"I want to take you on a journey." "It's a journey like no other." "A journey out there..." "Look up at the night sky." "What do you see?" "The planets, the stars, a million points of light..." "You're looking at your universe." "This series will take you there." "We'll experience first-hand the wonders of the universe, its power and its danger." "And to take a CLOSER look, we'll even bring space down here to Earth." "We'll seek out alien life." "Witness the birth of new worlds." "And we'll discover why what happens out there in space affects all of us here on the one small planet we call our home." "We'll take you from the beginning of time..." "..to the far future of humanity." "This is the voyage of a lifetime." "This is the voyage into space." "We begin with the BIG question:" "where did we come from?" "Aliens." "What would you think if I told you that you, me, everyone came from outer space?" "Weird though it sounds, it's true - we're all aliens." "Once upon a time, every single thing that makes us what we are came from the stars." "We live in a small corner of the universe." "This is our neighbourhood - the solar system." "At its centre, the sun." "And just 150 million kilometres away is our home: the Earth." "It's an astonishing planet." "The only place we know of in the whole universe where conditions are right for life." "The air we breathe..." "Rich seas and oceans..." "Our planet is alive!" "And what's remarkable is, it shouldn't be!" "Life on Earth shouldn't even exist." "So where DID it all come from - me, you, the planet we live on, even our sun?" "It's a puzzle because at the beginning none of it was here." "Let me show you what I mean." "This is the moment it all started - the Big Bang." "(EXPLOSION)" "And that was it." "The Big Bang created the universe, but a universe containing only a vast cloud of hydrogen gas." "So how did something so featureless create our world?" "And how did it create us?" "The journey from a cloud of hydrogen to the building blocks of life is extraordinary." "The calcium in my bones, the oxygen we breathe, where did it come from?" "It all began at the time the universe gave birth to the stars." "For millions of years, the entire universe was nothing but the single vast cloud of hydrogen gas created in the Big Bang." "But within the cloud, something amazing was happening." "Shock waves from the Big Bang were echoing through the cloud, making it billow and swirl." "Huge whirlpools of hydrogen formed, sucking in the cloud that created them, spinning them tighter and faster to form huge balls of gas." "And as they span, these enormous spheres got hotter and hotter until the moment came that changed the universe forever." "The first-ever stars were born." "But these stars alone are not enough to explain why WE'RE here." "What turned stars into us?" "Beneath the deserts of Arizona is a device which may reveal the answer." "Lawrence Krauss is a physicist, but this isn't a lab he's visiting." "It's a weapons silo." "The closest we've been able to come to that incredible release of energy associated with the violent birth of a star is with the hydrogen bomb, or the superbomb." "Hidden in bunkers like this is the technology that allows us to understand what goes on in the heart of a star." "(ALARM BELL)" "(SIREN)" "It's the most destructive weapon on our planet." "(ALARM)" "(CONTINUOUS SIREN)" "This is the power of a hydrogen bomb." "It's the same hydrogen that fuels the fire of every star in the universe." "(KRAUSS) I'm standing on the gantry near the very top of a Titan intercontinental ballistic missile." "A huge rocket designed to propel, at its very top, a small payload containing the most explosive device ever created by mankind." "The amount of hydrogen gas in an H-bomb is tiny." "It's barely enough to fill a party balloon." "But the energy it can unleash is devastating." "(EXPLOSION)" "This is the same energy which keeps the stars alight." "All this is from a single balloonful of hydrogen." "The ball of hydrogen that makes a star is a million kilometres across." "A star releases the energy of millions of H-bombs every second." "(EXPLOSION)" "But, far from being destructive, inside the nuclear furnace of every star there is an extraordinary process of creation." "As I stand here in this silo and look up at the thermonuclear device 100 feet above..." "If it were to go off, I and everything in a ten-mile radius would be evaporated." "But it's also likely that almost every element in the universe would be created." "Just as inside stars hydrogen fuses to form helium, which fuses to form carbon, then nitrogen, then oxygen, silicon, iron..." "As I look around me, everything I see was once the inside of a star." "Every atom came from inside of a star." "The universe began with hydrogen." "And hydrogen created the stars." "And the stars created the elements we need for life:" "oxygen in the air, calcium in our bones." "It all came from the stars, but how?" "If it was created THERE, how did it make our world?" "It's astonishing to think all the ingredients to make the Earth and every living thing were created inside stars." "Every star is an immense factory churning out billions of tons of chemicals." "But the chemicals aren't much use to anybody while they're in there." "Luckily for us, stars don't last forever." "Just occasionally, they explode." "Amazing but true." "Entire stars can blow themselves apart." "To understand WHY, let me take you back to the very last few moments of a star's life, just as it teeters on the point of destruction." "This is a star that died billions of years ago." "It's huge." "Its life has been violent and short." "And its death made our lives possible." "You are about to witness one of the most violent and wondrous events in the cosmos." "The star has run out of hydrogen fuel." "The nuclear fires that have kept it burning for millions of years have gone out." "As it cools, it shrinks." "It starts to collapse under its own weight." "It crashes inwards and explodes." "The whole event is over in a thousandth of a second." "They call it a supernova, an explosion so bright it outshines entire galaxies." "Billions of tonnes of star stuff... ..hurtle outwards, into space." "So look at a supernova and you're witnessing a moment of creation." "Even with our most powerful telescopes, these explosions remain frustratingly distant." "The best way to find out what happens when a star dies is up close and personal." "We are now charging." "Process..." "Ten, nine, eight seven, six, five, four, three, two, one." "(THREE BANGS)" "To understand the moment of creation that happens when a star dies, you have to study the explosion." "So we really ARE mistimed by two nanoseconds?" "Paul Drake's job is to recreate the most violent explosion in the universe in a lab in upstate New York." "It may not LOOK like it, but this is our version of an exploding star in the lab." "Exploding stars release a huge amount of energy." "We can't do that on Earth." "We'd blow up the solar system." "What we CAN do is concentrate a great deal of energy into a small volume." "To generate anywhere near the force of a supernova," "Drake uses the world's most powerful laser and focuses it onto a point smaller than the head of a pin." "Here we are in the laser bay, where the laser meets the tiny target." "We wear these bunny suits to protect the laser." "We wear glasses to protect our eyes from the laser." "The laser's in the room next to us." "It's the size of a football field." "It's huge." "The energy in that beam is 20 times the amount of electrical energy flowing throughout the entire USA at any one time." "The target is a tiny tube containing the same materials you'd find at the heart of a star." "When the laser hits this target, that creates a shockwave that's so strong that it shreds the material inside that tube." "It tears the atoms apart." "Inside the tiny target is Paul Drake's version of a star just before it explodes." "The inside of a dying star is made up of layers, like the layers of an onion." "The outer layers are the remnants of the gases that fuelled the star, mostly hydrogen." "Deeper, there are layers of calcium, sulphur, carbon, and at its heart, a dense core of molten iron." "Drake's tiny target is packed with these same layers - like a slice through a star." "(EXPLOSION)" "His aim is to see what happens when a star explodes." "Five... ..four..." "..three... ..two..." "..one." "(REPEATED EXPLOSIONS)" "Here, slowed down millions of times, is what his experiment reveals." "The complex patterns of an exploding star shown in astonishing detail." "The beautiful and precise motions that scatter the building blocks of life out into space." "That explosion throws the elements that were formed in the star outwards into the galaxy." "Some of them gather together and form other stars, solar systems, even planets, like the Earth." "These images, captured by our most powerful telescopes, show the remains of these violent events." "Vast clouds of star stuff expanding though space, one of the most breathtaking sights in the universe." "But there's a puzzle in these pictures." "It may be the stuff of life, but these are just clouds." "What could turn a cloud into rocks or water?" "What could turn a cloud into life?" "We've begun to piece the puzzle together." "We've traced the process from the death of a star to the creation of new worlds." "It has taken the most powerful telescopes and years of patient searching by hundreds of scientists." "One of them is Professor Bob Kirshner." "They call him the godfather of supernovas." "There's a bright supernova once every hundred years or so in a galaxy." "So you're pretty lucky if you see one in your own lifetime." "In 1987, the astronomers' dedication finally paid off." "For the first time, they saw the moment of destruction." "A star exploding." "A supernova in a nearby galaxy." "This is Supernova 1987A." "We can see parts of this exploding star." "The heavy elements that could make a new planet some day are in this little dot down in the centre." "That's the actual new stuff." "Over tens of thousands of years, that shrapnel from the exploding supernova gets mixed in with the gas between the stars, and THAT becomes the stuff which contracts under gravity to become new stars, new solar systems, new planets." "When you pick up a rock, you have a piece of the universe that was formed five or seven billion years ago." "The silicon that makes up these bits of quartz were manufactured inside massive stars and blasted into the gas between the