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Speaker 1: Perhaps the greatest question facing the human race is to

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discover where we came from and to find out what

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is our ultimate fate.

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Speaker 2: Every culture, every age has asked that question and tried

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to answer it.

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Speaker 3: It's one of the greatest adventures of the human mind

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to find out where we came from, where we are,

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and of course, in the end, where we're going.

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Speaker 4: Astronomy provides the basic information that each person needs to

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understand where he or she came from and where the

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human race is going.

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Speaker 1: Now, at the dawn of a new millennium, we are

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on the threshold of understanding how our universe began and

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how it will end. Cosmologists around the world are trying

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to unlock the origin and destiny of everything we see

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around us. One of this elite group is Bob Keshner.

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He's on a journey to Sero to Lolo in Chile

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to measure if there's enough gravity to hold the universe together.

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Speaker 5: We've known for a long time that the universe is

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expanding and coasting along since the Big Bang. One of

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the questions has been how much gravity has been slowing

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down the expansion of the universe. Just like when you

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drive a car up a hill. You can slow down

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if you don't apply power, because gravity is pulling back

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on you. We think that the expanding universe would be

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slowed down by the gravity by all the stuff that's.

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Speaker 6: In the universe.

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Speaker 5: One of the interesting things is that we've been able

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to do some work to try to measure that, and

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we found a surprising result, not the one that we

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expected to find, but one that really turns the whole problem.

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Speaker 6: On its head.

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Speaker 1: Kirshner's team may have discovered answers that seal the fate

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of our universe. They've discovered that it's not just expanding,

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it's speeding up. Cosmologists now realize that to understand what

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the future may hold, they first have to unravel what

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happened at the beginning of the universe, at the start

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of time itself. In our daily lives, time is constant

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and dependable. It's almost impossible for us to imagine. But

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before the creation of the universe, there was no time.

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Speaker 7: We can trace back cosmic history to a stage when

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everything was very dense, very compressed, very hot. But the

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further we go back, conditions were so extreme that we

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can't really rely on any of our common sense intuitions.

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We can say that time in the sense we understand

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it didn't really exist before that.

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Speaker 1: So when did the clock start ticking twelve billion years ago?

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There was absolutely nothing, no matter, no space, no time.

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We may never know how or why it happened, but

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a seething mass of energy smaller than an atom grew

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from nothing your inside The Big Bang, the birth of

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our universe, a violent fireball of unimaginable heat. For England's astronomer,

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Royal Martin Reece, understanding the Big Bang is the key

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to the universe.

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Speaker 7: Something that was literally originally only the size of a

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single atom or smaller, expanded to be large enough to

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encompass everything in our present universe.

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Speaker 1: Only the minutest fraction of a second had passed, But

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all of this was puny compared to what was about

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to happen. Propelled by a new surge of internal energy,

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the universe suddenly entered an incredible period of inflation. It

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expanded one hundred trillion trillion, trillion trillion times to the

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size of a grapefruit. Einstein's famous equation E equals mc

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squared told us that energy and mass were interchangeable. It

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gave us the knowledge to build weapons of mass destruction,

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and the knowledge to understand how our universe was born.

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When a nuclear bomb explodes, a tiny amount of matter

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is completely annihilated and converted into energy. But in the

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Big Bang, the exact opposite it happened. Pure energy was

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converted into matter. Approaching a millionth of a second old,

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the universe was brimming with energy so intense that it

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was spontaneously converted into lumps of matter and its arch rival, antimatter.

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A titanic battle ensued. Some atomic particles annihilated each other,

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blow for blow, particle for particle. When matter and antimatter meat,

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they mutually destruct. This is the most powerful release of

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energy known.

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Speaker 7: If our universe started off with equal amounts of matter

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and antimatter, all the atoms were denihilate with anti atoms,

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and we'd end up with universe consisting just of heat

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and radiation, but nothing from which we and the stars

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could have been made.

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Speaker 1: But somewhere in this tiny, blazing inferno, the process was

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slightly imperfect. There was more matter than antimatter. At the

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end of the battle, matter had won, and the universe

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was far from empty. Every time a particle of antimatter

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had been annihilated. The energy was converted into radiation, and

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that radiation is right before our very eyes. Don't adjust

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your set. Hidden in the interference on a badly tuned

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TV set is the energy signal left from the first

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second of the universe. The discovery of the Big Bang

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was one of the greatest scientific discoveries of all time,

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even though it was an accident. This is the Horn

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antenna the Bell Research Labs in New Jersey. Its unusual

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funnel shape was designed to collect faint radio waves from

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early communication satellites. It was being used for an entirely

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different experiment when it detected something truly remarkable, a discovery

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that would win two American scientists the Nobel Prize.

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Speaker 8: When I visit the Horn antenna, I'm always reminded of

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the days back in the sixties when hornaut and I

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were using it. Seriously, if it's amazing to think about

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just doing your experiment and discovering the beginning of the universe,

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But there it is.

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Speaker 1: In nineteen sixty four, Bob Wilson and his colleague are

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No Penziers were using the Horn antenna to search for

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natural radio emissions from our own galaxy. But as soon

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as they switched their giant earps on, it started humming.

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It was picking up weak but constant background interference. Wilson

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and Penziers had no idea where the signal was coming from.

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At first, they suspected nearby New York, but when they

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ruled that out, their suspicions turned on the local bird population.

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Speaker 8: There were a pair of pigeons living in the antenna.

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Once a week we'd come up and disturb them. They'd

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fly away, but the next day, when we were gone,

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they'd come back. So the inside of the horn was

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covered with white pigeon droppings. We got up in the

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horn reflector the broom and swept it all out.

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Speaker 1: With the pigeons evicted, The two scientists were disappointed to

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find the interference was still there.

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Speaker 8: We looked in various directions. Sometimes we looked at specific objects,

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other times we looked at random parts of the sky,

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And every time we did that, we saw the same level,

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the same amount of excess noise, and it was the

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same in all directions.

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Speaker 1: They began to realize that it could have a more

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dramatic origin. What Wilson and Prenzius had stumbled across was

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a background of microwave radiation, a faint afterglow of the

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battle that defeated antimatter twelve billion years before.

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Speaker 8: The microwave background comes from the initial, very dense and

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hot state stage of the universe, and as the universe expands,

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the radiation expands with it, and just like anything else

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that expands, it tends to cool off. It came from

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the early stages of the universe, and it's just out there.

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If you go outside, it'll hit you on the head.

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You won't notice it because it's so weak. It's at

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such a low level that it's almost undetectable.

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Speaker 1: Every television set on Earth can detect the radiation from

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the Big Bang. Antimata had been defeated and the universe

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was still only a second old. Over the next three minutes,

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the explosions created the kind of matter we would recognize today,

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hydrogen and helium. It was still too early for the

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universe to shine. In the dark ages that followed the

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Big Bang, these elements would combine together and provide the

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building blocks of the first generation of stars and galaxies.

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The atoms created twelve billion years ago are still with

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us today. Every time you take a sip of water,

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you're swallowing hydrogen atoms that were created at the very

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beginning of the universe. Most of the atoms in our

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bodies were created in the first moments of the Big Bang.

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Speaker 9: We tend to often associate ourselves from the universe. We

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tend to think of asking questions about it versus us,

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But of course that's not really true. We're a part

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of the universe, and when we ask about the origin

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and evolution of the universe itself, we're really asking questions

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about the origin and evolution of ourselves.

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Speaker 1: Since the Big Bang, the universe has continued to grow

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and expand. To understand just how big it has grown,

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we need to take an imaginary spaceship ride from the

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Earth to the edge of the visible universe. Our nearest

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neighbor is the Moon, just a quarter of a million

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miles away at the center of our solar system. Ninety

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three million miles away is our Sun. After crossing the

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center of our solar system, we continue our flight beyond

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the orbit of the Earth. The next planet out is Mars.

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Beyond the orbit of Mars is the asteroid belt. A

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billion miles away is the giant outer planet Saturn, almost

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a thousand times the size of Earth. As we leave

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the Solar System, we would pass one of our our

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earliest interplanetary explorers, Voyager one, launched in nineteen seventy seven

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and traveling at a mere forty thousand miles per hour.

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Proxima Centauri and Alpha Centauri A and b our nearest

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stars are twenty five million million miles away. Our Solar

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system sits in the quiet suburbs of a spiral galaxy,

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the Milky Way, a star city containing over one hundred

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billion stars. Every star we can see in the night

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sky lies within our own galaxy.

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Speaker 10: This is deep space.

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Speaker 1: Out beyond the Milky Way, ten million, million million miles

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from Earth is the next spiral galaxy, Andromeda. Even traveling

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at the speed of light, it would take two million

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years to reach here. Andromeda and the Milky Way form

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part of a small cluster of galaxies called the Local Group,

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But stretching out way beyond the Local Group are much greater.

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Speaker 10: Clusters of galaxies.

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Speaker 1: If it were possible to travel fast enough for long

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enough and reach the edge of the known universe, this

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is what we would see uneven clusters of galaxies, a

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pattern that was predetermined in the very first second of

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the Big Bang.

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Speaker 11: This is as far as our spaceship can take us.

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Speaker 1: We are now fifty billion trillion miles from Earth. This

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is where science ends and speculation begins. Astronomers may never

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see what lies beyond here. This is where the secrets

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of the universe are hidden. For centuries, astronomers have been

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trying to locate our exact position by looking further and

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further across the vast expanses of deep space. For four

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hundred years, since Galileo first pointed his telescope at the sky,

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astronomers have not only been looking across the far reaches

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of space, but back in time. Because the light from

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distant objects it takes so long to reach us, every

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telescope is a time machine. Even traveling at an unbelievable

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one hundred and eighty six thousand miles per second, light

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takes a long time to cross space. Light reflected off

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the surface of the Moon is already over a second

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old by the time it reaches us on Earth. Look

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up at Saturn and you're seeing it as it was

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one and a half hours ago. And we see Andromeda

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as it was when the first humans walk the Earth.

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Speaker 11: Its light has been traveling across space for over two

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million years.

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Speaker 1: Here at the lick ofservatory soundra Faber spent her early

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career unraveling the mysteries of the most distant galaxies.

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Speaker 4: The biggest telescopes on Earth now are taking us back

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billions of years into the past, ninety percent of the

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way back to the beginning.

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Speaker 12: Of the universe.

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Speaker 1: View light from the furthest visible galaxies, and you're seeing

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them as they were over eleven billion years ago.

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Speaker 4: A galaxy is really like a city of stars. Just

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as there are billions of people on Earth or millions

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of people in a city, there are hundreds of billions

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of stars in a typical galaxy.

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Speaker 1: The universe contains over one hundred billion galaxies. Like giant

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hurricanes in space, their resident stars spin around a giant

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central core. To see into the heart of them, the

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most distant galaxies would require a very special telescope. In

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nineteen ninety, the launch of the Hubble Space telescope promised

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astronomers a view of the early universe they had only

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dared dream of. High above the Earth's atmosphere, this billion

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dollar looking glass would have a totally clear view of

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the most distant galaxies, But the dream turned into a nightmare.

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Soon after it was launched, they discovered that the mirror

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was misshapen. It saw everything out of focus. One of

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the repair men sent up to fix the stricken telescope

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was astronaut Jeff Hoffman.

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Speaker 13: It was unbelievably embarrassing from Nasen and for the astronomical community.

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I mean, I had astronomer friends who that summer when

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they were on holiday and people asked, well, you know,

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what do you do for a living. They didn't even

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want to say I'm an astronomer because the first thing

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everybody would say, oh, the Hubble telescope.

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Speaker 6: Ha, you know, it was a big joke.

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Speaker 1: First, the crew of the rescue mission had to capture

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the crippled telescope, helloaed Yeah, then execute a repair mission

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unprecedented in the history of spaceflight, spread over five days

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of spacewalks. They repaired the faulty optics. The replacement parts

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fitted perfectly. The problems came when Hoffman attempted to close

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the huge access doors.

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Speaker 14: Law and behold they did not close.

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Speaker 15: And I worked.

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Speaker 14: I went up to the top of the doors, I

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went to the bottom of the doors. But what we

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figured out was that we could use an extra tool

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which had a little strap and wrap that around and

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bolts to gradually winch the door close. We ended up

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spending over eight hours outside, which is the second one

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the space what has ever been done.

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Speaker 1: At one point in the mission, they even had to

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dump a damaged solar panel overboard.

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Speaker 11: With all the repairs.

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Speaker 1: Completed, the cosmological community held its collective breath to see

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if the most expensive telescope ever built would finally deliver

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what its designers originally promised. This is what Hubble saw.

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The images they received were beyond anyone's wildest imagination.

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Speaker 11: Free from the.

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Speaker 1: Distortion of the Earth's atmosphere, images captured by the Space

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Telescope left even the most hardened of cosmologists in awe.

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Hubble captured the final moments of a star's life, when

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it explodes and blows off layers of gas and dust.

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It also captured interstellar nurseries of newly born stars, each

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one as varied and unique as a human fingerprint, and

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dark pillars of cosmic dust more than a million million

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miles long, ready to spawn a new generation of stars

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and planets. But Hubble's true moment of glory was still

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to come. The mission controllers pointed the telescope at a distant,

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empty patch of deep space and waited over a period

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of ten days in nineteen ninety five. Emerging across the

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coldness of space, the Hubble Deep Field Image revealed a

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tapestry of distant galaxies. This was the furthest back in

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space and time we had ever seen.

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Speaker 2: To point the telescope for hundreds of hours and let

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this light that has traveled for ten billion years slowly

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dribble in and accumulate. When you see so far back

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and see so many galaxies, and imagine that the sky

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is filled with them, billions of galaxies, that's like ten

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galaxies for every person on Earth, something like fifty to

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one hundred billion galaxies, and each one of them containing

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fifty to one hundred billion stars. Say, that's an enormous

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number of places where there might be planets and life

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and very interesting things going on in the universe.

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Speaker 1: Powerful computers have turned the real galaxies of the deep

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Field image into a remarkable three D journey to the

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edge of the universe. In the foreground, our mature galaxies

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like our own, further back in time, our younger, energetic galaxies.

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But beyond here the structures begin to thin out. This

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is as far as we can see. This is the

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edge of the visible universe, over ninety percent of the

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way back to the beginning of everything, faint galaxies that

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will formed just a billion years after the Big Bang.

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Beyond these galaxies, we can see nothing. We're entering the

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universe's dark.

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Speaker 2: Ages, sometime a few hundred million years after the Big Bang.

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This dark age must have ended when the first stars

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were born, and so the universe lit up for the

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first time perhaps half a billion years after the Big Bang,

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and it's been lit by stars ever since.

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Speaker 1: The universe is so vast, some astronomers have decided to

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make a map of exactly where we are, just as

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Galileo tried to make sense of our place in the heavens.

