short. 111 00:12:14,647 --> 00:12:17,445 And its death made our lives possible. 112 00:12:22,727 --> 00:12:28,597 You are about to witness one of the most violent and wondrous events in the cosmos. 113 00:12:33,127 --> 00:12:36,005 The star has run out of hydrogen fuel. 114 00:12:36,167 --> 00:12:41,400 The nuclear fires that have kept it burning for millions of years have gone out. 115 00:12:46,087 --> 00:12:49,045 As it cools, it shrinks. 116 00:12:50,647 --> 00:12:53,445 It starts to collapse under its own weight. 117 00:12:55,447 --> 00:12:57,517 It crashes inwards 118 00:12:57,687 --> 00:12:59,882 and explodes. 119 00:13:11,087 --> 00:13:14,636 The whole event is over in a thousandth of a second. 120 00:13:19,087 --> 00:13:21,885 They call it a supernova, 121 00:13:22,047 --> 00:13:26,006 an explosion so bright it outshines entire galaxies. 122 00:13:32,967 --> 00:13:35,640 Billions of tonnes of star stuff... 123 00:13:37,087 --> 00:13:39,647 ..hurtle outwards, into space. 124 00:13:42,967 --> 00:13:48,325 So look at a supernova and you're witnessing a moment of creation. 125 00:13:52,287 --> 00:13:58,203 Even with our most powerful telescopes, these explosions remain frustratingly distant. 126 00:13:58,367 --> 00:14:03,441 The best way to find out what happens when a star dies is up close and personal. 127 00:14:05,887 --> 00:14:08,037 We are now charging. Process... 128 00:14:10,167 --> 00:14:13,045 Ten, nine, eight 129 00:14:13,127 --> 00:14:15,721 seven, six, five, 130 00:14:15,887 --> 00:14:17,798 four, three, 131 00:14:17,967 --> 00:14:19,559 two, one. 132 00:14:19,727 --> 00:14:21,957 (THREE BANGS) 133 00:14:24,967 --> 00:14:29,040 To understand the moment of creation that happens when a star dies, 134 00:14:29,207 --> 00:14:31,482 you have to study the explosion. 135 00:14:31,647 --> 00:14:34,719 So we really ARE mistimed by two nanoseconds? 136 00:14:34,887 --> 00:14:39,199 Paul Drake's job is to recreate the most violent explosion in the universe 137 00:14:39,367 --> 00:14:41,756 in a lab in upstate New York. 138 00:14:44,087 --> 00:14:50,196 It may not LOOK like it, but this is our version of an exploding star in the lab. 139 00:14:50,367 --> 00:14:53,757 Exploding stars release a huge amount of energy. 140 00:14:53,927 --> 00:14:57,522 We can't do that on Earth. We'd blow up the solar system. 141 00:14:57,687 --> 00:15:02,477 What we CAN do is concentrate a great deal of energy into a small volume. 142 00:15:04,327 --> 00:15:07,319 To generate anywhere near the force of a supernova, 143 00:15:07,487 --> 00:15:10,559 Drake uses the world's most powerful laser 144 00:15:10,727 --> 00:15:15,198 and focuses it onto a point smaller than the head of a pin. 145 00:15:17,247 --> 00:15:21,923 Here we are in the laser bay, where the laser meets the tiny target. 146 00:15:22,087 --> 00:15:24,999 We wear these bunny suits to protect the laser. 147 00:15:25,167 --> 00:15:28,239 We wear glasses to protect our eyes from the laser. 148 00:15:28,407 --> 00:15:34,118 The laser's in the room next to us. It's the size of a football field. It's huge. 149 00:15:34,287 --> 00:15:38,041 The energy in that beam is 20 times the amount of electrical energy 150 00:15:38,207 --> 00:15:40,880 flowing throughout the entire USA at any one time. 151 00:15:55,327 --> 00:16:00,606 The target is a tiny tube containing the same materials you'd find at the heart of a star. 152 00:16:06,487 --> 00:16:10,605 When the laser hits this target, that creates a shockwave that's so strong 153 00:16:10,767 --> 00:16:14,680 that it shreds the material inside that tube. It tears the atoms apart. 154 00:16:17,407 --> 00:16:23,403 Inside the tiny target is Paul Drake's version of a star just before it explodes. 155 00:16:29,047 --> 00:16:34,440 The inside of a dying star is made up of layers, like the layers of an onion. 156 00:16:36,167 --> 00:16:42,322 The outer layers are the remnants of the gases that fuelled the star, mostly hydrogen. 157 00:16:45,047 --> 00:16:49,165 Deeper, there are layers of calcium, sulphur, carbon, 158 00:16:49,327 --> 00:16:53,081 and at its heart, a dense core of molten iron. 159 00:16:57,967 --> 00:17:04,076 Drake's tiny target is packed with these same layers - like a slice through a star. 160 00:17:04,247 --> 00:17:06,522 (EXPLOSION) 161 00:17:08,207 --> 00:17:12,166 His aim is to see what happens when a star explodes. 