stars." "But it's not just the rock - it's everything that you see in the Earth." "In this countryside of Arizona you can see the beautiful mountains which are all formed out of elements that were manufactured a long time ago from generations of stars that blew up five or seven billion years ago." "Over hundreds of thousands of years, countless supernovas spread and mingle." "This is what they become:" "immense clouds made from ancient hydrogen gas mixed with the remains of long-dead stars." "It's a stellar nursery, a place where new stars and new planets are born." "This is the Eagle Nebula - a vast cloud of debris, the remains of an ancient explosion." "At its heart, new stars and worlds are being created." "These interstellar clouds are immense." "Each one of these bright dots is a star, many of them much bigger than our own sun." "It was in a place like this that our solar system was born." "All the ingredients needed for the creation of everything are in here." "It just takes a little time for them to come together." "It's a dance that lasts millions of years." "It starts when the gas and dust form microscopic clumps and it ends with new worlds." "(WALTZ MUSIC:" ""THE BLUE DANUBE")" "As the clumps get bigger, they start to stick together, too." "They form clumps of clumps, always bigger, always heavier, all swirling around each other." "And at the centre of them all... ..a vast cloud of gas and dust takes shape." "A whirling ball of matter, sucking in everything." "It grows bigger and bigger, hotter and hotter until..." "..a new generation of stars is born." "And this one is OUR sun." "The remaining gas and dust is blown away, leaving behind the planets." "They keep growing." "Smaller lumps of rock fall onto them for millions more years." "And when it's over, a new world is revealed." "Our world, the Earth." "But if that's how the Earth got here, then how did WE get here?" "Eventually, water and an atmosphere came." "But there was one thing missing:" "life." "Life could have started in the sea, or even in rock pools." "But there is another possibility." "Life could well have started in a far-flung region of the universe and hitched a ride here on the back of a comet." "(SWOOSH)" "It may be the most intriguing theory of them all." "Some scientists think life on Earth appeared so quickly that maybe it came from somewhere else." "Comets may hold the answer." "Huge chunks of ice, kilometres across." "If very simple lifeforms could survive inside them, life could have spread throughout the universe." "(THUNDER AND MUSIC FROM "CARMINA BURANA")" "If the theory is right, you're about to watch the moment when life on Earth began." "Hurtling through space, the comet heads towards Earth." "Conditions are perfect:" "rich seas and atmosphere." "("CARMINA BURANA")" "All that's needed is the spark." "Crashing into Earth, our alien ancestors are thrown in every direction, scattering across the globe." "And our once lifeless planet is transformed forever." "Everything that makes up our world and us came from the stars thousands of millions of years ago." "So next time someone asks you where you came from, tell them this." "You came from outer space, created in the heart of a star." "Take a walk on planet Earth." "It's a wonderful place." "But don't take it for granted, because one day it might just vanish - forever." "This is the story of the universe we live in... ..and the dangers we face just by being here." "We'll fly with the comets and asteroids which threaten all life on our planet." "Here on Earth, we'll recreate our sun's headlong plunge around the galaxy and watch disasters unfold which could spell the end for us all." "Our planet is under threat." "Our mission... ..is to stay alive." "If you're a gambler, this is the planet to live on, because just by being here, we're all taking a risk." "And the odds are stacked against us." "Do you feel lucky?" "You should do." "You may not realise it, but we are all winners." "We human beings are lucky to be here, because the universe keeps trying to wipe us out." "Trying... ..and failing." "We have survived every disaster the universe has ever thrown at us - so far." "But our run of luck won't last forever." "When it ends, our planet and our entire species will cease to exist..." "..unless we can do something about it." "Could our whole planet really be in danger?" "What could threaten a globe 13,000 km across, or 6 billion people?" "To understand the threat, you have to see it first hand." "I want to show you planet Earth as it was in its earliest days." "(WHOOSHING AND CRACKLING)" "This is where it all begins." "We're lucky there's even a planet here for us to live on, because it was very nearly blown apart before life had even begun." "This is planet Earth, billions of years ago, at the very beginning of its life." "As you can see, it is under attack." "These are asteroids, rocks left over from the creation of the planets themselves." "Some of them were vast, and one of them was on a collision course with Earth." "This collision nearly smashed our Earth to pieces." "We were hit by a ball of molten rock the size of Mars travelling at colossal speed." "(EXPLOSION)" "The impact ripped huge chunks out of our planet." "Somehow it survived." "But what about the future?" "Smaller chunks of rock are still flying around our solar system today." "We call them asteroids, and they could put an end to human civilisation." "Asteroids range in size from pebbles to mountains, or even bigger." "And they're dangerous." "They're flying around at incredible speeds." "To get an idea of the damage they can do, just take a trip to the moon." "(MISSION CONTROL) Three, two one, zero." "All engines running." "(BROADCAST) Man, a species born and who's lived all his life on Earth, moves with this journey out into the solar system." "What can you say about a sight like that?" "(MISSION CONTROL) You are go to continue power descent." "In 1969, for the first time ever, human beings walked on the surface of another world... (BANG, FOLLOWED BY ASTRONAUT'S VOICE)" "..the moon." "Tranquillity Base here." "The eagle has landed." "(MISSION CONTROL) Roger, Tranquillity, we copy." "And what a world it was - airless, barren, hostile." "And bearing the disturbing evidence of a terrifying threat." "The moon is scarred with craters, the marks of countless asteroids that have slammed into it." "The moon is under attack." "And travelling through space, alongside the moon, is another planet, the one we call home." "So why aren't we taking the same pounding?" "There's a simple answer to that... we are." "This crater was formed in a few seconds about 49,000 years ago." "It's almost 1.2 kilometres in diameter." "It's almost 200 metres deep." "It was caused by an asteroid about 40 metres in diameter." "It came in with a velocity of about 25 km/second, and it exploded with the force of a 15-megaton hydrogen bomb." "(EXPLOSIONS)" "This is Meteor Crater in Arizona." "Geologist Jeff Wynn thinks that what happened here could happen again, soon." "Local effects would have been devastating." "Anything within the circumference of the crater would have been obliterated." "If you were an animal grazing within a few kilometres, you would have been killed." "If you were beyond that, depending on where the wind was blowing, the ejector coming down would have killed you." "This is just one example of what could happen if one of these things did hit." "Geologists are discovering more and more evidence of asteroid impacts here on Earth." "Meteor Crater would be hard to miss." "Other impacts are more difficult to spot." "But we have seen them." "We've photographed them from space." "These are the remains of titanic collisions, some of them vast, 20 or 30 km across." "The Earth is being pounded all the time." "Siberia, 1908, an entire forest was flattened." "There was an impact in Saudi Arabia in 1933." "(MUFFLED ROAR)" "This was caught on camera in Canada in 1972." "A near miss - it flew back out into space." "If it had crashed on Earth, it would have exploded with more force than an atom bomb." "Amazingly, in all these events, no one at all was killed." "But even if an asteroid doesn't hit us, it could do something even more dangerous." "It could hit the sea." "If a big asteroid smashes into the ocean, it could create a huge deadly wave that could wipe out entire cities." "(WYNN) I think there's a realistic possibility that something like this could cause serious problems to human civilisation some time in the next century or two." "It's not an appealing thought, but the threat is real." "Whole cities could be obliterated from space." "Whether it's your city comes down to luck." "But before you feel too lucky, think about this." "It may not matter where you live." "There are things out there which could wipe all life from the face of the planet." "Space contains dangers that make asteroids... ..seem utterly insignificant." "Our telescopes have captured images of truly colossal disasters." "This photograph shows a star a hundred times bigger than our sun blasting incandescent gas out into space." "And this is a black hole spewing out jets of super-hot matter at close to the speed of light." "If these had been near us, there's almost no chance that we'd have survived." "It looks as though fortune has been on our side." "At least it has so far." "But for how much longer?" "Professor Mike Rampino thinks the odds for long-term survival of life on Earth are slim." "Luck plays a big role in the existence of life on the planet Earth." "You have to realise that the galaxy is a very violent place." "If we get unlucky, that could put an end to complex life on the planet." "Here's the problem." "We don't notice it, but planet Earth is on the move." "While we get on with our lives, the world is hurtling around our galaxy at 230 kilometres a second." "And high speed means high risk - some you win, some you lose." "We may not realise it, but we're on the ride of our lives." "Think of the Earth's orbit as a kind of cosmic roller-coaster ride." "As we move in this orbit, we're moving past gas clouds." "We can come close to black holes." "We can get close to stars." "We can come close to supernova explosions." "Any of these objects could cause catastrophes on the Earth." "Sound incredible?" "It's very real." "Life on Earth has been all but eradicated on 20 separate occasions." "And to make matters worse, it's going to happen again." "After all, remember what happened to the dinosaurs." "Flying through space is a dangerous business." "It's not just that