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Here at Apache Point, New Mexico, a group of astronomers

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are trying to locate our position by constructing the biggest

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map that anyone has ever seen, built specifically to map

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over a million galaxies. This is the home of the

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Sloan Sky Survey. Over a period of five years, astronomer

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Jim Gunn and his colleagues are about to start mapping

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our exact position in the universe.

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Speaker 3: We're in a galaxy which is not a particularly remarkable galaxy.

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But this three D picture that we will make of

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the nearby universe tells us how we fit into this

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vast scheme of things that is the universe. And I

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think we'll give us a much better idea of our place.

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Speaker 1: By systematically scanning the entire night sky from a site

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high above the desert floor. The results will be plotted

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not as a two dimensional route map, but a fully

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interactive three dimensional guide to the universe.

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Speaker 3: If you think about that from a kind of cinematic

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point of view, one could take this map very easily,

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put this map on a computer and enable you to

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rotate the map to fly through space if you like,

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to look at our galaxy from outside, to look at

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the other galaxies around us from the other side, and

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take not only from any angle you want, but from

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any place in this map, and look out and see

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what it's like to be somewhere else in the universe

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and what we are, which is of course what you

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see in science fiction films all the time, but you

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will actually be able to do it with the galaxies

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that are there.

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Speaker 1: Gym Gunn Survey is an ambientious project, and it's only

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just beginning. This is how the final map may look.

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It's a computer simulation of superclusters of galaxies massed together

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in giant blobs.

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Speaker 11: You are here.

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Speaker 1: This would be the position of our planet, our Solar System,

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and our own Milky Way. But on this scale it

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would be impossible to see us or even any of

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our neighboring galaxies. This is a map of everything. We

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can see everything in the universe. All the visible stars

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and galaxies were born in the same furnace.

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Speaker 16: The Big Bang.

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Speaker 6: A ball of.

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Speaker 1: Intense heat, still cooling as it continues to expand. Cosmologists

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are not only confident that they have unearthed the universe's past,

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but that they can also predict its future. Space, like

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the surface of hot blown glass, cools as it expands,

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just as flecks of color embedded in the glass move

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further apart the more it stretches sow to the galaxies.

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Space is expanding in all directions at once. Modern cosmologists

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are now trying to measure if this expansion will continue forever,

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how will the universe end? The key to the future

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of the universe was discovered long before modern astronomers built

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their giant telescopes. Back in the sixteen sixties, when Sir

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Isaac Newton had an encounter with a falling apple and

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discovered gravity, Newton formulated laws of physics, which form the

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basis of modern science.

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Speaker 9: You realized that the same force that takes an apple

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and pulls it down from a tree towards the Earth,

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pulls the Moon towards the Earth, and in fact pulls

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the Earth towards the Sun and pulls the Sun towards

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the center of our galaxy.

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Speaker 15: But in fact, gravity is the weakest force in nature.

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Speaker 9: If you want to show someone how weak gravity is,

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just take a friend to the top of a tall

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building and push them off, and it may take twelve

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stories for them to fall, and gravity to accelerate them

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all the way down to the ground. But electricity and

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magnetism in a fraction of a second and a fraction

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of an inch will stop them. Because the reason you

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don't go through things is not that the atoms in

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your body hit the atoms in the table, but rather

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it's the electric fields between those atoms that stop you.

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So electricity and magnetism stops you in a fraction of

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a second, even though it takes gravity all that time

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to accelerate you.

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Speaker 1: Gravity may be the weakest force, but it's the force

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that holds the planets and the stars together. After Newton,

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perhaps the greatest scientists and mathematician of all time was

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Albert Einstein. Einstein had been an unremarkable student, and his

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first job was as a clerk in the local patent office.

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His General Theory of Relativity, announced in nineteen fifteen, explain

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for the very first time how everything within the universe

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interacts space, matter, even time. His calculations told him that

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the stars and galaxies should exert a gravitational pull on

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each other and should eventually collapse together in a catastrophic fireball.

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But they hadn't collapsed. So to make his equations work,

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he invented a special repulsive force. But it was a

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makeshift solution, and deep down Einstein knew it. Then a

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decade later, along came a man with the solution to

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Einstein's puzzle. Here at the Mount Wilson Observatory in California,

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Edwin Hubble took the first steps towards forecasting the fate

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of our entire universe. Hubble was a World War One

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veteran and a brilliant lawyer. When he turned his renowned

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skills to astronomy, he came up with a remarkable discovery

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that would change the way we view the universe forever.

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He made the astronomical discovery of the century that the

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universe was expanding.

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Speaker 11: Seventy five years on.

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Speaker 1: Measuring the precise speed of that expansion is the job

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of astronomer Wendy Friedman.

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Speaker 17: What Hubble found was that almost all galaxies appeared to

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be moving away from us, and this led to the

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idea that the universe is expanding. Here was evidence for

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the first time that the universe was actually in motion,

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that galaxies are moving apart. What that means is that

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you can essentially extrapolate backwards in time. It's like running

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a film in reverse. If galaxies are expanding now, then

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as sometime in the past, they must have been closer

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and closer together. And what that implies is that sometime

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early in the history of the universe, galaxies would have

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been much closer together the matter in the universe it

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would have been much denser and much hotter, and this

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gave rise to the idea of a Big Bang.

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Speaker 11: Universe.

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Speaker 1: Hubble's revelation stood the astronomical communities understanding of the cosmos

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on its head. He'd use the same technique that police

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forces around the world used today to catch speeding motorists.

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Hubble used the astronomical equivalent of a police radar. Instead

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of using radar signals, Hubble measured the light that came

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from distant galaxies. He knew that their color would be

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slightly altered if they were traveling towards or away from us.

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Speaker 17: If an object is moving away from us, then the

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light from that object will be shifted toward the red

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part of the spectrum. If an object is coming towards us,

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the light will be shifted toward the blue.

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Speaker 10: Part of the spectrum.

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Speaker 1: By determining just how much the color had been changed,

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Hubble could work out how fast a galaxy was traveling.

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It's an effect known as the Doppler shift, and it

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applies to both light and radar. Hubble found that all

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the light from all the galaxies was shifted towards the

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red part of the spectrum. They were traveling away from

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us at an incredible speed.

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Speaker 17: There have been dramatic improvements in the technology since Hubble's day,

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and we now have the advantage for the first time

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of being able to get outside of the Earth's atmosphere.

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That is, we can go to space use the Hubble

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Space telescope named after Edwin Hubble, to measure distances to galaxies.

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Speaker 1: Modern astronomers have calculated that we, along with all the

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contents of our own galaxy, are traveling away from the

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nearest cluster of galaxies at a.

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Speaker 11: Million miles an hour.

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Speaker 1: By the end of this program, the whole universe will

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have expanded a billion miles in all directions. Cosmologists need

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to find out if there's enough matter in the universe

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for gravity to stop it expanding and flying apart.

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Speaker 9: There isn't enough matter normal matter to count for all

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the matter we can weigh in the universe. We can

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actually weigh the galaxy the same way we weigh the

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Sun and the Earth using Newton's laws. We watch the

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Sun go around the galaxy and we use gravity to

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determine how heavy the galaxy really is. And when we

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do that, we find there's a lot more out there

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than meets the eye.

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Speaker 1: Wondering if there is enough matter in the universe to

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stop it expanding is a prime concern of Professor Stephen Hawking,

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born three hundred years after Newton. Hawking now holds Newton's

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old job at Cambridge University. Hawking already knows that the

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visible galaxies do not produce enough gravity.

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Speaker 11: He now suspects that the universe is full of invisible

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dark matter.

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Speaker 18: If the universe continues to expand forever, everything will burn

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out and decay. The amount of matter we observe in

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stars and gas clouds is only about ten percent of

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what is required to stop the expansion of the universe

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and cause it to collapse again. However, there might be

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other dark matter that we can see but which can

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still affect the expansion of the universe.

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Speaker 1: Dark matter is everywhere. The reason we can't see it

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is because of its signs. Particles of dark matter are

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so tiny they can pass through anything. Neil Spooner and

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a dedicated band of astrophysicists are attempting to trap dark

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matter particles called WIMPs weekly interacting massive particles a mile

482
00:38:07,800 --> 00:38:10,320
underground at Bulby Mine in England.

483
00:38:11,039 --> 00:38:13,159
Speaker 19: That it just makes up so much matter, so much

484
00:38:13,400 --> 00:38:16,159
of the universe. It's at least ninety percent, probably ninety

485
00:38:16,239 --> 00:38:20,400
nine percent. If it wasn't for this material, our galaxies

486
00:38:20,400 --> 00:38:29,119
would just fly apart. We believe that not much was

487
00:38:29,119 --> 00:38:31,760
composed of elementary particles that arose in the Big Bang,

488
00:38:31,800 --> 00:38:34,480
and they're around us all the time, and they're passing

489
00:38:34,480 --> 00:38:35,360
through us all the time.

490
00:38:37,239 --> 00:38:40,519
Speaker 1: Neil Spooner and his team feel sure that any particles

491
00:38:40,519 --> 00:38:44,360
that could penetrate through five thousand feet of solid rock

492
00:38:44,840 --> 00:38:52,599
would be dark matter. The team are attempting to record

493
00:38:52,679 --> 00:38:56,440
collisions between particles of dark matter and the atoms in

494
00:38:56,519 --> 00:39:03,320
a light emitting crystal, but it's a long vigil that

495
00:39:03,480 --> 00:39:05,719
requires an unusual level of patience.

496
00:39:07,599 --> 00:39:12,199
Speaker 19: Occasionally, like about once a day, you might get one interaction.

497
00:39:12,280 --> 00:39:16,480
Other words, the particle comes in, strikes an atom, it recoils,

498
00:39:16,519 --> 00:39:19,639
and it produced a little burst of light, ordinary visible light,

499
00:39:19,840 --> 00:39:22,559
which we can detect with our instruments and then amplify

500
00:39:22,599 --> 00:39:23,880
and record into our computers.

501
00:39:25,079 --> 00:39:28,800
Speaker 1: It will take years, but if their equipment successfully detects

502
00:39:28,920 --> 00:39:32,679
dark matter, Spooner's team will have discovered the invisible ninety

503
00:39:32,679 --> 00:39:37,159
percent of our universe. But this may not be enough.

504
00:39:37,519 --> 00:39:40,000
There may still be too little gravity to stop the

505
00:39:40,119 --> 00:39:42,079
universe expanding for eternity.

506
00:39:43,440 --> 00:39:46,719
Speaker 19: It could be that the universe will basically expand forever

507
00:39:46,800 --> 00:39:50,280
and simply dissipate and eventually will end up with a

508
00:39:50,559 --> 00:39:54,199
like a soup of rather boring atoms and dark matter

509
00:39:54,239 --> 00:39:57,639
diffused around, and it will be a sort of slow

510
00:39:57,760 --> 00:40:00,000
death and on into infinity in the.

511
00:40:05,199 --> 00:40:07,599
Speaker 1: For some, the challenge of predicting the fate of our

512
00:40:07,679 --> 00:40:12,239
universe is compulsive. Their passion for cosmology often turns into

513
00:40:12,280 --> 00:40:13,599
a lifelong obsession.

514
00:40:15,760 --> 00:40:18,320
Speaker 5: There are a lot of people engaged in trying to

515
00:40:18,360 --> 00:40:21,159
find out what the universe is, and I think it's

516
00:40:21,199 --> 00:40:25,599
mostly the same kind of curiosity that kids have when

517
00:40:25,599 --> 00:40:28,639
they're six years old or eight years old. It seems

518
00:40:28,639 --> 00:40:31,079
to get beaten out of them in school, But we're

519
00:40:31,119 --> 00:40:31,960
sort of the ones.

520
00:40:31,760 --> 00:40:34,199
Speaker 20: That I don't know, the schools didn't affect.

521
00:40:33,920 --> 00:40:37,280
Speaker 5: Or something like that. We're still asking those same questions

522
00:40:37,280 --> 00:40:41,000
and still trying to get answers to them.

523
00:40:41,039 --> 00:40:45,480
Speaker 1: Here at Cero Tololo, cosmologists have made a startling new discovery.

524
00:40:51,880 --> 00:40:55,480
Bob Kirshner believes that dark matter may not be holding

525
00:40:55,480 --> 00:40:56,559
the universe.

526
00:40:56,159 --> 00:40:56,920
Speaker 11: Together at all.

527
00:41:01,800 --> 00:41:05,400
Speaker 1: They're forecasting how the universe will end by observing one

528
00:41:05,400 --> 00:41:09,199
of the most violent cosmic events, stars that explode in

529
00:41:09,280 --> 00:41:13,280
distant galaxies with unbelievable ferocity when they reach the end

530
00:41:13,320 --> 00:41:22,519
of their life supernovae. From the brightness of these explosions,

531
00:41:22,639 --> 00:41:25,159
Kirshner and his team can tell if a galaxy is

532
00:41:25,239 --> 00:41:33,639
near or far away. They measure the distant supernovae as

533
00:41:33,760 --> 00:41:36,639
markers to help them work out how fast the universe

534
00:41:36,719 --> 00:41:37,400
is expanding.

535
00:41:38,840 --> 00:41:41,199
Speaker 5: This is a very sensitive system that we're using.

536
00:41:41,400 --> 00:41:43,880
Speaker 21: It has an electronic detector and of course it's connected

537
00:41:43,920 --> 00:41:47,559
to a gigantic telescope. It lets you see objects which

538
00:41:47,599 --> 00:41:51,199
are about one hundred million times fainter than you can

539
00:41:51,239 --> 00:41:53,039
see with your dark adapted eye.

540
00:41:53,920 --> 00:41:57,199
Speaker 1: Like Edwin Hubble, they're using the light from distant galaxies

541
00:41:57,239 --> 00:41:59,679
to get an accurate fix on the universe's rate of

542
00:41:59,679 --> 00:42:03,440
excit pansion. They thought they would be measuring how much

543
00:42:03,480 --> 00:42:07,039
the gravitational pull from dark matter was slowing the expansion

544
00:42:07,119 --> 00:42:11,320
rate down, but what they have found has stunned the

545
00:42:11,360 --> 00:42:12,719
cosmological community.

546
00:42:14,199 --> 00:42:19,719
Speaker 5: Well, maybe it's the other galaxy.

547
00:42:20,119 --> 00:42:24,320
Speaker 1: Rather than slowing down, the universe is speeding up. The

548
00:42:24,400 --> 00:42:29,760
galaxies are moving apart faster than ever before. Dark matter

549
00:42:30,159 --> 00:42:31,440
is not powerful enough.

550
00:42:32,079 --> 00:42:34,039
Speaker 21: See what it looks to me like, there's still something

551
00:42:34,079 --> 00:42:35,239
there at the location that.

552
00:42:35,280 --> 00:42:38,119
Speaker 13: Is the right there.