162 00:17:17,287 --> 00:17:18,720 Five... 163 00:17:20,727 --> 00:17:22,126 ..four... 164 00:17:24,007 --> 00:17:25,406 ..three... 165 00:17:26,567 --> 00:17:28,046 ..two... 166 00:17:29,527 --> 00:17:31,119 ..one. 167 00:17:32,887 --> 00:17:35,082 (REPEATED EXPLOSIONS) 168 00:17:46,007 --> 00:17:51,365 Here, slowed down millions of times, is what his experiment reveals. 169 00:18:04,927 --> 00:18:10,604 The complex patterns of an exploding star shown in astonishing detail. 170 00:18:10,767 --> 00:18:12,917 The beautiful and precise motions 171 00:18:13,087 --> 00:18:17,478 that scatter the building blocks of life out into space. 172 00:18:27,487 --> 00:18:32,197 That explosion throws the elements that were formed in the star outwards 173 00:18:32,367 --> 00:18:37,805 into the galaxy. Some of them gather together and form other stars, 174 00:18:37,967 --> 00:18:40,686 solar systems, even planets, like the Earth. 175 00:18:52,207 --> 00:18:55,483 These images, captured by our most powerful telescopes, 176 00:18:55,647 --> 00:18:58,445 show the remains of these violent events. 177 00:19:02,567 --> 00:19:06,162 Vast clouds of star stuff expanding though space, 178 00:19:06,327 --> 00:19:09,683 one of the most breathtaking sights in the universe. 179 00:19:16,167 --> 00:19:18,886 But there's a puzzle in these pictures. 180 00:19:19,047 --> 00:19:22,926 It may be the stuff of life, but these are just clouds. 181 00:19:27,287 --> 00:19:30,518 What could turn a cloud into rocks or water? 182 00:19:30,687 --> 00:19:33,838 What could turn a cloud into life? 183 00:19:39,207 --> 00:19:41,880 We've begun to piece the puzzle together. 184 00:19:42,047 --> 00:19:46,962 We've traced the process from the death of a star to the creation of new worlds. 185 00:19:53,927 --> 00:19:56,646 It has taken the most powerful telescopes 186 00:19:56,807 --> 00:20:00,880 and years of patient searching by hundreds of scientists. 187 00:20:03,407 --> 00:20:05,967 One of them is Professor Bob Kirshner. 188 00:20:06,127 --> 00:20:09,597 They call him the godfather of supernovas. 189 00:20:21,727 --> 00:20:28,917 There's a bright supernova once every hundred years or so in a galaxy. 190 00:20:29,087 --> 00:20:31,760 So you're pretty lucky if you see one in your own lifetime. 191 00:20:41,487 --> 00:20:46,038 In 1987, the astronomers' dedication finally paid off. 192 00:20:46,207 --> 00:20:49,643 For the first time, they saw the moment of destruction. 193 00:20:49,807 --> 00:20:54,801 A star exploding. A supernova in a nearby galaxy. 194 00:20:54,967 --> 00:20:59,722 This is Supernova 1987A. We can see parts of this exploding star. 195 00:20:59,887 --> 00:21:03,846 The heavy elements that could make a new planet some day 196 00:21:04,007 --> 00:21:08,159 are in this little dot down in the centre. That's the actual new stuff. 197 00:21:08,327 --> 00:21:12,923 Over tens of thousands of years, that shrapnel from the exploding supernova 198 00:21:13,087 --> 00:21:16,966 gets mixed in with the gas between the stars, 199 00:21:17,127 --> 00:21:20,676 and THAT becomes the stuff which contracts under gravity 200 00:21:20,847 --> 00:21:25,398 to become new stars, new solar systems, new planets. 201 00:21:42,367 --> 00:21:45,484 When you pick up a rock, you have a piece of the universe 202 00:21:45,647 --> 00:21:49,196 that was formed five or seven billion years ago. 203 00:21:49,367 --> 00:21:54,566 The silicon that makes up these bits of quartz were manufactured inside massive stars 204 00:21:54,727 --> 00:21:57,195 and blasted into the gas between the stars. 205 00:21:57,367 --> 00:22:02,077 But it's not just the rock - it's everything that you see in the Earth. 206 00:22:02,247 --> 00:22:06,001 In this countryside of Arizona you can see the beautiful mountains 207 00:22:06,167 --> 00:22:11,036 which are all formed out of elements that were manufactured a long time ago 208 00:22:11,207 --> 00:22:15,917 from generations of stars that blew up five or seven billion years ago. 209 00:22:24,287 --> 00:22:29,281 Over hundreds of thousands of years, countless supernovas spread and mingle. 210 00:22:29,447 --> 00:22:31,881 This is what they become: 211 00:22:32,047 --> 00:22:35,084 immense clouds made from ancient hydrogen gas 212 00:22:35,247 --> 00:22:38,398 mixed with the remains of long-dead stars. 