we're moving, it's where we're going." "Planet Earth regularly flies through some of the most dangerous areas of the galaxy." "(RAMPINO) If one could speed up time and watch the orbit of the Earth through the galaxy and around the galaxy, it would look like a very, very fast carousel - the sun and the planets moving up and down," "and at the same time moving around the galaxy very rapidly." "We go around the galaxy about once every 250 million years." "But, also, we go through the densest part of the galaxy every 30 million years." "That's the danger zone." "Every 30 million years, planet Earth travels through a region heavily packed with stars." "And it so happens that it's every 30 million years or so that life on Earth comes close to being wiped out." "Coincidence?" "Here is our galaxy, a huge flat pancake of 400,000 million stars, all whirling around." "The brightest areas are where the stars are most tightly packed." "These are the danger zones." "And this star is our sun." "At the moment... ..it's just there, just another pinprick in the cloud of stars that makes up our galaxy." "But take a closer look and see how it's moving." "It doesn't just go round the galaxy." "It also goes up and down." "And where the sun goes, the Earth goes." "So, regular as clockwork, we plunge through the danger zone." "And every time we do so, the odds are stacked against us." "Here's how it works." "This is our sun, and each of those other dots is a star." "As our sun bobs up and down through the galaxy, we're passing them by the million." "And where the stars are densest, the danger is greatest." "The reason those other stars are dangerous is the powerful effect of their gravity on our solar system." "Fly outwards from the sun, away from the Earth and the other planets, and eventually you encounter these:" "chunks of ice, trillions of them, a vast cloud in space." "If another star comes too close, its gravity disturbs the cloud... ..and catapults ice chunks in towards the sun." "More than 10 km across, travelling at 40 km a second, it begins its million-year journey into the heart of our solar system." "We know these huge snowballs by another name." "This is a comet." "As it plunges towards the sun, it warms up and belches out a haze of gas and dust." "An immense cloud trails through space behind it... ..the comet's tail." "But this comet doesn't hit the sun." "It skims round it and out." "It drifts past Mercury, and the planet's gravity swings it onto a new path." "Finally, it shoots past the moon and on to a collision course with Earth." "This is what happened to the dinosaurs 65 million years ago." "How much time have WE got?" "(RAMPINO) So far we've been lucky." "If you look at the history of life on the Earth, the average lifetime of a species is just a few million years." "Human beings have been around for a few million years." "It doesn't bode well for the future of the existence of human beings on the Earth." "We last passed through the danger zone one million years ago." "But that doesn't mean we're safe yet." "Because a million years is how long it takes for comets to enter our solar system." "And in July 1994, one smashed straight into Jupiter, drawn in by its immense gravity." "These blurred photographs reveal a colossal explosion." "It covered an area bigger than our entire planet." "If Jupiter hadn't intercepted that comet, if it had hit the Earth instead, it could have been the end of us." "I told you we were lucky." "It's not just that Jupiter saved us six years ago." "It's saved us thousands of times." "It's been doing so since the dawn of our solar system." "Without Jupiter, life on Earth would never even have got started." "Remember all those asteroids in the early solar system?" "There were so many of them flying around that life couldn't even get started." "What changed that was Jupiter." "Its powerful gravity sucks in anything that comes too close." "You're watching at a million years per second." "Jupiter made life on Earth possible." "It drew the asteroids' fire and shielded our planet." "It's still catching asteroids today." "But unfortunately for us, the number of asteroids out there is all but limitless." "Sooner or later our luck will run out, just as it did for the dinosaurs." "Jupiter can't catch them all." "And one is all it takes." "This one, for example." "The question is, what on earth are we going to do about it?" "It seems we have a problem." "This asteroid is huge, 50 km across, 100 billion tonnes of rock surrounded by clouds of dust and debris." "It's travelling at 40 km a second." "And it's heading straight towards Earth." "So what ARE we going to do about it?" "The American military are on alert." "The man who runs Earth's asteroid detection system is Sergeant Rob Medrano." "Comets and asteroids represent the most significant threat that we have from space." "They do impact the Earth routinely, but mostly objects that are very small." "We're concerned about those large objects that penetrate the Earth's atmosphere." "With that in mind, on average we're discovering about four a month." "The asteroid passes Mars." "It is now only 45 days from the Earth." "Already time is running out for us all." "Detecting the threat is not enough." "The point is to DO something about it." "(WYNN) There are several possibilities." "One is to send a rocket up with a nuclear device and blow it to pieces." "Another possibility is to put chemical rockets on the object and try to shove it out of the way." "This all requires that we have time to mount a project and do something about it." "There are two possibilities for human beings to survive far into the future." "One is some kind of planetary protection." "The other is insurance - moving off of this planet onto other planets..." "..so if there are catastrophes on this individual planet, it wouldn't wipe out human beings entirely." "The potential exists for an asteroid to impact the Earth that would essentially wipe out life as we know it." "(MUFFLED ROAR)" "(ALARM)" "In terms of defending ourselves today, predicting where the asteroid is going to actually impact, that's really all that we have." "(MUFFLED ROAR)" "So far, we have survived." "But what about the future?" "To safeguard that, we should be acting now." "One day our planet's luck will run out." "It's a matter of time." "We must develop the technology to defend ourselves." "Because if we're not prepared, the odds are that one day... (ROAR)" "..one day the human race may cease to exist." "Humanity, ignorant in bliss." "We go about our lives unaware that in the depths of space lurk invisible monsters." "Destroyers powerful enough to tear apart our sun and leave our Earth a shattered, burned-out ruin." "You are about to enter the world of the universe's ultimate killer." "We will be there when the monster is created - in the heart of a dying star." "We will search for its telltale signs in the darkness of deep space." "This is the story of the power that may one day destroy us all - the black hole." "There's an old saying - what goes up... ..must come down." "Thing is, it's not always true." "If you throw something hard enough, it might never come down." "If something goes up fast enough, it can escape the Earth altogether." "Faster still, and it can escape the immense pull of our sun, the force that holds the planets in place." "Travel fast enough, and you can even escape the pull of the billions of stars that make up our galaxy..." "..the Milky Way." "But there is one object out there whose pull is so powerful you can never escape, no matter how fast you go, not even if you travel at the speed of light." "Meet the monster." "This is a black hole in action." "It is tearing apart a star that has strayed too close." "Anything that comes near is destroyed." "It's hard to believe anything is powerful enough to destroy a planet or a star, but it's true." "Let's take a closer look." "Put a black hole near something and immediately it starts ripping it apart." "There's a star in there - it could just as easily be our sun - and it is being pulled apart by a black hole." "On this scale, our Earth would be no bigger than a pebble." "We wouldn't stand a chance." "The shocking thing is how small the black hole is." "The black hole itself is right at the centre of the disc." "It's tiny." "It's a million times smaller than the star." "Just look what it can do." "What is it about a black hole that makes it so powerful?" "The answer is gravity." "It's the force that keeps us all stuck to the surface of our planet." "If something's heavy enough, it pulls YOU towards it." "And planet Earth is heavy - so heavy, in fact, that to get off it, you have to do this." "All of this, just to escape from our tiny globe." "And if Earth's gravity seems strong... ..imagine the pull of the sun." "Our sun is a million kilometres across." "This is the real heavyweight of the solar system." "But if you think our sun is big, think again." "There are stars out there that are vast." "Their gravity is mind-boggling." "But compared to a black hole, even this star is a weakling." "A black hole weighs as much as a massive star, but it's crammed into an area smaller than a pea." "A black hole is gravity gone mad." "Nothing can ever escape." "What could create such a monster - something so heavy and yet unimaginably small?" "An event powerful enough to create a black hole should be visible right across the universe." "And recently, we might actually have witnessed one as it happened." "A team in Australia, headed by Professor Brian Boyle, spotted it." "The first clue that led to his discovery came in the form of radiation - gamma rays - that are invisible to the human eye." "The night sky that we can see with our own eyes is only part of the picture." "Light comes to us in many different forms, from low-energy radio waves to the highest energy form of light:" "the gamma rays, the form of light that packs the biggest punch." "Every night, in the gamma-ray sky, is fireworks night." "We've been detecting violent bursts of gamma rays for decades, but we've never actually seen what causes them." "It has to be a violent event, but what kind?" "The problem is, gamma-ray bursts only last a few seconds." "And to make things harder, the best way to detect them is from space." "(MAN) Gamma Ray Observatory to Atlantis... (WOMAN) Houston, no need to respond..." "(MAN 2) ..This gorgeous spacecraft..." "During a routine observation, the Gamma Ray Observatory detected an enormous blast of energy going off in deep space." "What had triggered it?" "Brian