553
00:42:40,000 --> 00:42:43,159
Speaker 1: Scientists now believe that the universe will not collapse in

554
00:42:43,199 --> 00:42:47,920
a catastrophic fireball, nor will it coast on serenely. Instead,

555
00:42:47,960 --> 00:42:52,280
its contents will speed apart, faster and faster, until lost

556
00:42:52,320 --> 00:42:54,159
in the vast blackness of space.

557
00:42:55,280 --> 00:42:57,880
Speaker 5: So if the picture that is coming from the supernob

558
00:42:58,039 --> 00:43:01,719
is really right, the universe will expect and forever, in fact,

559
00:43:02,039 --> 00:43:05,239
faster and faster on into the future. Now, this is

560
00:43:05,320 --> 00:43:08,760
really not anything to worry about, even though it is

561
00:43:08,800 --> 00:43:13,760
a kind of obleak future of an empty, cold, dark universe.

562
00:43:16,079 --> 00:43:19,320
Speaker 1: What Kirshner may have discovered as a remnant of the

563
00:43:19,360 --> 00:43:23,880
original Big Bang, the inflation that started in the very

564
00:43:23,960 --> 00:43:27,199
first second of the universe, is taking off again.

565
00:43:29,400 --> 00:43:31,400
Speaker 9: What makes cosmology at the end of the twentieth century

566
00:43:31,440 --> 00:43:34,079
so exciting is that, in fact we understand that the

567
00:43:34,199 --> 00:43:36,480
largest things in the universe are really determined by the

568
00:43:36,519 --> 00:43:39,519
smallest things in the universe. That there's this connection because

569
00:43:39,639 --> 00:43:43,719
the very early Big Bang, the fundamental forces governing the

570
00:43:43,719 --> 00:43:47,400
microscopic structure matter really determined the structures we see today

571
00:43:47,599 --> 00:43:49,920
on scales as large as galaxies and superglusters.

572
00:43:51,079 --> 00:43:54,400
Speaker 1: The shape of our universe, everything we see around us

573
00:43:54,519 --> 00:43:57,559
was determined when the universe was smaller than an atom

574
00:43:57,840 --> 00:44:34,079
and only a fraction of a second order. Our universe

575
00:44:34,280 --> 00:44:37,920
is cooling and dying. In a billion years from now,

576
00:44:38,320 --> 00:44:42,360
our first unmanned spacecraft like Voyager one, will leave the

577
00:44:42,400 --> 00:44:49,239
Milky Way and drift unhindered through the universe. As the

578
00:44:49,360 --> 00:44:53,840
universe reaches middle age, even the longest lived stars will

579
00:44:53,880 --> 00:44:54,880
start to burn out.

580
00:44:56,880 --> 00:45:00,440
Speaker 18: Our sun has about five billion years of life clift,

581
00:45:00,920 --> 00:45:04,400
and very few stars will still be shining ten billion

582
00:45:04,519 --> 00:45:08,079
years from now. The dead stars will still orbit around

583
00:45:08,119 --> 00:45:12,000
the center of the galaxy, but your delisiens will gradually

584
00:45:12,199 --> 00:45:15,719
cause most of them to fall into a giant legged

585
00:45:15,760 --> 00:45:16,840
hole at the center.

586
00:45:21,800 --> 00:45:25,280
Speaker 7: Suppose we look ahead to when universe is one hundred

587
00:45:25,320 --> 00:45:30,199
billion years old, Then it would be a rather dull

588
00:45:30,440 --> 00:45:33,960
and dark place because all but the faintest and most

589
00:45:33,960 --> 00:45:36,679
slow burning stars would have died. So the universe will

590
00:45:36,719 --> 00:45:40,559
not only disperse, but all the galaxies will get fainter.

591
00:45:44,559 --> 00:45:48,519
Speaker 1: As the universe expands with age, gravity will lose its

592
00:45:48,559 --> 00:45:52,360
precarious grip. If you could be there to witness it,

593
00:45:52,880 --> 00:46:02,840
you would see absolutely nothing. Is there anything that human

594
00:46:02,920 --> 00:46:05,800
race could do to flee from such a dark fate.

595
00:46:06,920 --> 00:46:10,559
Could we escape into another dimension, into another universe?

596
00:46:13,559 --> 00:46:16,159
Speaker 7: The best ideas that people have come up with do

597
00:46:16,239 --> 00:46:19,719
suggest that maybe our big Bang was not the only one,

598
00:46:20,320 --> 00:46:23,639
and that the inflation which led to our universe may

599
00:46:23,679 --> 00:46:27,639
have happened elsewhere, maybe anifer a number of times in

600
00:46:27,719 --> 00:46:29,840
some grand eternal cosmos.

601
00:46:33,400 --> 00:46:37,559
Speaker 1: If other universes do exist, could we ever find a

602
00:46:37,599 --> 00:46:48,840
way of traveling into one.

603
00:46:55,960 --> 00:46:59,119
Speaker 9: It's incredibly interesting that there's a lot more we don't

604
00:46:59,159 --> 00:47:01,440
know about the universe than we do in spite of

605
00:47:01,480 --> 00:47:03,840
all we've learned up to day, and therefore some of

606
00:47:03,840 --> 00:47:07,039
the wild ideas from science fiction, including things like even wormholes,

607
00:47:07,519 --> 00:47:08,719
might or might not be possible.

608
00:47:08,760 --> 00:47:10,159
Speaker 15: We just don't know at this point.

609
00:47:13,599 --> 00:47:18,760
Speaker 1: Wormholes are another prediction of Einstein's theories. Here space is

610
00:47:18,800 --> 00:47:22,000
so twisted that it forms a tunnel from one universe

611
00:47:22,039 --> 00:47:26,599
to another. Even if these hypothetical holes in space and

612
00:47:26,760 --> 00:47:31,079
time do exist, entering a neighboring universe could be on

613
00:47:31,239 --> 00:47:37,840
wives travel into one where the laws of physics are

614
00:47:37,880 --> 00:47:41,519
even slightly different from our own, and you'd cease to

615
00:47:41,559 --> 00:47:42,280
exist at all.

616
00:47:49,960 --> 00:47:52,840
Speaker 5: Even though we have very small brains and we lead

617
00:47:53,000 --> 00:47:56,239
very brief lives and so on, the fact is we're

618
00:47:56,360 --> 00:47:59,880
able to understand where we are. And because we can,

619
00:48:00,000 --> 00:48:03,559
we use instruments like the big telescopes, the physics that

620
00:48:03,599 --> 00:48:06,239
we learn on the surface of the Earth, and the

621
00:48:06,320 --> 00:48:09,199
ideas that people have had over the last few centuries

622
00:48:09,440 --> 00:48:12,000
to build up a coherent picture. And I think we

623
00:48:12,000 --> 00:48:13,920
should be proud of that We've done pretty well.

624
00:48:14,199 --> 00:48:17,599
Speaker 4: I feel it's been a great privilege and a huge

625
00:48:17,599 --> 00:48:21,239
amount of luck to be present to witness an important

626
00:48:21,280 --> 00:48:23,400
science like cosmology hit its peak.

627
00:48:25,679 --> 00:48:29,760
Speaker 2: In some way, creatures like us, and there probably are

628
00:48:29,840 --> 00:48:34,159
many are the consciousness or the intelligence of the universe.

629
00:48:34,199 --> 00:48:37,280
It's almost as if the universe invented a way to

630
00:48:37,400 --> 00:48:38,119
know itself.

631
00:48:40,559 --> 00:48:44,599
Speaker 1: After centuries of gazing at the heavens, scientists now know

632
00:48:44,800 --> 00:48:49,079
that everything in our universe was born twelve billion years ago.

633
00:48:51,199 --> 00:48:53,719
Speaker 11: Before the Big Bang, there was nothing.

634
00:48:56,000 --> 00:49:00,159
Speaker 1: This violent explosion gave birth to everything we can see,

635
00:49:00,840 --> 00:49:13,239
countless galaxies, stars and planets, even life itself. Our universe

636
00:49:13,519 --> 00:49:17,480
is alive with the shimmering of countless stars, but our

637
00:49:17,599 --> 00:49:21,519
vision from beneath the Earth's protective atmosphere shields us from

638
00:49:21,559 --> 00:49:32,800
the real dangers. These are the most violent objects in

639
00:49:32,840 --> 00:50:00,639
the universe. Bob Kirshner is a Harvard professor the passion

640
00:50:00,719 --> 00:50:05,119
for the stars. He spent a lifetime studying them from

641
00:50:05,119 --> 00:50:06,559
their cradle to their grave.

642
00:50:09,119 --> 00:50:11,039
Speaker 5: I remember as a kid going out and seeing the

643
00:50:11,119 --> 00:50:15,039
stars at night, and I lie on the snow a

644
00:50:15,079 --> 00:50:18,440
flashlight and a star map and try to dope out

645
00:50:18,840 --> 00:50:21,159
what things were where in the sky. And my mother

646
00:50:21,239 --> 00:50:24,320
used to call at the back door and she said, Bobby,

647
00:50:24,760 --> 00:50:27,519
come in, get off that snow.

648
00:50:29,400 --> 00:50:33,239
Speaker 1: Today, instead of lying in the snow, Kirshner comes to

649
00:50:33,320 --> 00:50:34,559
Kick Peak Observatory.

650
00:50:37,400 --> 00:50:40,239
Speaker 5: Kin Peak is at about seven thousand feet, so it's

651
00:50:40,280 --> 00:50:44,000
not a particularly high mountain, but it is considerably above

652
00:50:44,000 --> 00:50:48,280
the valley floor, so it's a good site for astronomy. Also,

653
00:50:48,320 --> 00:50:50,440
the weather is very good down here in Arizona, so

654
00:50:50,480 --> 00:50:52,199
we get a lot of clear nights.

655
00:50:54,920 --> 00:50:57,519
Speaker 1: He has a date with the night sky to look

656
00:50:57,559 --> 00:51:00,119
for one of the most dramatic and beautiful events in

657
00:51:00,159 --> 00:51:13,400
the universe, the birth of a new star, as the

658
00:51:13,480 --> 00:51:17,440
sun sets over the Arizona Desert. The observatory is open

659
00:51:17,519 --> 00:51:25,199
for work. This mountaintop gives astronomers an unrivaled view of

660
00:51:25,239 --> 00:51:29,920
the sky, high above the clouds and obscuring lower atmosphere.

661
00:51:32,400 --> 00:51:35,840
Kirshner is looking for giant clouds of gas inside our

662
00:51:35,920 --> 00:51:39,039
galaxy in the Milky Way that may give birth to

663
00:51:39,159 --> 00:51:39,920
new stars.

664
00:51:40,519 --> 00:51:44,920
Speaker 5: Okay, ready, let's go to the first one man, all right,

665
00:51:47,960 --> 00:51:51,280
there are catalogs of regions where stars have been forming

666
00:51:51,360 --> 00:51:53,559
or where there are big clouds of gas that people

667
00:51:53,559 --> 00:51:56,880
have compiled over the years, And so by looking at

668
00:51:57,039 --> 00:51:59,000
some of these things from the catalog, we can begin

669
00:51:59,079 --> 00:52:02,840
to investigate into areas where there really are stars forming

670
00:52:02,840 --> 00:52:05,119
and where we look deep into them to see what's

671
00:52:05,159 --> 00:52:05,599
going on.

672
00:52:13,480 --> 00:52:17,159
Speaker 1: With their high power telescopes, Kirshner and his colleagues have

673
00:52:17,280 --> 00:52:20,960
been peering into enormous gas clouds inside our own galaxy.

674
00:52:22,119 --> 00:52:26,119
This is the Lagoon Nebula, an interstellar nursery which is

675
00:52:26,159 --> 00:52:42,159
giving birth to hundreds of new stars. The clouds are

676
00:52:42,199 --> 00:52:46,239
mostly made of hydrogen, the most abundant element in the universe.

677
00:52:53,000 --> 00:52:56,880
They are so dense they begin spiraling inwards under their

678
00:52:56,920 --> 00:53:11,599
own gravity. The matter collects and begins to form a

679
00:53:11,679 --> 00:53:20,679
fledgling star, a protostar with a disk of gas and

680
00:53:20,800 --> 00:53:25,800
dust falling inwards. It spins faster and faster. This was

681
00:53:25,880 --> 00:53:29,039
probably how our sun and the Solar System was born.

682
00:53:32,320 --> 00:53:36,239
Speaker 5: After a while, the material that is in orbit around

683
00:53:36,239 --> 00:53:39,880
the protostar starts bumping into itself, and so it builds

684
00:53:39,960 --> 00:53:44,320
up bigger particles out of smaller ones, eventually makes dust

685
00:53:44,800 --> 00:53:48,519
and makes gravel, and then very quickly probably builds up

686
00:53:48,519 --> 00:53:49,760
things as big as planets.

687
00:53:54,320 --> 00:53:56,920
Speaker 1: This is the moment of birth of a new star,

688
00:53:57,960 --> 00:54:01,800
With a new sun spawning a disc of orbiting planets.

689
00:54:09,079 --> 00:54:11,639
Speaker 5: The star shrinks down more and more until it becomes

690
00:54:11,639 --> 00:54:14,840
hot enough and dense enough for the nuclear reactions in

691
00:54:14,880 --> 00:54:17,519
the center to get going that turn it from being

692
00:54:17,559 --> 00:54:21,000
a glowing ball of gas into a real star, something

693
00:54:21,000 --> 00:54:23,199
that has a nuclear fire down in the center.

694
00:54:32,880 --> 00:54:36,719
Speaker 1: The same nuclear reactions that take place in a hydrogen bomb,

695
00:54:37,280 --> 00:54:41,840
converting hydrogen into helium produces the energy that causes stars

696
00:54:41,920 --> 00:54:52,719
to shine. When the nuclear fires ignite, a new star

697
00:54:52,880 --> 00:55:11,000
is born. Since the birth of our Solar system, the

698
00:55:11,079 --> 00:55:15,360
closest and most familiar star of all our sun has

699
00:55:15,440 --> 00:55:20,800
bathed our planet in heat and light. At the heart

700
00:55:20,840 --> 00:55:24,360
of the Sun, six hundred million tons of hydrogen are

701
00:55:24,400 --> 00:55:28,800
converted into helium every second in a nuclear reaction that

702
00:55:28,960 --> 00:55:41,480
fired up four and a half billion years ago. For generations,

703
00:55:41,599 --> 00:55:45,559
the only way astronomers could study the Sun's fiery atmosphere

704
00:55:45,880 --> 00:55:50,480
was during a total solar eclipse, for a few fleeting minutes,

705
00:55:50,679 --> 00:55:54,159
the Sun drops its guard, allowing us a glimpse of

706
00:55:54,159 --> 00:56:10,440
its awesome power. Francisco Diego, a professional eclipse chaser, saw

707
00:56:10,639 --> 00:56:14,400
his first eclipse as a teenager in Mexico. It began

708
00:56:14,480 --> 00:56:16,639
a lifelong fascination with the Sun.