213 00:22:38,567 --> 00:22:44,676 It's a stellar nursery, a place where new stars and new planets are born. 214 00:23:02,047 --> 00:23:06,563 This is the Eagle Nebula - a vast cloud of debris, 215 00:23:06,727 --> 00:23:09,958 the remains of an ancient explosion. 216 00:23:15,887 --> 00:23:20,244 At its heart, new stars and worlds are being created. 217 00:23:20,407 --> 00:23:23,160 These interstellar clouds are immense. 218 00:23:25,167 --> 00:23:27,886 Each one of these bright dots is a star, 219 00:23:28,047 --> 00:23:30,925 many of them much bigger than our own sun. 220 00:23:31,927 --> 00:23:36,079 It was in a place like this that our solar system was born. 221 00:23:36,247 --> 00:23:40,684 All the ingredients needed for the creation of everything are in here. 222 00:23:40,847 --> 00:23:44,123 It just takes a little time for them to come together. 223 00:23:54,447 --> 00:23:57,996 It's a dance that lasts millions of years. 224 00:23:58,167 --> 00:24:02,046 It starts when the gas and dust form microscopic clumps 225 00:24:02,207 --> 00:24:05,324 and it ends with new worlds. 226 00:24:09,807 --> 00:24:13,800 (WALTZ MUSIC: ''THE BLUE DANUBE'') 227 00:24:17,247 --> 00:24:21,160 As the clumps get bigger, they start to stick together, too. 228 00:24:21,327 --> 00:24:25,206 They form clumps of clumps, always bigger, always heavier, 229 00:24:25,367 --> 00:24:28,006 all swirling around each other. 230 00:24:38,287 --> 00:24:40,926 And at the centre of them all... 231 00:24:41,887 --> 00:24:45,197 ..a vast cloud of gas and dust takes shape. 232 00:24:46,567 --> 00:24:49,843 A whirling ball of matter, sucking in everything. 233 00:24:50,007 --> 00:24:54,444 It grows bigger and bigger, hotter and hotter until... 234 00:24:59,247 --> 00:25:02,557 ..a new generation of stars is born. 235 00:25:02,727 --> 00:25:05,764 And this one is OUR sun. 236 00:25:07,527 --> 00:25:12,555 The remaining gas and dust is blown away, leaving behind the planets. 237 00:25:25,007 --> 00:25:29,876 They keep growing. Smaller lumps of rock fall onto them for millions more years. 238 00:25:33,327 --> 00:25:36,797 And when it's over, a new world is revealed. 239 00:25:36,967 --> 00:25:39,959 Our world, the Earth. 240 00:25:43,047 --> 00:25:47,723 But if that's how the Earth got here, then how did WE get here? 241 00:25:48,767 --> 00:25:53,795 Eventually, water and an atmosphere came. But there was one thing missing: life. 242 00:25:53,967 --> 00:25:59,325 Life could have started in the sea, or even in rock pools. But there is another possibility. 243 00:25:59,487 --> 00:26:02,923 Life could well have started in a far-flung region of the universe 244 00:26:03,087 --> 00:26:07,000 and hitched a ride here on the back of a comet. 245 00:26:07,167 --> 00:26:09,158 (SWOOSH) 246 00:26:18,567 --> 00:26:21,604 It may be the most intriguing theory of them all. 247 00:26:26,127 --> 00:26:29,597 Some scientists think life on Earth appeared so quickly 248 00:26:29,767 --> 00:26:32,565 that maybe it came from somewhere else. 249 00:26:34,127 --> 00:26:38,757 Comets may hold the answer. Huge chunks of ice, kilometres across. 250 00:26:38,927 --> 00:26:41,885 If very simple lifeforms could survive inside them, 251 00:26:42,047 --> 00:26:45,164 life could have spread throughout the universe. 252 00:26:51,887 --> 00:26:55,675 (THUNDER AND MUSIC FROM ''CARMINA BURANA'') 253 00:26:59,087 --> 00:27:04,957 If the theory is right, you're about to watch the moment when life on Earth began. 254 00:27:08,247 --> 00:27:11,956 Hurtling through space, the comet heads towards Earth. 255 00:27:12,127 --> 00:27:16,359 Conditions are perfect: rich seas and atmosphere. 256 00:27:17,607 --> 00:27:19,598 (''CARMINA BURANA'') 257 00:27:26,287 --> 00:27:28,881 All that's needed is the spark. 258 00:27:47,367 --> 00:27:51,724 Crashing into Earth, our alien ancestors are thrown in every direction, 259 00:27:51,887 --> 00:27:54,196 scattering across the globe. 260 00:28:04,007 --> 00:28:08,717 And our once lifeless planet is transformed forever. 261 00:28:13,407 --> 00:28:16,240 Everything that makes up our world and us 262 00:28:16,407 --> 00:28:20,116 came from the stars thousands of millions of years ago. 263 00:28:20,287 --> 00:28:24,803 So next time someone asks you where you came from, tell them this. 264 00:28:24,967 --> 00:28:30,519 You came from outer space, created in the heart of a star.