Boyle's team, guided by the space observatory, turned their ground-based optical telescopes on to the blast in the hope of seeing it before it faded." "(BOYLE) The information was really down to the ground." "The optical telescopes sprang into action, to try to localise where this burst of energy had come from." "What we found was something we didn't expect, that this light was actually coming from a supernova." "What they'd seen with their telescopes was an exploding star." "But the explosion was far larger than anyone had ever witnessed before." "(EXPLOSION)" "And in the heart of that cataclysmic explosion, the researchers realised that something astonishing and terrifying had happened." "As the massive star died, a monster had been born." "We'd witnessed the birth of a black hole." "What Boyle's team had seen was the death of a star so heavy that when it exploded, its mass collapsed inwards instead of blasting out into space." "This star is absolutely huge." "It's a hundred times bigger than our sun and thousands of times brighter." "(EXPLOSION)" "But it doesn't just explode." "As its surface layer blasts upwards, its core is smashed inwards." "The centre of the star collapses in on itself, billions of tonnes of star stuff crushed smaller and smaller, until the whole star is squeezed to a single microscopic point." "And from the remains of the dying star, a black hole is born." "In our galaxy, a massive star explodes and creates a new black hole every 1,000 years - which may not sound like a lot, until you remember that the galaxy has been here a very long time." "Speeding up its history, you can see that stars have been going off like firecrackers." "And when a black hole is born, it never dies." "Every hole that was ever created is still out there, so there should be around ten million of them, somewhere." "The question is - where?" "Until recently, black holes remained unseen in the depths of space." "But something as deadly as a black hole can't remain hidden forever." "Like most predators, they leave a trail of destruction." "And scientists are now beginning to recognise these telltale signs." "One black hole hunter is Janna Levin." "Even though black holes are invisible, it doesn't mean they have no effects." "They're extremely strong vortices and pull matter in these swirling winds around them, a lot like a tornado." "And like a tornado, you might not see it until the debris gets sucked up, like THIS tornado is now pulling the gases in it." "So suddenly you can see the presence of this vortex, this strong swirling wind." "It isn't the wind of a tornado you see - it's the havoc it creates." "(EMERGENCY VEHICLE SIRENS)" "That's how we detect black holes, too - by the damage they do." "(LEVIN) Tornados are incredibly powerful, but you don't SEE them until they suck stuff into them, until you see them pulling up houses and cars, and gas and smoke and clouds." "It's the same with black holes." "You don't see them until they pull in the matter around them." "This is what astronomers look for." "Not the black hole itself, but stars caught in the black hole's incredible gravitational pull." "This one is tearing apart a star that drifted too close." "A feeding black hole is anything but black." "The whole star is wrenched out of shape as the monster tugs at it." "Gas from the star whirls around the hole." "It forms a super-hot disc of star debris, 100,000 km across." "It's a deadly embrace that will last millions of years." "And what the black hole can't swallow, it belches out." "Huge jets of uneaten star are spat out into space." "Some of the most spectacular black holes we've seen are SO powerful and spinning SO rapidly that they create these huge jets, these powerful funnels of material." "They're thin but incredibly, incredibly long, incredibly vast." "And the jets themselves can cross an entire galaxy." "They're absolutely huge." "The damage a black hole inflicts on a star can be seen clear across the universe." "Once astronomers knew what to look for, they began to hunt for feeding black holes." "Using powerful space telescopes, we've tracked down more and more of them." "And these are the actual images - black holes tearing apart everything they meet." "Most of them are remote." "They're in distant corners of the universe." "And we've only found them BECAUSE they're feeding." "But what about the ones that aren't feeding?" "Where are the millions of black holes that should be wandering through OUR galaxy?" "They remain hidden against the dark background of space." "Luckily, there is a way of tracking even the blackest of black holes." "And THIS is what gives them away - light." "A black hole's powerful gravity affects everything around it." "It can even bend light." "So when a black hole passes in front of a star, the light from that star is distorted... ..and the black hole gives itself away." "Finding a star at the precise moment it's distorted by a black hole is a daunting task." "But that didn't stop one very, very patient astronomer from trying to see the invisible." "Tim Axelrod has dedicated many years of his life to the pursuit of the universe's hidden objects." "For eight years, we've been looking at the same patch of sky, monitoring the brightness of 20 million stars." "We're looking for micro-lensing events." "These events are extremely rare." "They occur when a massive object passes across our line of sight to a distant star." "Axelrod set about his search for what he calls "gravitational micro-lensing" - when a star's light is distorted by a massive object like a black hole." "But the odds were stacked against him." "At best, his chance of finding the right star was one in a million." "That factor seemed impossibly large, so most people thought we would fail pretty dismally." "Undaunted by the enormity of the task and the scepticism of his colleagues," "Axelrod set about looking for that one telltale pinprick of light amongst 20 million stars, every night for eight entire years." "Then, one night, he hit the jackpot." "This is a view of the Large Magellanic Cloud." "The blue square shows the field of view of our telescope." "Now we've zoomed in a bit." "The star we're interested in is a pretty inconspicuous fellow right in the centre of the cross here." "Now we zoom in yet again." "This is picking the needle out of the haystack." "And what we saw when we looked at it over a period of time was this." "We were, naturally, ecstatic." "Everyone that saw it agreed immediately that this was gravitational micro-lensing, so we were just over the moon." "Far out in space, he had seen the impossible." "A massively heavy object like a black hole, sliding silently in front of a distant star." "Next, Axelrod turned to our own galaxy." "What he saw was disturbing - evidence not of one or two black holes, but hundreds." "But is that anything for us here on Earth to worry about?" "Could our own fragile planet ever encounter one of these invisible monsters?" "If we do ever meet a black hole, it would tear our world to shreds." "But one thing is sure - our skies seem to be full of them." "And our galaxy still has one last dark secret, and it took the most powerful telescope in the world to unlock it - the Keck in Hawaii." "One of the astronomers using it is Andrea Ghez." "The Keck telescope is a fabulous telescope to use." "It's great because it's large." "This is a case where bigger IS better." "You can collect a lot of photons, so you can see very faint things and very fine detail." "The telescope's vast mirror allows Andrea Ghez to study the centre of our galaxy with more accuracy than ever before." "What astronomers have seen is a black hole a million times more powerful than normal." "(GHEZ) Here's an example of an image we got just last night." "We see that there are fainter stars towards the centre." "These stars are very important." "It's the motion of these stars that reveal the presence of the black hole." "There is a black hole at the centre of our galaxy that is SO powerful that it spins whole stars around itself at impossible speeds." "The fact that they're going 1,000 km per second tells us there's two million times the mass of the sun of matter there." "This is no ordinary black hole." "This black hole is a giant, two million times as heavy as our sun." "And it's not in some far-flung region of the universe." "This black hole is sitting right at the centre of OUR galaxy." "Suddenly the idea that the Earth might one day fall victim to a black hole doesn't seem quite so unlikely." "If we ARE ever unlucky enough to meet one, what would it be like?" "It begins far out in space, beyond the furthest planets." "A black hole ploughs into the cloud of comets that surrounds our solar system and flings them towards Earth with incredible force." "(WHOOSHING)" "(EXPLOSION)" "These impacts are the first warning of our fate." "As the black hole comes closer, its next victim is Jupiter, the giant of our solar system." "Even from so far away, the black hole's gravity makes itself felt here on Earth." "Our world is being shaken apart." "But the black hole hasn't finished yet." "It's heading straight for the heart of the solar system, our sun." "Though tiny in comparison, it tears the sun apart." "Dragging the sun with it, the black hole heads towards Earth." "The Earth is now unbearably close to the sun." "All life has long since ceased to exist." "And our planet starts to melt." "Quietly, our battered world disintegrates, and is consumed." "And all that is left is the black hole, drifting through space." "Earth eaten by a black hole?" "It sounds bizarre." "But we know there are millions of these monsters out there." "What we don't know, is..." "We've all grown up wondering if we're alone in the universe, or if, one day, we might come face to face with an alien." "This is the story of our search for extra terrestrials." "Does ET really exist?" "We're going on a journey to find out." "We'll visit alien planets in search of life." "We'll dive into the oceans of distant moons." "Here on Earth, we'll scan the universe for alien life." "And seek out the answer to one of the greatest questions - is there life on other worlds?" "Or, in all the vastness of space, could it really be that we are completely and utterly alone?" "We already know that we are not alone." "We share our planet with at least ten million other species." "This is life on Earth." "From the ordinary... to the utterly bizarre." "So, what about other planets?" "Could they have produced life, too?" "There's one creature on Earth that would like to know - us!" "If intelligent life could evolve here on Earth, then why not elsewhere?" "We're the first generation that might actually find out." "Scientists have begun to discover new worlds out there in space." "Places where one day we might encounter alien life." "So, how long before we find the answer to the question we really want answered?" "Is there anybody out there?" "Look at the stars." "Each of them is a sun like ours, and our sun has planet Earth." "Could this really be the only planet anywhere that's full of life?" "To find out, we must leave our own world behind." "Let's travel further." "Beyond our sun and out into space." "There's Mars, cold and inhospitable." "Next is Jupiter, a vast and lifeless ball of gas." "Then another gas giant" " Saturn." "Then Uranus, Neptune and on." "All the other planets of our solar system are barren worlds, devoid of life." "But beyond our solar system are the stars and, remember, each of these is another sun." "400,000 million of them in a vast, swirling cloud." "The Milky Way - our galaxy." "And when you leave our galaxy behind, you begin to realise just how vast the universe is." "Because each of these is a galaxy just like ours." "And these are clouds of galaxies." "Is it really possible that the only planet with intelligent life is this one?" "It's all a question of numbers." "If there are enough stars out there, the chances that alien life exists could be very good indeed." "It's hard to comprehend just how many stars there are." "Each point of light is a whole galaxy, billions of stars in every pinprick of light." "Look at a handful of sand." "How many grains?" "Thousands?" "Hundreds of thousands?" "How many grains on a whole beach?" "The numbers are too big to think about." "Well, think about this." "For every grain of sand on our entire planet, there are a million stars out there in space." "A million stars just like our sun for every grain of sand." "Where there are stars, there may be planets." "And where there are planets, there may be life." "It's happened here." "So, where is everybody else?" "If there are intelligent beings up there trying to contact us, their messages will be picked up here probably before anywhere else." "But to hear the voices of the planets, you need a big ear." "This is the biggest ear on Earth." "For the last 35 years, scientists have been working on a project to settle the question of whether we're alone." "Their mission - to scan every star in the sky for signs of alien life." "It's called SETI - the Search for Extra Terrestrial Intelligence." "And they're still doing it today." "CQ, 20 metres, this is N6 Uncle Donald Kilowatt calling and standing by." "Seth Shostack is a SETI astronomer." "His job is to listen out for ET on the radio." "Radio cuts right through the gas and dust that hangs between the stars." "Radio is an easy communication medium for us and them to use, so we figure they're probably using a lot of radio." "There is so much cosmic real estate, so many stars, that it's hard to believe that this is only bit in the entire cosmos that's populated by beings able to develop radio technology." "In the first decade of searching, SETI had nothing to show." "Then, in 1977, that changed." "A SETI computer detected exactly what they were looking for - a powerful radio beam from another star." "Could it have been a signal from an alien race?" "We may never know." "By the time they could train more instruments on it, the signal had vanished." "It remains unexplained." "One sniff of success in 35 years of searching might put you off, but Seth Shostack is undaunted." "If we do this for 100 years and don't find a signal, I'd be nonplussed." "I'd also be dead, but it would surprise me." "I think that this experiment is almost guaranteed to succeed." "But despite Seth's optimism, finding extra terrestrials could take some time." "There are too many stars to search." "The problem is, our galaxy is truly immense." "This is us, just here." "That star is the sun." "And this is the area we've searched so far for alien signals." "Not bad, until you see how many stars there are to search." "Finding extra terrestrial beings might seem like a daunting task, but it may not be in vain." "We've started to find places where they could live." "Hawaii." "Far above the clouds of Big Island sits the largest telescope in the world." "Scientists come here to search for what they recently believed was impossible." "Evidence of planets circling around distant stars." "What object next, guys?" "We'll continue stepping down 93 31." "All right, lining up on slit." "We are ready for exposure." "And...shooting." "At first glance, their task seems hopeless." "Finding a planet around another star is like finding a grain of sand on the moon." "But there's a trick to it." "Don't even look for the planet." "Look at the star." "Geoff Marcy is one of a new breed of scientist - a planet hunter." "If there's a planet going round a star, we'll never see the planet lost in the glare of the star." "What we do, is we watch the star itself." "We watch if it wobbles in space." "It's very much like a hammer thrower." "As the hammer thrower wheels this huge mass around his head, the hammer thrower wobbles around, pulled by the hammer." "Even if you couldn't see the hammer, you'd be able to tell that he had a large mass at the end of a rope." "So, you can tell a lot about the planets going around a star by just watching the star itself." "The idea that you can detect a planet by the minuscule wobble it creates in a star is frankly astonishing." "Small wonder that success was a long time coming." "We started our planet search way back in 1986." "We went for nine years without finding anything." "And then in 1995, we started finding some." "And now we're finding planets so fast, we can barely keep up." "Every month, we find another two or three." "It's like we have to stuff the planets in our mouths to pretend that we are keeping up, when, in fact, we're not." "There's almost no question that there are literally hundreds of billions of planets just in our own galaxy, many of which could harbour life." "One by one, astronomers were finding alien worlds." "But their hopes of finding alien beings soon faded." "Every world they've discovered appears lifeless." "These are gas giants, with no solid surface for life to live on, and most are so close to their stars that the heat would be lethal." "To find worlds where aliens could live, they'll need a whole new approach." "And this could be it." "A fleet of orbiting telescopes flying in laser-guided formation." "Each is many times more powerful than the Hubble space telescope." "When they are launched in 2025, the telescopes won't be looking for the subtle wobble of a star." "They'll look straight at the planet itself." "They'll analyse its atmosphere, perhaps even tell us if there's life." "One day, we'll be able to look out into space and see other worlds like ours." "I think, for almost any human being, the picture of another Earth orbiting another star would be like looking in the mirror, but not one you see in the morning." "This would be a mirror of our whole solar system and our beloved planet." "Seeing it mirrored in another star would be one of the most exciting days in any life." "It is an astonishing prospect." "But if we're looking for alien life, finding another planet so much like our own may not be necessary." "Our planet has everything life needs - air, water, even sunlight, if you're lucky." "Conditions here are just right - for us." "But who's to say alien life would thrive on the same things?" "What if it doesn't need sun or air?" "Three kilometres down in the ocean lies one of the harshest environments we know." "This is a volcanic vent." "The temperature here is over 100 degrees." "There's total darkness, pressures to crush a human to a pulp." "These creatures should literally be cooked." "But here they are." "If living things can thrive here, then where else?" "Scientists' quests for new lifeforms have led them to the most hostile environments." "This cave is the relic of a vast volcanic eruption that occurred millions of years ago." "It's a lava tube - a gully left behind by a river of molten rock, sterilised by the heat." "When the rock solidified, the tube was sealed off from the world." "There's nothing here to live on." "No sunlight." "Nothing but rock." "This truly is another world." "Penny Boston is a specialist in finding life where it shouldn't exist." "The important thing about looking for life on other planets is to keep your imagination as broad as you possibly can." "Try not to go with pre-conceptions, because you never know what you'll find." "We can only go with our best guesses, depending on what we find on Earth." "If Penny's team finds life here, it is surviving conditions we used to claim were impossible." "If life can survive impossible conditions on Earth, why not on other worlds?" "And this is the first place to look" " Mars." "Like the caves on Earth, there's little here for life - not much water or air, nothing but rock to live on." "But perhaps the rocks of Mars will hide similar wonders to those of Earth." "The miracle of life." "That is cool." "Look how much it narrows down there." "Could that be a nematode?" "Penny's discoveries in these caves make the odds of finding life on Mars far higher." "And life on Mars could mean life on other planets as well." "If we find life on Mars," "I think that our chances of finding life beyond Mars, and other places in the universe, go up enormously." "Two planets in just one solar system have life on them." "That means that life is a pretty common phenomenon in the universe." "So, where to search after Mars?" "This is probably the strongest candidate for alien life in our solar system." "It's one of Jupiter's 16 moons - Europa." "It appears tiny next to Jupiter, but Europa is almost as big as Earth." "This is an ice world, its surface frozen to a crippling 150 below zero." "Life here looks impossible." "But there is a plan to drop a probe onto Europa." "And if they do, scientists expect to find something amazing." "Beneath Europa's ice, there is an ocean." "What will we find there?" "Scientists are almost certain the probe will find deep sea vents similar to those on Earth." "Could the vents on Europa have life?" "If so, it seems certain we'll find life across the universe." "I think there's frankly no doubt that there must be life elsewhere in our galaxy, at least primitive life." "The bio-chemists tell us that if a planet has liquid water, you