709
00:56:20,960 --> 00:56:24,840
Speaker 22: The total solar eclipse is an event that when you

710
00:56:24,880 --> 00:56:27,360
see it, you will never forget. The day of the

711
00:56:27,360 --> 00:56:30,239
eclipse is very special. When you look at the Sun,

712
00:56:30,320 --> 00:56:34,960
you see this beautiful, complete, perfect disk. But the day

713
00:56:34,960 --> 00:56:37,960
of the eclipse exactly at the time that has been

714
00:56:38,000 --> 00:56:41,320
predicted for many, many years. In the bands, you see

715
00:56:41,360 --> 00:56:43,480
how the moon starts eating into it.

716
00:56:46,280 --> 00:56:50,199
Speaker 1: At total eclipse, the Moon will align itself perfectly between

717
00:56:50,199 --> 00:56:51,280
the Sun and the Earth.

718
00:56:52,239 --> 00:56:53,440
Speaker 11: The Moon is four.

719
00:56:53,280 --> 00:56:56,480
Speaker 1: Hundred times closer to the Earth than the Sun, and

720
00:56:56,599 --> 00:57:02,840
by extraordinary cosmological coincidence, also exactly four hundred times smaller.

721
00:57:08,679 --> 00:57:13,119
Diego and his astronomical colleagues will travel anywhere on Earth

722
00:57:13,199 --> 00:57:17,960
to study this rare celestial event. Each eclipse will last

723
00:57:18,119 --> 00:57:19,800
just a few precious minutes.

724
00:57:33,880 --> 00:57:37,760
Speaker 22: The temperature starts dropping and he drops up to about

725
00:57:37,760 --> 00:57:41,000
ten or fifteen degrees. In some cases, he's very noticeable.

726
00:57:46,719 --> 00:57:51,400
You feel this wind, this atmosphere is agitating, and it

727
00:57:51,519 --> 00:58:03,360
is very very tense moment. Then you look at the west,

728
00:58:03,400 --> 00:58:05,639
because the shadow of the moon is coming towards you

729
00:58:06,719 --> 00:58:26,119
very fast, at three thousand kilometers per hour. The landscape

730
00:58:26,159 --> 00:58:27,280
looses its colors.

731
00:58:37,199 --> 00:58:40,599
Speaker 1: One hundred miles wide. Shadow will pass over the surface

732
00:58:40,599 --> 00:58:49,760
of the Earth. The brightness of the midday sun will

733
00:58:49,840 --> 00:58:51,239
slowly turn tonight.

734
00:59:23,480 --> 00:59:26,039
Speaker 22: The sky gets so dark that the corona, which is

735
00:59:26,119 --> 00:59:27,639
very faint, is now visible.

736
00:59:27,960 --> 00:59:29,119
Speaker 15: It really flourishes.

737
00:59:29,199 --> 00:59:32,280
Speaker 22: It's like a flower, a white flower that opens its

738
00:59:32,320 --> 00:59:34,159
petals in the sky.

739
00:59:35,960 --> 00:59:40,920
Speaker 1: This is the Sun's corona, a glowing atmosphere normally obscured

740
00:59:40,960 --> 00:59:45,119
by the intense clare. It burns at over a million degrees.

741
01:00:00,119 --> 01:00:04,199
Giant prominences irrupt from its surface. They could swallow the

742
01:00:04,239 --> 01:00:08,639
Earth dozens of times over like giant fingers. They stretch

743
01:00:08,719 --> 01:00:21,760
for millions of miles into the vacuum of space. But

744
01:00:21,960 --> 01:00:25,880
for solar astronomers like Diego, a total eclipse is over

745
01:00:25,960 --> 01:00:30,280
all too soon. After just a few minutes, the alignment

746
01:00:30,360 --> 01:00:46,280
is lost. The Sun's brilliant light bursts out from behind

747
01:00:46,320 --> 01:00:50,199
the Moon, a magical sight that eclipse watches have named

748
01:00:50,559 --> 01:00:51,639
the diamond Ring.

749
01:00:52,599 --> 01:00:55,719
Speaker 22: When you finish looking at the diamond ring and you

750
01:00:55,760 --> 01:00:58,360
see the shard of the Moon rushing away from you

751
01:00:58,480 --> 01:01:01,840
now towards the east, then you see that was it.

752
01:01:02,519 --> 01:01:04,960
Those two or three minutes are gone. You have been

753
01:01:04,960 --> 01:01:07,960
waiting for that for years, and suddenly it is gone.

754
01:01:08,079 --> 01:01:10,679
You feel like a vacuum and you say, this is

755
01:01:10,719 --> 01:01:12,400
not enough. I want more.

756
01:01:19,280 --> 01:01:22,840
Speaker 1: As the Sun breaks out from behind the Moon once again,

757
01:01:22,960 --> 01:01:29,760
the Earth is bathed in its light. We rely on

758
01:01:29,840 --> 01:01:33,159
the Sun's constant energy to breathe life into our planet.

759
01:01:33,920 --> 01:01:39,199
It gives us free energy, its heat evaporates water to

760
01:01:39,280 --> 01:01:43,199
produce the clouds and rain. The slightest change in its

761
01:01:43,239 --> 01:01:46,599
behavior could put the world and even the human.

762
01:01:46,360 --> 01:01:57,840
Speaker 10: Race at risk.

763
01:02:00,760 --> 01:02:04,039
Speaker 1: To keep a constant vigil on the Sun's enormous power

764
01:02:04,119 --> 01:02:08,760
from above the Earth's shimmering atmosphere, a new satellite, SOHO,

765
01:02:09,320 --> 01:02:13,159
was designed and built by NASA and the European Space Agency.

766
01:02:16,719 --> 01:02:20,079
Launched in nineteen ninety five, SOHO was to promise a

767
01:02:20,159 --> 01:02:24,400
breakthrough in Sun observations and give astronomers a front row

768
01:02:24,559 --> 01:02:34,280
view of our nearest star. Douglas Goff a solar astronomer

769
01:02:34,320 --> 01:02:36,960
at Cambridge University, was one of the members of the

770
01:02:37,000 --> 01:02:38,679
SOHO team.

771
01:02:38,920 --> 01:02:41,400
Speaker 23: The satellite has gone to a position between the Earth

772
01:02:41,400 --> 01:02:45,360
and the Sun where the gravitational pull of the two cancils,

773
01:02:45,719 --> 01:02:47,840
so it sits there, looking at the Sun continuously and

774
01:02:47,920 --> 01:02:49,639
beaming back the information to Earth.

775
01:02:59,280 --> 01:03:03,320
Speaker 1: The images as it beam back were beyond their wildest dreams.

776
01:03:04,280 --> 01:03:09,239
The Sun's raging surface is a turbulent world, its eruptions

777
01:03:09,360 --> 01:03:25,199
ripped and torn by enormous magnetic fields. SOHO revealed that,

778
01:03:25,480 --> 01:03:30,519
like the Earth, the Sun has weather. Gigantic solar tornadoes

779
01:03:30,639 --> 01:03:46,039
twist through its atmosphere and gigantic shockwaves rip across its surface.

780
01:03:55,639 --> 01:03:59,840
The surface of the Sun is heaving. Every five minutes,

781
01:03:59,840 --> 01:04:04,800
the entire star breathes in and out. Our Sun is pulsating.

782
01:04:05,760 --> 01:04:09,199
This is the real sound of it, vibrating, speeded up

783
01:04:09,400 --> 01:04:10,559
thousands of times.

784
01:04:17,840 --> 01:04:20,559
Speaker 23: The outside of the Sun is in a very dynamical

785
01:04:20,679 --> 01:04:24,360
turbulent motion, just like the turbulence behind the back of

786
01:04:24,360 --> 01:04:28,639
a jet engine. The jet engine creates a lot of noise. Similarly,

787
01:04:28,679 --> 01:04:31,559
this motion creates a lot of noise inside the Sun,

788
01:04:31,800 --> 01:04:35,480
which reverberates around and makes the Sun sing and By

789
01:04:35,519 --> 01:04:37,960
listening to those tones, we can learn about the structure

790
01:04:37,960 --> 01:04:38,320
of the Sun.

791
01:04:38,360 --> 01:04:38,760
Speaker 11: Inside.

792
01:04:49,760 --> 01:04:53,599
Speaker 1: Below its churning surface, there's a nuclear furnace that will

793
01:04:53,639 --> 01:04:58,840
burn for billions of years from its nuclear heart, trillions

794
01:04:58,880 --> 01:05:03,480
and trillions of time, any particles of radiation photons make

795
01:05:03,519 --> 01:05:12,239
their arduous journey from the core to the surface. The

796
01:05:12,320 --> 01:05:16,840
photons collide with super dense gas. They take so many

797
01:05:16,960 --> 01:05:19,519
hits that a trip that should take just a few

798
01:05:19,559 --> 01:05:26,199
seconds takes millions of years. But after the photons escape

799
01:05:26,199 --> 01:05:29,280
from the surface's light, they take only eight and a

800
01:05:29,400 --> 01:05:32,239
third minutes to travel from the Sun to the Earth.

801
01:05:42,360 --> 01:05:45,320
Every summer, millions of people go out of their way

802
01:05:45,400 --> 01:05:54,000
to worship their local star, even ninety three million miles away.

803
01:05:54,440 --> 01:05:59,199
We can feel the Sun's enormous destructive power, but not

804
01:05:59,280 --> 01:06:02,719
all of us are nowatually protected against the Sun's lethal rays.

805
01:06:03,599 --> 01:06:08,079
Fair skinned people have weak defenses. The result is sunburn

806
01:06:08,480 --> 01:06:25,960
from the Sun's deadly ultraviolet radiation. This anti burn patrol

807
01:06:26,400 --> 01:06:34,639
is on the lookout for unprotected babies. The greater the

808
01:06:34,719 --> 01:06:37,599
exposure to the Sun, the greater the risk of getting

809
01:06:37,679 --> 01:06:58,079
skin cancer, especially deadly malignant melanomas. Even greater dangers are

810
01:06:58,119 --> 01:07:01,599
whipped up when the Sun's surfaces twisted and contorted by

811
01:07:01,679 --> 01:07:06,639
powerful magnetic fields. These fields can puncture the surface and

812
01:07:06,800 --> 01:07:13,440
create dark areas called sunspots. Each one is big enough

813
01:07:13,480 --> 01:07:17,599
to swallow the entire Earth, and their presence is a warning.

814
01:07:22,679 --> 01:07:28,360
The magnetic disturbances cause enormous eruptions, blasting huge amounts of

815
01:07:28,440 --> 01:07:41,920
radiation billions of tons of charged particles into space. Every

816
01:07:42,039 --> 01:07:46,199
eleven years, the sun spots increase in number and size,

817
01:07:46,880 --> 01:07:50,880
a mass of intense energy can head our way, engulfing

818
01:07:50,920 --> 01:07:55,400
the entire Earth. When this happens, is not just the

819
01:07:55,480 --> 01:08:01,519
sun bathers who need to head for cover. March nineteen

820
01:08:01,559 --> 01:08:04,960
eighty nine, the Sun was about to give Eastern Canada

821
01:08:05,079 --> 01:08:08,719
an early wake up call. It was the height of

822
01:08:08,760 --> 01:08:16,560
the Sun's eleven year cycle, the solar maximum. Out in space,

823
01:08:16,760 --> 01:08:20,680
a cloud of incandescent matter over one million miles long

824
01:08:20,880 --> 01:08:28,720
was heading straight for Earth. Night workers at the National

825
01:08:28,720 --> 01:08:31,920
Grid Control Center had no idea what was in store.

826
01:08:32,560 --> 01:08:35,560
At a quarter three in the morning, engineers noticed an

827
01:08:35,720 --> 01:08:39,520
enormous surge in their power system. When the cloud hit

828
01:08:39,560 --> 01:08:43,119
the Earth, it induced a massive surge of electricity inside

829
01:08:43,199 --> 01:08:48,359
the power cables. Engineers struggled to reduce the load, but

830
01:08:48,439 --> 01:08:50,840
in a matter of minutes they'd lost control of the

831
01:08:50,920 --> 01:09:00,800
whole system. Power plants over half a min million square

832
01:09:00,840 --> 01:09:07,760
miles of Quebec were swamped with excess current. Moments later,

833
01:09:08,039 --> 01:09:12,960
the whole grid blew the city was plummeted into darkness.

834
01:09:13,479 --> 01:09:20,680
Power was lost to eight million homes. Further north, the

835
01:09:20,720 --> 01:09:24,359
same cloud that had plunged Quebec into darkness was lighting

836
01:09:24,399 --> 01:09:28,119
up the night sky in a massive celestial fireworks display.

837
01:09:29,319 --> 01:09:37,600
This is the Aurora Borealis. Some of the particles from

838
01:09:37,600 --> 01:09:40,960
the cloud had become trapped inside the Earth's magnetic field.

839
01:09:41,800 --> 01:09:44,920
As they passed through the atmosphere, they reacted with the

840
01:09:44,960 --> 01:09:49,439
air like a giant neon light. The solar radiation lit

841
01:09:49,560 --> 01:10:04,560
up the night sky. Our Sun is not the only

842
01:10:04,640 --> 01:10:10,159
star that threatens our existence. Space is filled with harmful

843
01:10:10,239 --> 01:10:16,399
particles and radiation. Traveling above the Earth's protective atmosphere is

844
01:10:16,520 --> 01:10:42,560
extremely dangerous. Despite the dangers of traveling above the atmosphere,

845
01:10:42,960 --> 01:10:46,119
our desire to conquer space is so great that we

846
01:10:46,159 --> 01:10:56,039
are prepared to risk the consequences. In nineteen sixty nine,

847
01:10:56,600 --> 01:11:01,239
US Aldrin, Neil Armstrong and Mike Collins began their historic

848
01:11:01,319 --> 01:11:03,680
Quarter of a million mile journey to the Moon.

849
01:11:04,960 --> 01:11:08,560
Speaker 24: Hello, Neil and Burse, I'm talking to you by telephone

850
01:11:08,600 --> 01:11:11,479
from the over room at the White House, and this

851
01:11:11,520 --> 01:11:15,479
certainly has to be the most historic telephone call made.

852
01:11:16,079 --> 01:11:20,239
Speaker 1: Celebrations ran high as Aldron and Armstrong stepped onto the

853
01:11:20,319 --> 01:11:25,399
lunar surface for the first time, but behind the euphoria,

854
01:11:25,520 --> 01:11:28,960
the pair were keeping a secret from mission control in Houston.

855
01:11:30,000 --> 01:11:33,079
They'd seen more than just the dust of the Moon's surface.