will get replicating molecules." "The most successful would compete with other replicating molecules, and there, voilà, you have life, ever more complex." "The question for which we don't have an answer is whether our Milky Way galaxy harbours any intelligent life." "And that is the $64 million question." "So, are we alone?" "The only intelligent creatures in a universe teeming with simpler lifeforms?" "It's hard to believe." "With so much life, some of those creatures should surely have evolved into intelligent beings." "Perhaps beings a little like us." "That just begs more questions." "Where are they?" "Why haven't THEY contacted US?" "After all, we've been making noise for more than 50 years." "(RADIO PLAYS "MOONLIGHT SERENADE" BY GLEN MILLER)" "Here's the puzzle." "Our radio broadcasts don't just reach us." "They also beam out into space." "(GEORGE W BUSH) I do solemnly swear that I will faithfully execute the office of President of the USA." "Planet Earth's history is being broadcast to the universe." "So, if extra terrestrials exist, they should already know that we are here." "(BILL CLINTON) I do solemnly swear... ("ALL RIGHT NOW" BY FREE PLAYS)" "But even radio takes years to reach the stars." "(RONALD REAGAN) I do solemnly swear..." "# I'm the urban spaceman, baby... #" "(JIMMY CARTER) I do solemnly swear..." "# And it's hi ho, silver lining... #" "(RICHARD NIXON) I do solemnly swear..." "Our radio broadcasts have beamed into space for five decades." "But in all that time, they've only reached a handful of the closest stars." "To most of space, our planet appears completely silent." "(DWIGHT EISENHOWER) I do solemnly swear..." "# Life could be a dream, sweetheart Hello, hello again, she-boom... #" "There's this bubble of TV, if you will, moving out into space." "The earliest shows have gone 50 light years." "There's only a few hundred stars that close." "The aliens don't know we're here." "That's why we haven't heard from them." "Some day, as that radio bubble expands, someone out there might learn that we're here, but when?" "And what happens next?" "It's the sheer size of the galaxy." "That's the problem." "If extra terrestrials exist, they could live on the other side from Earth." "It would take our radio and TV broadcasts 100,000 years to reach them." "We've only been sending out signals for around 50I" "It just depends where ET lives." "Our signals have only reached a handful of stars, but that may be enough." "This star is just receiving our first radio broadcast." "So, if ET lives on a planet round here, they might have just found out that we exist." "If they choose to answer, the message will take another 50 years to come back to us." "So we might be waiting a while before we discover we are not alone." "Unless, of course, they had one of these." "Intelligent beings from another world." "Gee whiz!" "What would they be like?" "Almost certainly like nothing we've ever imagined." "For now, we can only speculate, but our search continues." "And that means that one day, we may actually find out." "The sun - brilliant, powerful, giver of life." "But this is the story of how the sun will one day become our enemy." "If we are to survive, we will have to leave the Earth." "We'll need to seek out new homes in amazing new places." "And change other worlds to re-create the Earth we left behind." "In the far future, our sun will become a monster." "It will burn all life from our planet, destroy entire worlds." "And finally, our sun will even destroy itself." "It's going to happen." "Our sun will die and we'll go with it." "It's time to think about the future." "For five billion years, the sun has nourished the Earth." "It is the sun that provides energy for plants to grow." "It is the sun that makes life on Earth possible." "But that will change." "Slowly, unstoppably, our sun is getting hotter and hotter." "Once it gave life to us all." "But what it gave..." "..it can also take away." "If human beings are to have a long-term future, we must leave our planet behind and search for new places to live." "One day, our homes will be out there... ..somewhere in space." "In the distant future, this could be our home." "Out here in space, we'll have to seek refuge on new worlds where we could settle and live." "And the reason is, we have to escape from our sun." "Some new worlds may be difficult to adapt to." "Others may be very like our own." "But what is it that makes our planet so special?" "And why is it so dependent on the sun?" "Here is the sun as it is today, in the centre of our solar system." "The Earth goes round it about there." "And there are the other planets." "The reason our planet is the one with life on it is that it's the right distance from the sun." "Closer in and we'd boil, further out and we'd freeze." "We live in a kind of safe zone that's perfect for life." "Trouble is, that zone is moving." "The sun is getting hotter and the region where life can exist is shifting further out." "Ultimately, the safe zone will leave Earth behind." "When it does, we'll be in serious trouble." "Our planet will die." "This is how it will happen." "As the sun burns up its nuclear energy, it'll become ever hotter." "By the time it's 5% hotter, plant life everywhere will be dying." "10% hotter and animals, too, will begin to die." "15% hotter, rivers and oceans will evaporate, creating huge cloud banks, trapping more and more heat." "In the far future, life on Earth will become impossible." "And there's nothing we can do about it." "What will happen to us then?" "Astronautical engineer Robert Zubrin believes he has the answer." "He wants to find us a new place to live." "The only real choice that we have is to grow, expand, become a space-faring civilisation, or become extinct." "Not only would WE become extinct, but unless we bring Earth life out with us into the universe, all life on Earth will become extinct." "Robert Zubrin's goal is to make us a home...on Mars." "Today, Mars is cold and lifeless." "Temperatures regularly drop to 100 below freezing." "Its atmosphere is 200 times thinner than ours." "A person standing unprotected on the surface would die in seconds." "Yet some scientists believe we could learn to call this home." "Mars is the only other planet in our solar system that has all the resources needed to support life." "It has water, albeit frozen as ice and permafrost." "It's got carbon dioxide and nitrogen in the atmosphere." "If humans go to Mars and develop the craft of using these resources, then we can make Mars a place where we can sustain ourselves." "A world for our posterity." "No species can expect to last long if it stays in one place." "In a sense, humans aren't native to the Earth." "We're not native to America or Europe." "We're native to Kenya - long arms, no fur." "But humans were able to leave there and colonise the Earth by becoming creative." "That's how we coped with Ice Age Europe and it's how we'll cope with Mars." "In a remote part of Canada, researchers have already been preparing for life on Mars." "Living in a space pod did prove difficult, but they coped." "Zubrin is optimistic." "We're ready to take this on." "Frankly, if we shrink from this challenge, what it will mean is that we've become much less than the kind of people we once were." "We are much better prepared today to send humans to Mars than we were to send people to the moon in 1961 at the start of Apollo." "I believe this nation should commit itself to achieving the goal of landing a man on the moon and returning him safely to Earth." "(ZUBRIN) We were there eight years later." "Nothing in this is beyond our technology." "It's a question of showing moxie." "For Zubrin, it's not the technology that's lacking." "It's the will." "But technology and willpower alone may not be enough." "Just look at what we'd leave behind." "This is our life support system - the plants that create oxygen, countless species of animal." "How will we fare without them?" "Our survival depends on the living things we share our planet with." "The air we breathe, the food we eat - all this is created by other forms of life." "If Mars is to be our home, it must be home to all this, too." "15 years ago, we thought we knew the answer." "This is Biosphere Two - a huge glass dome covering three acres of Arizona Desert completely sealed off from the planet." "The theory was that people could survive in it because it was self-sustaining." "Trees would provide oxygen." "Artificial clouds and oceans would regulate the climate." "But the experiment failed." "Food rapidly ran short." "Extra air had to be pumped in." "On Mars, that failure would have killed them all." "If we're ever going to call the red planet our home, clearly something's going to have to change." "And the easiest thing to change may be Mars itself." "It's an idea called terra forming." "The aim is to transform a planet from somewhere we couldn't survive, to one where we could." "NASA scientist Chris McKay believes we can turn Mars into something surprisingly like Earth." "When we think about going into space, we focus on humans." "In fact, it's easier for plants and micro organisms to go to Mars first." "They'll be the first Martians." "In Death Valley, California," "McKay is seeking the Earth's hardiest creatures." "Creatures that might survive on Mars." "That's our guy!" "These green smears are algae, microscopic organisms that can thrive even in the harsh variable climate of Death Valley." "And they could thrive on Mars, too, sucking in its thin atmosphere of carbon dioxide, and pumping out oxygen in its place." "Except, at the moment, even the algae would find Mars deadly." "The first step to making Mars habitable is to warm it up a bit." "Right now, it's too cold and dry for any type of life from Earth." "Warming up a planet is something we know." "We're doing it on Earth." "The pollution on Earth would be the medicine on Mars." "It's a strange twist." "The best way to make Mars a place we could live may be to pollute it." "Here's how it would work." "First, a spacecraft has to drop off the pollution-creating machines." "The machines' job is to suck up a mixture of dust and atmosphere and process it into new chemicals." "It belches out these greenhouse gases to warm the planet and dark soot to soak up heat from the sun." "If we send enough machines, over time," "Mars will warm enough to allow these algae to survive." "The algae will begin to give Mars an oxygen atmosphere." "But for speed, we'd need more efficient oxygen makers." "And the best that we know are plants and trees." "The real goal is to get trees growing there." "Those trees will be the ones that make a habitable world." "Then things will really start happening." "As the oxygen level rose, insects then larger animals could survive." "We could change Mars." "If I laid out a timescale, I'd say, 50 years humans go to Mars, and soon thereafter the algae and bacteria go to Mars." "Maybe 30 years later, the trees go to Mars and then the humans come back, but this time to a setting biologically suitable for them." "And then we've learned to become a lifeform that lives on two planets." "Not just humans, all life." "It's a bold and astonishing plan." "If it works, we could turn Mars into a planet very like Earth." "But even Mars will not last forever." "Even there, we could never escape the power of the sun." "As the sun keeps getting hotter, the safe zone for life moves further out." "This is Mars." "Now Earth's dead, this is our home." "Thanks to our terra forming, it looks a lot like Earth, and thanks to a hotter sun, it's now in a safe zone." "The only trouble is, the sun is still getting hotter." "Eventually, the safe zone will leave Mars behind, too." "With Mars dead, where next?" "Once again, human beings will be looking for a new home." "And, once again, we'll have to move further from our brightening sun." "But the planets further out are impossibly hostile worlds." "Gas giants like Jupiter and Saturn are not places we could ever hope to transform." "If we're going to survive on these alien worlds, it won't be the planets we'll have to change..." "..we may have to change ourselves." "David Brin is a science fiction writer." "He imagines future worlds for a living." "It's a big universe and the Earth is a very specialised environment." "We won't find many Earths out there." "If we want to spread out, then we're going to have to adapt to the universe." "It's not easy for humans to get accustomed to that idea because we're used to making the universe adapt to us." "(CHILDREN) Five, four, three, two, one!" "As the sun becomes hotter, new worlds will form into life." "This is Europa, one of Jupiter's huge moons." "We know it today as a frozen planet - airless, with a crust of iron-hard ice." "But in the future, it will be something else entirely." "The ice will have melted." "Europa will become an ocean world." "After Mars, perhaps we'll come here and make this our new home." "We could live in cities at the bottom of an alien sea." "But David Brin thinks that, in the end, a life behind glass may not be the solution." "Now we're thinking of going to other planets." "At first, we'll arrive in spacesuits, live in domes, bring environments with us." "But we'll want to get out of those domes, so we'll have to change ourselves to fit into new environments." "Our ancestors evolved for life on Earth." "But Brin thinks our descendants may redesign themselves for a future on other worlds." "Human beings have been wonderfully inventive in the last 20 million years." "And yet, other species have not been idle." "Birds developed lungs in which the air flows from one side to the other so that all the lungs are used." "We only use half our lung capacity." "If we genetically engineered ourselves so our lungs flowed through, think of the thin atmospheres we could live in." "Wouldn't it be great to hibernate like a bear?" "We'd be able to travel to far planets, possibly even far stars." "And if they live and work in zero gravity, they'll get tired of pulling around these useless legs, which are only good occasionally for pushing us against walls." "Why have legs if you're in zero gravity, when you could have additional arms?" "Wouldn't it be more functional jumping all over the place like gibbons?" "Can genetic engineering achieve any of these things?" "Who knows?" "We're just at the beginning of this grand adventure." "But it's an extravagant version of tomorrow that we should be thinking about." "Wouldn't it be a desirable thing if we're happy, creative, productive, part of a great civilisation?" "Vive la différence!" "We can only guess at the future." "What will our descendants be like?" "We'll have to wait and see." "And where will they live?" "The only certainty is, it cannot possibly be here." "It's not just that the sun will have seared all life from Earth." "It's that the planet itself will no longer exist." "Everything we know will have disappeared." "In the far future, our sun will turn into a monster." "It's going to consume the solar system." "Its first victim is the closest planet" " Mercury." "Next, Venus is transformed into a molten fireball... and, ultimately, boiled away." "And still the sun grows." "It's 160 times its original size, 2,000 times hotter!" "And its next victim is the Earth." "Long since seared barren by the sun, the place we once called home now melts and is engulfed." "Seven billion years from now, the Earth will be gone." "For us today, one question remains." "Is the future of our planet also OUR future?" "Can we really survive the death of Planet Earth?" "Look at how far we have come." "Compared to the world of 100 years ago, we're living in a science fiction universe with skyscrapers 100 storeys tall!" "Who can believe, seeing that, that looking forward 100 years, there will not be a new civilisation on Mars?" "And look back 1,000 years - the world lit only by fire." "Who can say that 1,000 years from now, there will not be hundreds of new branches of human civilisation filling worlds, orbiting hundreds of stars and listening to the galaxy?" "Some people think that we are living at the end of history, but I think we're living at the beginning of time." "We're present at the creation." "It's a glorious time to live." "(JOHN MCKAY) For all we know, we might be the only lifeform in the universe." "If that's true, that really deepens the importance of spreading life beyond the Earth." "If we're the only spark of life, we certainly don't want that spark to go out." "Our scientists today are already imagining strange, far-off tomorrows for our kind." "And, if we do survive, perhaps we will be there to witness the moment when our sun's transformations finally end." "It was first the giver of life, then the destroyer of worlds... ..and now, it, too, is doomed." "This is the sun at the end of its life." "Layer after layer, it is blowing itself apart." "Huge clouds of star stuff drift into space." "It's a slow process that takes millions of years." "What follows is inevitable - the death of our sun." "It casts off one final layer, and its spark is extinguished forever." "So, the sun will one day go out." "Will it be significant to our descendants in billions of years?" "I don't think so." "They will have observed similar phenomena on innumerable other stars before then." "But, if they did think about it, they'd note with gratitude that their ancestors did not stay on that one little world and await their doom, but spread into the universe and made their life possible." "No one can know our future, but our sun's future is certain." "There will come a time when we must leave our Earth behind." "Our planet will be gone." "Our home will be in space." "We humans have come a long way." "Travelling our world in search of new lands." "Spreading to every corner of the globe." "But the time has come to look to new destinations." "To go, once more, into the unknown." "This is the story of our journey in space." "We will fly to the stars on a ship that sails on sunlight." "We'll explore the most distant edges of the cosmos by taking a roller-coaster ride through the fabric of our universe." "We'll discover the machine that has charted the heavens as never before." "It's the voyage of a lifetime, a voyage to our future in space." "We've always had the urge to explore." "Our ancestors journeyed into the unknown to discover new lands." "And now it's time to do it again." "And this time, it's not a voyage between continents." "This time, it's a voyage to the stars." "As our telescopes get ever more powerful, they've shown us a universe of unimaginable beauty and power." "Vast clouds where new stars are born." "Strange galaxies." "Even tantalising hints of new worlds." "But they have also shown dangers." "Disasters so huge, they could destroy the Earth in seconds." "Space is full of terrors..." "and wonders." "But will we ever see them for ourselves?" "(MISSION CONTROL) We have lift off!" "It's less than 50 years since we took our first steps into space." "Since then, thousands of rockets carrying hundreds of people have made the ten-minute flight into orbit." "Astronaut Story Musgrave is one of a new breed of space adventurers." "When you see a launch from the outside, it's a rather glorious thing." "Inside, it's the absolute opposite of that." "It's 137 decibels." "It's shaking." "Everything is shaking." "You have a solid block of boosters that are really pounding the vehicle." "You have atmospheric turbulence that adds another shake, rattle and roll." "You're basically in a small closet with belts and straps and helmets and gloves and parachutes, survival gear." "That's all over you and, at the same time, you're being shook." "And it can't help but pass through your mind that you just want the whole stack to hold together." "You're along for the ride and you want to survive." "So, it's not a joyride for me." "It's what I need to go through to get into the serenity and the celestial dance of zero gravity." "(OVER RADIO ) Hello, Houston, we are inspired." "We are ready." "Let's go and fix something." "We are becoming space farers." "It's a strange and unfamiliar world." "But for the privileged few who go there, it is an experience they can never forget." "Space walking is more like dance than anything." "You choreograph every move." "You choreograph every finger, every toe, every body position and how you will do all of that." "It's just as precise as a ballet." "Going into space is opening night at the ballet." "During a space walk," "I live to look at my feet." "You see your boots going 25,000 feet per second." "You see them going down the road." "If you ever want to play Superman, that's where to do it." "We stand on the edge of space." "Our most ambitious project is testament to what we have achieved:" "the international space station Freedom." "But it's surprisingly close to home." "It is floating less than 400 kilometres above our heads." "The furthest we have travelled into space is this." "In 1969, we set foot on the moon." "(NEIL ARMSTRONG) That's one small step for man, one giant leap for mankind." "For the first