856
01:11:38,800 --> 01:11:41,760
It was only when they returned to Earth that Armstrong

857
01:11:41,800 --> 01:11:46,720
and Oldering revealed their secret. They reported seeing strange, white

858
01:11:46,760 --> 01:11:55,800
streaks of light flashing in their eyes. NASA decided to

859
01:11:55,880 --> 01:11:59,079
run tests on future missions to discover exactly what the

860
01:11:59,159 --> 01:12:06,279
light flashes might be. Astronaut Chinlie Duke was that guinea

861
01:12:06,319 --> 01:12:09,920
pig on board upon O sixteen. He was asked to

862
01:12:09,960 --> 01:12:12,000
watch out for the mysterious flashes.

863
01:12:16,960 --> 01:12:19,319
Speaker 25: We're on our way to the Moon, and uh, all

864
01:12:19,319 --> 01:12:21,960
of a sudden, I closed my eyes and I saw one.

865
01:12:22,359 --> 01:12:24,520
It was like a The first one was like a

866
01:12:24,560 --> 01:12:27,840
flashbulb exploding inside your eye.

867
01:12:28,560 --> 01:12:28,880
Speaker 26: Uh.

868
01:12:28,920 --> 01:12:30,640
Speaker 25: It was very bright, very white.

869
01:12:31,279 --> 01:12:31,399
Speaker 18: Uh.

870
01:12:31,600 --> 01:12:34,159
Speaker 26: And uh, I said, hey.

871
01:12:34,279 --> 01:12:35,319
Speaker 5: I saw my first one.

872
01:12:41,640 --> 01:12:44,640
Speaker 25: It was just this streak of light very fast and

873
01:12:45,279 --> 01:12:46,640
just as white as it could be.

874
01:12:47,279 --> 01:12:49,720
Speaker 11: Uh uh in very bright.

875
01:12:57,600 --> 01:13:01,279
Speaker 1: A young researcher, Larry Pinski, was assigned to work with

876
01:13:01,399 --> 01:13:04,640
Duke and find out what was causing the flashes.

877
01:13:06,600 --> 01:13:09,000
Speaker 27: White in the right eye upper center.

878
01:13:11,600 --> 01:13:15,399
Speaker 1: He recorded Duke's comments back in Houston and eventually realized

879
01:13:15,439 --> 01:13:17,560
the flashes could only be one thing.

880
01:13:23,640 --> 01:13:25,039
Speaker 24: Faint white and the.

881
01:13:25,399 --> 01:13:28,279
Speaker 11: Left dye were well.

882
01:13:28,319 --> 01:13:30,800
Speaker 28: It turns out that they were seeing cosmic rays. They

883
01:13:30,840 --> 01:13:36,199
were seeing these elementary particles that permeate space, that penetrate

884
01:13:36,239 --> 01:13:38,960
the spacecraft, actually penetrate the body and in this case,

885
01:13:39,000 --> 01:13:39,960
penetrate the eye.

886
01:13:40,279 --> 01:13:43,920
Speaker 24: We're feeling gooding, How about an expansion? You got?

887
01:13:44,760 --> 01:13:47,560
Speaker 1: What Pinsky had worked out was the Duke and the

888
01:13:47,600 --> 01:13:51,760
other astronauts were seeing high energy particles produced from one

889
01:13:51,760 --> 01:13:58,079
of the universe's most violent acts of destruction, when a

890
01:13:58,159 --> 01:14:02,479
massive star trillions of miles away explodes as a supernova.

891
01:14:16,680 --> 01:14:19,680
As a heavyweight star nears the end of its life,

892
01:14:20,079 --> 01:14:25,680
it incinerates all the fuel in its core. The heavier

893
01:14:25,800 --> 01:14:41,760
star is, the more catastrophic it's death. The core becomes unstable,

894
01:14:42,319 --> 01:14:45,720
it loses energy and starts a headlong collapse that for

895
01:14:45,800 --> 01:14:49,199
one second gives off as much energy as all the

896
01:14:49,239 --> 01:14:51,840
stars in all the galaxies in the universe.

897
01:15:16,920 --> 01:15:21,560
Speaker 28: Cosmic rays are actually particles, They're actually little pieces of matter.

898
01:15:21,680 --> 01:15:27,399
They are the nuclei of atoms. The atoms come from supernovae,

899
01:15:27,600 --> 01:15:30,880
and they're just the bare nucleus accelerated to very very

900
01:15:30,960 --> 01:15:31,960
high velocities.

901
01:15:36,560 --> 01:15:38,640
Speaker 25: I'm sure they were there all the time, but the

902
01:15:38,640 --> 01:15:40,760
only time you'd ever noticed them is when you sort

903
01:15:40,760 --> 01:15:43,439
of got quiet, closed your eyes and thought about it,

904
01:15:43,479 --> 01:15:44,960
and then you see them going.

905
01:15:44,760 --> 01:15:52,079
Speaker 24: Off faint, faint white butt and then left eye.

906
01:15:53,239 --> 01:15:55,479
Speaker 25: There wasn't any pain associated with it.

907
01:15:55,479 --> 01:15:57,039
Speaker 26: It's just sort of like a.

908
01:15:57,079 --> 01:16:01,840
Speaker 25: Very spectacular fireworks display going off inside your eyeball.

909
01:16:07,920 --> 01:16:11,560
Speaker 1: When the astronauts returned to Earth, Penske took a closer

910
01:16:11,560 --> 01:16:19,800
look at Duke's space helmet. He found hundreds of microscopic

911
01:16:19,880 --> 01:16:23,039
tracks where the cosmic rays had tunneled right through.

912
01:16:25,119 --> 01:16:29,119
Speaker 28: They are tremendously penetrating and do considerable damage to the

913
01:16:29,119 --> 01:16:32,039
molecular structure of whatever they passed through, and this is

914
01:16:32,119 --> 01:16:34,479
the reason why they're a hazard to people.

915
01:16:34,520 --> 01:16:35,479
Speaker 6: When they passed through you.

916
01:16:36,159 --> 01:16:38,399
Speaker 25: The thought occurred to me, you know, if I was

917
01:16:38,399 --> 01:16:41,800
out here maybe a couple of years, these little things.

918
01:16:41,800 --> 01:16:45,560
Burning a hole through my head might cause me some

919
01:16:45,680 --> 01:16:48,159
problems in the future, but we didn't worry about it,

920
01:16:48,199 --> 01:16:50,199
of course, on a short mission like we were on.

921
01:16:55,680 --> 01:16:58,600
Speaker 1: But if a supernova is too close, it won't be

922
01:16:58,640 --> 01:17:03,159
only astronauts who will at risk. It could kill everything

923
01:17:03,279 --> 01:17:11,520
down here on Earth. Our galaxy is packed with over

924
01:17:11,560 --> 01:17:15,319
one hundred billion stars, many of them near the end

925
01:17:15,319 --> 01:17:19,920
of their natural life. At least one or two supernovas

926
01:17:20,039 --> 01:17:27,039
explode in our galaxy every century. Two young astronomers from

927
01:17:27,159 --> 01:17:29,960
Caltech have now come up with a new theory of

928
01:17:30,039 --> 01:17:36,520
life on Earth that has shaken our scientific beliefs, a

929
01:17:36,600 --> 01:17:40,359
theory that links the death of stars to mass extinctions

930
01:17:40,399 --> 01:17:42,399
on Earth.

931
01:17:47,760 --> 01:17:49,920
Speaker 29: The fossil record of the last five hundred million years

932
01:17:49,920 --> 01:17:53,840
shows five or six huge extinction events in which anywhere

933
01:17:53,840 --> 01:17:57,600
from sixty to ninety five percent of species on Earth dinosaurs, reptiles,

934
01:17:57,680 --> 01:18:00,760
et cetera, were wiped out. And so I really set

935
01:18:00,760 --> 01:18:03,039
out to do was to come up with some sort

936
01:18:03,079 --> 01:18:06,039
of model that would explain why the major extinctions happen.

937
01:18:05,880 --> 01:18:06,279
Speaker 11: When they do.

938
01:18:09,039 --> 01:18:13,640
Speaker 1: Eric Lych and Gautam Vasish have calculated exactly when the

939
01:18:13,680 --> 01:18:16,520
Earth may have been close to ancient supernovas.

940
01:18:20,119 --> 01:18:20,880
Speaker 26: The key to.

941
01:18:20,880 --> 01:18:24,199
Speaker 1: Their model was understanding the rotation of the Milky Way.

942
01:18:25,159 --> 01:18:28,520
Like a giant spinning wheel. The Milky Way is circled

943
01:18:28,560 --> 01:18:31,760
by spiral arms packed with billions of stars.

944
01:18:40,199 --> 01:18:43,520
Speaker 30: Spiral arms are really disturbances that sweep through the disk

945
01:18:43,600 --> 01:18:46,520
of the galaxy, and the gas and dust tends to

946
01:18:46,560 --> 01:18:48,439
accumulate along these disturbances.

947
01:18:48,880 --> 01:18:51,279
Speaker 29: If you imagine looking at our galaxy face on, the

948
01:18:51,279 --> 01:18:53,840
spiral arms appear like swirls going out from the center

949
01:18:53,840 --> 01:18:56,319
to the outer edge, rather like the kind of whirlpool

950
01:18:56,359 --> 01:18:57,680
you see when water goes down and drain.

951
01:19:00,199 --> 01:19:05,000
Speaker 1: The spiral arms are wherein supernovas are most likely to explode.

952
01:19:05,199 --> 01:19:08,359
Our solar system passes in and out of the arms

953
01:19:08,399 --> 01:19:10,439
once every fifty million years.

954
01:19:12,439 --> 01:19:15,479
Speaker 30: We know the location of the spiral arms fairly well,

955
01:19:15,640 --> 01:19:18,319
so we could trace the orbit of the Earth back

956
01:19:18,359 --> 01:19:21,359
into time. The hope was to find a link between

957
01:19:21,479 --> 01:19:25,720
the times of occurrences of the extinctions and the timing

958
01:19:25,760 --> 01:19:28,880
of the passage of the Earth through the spiral arms.

959
01:19:36,399 --> 01:19:41,920
Speaker 1: Their calculations revealed that the biggest mass extinctions correspond exactly

960
01:19:41,960 --> 01:19:44,079
with the dates when the Earth had passed through the

961
01:19:44,119 --> 01:19:49,600
spiral arms. If a supernova exploded nearby, the surface of

962
01:19:49,640 --> 01:19:52,279
the Earth would have been swamped by deadly radiation.

963
01:19:56,399 --> 01:19:58,319
Speaker 29: If the Solar system happens to be passing through a

964
01:19:58,359 --> 01:20:01,319
spiral arm, your chances of care entering a supernov explosion

965
01:20:01,439 --> 01:20:03,840
at close enough range to do serious damage to the

966
01:20:03,880 --> 01:20:06,600
Earth or quite high. In fact, we estimated something like

967
01:20:06,640 --> 01:20:07,600
fifty to fifty.

968
01:20:16,640 --> 01:20:20,920
Speaker 1: Understanding the mystery of just how massive stars die has

969
01:20:20,960 --> 01:20:26,479
taken astronomers centuries to unravel. Modern astronomers picked up their

970
01:20:26,520 --> 01:20:30,399
first clues from an unusual source during the Second World

971
01:20:30,439 --> 01:21:01,680
War in occupied Holland, Ian Duvand, a scholar of ancient

972
01:21:01,760 --> 01:21:06,239
Chinese manuscripts, discovered a document written in China nearly nine

973
01:21:06,319 --> 01:21:07,439
hundred years earlier.

974
01:21:08,319 --> 01:21:11,840
Speaker 31: It reported on the twenty second day of the seventh

975
01:21:11,920 --> 01:21:14,920
month of the first year of the period Chiwe said,

976
01:21:15,640 --> 01:21:19,359
frustrating myself, I have observed the appearance of a guest

977
01:21:19,439 --> 01:21:23,359
star in the fifth moon in the eastern heavens in Taurus.

978
01:21:23,800 --> 01:21:27,600
It was visible by day like Venus ponting Rates shut

979
01:21:27,600 --> 01:21:29,199
out from it on all sides.

980
01:21:32,880 --> 01:21:35,720
Speaker 1: The account told of a bright star that had appeared

981
01:21:35,760 --> 01:21:38,279
in the heavens in the summer of ten fifty four,

982
01:21:39,039 --> 01:21:59,680
which shone for twenty two months and then disappeared. Du

983
01:22:00,000 --> 01:22:04,239
and that realized the significance of his discovery. Through contacts

984
01:22:04,239 --> 01:22:07,279
in the Dutch underground, he smuggled a paper through enemy

985
01:22:07,359 --> 01:22:10,920
lines and across the Atlantic to astronomers in the United States.

986
01:22:23,720 --> 01:22:27,920
Twenty years earlier, American astronomers had discovered that a distant

987
01:22:28,000 --> 01:22:31,119
cloud of gas called the crab Nebula at the fringes

988
01:22:31,159 --> 01:22:35,640
of our galaxy was expanding. By working backwards, they had

989
01:22:35,680 --> 01:22:39,399
calculated that it originated from a single point some nine

990
01:22:39,479 --> 01:22:43,119
hundred years earlier, exactly the time of the Chinese Star.

991
01:22:44,319 --> 01:22:47,920
Astronomers believed that the crab Nebula was the debris from

992
01:22:47,920 --> 01:22:52,399
an exploding star a supernova, but at the time they

993
01:22:52,479 --> 01:23:03,199
had no proof. The Chinese Star was so bright it

994
01:23:03,239 --> 01:23:05,880
could be seen in daylight, and for a time it

995
01:23:05,960 --> 01:23:10,920
was even possible to write by its light. What's more,

996
01:23:11,319 --> 01:23:14,119
the star had appeared in exactly the same part of

997
01:23:14,159 --> 01:23:22,920
the sky as the crab Nebula. It clinched the argument

998
01:23:23,880 --> 01:23:26,680
it had to be the remains of an exploding star.

999
01:23:29,079 --> 01:23:32,479
The blue glow of the crab Nebula comes from escaping

1000
01:23:32,560 --> 01:23:37,720
cosmic rays. The colored pincers are the remnants spewed out

1001
01:23:37,760 --> 01:23:45,319
in the giant explosion. But for this star, the supernova

1002
01:23:45,319 --> 01:23:50,560
explosion wasn't the end. Left behind was a strange corpse.

1003
01:24:05,600 --> 01:24:10,000
Professor Anthony Huish from Cambridge University discovered there was life

1004
01:24:10,039 --> 01:24:13,039
beyond the grave for dead stars when he built an

1005
01:24:13,119 --> 01:24:15,520
unusual telescope in the nineteen sixties.

1006
01:24:18,560 --> 01:24:21,880
Speaker 32: We started building in nineteen sixty five. The thing was

1007
01:24:22,000 --> 01:24:25,640
we wanted a large radio telescope which was very sensitive,

1008
01:24:25,840 --> 01:24:28,720
but it had to be rather cheap, and I decided

1009
01:24:28,760 --> 01:24:37,399
on this construction of big dipole array. We all took

1010
01:24:37,439 --> 01:24:40,399
our turns in hammering the posts into the ground and

1011
01:24:41,000 --> 01:24:43,279
hanging up the wires and putting into the cables. It

1012
01:24:43,319 --> 01:24:44,560
was just very much a team effort.

1013
01:24:58,439 --> 01:25:01,520
Speaker 1: Over the next two years, Huish and a small team

1014
01:25:01,560 --> 01:25:04,880
of students built a jumble of wires and poles spread

1015
01:25:04,880 --> 01:25:09,680
over a four acre site. This strange looking telescope was

1016
01:25:09,720 --> 01:25:13,319
to discover the weirdest object in the universe and win

1017
01:25:13,479 --> 01:25:22,680
Hwish the Nobel Prize. The task of running it was

1018
01:25:22,720 --> 01:25:26,239
the responsibility of then research student Joscelyn Bell.

1019
01:25:31,880 --> 01:25:36,279
Speaker 33: That was producing miles of chart paper, ninety six feet

1020
01:25:36,319 --> 01:25:40,159
of chart paper every day, and we kept scanning the

1021
01:25:40,199 --> 01:25:43,560
sky over and over and over again. I ran it

1022
01:25:43,640 --> 01:25:46,880
for six months and generated several miles.

1023
01:25:46,600 --> 01:25:47,399
Speaker 12: Of chart paper.

1024
01:25:51,039 --> 01:25:55,119
Speaker 1: In August nineteen sixty seven, after just one month of operation,

1025
01:25:55,840 --> 01:25:59,399
an unusual signal caught her eye.

1026
01:26:02,079 --> 01:26:06,600
Speaker 33: As the pen ran over the chart paper went beep beep,

1027
01:26:06,920 --> 01:26:12,319
beep beep beep, regular poses about one and one third

1028
01:26:12,399 --> 01:26:13,199
seconds apart.

1029
01:26:15,399 --> 01:26:19,079
Speaker 32: Looked so artificial. It looks like an intelligent signal to

1030
01:26:19,079 --> 01:26:23,560
begin with, And intentional intelligent signals coming from out of space,

1031
01:26:23,600 --> 01:26:25,319
what are they? Well, you make a joke and say,

1032
01:26:25,319 --> 01:26:27,199
perhaps somebody is talking to us in some kind of

1033
01:26:27,239 --> 01:26:31,279
a code. So we call these things little Green Men LGM.

1034
01:26:32,119 --> 01:26:34,079
I mean, we didn't really believe it. On the other hand,

1035
01:26:34,079 --> 01:26:36,479
it was a possibility you couldn't immediately ignore.

1036
01:26:41,319 --> 01:26:44,640
Speaker 1: After months of analysis, Huish and Bell came to an

1037
01:26:44,680 --> 01:26:50,279
outstanding conclusion. Only a small, super dense spinning object could

1038
01:26:50,319 --> 01:26:59,560
be creating such a fast pulse. The only possibility was

1039
01:26:59,600 --> 01:27:03,399
the collect asked core of a super nova, a neutron star.

1040
01:27:04,520 --> 01:27:06,239
Here was the living courts.

1041
01:27:07,039 --> 01:27:10,239
Speaker 32: I really didn't know neutron stars existed until I started

1042
01:27:10,239 --> 01:27:12,079
talking to people and said, look, can you tell me

1043
01:27:12,119 --> 01:27:15,199
any sort of star that's but smaller than a thousand kilometers,

1044
01:27:15,439 --> 01:27:18,039
and up came the answer, neutron stars, and maybe we're

1045
01:27:18,039 --> 01:27:18,760
seeing the first one.

1046
01:27:18,840 --> 01:27:28,279
Speaker 33: Orthen the posts that come from one of these neutron

1047
01:27:28,319 --> 01:27:32,239
stars come to us because like a lighthouse, these stars

1048
01:27:32,279 --> 01:27:36,239
are spinning, and they have a beam that's focused by

1049
01:27:36,359 --> 01:27:38,920
the magnetic field of the star. And every time the

1050
01:27:38,960 --> 01:27:42,840
beam sweeps across us, across our radio telescope, we pick

1051
01:27:42,920 --> 01:27:43,560
up a Pultz.

1052
01:27:50,039 --> 01:27:52,840
Speaker 32: But for one year there are literally hundreds of theories

1053
01:27:52,880 --> 01:27:56,119
being published, and it was an absolutely open question, and

1054
01:27:56,680 --> 01:27:59,640
I think it only became generally accepted after about twelve

1055
01:27:59,640 --> 01:28:01,840
months that it had to be with Netles Bell.

1056
01:28:15,359 --> 01:28:20,319
Speaker 1: The revelation triggered a wave of activity. Radio telescopes all

1057
01:28:20,359 --> 01:28:24,239
over the world scanned the heavens looking for the mysterious pulses.

1058
01:28:28,760 --> 01:28:31,880
Less than a year later, the giant Aracibo dish in

1059
01:28:31,920 --> 01:28:35,520
Puerto Rico picked up a signal it was coming from

1060
01:28:35,560 --> 01:28:43,399
the heart of the crab nebula. They had found the

1061
01:28:43,439 --> 01:28:59,439
ticking corpse at the center of the Chinese supernova. The

1062
01:28:59,520 --> 01:29:04,560
spinning neutron star was not only giving off radio waves amazingly,

1063
01:29:04,720 --> 01:29:09,520
it was also visible. High speed television pictures revealed it

1064
01:29:09,600 --> 01:29:13,199
was flashing on and off thirty times a second. It

1065
01:29:13,319 --> 01:29:15,840
was the most powerful object that anyone.

1066
01:29:15,439 --> 01:29:16,680
Speaker 10: Had ever photographed.

1067
01:29:21,319 --> 01:29:25,159
Speaker 1: Neutron stars are like nothing else in the universe. They're

1068
01:29:25,239 --> 01:29:30,760
so dense a thimbleful would weigh over one hundred million tons.

1069
01:29:30,760 --> 01:29:33,880
Speaker 33: Supposing you somehow managed to land on a neutron star,

1070
01:29:34,520 --> 01:29:39,239
then you are experiencing phenomenal gravity, and the atmosphere, instead

1071
01:29:39,279 --> 01:29:43,840
of being five miles thick, is about five millimeters thick.

1072
01:29:44,439 --> 01:29:46,920
So if you stood on the neutron star, the atmosphere

1073
01:29:46,920 --> 01:29:48,760
would be sloshing around between your doors.

1074
01:30:06,439 --> 01:30:10,880
Speaker 1: But even a neutron star's phenomenal gravity is surpassed when

1075
01:30:10,880 --> 01:30:20,600
a real super heavyweight star dies. When a star a

1076
01:30:20,760 --> 01:30:23,640
hundred times heavier than our sun switches.

1077
01:30:23,239 --> 01:30:27,119
Speaker 16: Off, it goes with a bang.

1078
01:30:32,680 --> 01:30:36,600
Speaker 1: While we see the outward explosion is a supernova, this

1079
01:30:36,840 --> 01:30:41,079
masks the inward implosion. The core is collapsing into the

1080
01:30:41,079 --> 01:30:42,439
most dangerous.

1081
01:30:41,960 --> 01:30:43,239
Speaker 10: Object in the universe.

1082
01:30:48,000 --> 01:30:51,520
Speaker 1: The density becomes so great in the center that gravity

1083
01:30:51,640 --> 01:30:55,560
sucks in time and space itself from the outside universe.

1084
01:31:00,880 --> 01:31:04,000
A darkness forms at the heart of the collapsing star.

1085
01:31:05,239 --> 01:31:06,680
A black hole is born.

1086
01:31:10,359 --> 01:31:13,119
Speaker 34: If you have a massive star. Once the massive star

1087
01:31:13,199 --> 01:31:17,479
has exhausted its nuclear fuel, which is keeping it hot

1088
01:31:17,520 --> 01:31:20,359
and keeping it puffed up. Gravity becomes so strong that

1089
01:31:20,399 --> 01:31:25,039
it just overwhelms all pressure the material can provide, and

1090
01:31:25,399 --> 01:31:29,520
the star goes imploding inward in a and it's gone,

1091
01:31:29,920 --> 01:31:30,960
forming a black hole.

1092
01:31:33,319 --> 01:31:37,000
Speaker 1: Everyone has heard of black holes, no one has seen

1093
01:31:37,039 --> 01:31:45,079
them or be near one. At the center of a

1094
01:31:45,119 --> 01:31:49,399
black hole is a point called the singularity. Everything that

1095
01:31:49,439 --> 01:31:54,960
has ever fallen into a black hole is destroyed, crushed

1096
01:31:55,000 --> 01:31:59,840
into a pinpoint of infinite density and infinite smallness, evens

1097
01:31:59,800 --> 01:32:02,840
space and time are squelched out of existence.

1098
01:32:08,399 --> 01:32:13,760
Speaker 34: The singularity is a place where gravity is essentially infinitely strong.

1099
01:32:14,399 --> 01:32:19,840
It's a place where Madder gets destroyed. It's a place

1100
01:32:19,880 --> 01:32:22,640
where space and time as we know them get destroyed.

1101
01:32:29,600 --> 01:32:32,960
Speaker 1: At some time in the future, a spaceship from Earth

1102
01:32:33,000 --> 01:32:35,479
will be sent into the jaws of the most elusive

1103
01:32:35,520 --> 01:32:40,199
object in the universe. A spacecraft traveling towards a black

1104
01:32:40,199 --> 01:32:44,479
hole wouldn't see the singularity hidden deep inside. It would

1105
01:32:44,479 --> 01:33:06,680
only see the blackness around it its target as a

1106
01:33:06,720 --> 01:33:11,199
gravitational pull that is so great not even light can escape.

1107
01:33:12,159 --> 01:33:15,439
Speaker 34: As the spaceship goes flying into the core of the

1108
01:33:15,479 --> 01:33:19,439
black hole. I begin to feel my self being pulled

1109
01:33:19,439 --> 01:33:26,520
from head to foot and squeezed from the sides. My

1110
01:33:26,640 --> 01:33:30,560
body gives way. I die, the atoms of which I

1111
01:33:30,680 --> 01:33:33,640
may give way, and all is destroyed.

1112
01:33:33,880 --> 01:33:48,640
Speaker 16: In the singularity, all that remains is a perfect sphere

1113
01:33:48,760 --> 01:33:53,840
of absolute darkness, a gravitational ghost of the star that died.

1114
01:33:57,560 --> 01:34:01,720
Speaker 1: The perils of a black hole are thankfully remote. Even

1115
01:34:01,760 --> 01:34:05,079
the nearest is over five thousand like years from Earth.

1116
01:34:06,359 --> 01:34:15,000
Our nemesis lies much closer to home. Like every star

1117
01:34:15,119 --> 01:34:20,439
in the galaxy, our Sun has a finite lifespan. One

1118
01:34:20,520 --> 01:34:23,920
day it will run out of fuel and scorch the planets.

1119
01:34:25,119 --> 01:34:28,399
It's a terrible fate that astronomers have known for decades.

1120
01:34:30,520 --> 01:34:34,039
Speaker 5: We expect that the Sun will swell up in about

1121
01:34:34,079 --> 01:34:37,600
five billion years, and it will become a red giant star.

1122
01:34:38,199 --> 01:34:40,159
That's the beginning of the end for the Sun.

1123
01:34:44,520 --> 01:34:49,439
Speaker 1: In five billion years, our local star will have exhausted

1124
01:34:49,479 --> 01:35:05,960
its fuel supply. Without fuel, the Sun will die in

1125
01:35:06,039 --> 01:35:09,119
its death throes. The star that gave birth to life

1126
01:35:09,680 --> 01:35:14,159
will swell and engulf the Earth and Moon. Nothing will survive.

1127
01:35:19,800 --> 01:35:22,319
Speaker 5: The amount of energy would get from the Sun would

1128
01:35:22,399 --> 01:35:25,159
increase tremendously. The Earth would heat.

1129
01:35:25,039 --> 01:35:26,319
Speaker 18: Up, oceans would boil.

1130
01:35:26,479 --> 01:35:29,640
Speaker 5: Eventually, the mountains would melt and evaporate. The Earth would

1131
01:35:29,680 --> 01:35:32,920
be incinerated by our own friendly star, the Sun.

1132
01:35:43,640 --> 01:35:46,800
Speaker 1: The heat from this red giant will be so intense

1133
01:35:47,359 --> 01:36:03,279
the Earth will be scorched beyond recognition. The Earth's crust

1134
01:36:03,319 --> 01:36:07,880
will melt, the surface will become an ocean of molten rock.

1135
01:36:11,199 --> 01:36:23,359
Nothing will survive the ultimate catastrophe.

1136
01:36:18,680 --> 01:36:20,520
Speaker 5: And that's the end of the story for the Sun.

1137
01:36:21,079 --> 01:36:24,560
It will cool off, and as time passes, the Sun

1138
01:36:24,640 --> 01:36:29,119
will become a dimmer and dimmer, cooler and cooler clinker

1139
01:36:29,199 --> 01:36:30,319
of a leftover star.

1140
01:36:36,760 --> 01:36:40,359
Speaker 1: The Earth, devoid of all life, will sit in the

1141
01:36:40,359 --> 01:36:53,000
cold emptness of space. As ours Sun's brilliance dies somewhere

1142
01:36:53,000 --> 01:36:56,600
in the galaxy in an endless cycle of life and death,

1143
01:36:57,199 --> 01:37:04,800
a new star will be born, maybe it will spawn

1144
01:37:04,920 --> 01:37:09,479
its own solar system, even a new planet like Earth

1145
01:37:10,000 --> 01:37:16,199
and a new place where life can flourish.

1146
01:37:17,119 --> 01:37:26,239
Speaker 6: Our planet is extraordinary. It provides everything life needs, trillions

1147
01:37:26,279 --> 01:37:31,319
of creatures, plants, and us.

1148
01:37:33,760 --> 01:37:36,199
Speaker 20: Where you look down at the Earth from space, and

1149
01:37:36,640 --> 01:37:39,680
everything that we know of that's life is down there

1150
01:37:39,800 --> 01:37:44,439
on that planet, that beautiful planet that you now are

1151
01:37:44,479 --> 01:37:49,439
going around every hour and a half, and that's almost overwhelming,

1152
01:37:49,600 --> 01:37:50,479
just the beauty.

1153
01:37:50,159 --> 01:37:50,640
Speaker 27: Of the Earth.

1154
01:37:53,039 --> 01:37:57,279
Speaker 6: It's unique in our solar system, but is it unique

1155
01:37:57,560 --> 01:37:58,399
in the universe.