time ever, we looked back at our home from the surface of another world." "It's amazing to think that people have actually walked up there." "The trouble is, it may have been a giant leap for us, but in the vastness of space, it really was one small step." "Although we humans haven't reached any further than the moon, our robot ambassadors are already reaching for the stars." "Where we cannot go, we have sent machines." "This is the Voyager probe." "Nothing we've created has travelled so far." "It's left our solar system on its way to the stars." "Look at how far it has gone." "Voyager left Earth in 1976." "It passed Jupiter, then Saturn." "Now it has left all the planets far behind." "After decades in space, it's 14 billion kilometres from Earth." "It's an impressive journey until you consider this." "On this scale, the nearest star to our solar system is way over there." "In fact, it's over 100 kilometres away." "To reach it would take Voyager another 25,000 years." "At Voyager's speed, even reaching the nearest star is an impossible journey." "But perhaps there is hope." "It's easy to forget that in one lifetime we've gone from this..." "..to this." "And in our quest to reach the stars, some scientists believe the answer could be to go from this..." "..to this." "Deep Space One." "Its secret is a new kind of engine - the ion drive." "And it is the passion of NASA scientist Marc Rayman." "The idea for ion propulsion was around from before I was born, but I first heard of it on Star Trek." "They were using ion propulsion, and Spock said," ""Configuration unidentified." ""Ion propulsion." "High velocity." "Unique technology."" "And I thought, "Well, this is really amazing," ""but I'll never see anything like that in my lifetime."" "But in 1998, Marc's dream became reality." "Deep Space One." "But what is it that makes the ion drive so different?" "Compare it with a conventional rocket." "The rocket fuel burns with tremendous force." "And, as it thrusts down, it pushes the rocket up." "In the lab, Marc Rayman watches a prototype ion drive in action." "Instead of tonnes of rocket fuel, the engine uses a few grammes of a gas." "It gives the gas an electric charge and spits it out atom by atom at incredible speeds, creating a seemingly gentle blue haze." "The ion drive doesn't have the raw power of a rocket." "It has something better - staying power." "It's a bit like the hare... ..and the tortoise." "Conventional rocket engines create huge thrust and awesome acceleration." "But they burn through their entire fuel supply in just a few minutes." "After that... it's all over." "The ion drive is nowhere near as powerful." "In fact, it would take Deep Space One four days to get from nought to 60." "But the reason Deep Space One is the fastest spacecraft ever is because it has been accelerating for almost two years." "When we communicate with that craft out so far in the solar system, to think that our baby is out there, this little spacecraft that we built." "I just..." "I think it's really amazing." "Ion drive spacecraft will be fast enough to chase down comets or travel round the planets in our solar system in a few months." "But even ion drives don't last forever." "Eventually, they too will run out of fuel." "To travel further, to reach the stars, we'll need something new." "And it may be based on one of the oldest technologies we know - the sail." "Long ago, the limitless power of the wind carried our ancestors to new worlds." "In the future, we may use the same idea to travel to the stars." "On sails that catch nothing more than sunlight." "A solar sail, using only the light from our sun." "Many scientists are sure that this is the future of space travel." "One of them is Les Johnson." "The sun puts out photons - light." "Standing here on a sailboat, the photons that are falling on us are pushing on us." "But the push is so slight that we don't feel it." "The other forces around us are so much higher that it's not noticeable." "But in the vacuum of space, if you have a large and light enough material, the pressure exerted by solar photons can cause it to move." "To see if sunlight could drive a sail through space," "Johnson and his team built this - a man-made sun." "In front of me, we have a simulated sun, about three times wider than the sun is at the Earth." "That's the reason I'm wearing these UV protecting sunglasses." "It could damage my eyes if I was to accidentally look into the beam." "They are testing the ultra-thin, ultra-light material they would need to make a real solar sail." "It's mounted in the full glare of their sun." "As you look in there, you can see it slowly rocking back and forth." "What is causing that is the photon pressure as it's pushing on the sail." "Incredibly, it works." "This piece of sail material is being moved by nothing more than light." "Based on work that's being performed around the country, solar sail technology is getting to the point where very soon, we'll be flying it in space." "To reach the immense speeds needed to travel from star to star, the solar sail must start its voyage with as big a push as possible." "It must fly as close as it can to the source of its power - the sun." "It's a dangerous manoeuvre, but if it works, the craft will whip around the sun and hurtle out into space..." "..at almost three quarters of a million kilometres an hour." "A solar sail could reach the nearest stars in just decades." "It's a truly impressive start, but is it enough?" "Our galaxy is a very big place." "To get from one side to the other, even using a super-fast solar sail travelling at incredible speeds would still take 2.5 million years." "And our galaxy is only one of billions that make up our universe." "And this...is the final frontier." "If we ever want to be truly star travellers, we'll have to take a completely different approach." "We're going to have to learn how to manipulate the very fabric of space itself." "Some scientists believe there may be a quicker way to get around the universe." "One of them is cosmologist Peter Coles." "When early man first began to explore his environment, he would run into fundamental barriers when he got to mountains." "Mountains are not easy to cross when you're faced with a wall like these mountains around us." "You've no choice but to go around them or over the top." "Now, these days, it's exactly the same thing with space travel." "If I'm going to explore the galaxy, then the distances I have to travel are truly immense." "When it comes to space travel, we're still very much in the Stone Age." "The answer could be to take a shortcut." "Don't go round the obstacle, go through it." "If you travel through space, you are fundamentally limited by the speed of light." "But the laws of physics might have a kind of loophole in them which allows us to travel slower than the speed of light, but still travel huge distances quickly." "The way we can accomplish that is through a wormhole." "A wormhole is basically a tunnel that takes a shortcut through space-time." "Here to the nearest star could be connected by a short tunnel." "Wormholes may sound like science fiction, but creating one may just be possible." "First, we'd have to harness the incredible forces of an exploding star and use them to punch a hole through space." "We'd need exotic forms of energy to keep the tunnel open." "But the science IS sound." "At least in theory, it IS possible to create a tunnel that reaches clear across the universe." "Experiments have already begun to try and build the first tiny wormholes." "In theory, wormholes will take you across the universe... ..in literally no time at all." "Instant travel... ..anywhere!" "A wormhole could just as easily have taken me halfway across our galaxy." "But how do you decide where to go?" "For that, you're going to need a map." "Space, as we've discovered, is very big." "But Profesor Brian Boyle and a team of Australian astronomers may have the beginnings of an answer." "They are creating the biggest map imaginable - a map of our universe." "Traditionally, astronomers looked at the universe as a flat map on the plane of the night sky." "You can think of it like a map of the Earth." "For a hiker, a flat map is no use at all." "A flat map wouldn't tell you if there was a mountain in the way, or a huge ravine." "In the same way, the hikers of the future will need a three-dimensional map to guide them around." "To create a three-dimensional map," "Boyle and his team had to develop a unique piece of equipment." "Ten years to make, weighing over three tons, the device uses over 600 fibre optic cameras." "The whole apparatus is delicately manoeuvred into position high up on one of the biggest telescopes in the world." "Everything's connected up." "We're ready." "Fibres in position." "We'll take the telescope back up to the top and wait for the stars to come out." "Every night, the telescope looks at a new patch of night sky." "And, for each point of light it sees, a robot places a single fibre optic camera." "The light from the object is measured and its distance from the Earth accurately calculated." "So far, the tireless robot has looked at and logged the positions of tens of thousands of stars and galaxies." "Bit by bit, it has pieced together an unequalled picture of the universe." "And this is the result." "For the first time ever, we can see what our universe looks like in three dimensions." "When the map was first created," "I was really filled with a sense of a mixture of awe and excitement." "Here I could see, almost developing in front of my own eyes, the structure of the universe." "Giant archipelagos of galaxies stretching hundreds of millions of light years across intergalactic space." "(STORY MUSGRAVE) The day before I'm going to launch from right here," "I go to the beach right over there." "I go to the ocean." "I'm down by the ocean and I'm looking at the satellites crossing overhead." "But I look at those satellites just whizzing along and I think, "Tomorrow, that's me!"" "I think that kind of thing where you don't know if you're coming back, you don't know the final outcome and you don't really know where you'll end up..." "You focus on a journey, and that's what carries you forward." "There's a lot out there to explore, and one day, humanity may be lucky enough to do it." "Our descendants will reach for the stars." "So, the next time you look at the night sky, remember that space is stranger and more beautiful than we can begin to imagine." "And, above all, remember this... ..out there in space is our future."