1156
01:38:00,279 --> 01:38:03,520
Speaker 35: It's important for us to understand the conditions that led

1157
01:38:03,560 --> 01:38:05,479
to the formation of the Earth, because then we can

1158
01:38:05,479 --> 01:38:08,840
look for those conditions around other stars. And if we

1159
01:38:08,880 --> 01:38:11,920
find those conditions there, then that would suggest that other

1160
01:38:12,000 --> 01:38:13,880
Earths could be forming elsewhere in the universe.

1161
01:38:17,880 --> 01:38:21,079
Speaker 6: Could there be other planets like ours among the stars?

1162
01:38:24,920 --> 01:38:30,680
To find out, we must travel back in time and

1163
01:38:30,800 --> 01:38:42,560
discover how the Earth was made. Rewind the clot four

1164
01:38:42,640 --> 01:38:47,520
and a half billion years and this is what you see.

1165
01:38:49,119 --> 01:38:55,840
This speck of dust will become the Earth by combining

1166
01:38:55,920 --> 01:39:01,239
with countless others. They're all part of a giant cloud

1167
01:39:02,399 --> 01:39:07,840
called a stellar nursery. The first step of planetary formation

1168
01:39:08,159 --> 01:39:19,079
is about to start, an event that will transform the

1169
01:39:19,119 --> 01:39:26,520
cloud into thousands of infant solar systems, including our own.

1170
01:39:33,239 --> 01:39:37,800
The same process is happening today seven thousand like years

1171
01:39:37,840 --> 01:39:46,640
away in the Eagle Nebula, our own solar system formed

1172
01:39:46,880 --> 01:39:50,319
inside clouds of gas and dust like these.

1173
01:39:54,560 --> 01:39:57,439
Speaker 12: There are these three trunks of gas and they're nicknamed

1174
01:39:57,439 --> 01:40:01,000
the pillars of Creation. And they're truly of miles long.

1175
01:40:01,039 --> 01:40:02,319
These are huge structures.

1176
01:40:03,720 --> 01:40:07,800
Speaker 6: The clouds look dense, but they're actually very sparse.

1177
01:40:09,720 --> 01:40:12,920
Speaker 12: These gas clouds are incredibly tenuous. You'd have to compress

1178
01:40:13,079 --> 01:40:17,760
basically a mountain's volume worth of the stuff squeeze it

1179
01:40:17,800 --> 01:40:19,920
down just to make a little tiny rock like this.

1180
01:40:21,920 --> 01:40:25,800
Speaker 6: To compress the gas and dust into dense stars and

1181
01:40:25,960 --> 01:40:33,640
planets takes a supremely powerful event, one that can only

1182
01:40:33,760 --> 01:40:40,119
follow the death of a giant star. In two thousand

1183
01:40:40,119 --> 01:40:46,840
and seven, the Spitzer space telescope captured this image a

1184
01:40:46,920 --> 01:40:54,720
ball of hot gas behind the Eagle nebula, evidence that

1185
01:40:54,800 --> 01:40:59,439
a huge star has exploded and sent a vast wall

1186
01:40:59,520 --> 01:41:02,079
of gas racing toward the pillars.

1187
01:41:04,079 --> 01:41:07,319
Speaker 36: There's a wave of hot material approaching the Pillars of Creation,

1188
01:41:07,680 --> 01:41:10,079
and this may be a shockwave from a supernova a

1189
01:41:10,159 --> 01:41:10,760
dying star.

1190
01:41:15,800 --> 01:41:25,000
Speaker 6: Supernovas briefly outshine entire galaxies. Superheated plasma blasts into space

1191
01:41:25,640 --> 01:41:33,319
at seventy million miles per hour. A mighty shockwave speeds

1192
01:41:33,399 --> 01:41:43,800
toward the Pillars of Creation. When it hits, it will

1193
01:41:43,840 --> 01:41:53,399
demolish them. It will also create new worlds. Supernova shockwaves

1194
01:41:53,840 --> 01:41:59,159
smash into the pillars compressing the thin gas and dust

1195
01:41:59,399 --> 01:42:06,479
into dim clumps. Each is a new star, a new

1196
01:42:06,600 --> 01:42:09,319
solar system.

1197
01:42:09,520 --> 01:42:13,199
Speaker 37: Molecular cloud minding its own business gets blasted by a

1198
01:42:13,239 --> 01:42:18,159
supernova explosion, crushing the cloud down into stars and planets.

1199
01:42:20,199 --> 01:42:24,600
Speaker 6: Wind back four and a half billion years, and our

1200
01:42:24,720 --> 01:42:30,720
solar system starts the same way. A supernova crushes a

1201
01:42:30,760 --> 01:42:39,079
massive dusty cloud into a protoplanetary disk. A thin, nebulous

1202
01:42:39,079 --> 01:42:46,239
cloud becomes a dense whirlpool of gas and dust, a

1203
01:42:46,279 --> 01:42:53,039
solar system in the making. One star is destroyed, a

1204
01:42:53,119 --> 01:43:01,960
new star is born, our Sun and its planets. This

1205
01:43:02,119 --> 01:43:05,359
is the first link in the long and unlikely chain

1206
01:43:05,439 --> 01:43:12,720
of events that made our world. For Earth to even

1207
01:43:12,800 --> 01:43:17,119
be here, we had to beat astronomical odds.

1208
01:43:19,600 --> 01:43:22,479
Speaker 9: A host of different factors have to line up to

1209
01:43:22,520 --> 01:43:24,840
get a planet, just like the Earth. You have to

1210
01:43:24,920 --> 01:43:28,000
have the right distance, the right size, the right kind

1211
01:43:28,039 --> 01:43:28,399
of moon.

1212
01:43:31,279 --> 01:43:36,119
Speaker 6: On Earth, all the conditions are just right for life.

1213
01:43:36,560 --> 01:43:38,960
Speaker 15: To get a world like ours, you need a lot of.

1214
01:43:38,920 --> 01:43:43,680
Speaker 9: Ass Somehow, our solar system hit the jackpot, But the

1215
01:43:43,720 --> 01:43:46,479
big question is did it happen anywhere else?

1216
01:43:50,760 --> 01:43:55,680
Speaker 6: One of the universe's most violent events triggered the birth

1217
01:43:55,760 --> 01:44:03,319
of our planet a sparse cloud crushed into a dense

1218
01:44:03,640 --> 01:44:11,239
swirl of dust. Some of this dust will become planet Earth.

1219
01:44:13,000 --> 01:44:23,680
But how do tiny dust grains create entire worlds? A

1220
01:44:23,800 --> 01:44:28,880
supernova explosion triggers a chain of events that will eventually

1221
01:44:29,000 --> 01:44:38,479
create the Earth, the formation of our solar system. A

1222
01:44:38,560 --> 01:44:44,399
hot ball of gas grows in the center. This will

1223
01:44:44,399 --> 01:44:51,880
become our Sun. The dust that swirls around it will

1224
01:44:51,960 --> 01:44:58,960
form the planets. But first the grains must stick together.

1225
01:45:00,239 --> 01:45:03,800
Speaker 27: So we have this interesting conundrum. Right, So this disconsists

1226
01:45:03,840 --> 01:45:07,600
of gas and dust parties. They're about the size of

1227
01:45:07,760 --> 01:45:11,279
let's say particles and smoke, right, Let's say cigarette smoke.

1228
01:45:11,359 --> 01:45:11,520
Speaker 13: Right.

1229
01:45:11,560 --> 01:45:14,319
Speaker 27: So these are small things, and somehow we have to

1230
01:45:14,399 --> 01:45:18,279
get from those little grains to what we see on

1231
01:45:18,319 --> 01:45:18,720
the Earth.

1232
01:45:20,840 --> 01:45:26,359
Speaker 6: Gravity is a powerful attractive force. It shapes galaxies and

1233
01:45:26,560 --> 01:45:32,399
solar systems. But specks of dust are far too small

1234
01:45:32,520 --> 01:45:37,720
to pull on each other. Somehow they clump together to

1235
01:45:37,880 --> 01:45:44,000
form planets. So if gravity doesn't bind them, what does.

1236
01:45:47,640 --> 01:45:54,079
In Germany, scientists are on the case. They can simulate

1237
01:45:54,439 --> 01:45:59,199
how dust behaves in space inside a huge tower.

1238
01:46:01,640 --> 01:46:05,520
Speaker 38: Here we do free fall experiments. So the whole experimental setup,

1239
01:46:05,640 --> 01:46:09,199
including our dust aggregas are in perfect freefall. It is

1240
01:46:09,319 --> 01:46:12,800
simulation of space, but a very good one. Indeed, I

1241
01:46:12,840 --> 01:46:14,880
think this is the closest you can get a space

1242
01:46:15,079 --> 01:46:15,720
on Earth.

1243
01:46:17,359 --> 01:46:22,680
Speaker 6: Researchers place dust in a container and load it into

1244
01:46:22,720 --> 01:46:28,079
a launch capsule at the base of the tower. They

1245
01:46:28,159 --> 01:46:34,359
lower it into a super powerful catapult. This launches the

1246
01:46:34,520 --> 01:46:39,000
half ton capsule from zero to over one hundred miles

1247
01:46:39,000 --> 01:46:46,600
per hour in a quarter of the second. Four hundred

1248
01:46:46,600 --> 01:46:49,680
feet up, the capsule reaches the top of the tower,

1249
01:46:50,359 --> 01:46:57,600
then plunges back down. A drum of polystyrene balls thirty

1250
01:46:57,680 --> 01:47:05,119
feet deep breaks its fall. All this gives just ten

1251
01:47:05,279 --> 01:47:10,359
seconds of zero gravity, just enough time they hope for

1252
01:47:10,479 --> 01:47:18,600
the dust to stick three two, one and go. Moments

1253
01:47:18,640 --> 01:47:26,239
after the capsule launches, the dust inside becomes weightless. The

1254
01:47:26,359 --> 01:47:39,359
brains clump together, just like the early Solar system. These

1255
01:47:39,520 --> 01:47:44,439
images reveal how dust particles came together four and a

1256
01:47:44,479 --> 01:47:48,319
half billion years ago to form the Earth.

1257
01:47:49,439 --> 01:47:52,199
Speaker 38: The force that binds the aggregates together is not gravity.

1258
01:47:52,239 --> 01:47:56,800
They are too small for gravity to be efficient. We

1259
01:47:57,279 --> 01:48:01,159
think the force that binds the aggregates together is electrostatic force.

1260
01:48:03,439 --> 01:48:06,399
Speaker 37: It's the same reason that when you pull your clothes

1261
01:48:06,720 --> 01:48:09,760
out of the dryer. You know how the clothes sometimes

1262
01:48:09,800 --> 01:48:13,000
stick to you. That's the same effect that allows one

1263
01:48:13,079 --> 01:48:14,880
dust particle to stick to another.

1264
01:48:16,000 --> 01:48:19,399
Speaker 6: Dust particles joined to form balls of fluff.

1265
01:48:20,600 --> 01:48:23,000
Speaker 27: The little static charges that they have can make them

1266
01:48:23,039 --> 01:48:25,880
stick when they hit, and you get something sort of

1267
01:48:25,920 --> 01:48:27,479
like the dust bunnies that I have a lot of

1268
01:48:27,560 --> 01:48:28,359
underneath my bad.

1269
01:48:30,520 --> 01:48:37,199
Speaker 6: These cosmic dust bunnies are planets in the making. They

1270
01:48:37,239 --> 01:48:42,920
start out smaller than a pin head, then grow. The

1271
01:48:43,039 --> 01:48:48,399
dust is now in clumps, but it's still just balls

1272
01:48:48,479 --> 01:48:55,600
of dust. Turning dust balls into rocks takes a whole

1273
01:48:55,680 --> 01:49:07,680
new process. A comic electric storm space clouds build up charge,

1274
01:49:08,159 --> 01:49:14,479
just like clouds here on Earth, generating huge bolts of lightning.

1275
01:49:17,960 --> 01:49:21,479
Speaker 38: Balls of dust can turn into solid rocks by an

1276
01:49:21,600 --> 01:49:23,199
energetic event like lightning.

1277
01:49:25,000 --> 01:49:29,560
Speaker 6: The electric bolts smash through the dust balls and heat

1278
01:49:29,600 --> 01:49:37,399
them to three thousand degrees fahrenheit. In minutes, they cool

1279
01:49:38,319 --> 01:49:45,720
and fuse into solid rock. Meteorites today still carry these

1280
01:49:45,880 --> 01:49:52,600
ancient rock balls inside them. These tiny globules were once

1281
01:49:52,680 --> 01:49:59,279
the building blocks of planets. To form the Earth, these

1282
01:49:59,399 --> 01:50:04,079
tiny must collide, stick and grow.

1283
01:50:05,399 --> 01:50:08,079
Speaker 9: Rocks begin to build up by accidental collisions, which can

1284
01:50:08,119 --> 01:50:08,960
take a long time.

1285
01:50:09,359 --> 01:50:13,399
Speaker 37: Eventually, the proto planets, as we call them the baby planets,

1286
01:50:13,640 --> 01:50:17,039
get the size of asteroids kilometers across.

1287
01:50:18,479 --> 01:50:21,000
Speaker 6: The baby Earth is now the size of a few

1288
01:50:21,079 --> 01:50:26,079
city blocks, big enough for a new force to take

1289
01:50:26,159 --> 01:50:28,399
charge gravity.

1290
01:50:29,600 --> 01:50:34,600
Speaker 37: At that point, a single asteroid will gravitationally attract a

1291
01:50:34,760 --> 01:50:38,800
neighboring asteroid, and so those two asteroids that would have

1292
01:50:38,960 --> 01:50:43,039
passed in the night are gravitationally attracted and they hit

1293
01:50:43,119 --> 01:50:43,479
each other.

1294
01:50:45,920 --> 01:50:49,399
Speaker 12: Once gravity starts to rear its head, things really speed

1295
01:50:49,479 --> 01:50:52,600
up because instead of just randomly plowing through material and

1296
01:50:52,640 --> 01:50:56,680
getting bigger that way, now it's starting to draw material in.

1297
01:50:58,720 --> 01:51:05,159
Speaker 6: Gravity pulls rocks together, then holds them there to produce

1298
01:51:05,279 --> 01:51:07,680
bigger and bigger piles of rubble.

1299
01:51:10,399 --> 01:51:13,279
Speaker 12: So this formation process, which was taking a long time

1300
01:51:13,399 --> 01:51:16,000
to get to the size where gravity kicks in, suddenly

1301
01:51:16,039 --> 01:51:19,640
gets kicked into overdrive and the planet grows very rapidly.

1302
01:51:21,680 --> 01:51:28,239
Speaker 6: But planets are more than just overgrown rock piles. These

1303
01:51:28,359 --> 01:51:33,760
rocks are lumpy and inert. How did the Earth become

1304
01:51:33,920 --> 01:51:42,520
round and full of life? The early Solar System is

1305
01:51:42,560 --> 01:51:49,520
a construction site for planets. Dust sticks together to form rocks.

1306
01:51:51,439 --> 01:51:59,359
Rocks join to form asteroids. But most asteroids look nothing

1307
01:51:59,560 --> 01:52:02,039
like Earth, and when.

1308
01:52:01,880 --> 01:52:03,520
Speaker 37: You look at a toast up of an asteroid, it

1309
01:52:03,520 --> 01:52:07,239
looks like some kind of distorted peanut, like a potato

1310
01:52:07,359 --> 01:52:10,760
that's been sort of bassed. You can see giant craters

1311
01:52:10,800 --> 01:52:12,319
and oblong shapes.

1312
01:52:14,239 --> 01:52:19,279
Speaker 6: The young Earth is one of billions of misshapen space boulders.

1313
01:52:21,319 --> 01:52:27,199
To become a planet, it must first become round. That

1314
01:52:27,319 --> 01:52:33,399
process only starts when it's several hundred miles across, when

1315
01:52:33,439 --> 01:52:41,279
its own internal gravity begins to change its shape.

1316
01:52:42,359 --> 01:52:46,359
Speaker 36: Once you get enough material, enough mass, the gravitational force

1317
01:52:46,399 --> 01:52:50,279
becomes stronger. Any giant mountain will be crushed down by

1318
01:52:50,279 --> 01:52:52,079
the force of gravity.

1319
01:52:52,720 --> 01:52:56,520
Speaker 27: The gravity is so strong that can actually break rocks,

1320
01:52:56,840 --> 01:52:59,479
and the rocks itself can lackt like a fluid, making

1321
01:52:59,520 --> 01:53:00,000
an object.

1322
01:53:03,279 --> 01:53:10,079
Speaker 6: Huge outcrops of rock crumble and fall. The immense self

1323
01:53:10,119 --> 01:53:14,000
gravity of the early Earth crushes it into the most

1324
01:53:14,159 --> 01:53:26,199
efficient shape, a vast round ball of rock, a lopsided

1325
01:53:26,359 --> 01:53:37,680
pile of rubble transformed into a miniature world. The Earth

1326
01:53:38,079 --> 01:53:41,319
has a new shape, but it's still just a ball

1327
01:53:41,359 --> 01:53:49,640
of rock. Its structure will also soon change. Cosmic rocks

1328
01:53:49,680 --> 01:53:56,600
and boulders still rain down from space. Each collision heats

1329
01:53:56,680 --> 01:53:57,239
the ground.

1330
01:53:58,239 --> 01:54:01,000
Speaker 12: There's a huge amount of energy store in an object.

1331
01:54:01,039 --> 01:54:03,640
It's moving rapidly, and when that hits the Earth, all

1332
01:54:03,680 --> 01:54:06,039
that energy is dumped into the material, and that heats

1333
01:54:06,039 --> 01:54:08,840
it up and melts it. And the Earth became molten

1334
01:54:08,880 --> 01:54:10,680
and stayed that way for a long time.

1335
01:54:12,000 --> 01:54:16,119
Speaker 6: The young planet is no longer solid rock. It's a

1336
01:54:16,199 --> 01:54:24,439
seething molten mass, just like this blast furnace at the

1337
01:54:24,479 --> 01:54:28,560
Severstall plant in Detroit.

1338
01:54:31,239 --> 01:54:34,399
Speaker 39: Believe it or not, this process behind me makes life

1339
01:54:34,560 --> 01:54:35,960
on Earth possible.

1340
01:54:38,640 --> 01:54:43,199
Speaker 6: They feed in ground up iron ore, a mixture of

1341
01:54:43,359 --> 01:54:54,840
rock and metal, just like the early Earth. Put iron

1342
01:54:54,880 --> 01:55:00,920
ore in a furnace and the heat melts everything.

1343
01:55:03,399 --> 01:55:07,119
Speaker 39: This multon iron is at two thousand and seven hundred

1344
01:55:07,119 --> 01:55:10,880
degrees fahrenheit. That's about the temperature of the surface of

1345
01:55:10,920 --> 01:55:14,840
the Earth four and a half billion years ago. Imagine

1346
01:55:14,920 --> 01:55:19,920
an entire planet molten in the distance. You will see

1347
01:55:20,000 --> 01:55:22,880
thundering volcanoes spewing out lava.

1348
01:55:23,399 --> 01:55:24,840
Speaker 15: It would be a scene.

1349
01:55:24,640 --> 01:55:31,000
Speaker 39: Right out of Dante's Inferno.

1350
01:55:33,880 --> 01:55:39,239
Speaker 6: Iron is heavier than rock. Now molten they separate.

1351
01:55:42,279 --> 01:55:43,600
Speaker 15: This is amazing.

1352
01:55:43,640 --> 01:55:46,960
Speaker 39: We're witnessing a process which created the very crust of

1353
01:55:47,000 --> 01:55:49,680
the Earth billions of years ago, the crust that we

1354
01:55:49,760 --> 01:55:51,600
walk on every day.

1355
01:55:53,720 --> 01:55:58,079
Speaker 6: Molten rock rises to the surface and cools to form

1356
01:55:58,159 --> 01:56:06,279
the crust. Molten iron sinks underneath inside the Earth. It

1357
01:56:06,399 --> 01:56:11,840
sank all the way to the planet's core. The rocky

1358
01:56:11,920 --> 01:56:17,640
surface is where we live, but without Earth's molten iron core,

1359
01:56:18,840 --> 01:56:20,199
none of us could survive.

1360
01:56:22,399 --> 01:56:27,680
Speaker 39: This process separated the iron from the rocky minerals. As

1361
01:56:27,680 --> 01:56:31,000
the iron descended to the center of the Earth, it

1362
01:56:31,079 --> 01:56:36,039
eventually created a magnetic field, and that's why we're here today.

1363
01:56:37,119 --> 01:56:43,159
Speaker 6: The molten iron swirls inside the Earth's core and generates

1364
01:56:43,199 --> 01:56:50,239
a powerful magnetic field around the planet, a cosmic shield

1365
01:56:50,960 --> 01:56:58,039
against deadly radiation from space. But the young Earth is

1366
01:56:58,159 --> 01:57:08,039
still small, far smaller than the Moon. Today, this newly

1367
01:57:08,199 --> 01:57:16,000
formed world must grow. It must also avoid being blown

1368
01:57:16,079 --> 01:57:24,760
to pieces. Thousands of protoplanets are hurdling around the Solar System,

1369
01:57:24,840 --> 01:57:34,520
and some are heading straight for Earth. It's one hundred

1370
01:57:34,640 --> 01:57:39,920
thousand years since our Solar System formed. The young Earth

1371
01:57:40,399 --> 01:57:45,560
already looks like a planet. It's round, it has an

1372
01:57:45,600 --> 01:57:51,880
iron core and a rocky surface. Yet our baby planet

1373
01:57:52,239 --> 01:57:57,279
is just a few hundred miles across It has a

1374
01:57:57,359 --> 01:58:03,600
long way to go. It must grow four thousand times

1375
01:58:03,720 --> 01:58:12,279
more massive, and it has competition. Thousands of other protoplanets

1376
01:58:12,600 --> 01:58:18,359
shoot through the Solar System, often colliding at over twenty

1377
01:58:18,520 --> 01:58:25,199
thousand miles per hour. You can find proof of this

1378
01:58:25,479 --> 01:58:33,600
ancient destructive era in modern day Arizona. Not meteor Crater itself,

1379
01:58:34,399 --> 01:58:39,600
that's just fifty thousand years old, but the asteroid that

1380
01:58:39,800 --> 01:58:44,960
gouged it out, that was four and a half billion

1381
01:58:45,079 --> 01:58:52,800
years old. Mark Sykes and Marvin Hilgore think the asteroid

1382
01:58:52,920 --> 01:58:59,640
came from a violent event in the early Solar System.

1383
01:59:00,079 --> 01:59:05,520
Asteroid flew through space for billions of years, then it

1384
01:59:05,640 --> 01:59:11,760
hit Earth. They aimed to find a fragment of the asteroid,

1385
01:59:13,680 --> 01:59:17,920
a remnant from the period of planetary formation.

1386
01:59:20,239 --> 01:59:24,039
Speaker 40: About six miles from here's meteor crater, and that was

1387
01:59:24,560 --> 01:59:29,119
an impact fifty thousand years or so ago, and it

1388
01:59:29,479 --> 01:59:31,000
spewed a bunch of pieces out.

1389
01:59:31,520 --> 01:59:37,039
Speaker 6: They're convinced the original asteroid was rich in iron. So

1390
01:59:37,119 --> 01:59:41,239
they've come prepared with some impressive metal detectors.

1391
01:59:41,760 --> 01:59:54,560
Speaker 26: Does it work, Oh yeah, But.

1392
01:59:54,720 --> 02:00:00,800
Speaker 6: Even with a quad drawn metal detector, meteorites are hard

1393
02:00:00,880 --> 02:00:01,960
to find.

1394
02:00:04,399 --> 02:00:06,720
Speaker 26: Yeah. Are you pretty convinced there's nothing there.

1395
02:00:07,159 --> 02:00:10,760
Speaker 40: I yeah, I don't really, I'm not detecting anything.

1396
02:00:14,520 --> 02:00:17,880
Speaker 6: They find metal, but no meteorites.

1397
02:00:19,159 --> 02:00:23,359
Speaker 40: My great discovery of the afternoon has been this bolt.

1398
02:00:25,439 --> 02:00:26,600
Speaker 26: And this piece of wire.

1399
02:00:33,640 --> 02:00:40,079
Speaker 6: It takes hours of searching and many false alarms. Then

1400
02:00:40,760 --> 02:00:44,520
with the light fading, the detector sounds again.

1401
02:00:50,479 --> 02:00:51,720
Speaker 20: How about that success.

1402
02:00:51,760 --> 02:00:57,760
Speaker 6: At least this meteorite is over ninety percent iron and nickel.

1403
02:00:59,399 --> 02:01:03,079
It could only form right in the core of a

1404
02:01:03,119 --> 02:01:08,840
proto planet. The protoplanet that came from must have smashed

1405
02:01:08,880 --> 02:01:11,479
a part in a brutal collision.

1406
02:01:12,439 --> 02:01:15,439
Speaker 40: Well, in the early Solar System it was a pretty

1407
02:01:15,479 --> 02:01:21,079
violent place, and these protoplanetary embryos would smash into each other.

1408
02:01:21,239 --> 02:01:25,199
They would shatter each other, exposing the interior cores like this.

1409
02:01:25,920 --> 02:01:27,279
It's a very tumultuous time.

1410
02:01:29,960 --> 02:01:35,680
Speaker 6: Entire worlds reduced to chunks of rock and metal and

1411
02:01:35,800 --> 02:01:43,359
scattered into outer space. In the early Solar System, these

1412
02:01:43,800 --> 02:01:50,039
vast collisions are common. The young Earth is in danger.

1413
02:01:52,640 --> 02:02:00,520
The period's name is the Taidannomackian, literally the wool of

1414
02:02:00,560 --> 02:02:08,279
the Titans. All rocky planets, the Earth included, go through

1415
02:02:08,439 --> 02:02:19,479
this destructive phase. Sometimes they shatter completely. Sometimes one consumes

1416
02:02:19,560 --> 02:02:19,920
the other.

1417
02:02:20,920 --> 02:02:23,239
Speaker 27: All the big guys are sort of competing with one

1418
02:02:23,239 --> 02:02:27,680
another in a very violent way, actually, to see who

1419
02:02:27,680 --> 02:02:30,079
comes out on top by eating all their neighbors.

1420
02:02:32,079 --> 02:02:38,760
Speaker 6: The battle lasts over thirty million years. Finally, thousands of

1421
02:02:38,880 --> 02:02:51,239
protal planets have combined into a few full size planets Mercury, Venus, Earth, Mars,

1422
02:02:52,439 --> 02:03:01,239
and a fifth planet, THEA. It's racing toward Earth, our

1423
02:03:01,359 --> 02:03:09,199
planet's last giant impact. THEA is the size of Mars,

1424
02:03:10,520 --> 02:03:12,640
big enough to destroy the Earth.

1425
02:03:15,199 --> 02:03:17,359
Speaker 12: If that thing it hit us straight on, it could

1426
02:03:17,359 --> 02:03:20,000
have literally blown the Earth abits, and then we wouldn't

1427
02:03:20,039 --> 02:03:21,239
even have a planet today.

1428
02:03:21,680 --> 02:03:24,199
Speaker 41: If this Mars like object had a direct hit with

1429
02:03:24,279 --> 02:03:27,520
the Earth, perhaps there would have been another asteroid belt

1430
02:03:27,680 --> 02:03:29,359
where the Earth is today.

1431
02:03:30,600 --> 02:03:35,840
Speaker 6: But Earth is in luck. Instead of a head on crash,

1432
02:03:36,880 --> 02:03:47,159
THEA strikes a glancing blow. It's the most violent event

1433
02:03:47,479 --> 02:03:54,920
the Earth has ever known. The impact turns the Earth

1434
02:03:55,119 --> 02:04:02,640
back to a molten world of magma ocean six hundred

1435
02:04:02,760 --> 02:04:16,800
miles deep. The Earth barely survives, and the encounter changes

1436
02:04:16,960 --> 02:04:27,880
our world forever. Material blasts out into space, enough rock

1437
02:04:28,319 --> 02:04:33,399
to build a mountain as wide as America and ten

1438
02:04:33,600 --> 02:04:35,119
thousand miles high.

1439
02:04:36,439 --> 02:04:39,399
Speaker 12: It would have been so much energy, so much catastrophe.

1440
02:04:39,760 --> 02:04:42,319
Huge amounts of material blasted off and went into orbit

1441
02:04:42,359 --> 02:04:42,960
around the Earth.

1442
02:04:43,920 --> 02:04:49,479
Speaker 6: The debris forms a huge ring around the Earth. This

1443
02:04:50,000 --> 02:04:57,199
gathers together to form two rocky bodies, both orbiting the Earth.

1444
02:04:59,199 --> 02:05:01,439
Speaker 36: Something the size of Mars hit the Earth about four

1445
02:05:01,479 --> 02:05:04,479
billion years ago. Lots of material would have been thrown off.

1446
02:05:04,920 --> 02:05:07,279
We now think that it may form not only one moon,

1447
02:05:07,640 --> 02:05:08,920
but two.

1448
02:05:10,640 --> 02:05:18,479
Speaker 6: For millions of years, two moons dominate the Earth's sky.

1449
02:05:19,359 --> 02:05:35,000
Eventually they drift together and collide. Two moons merge into one,

1450
02:05:37,079 --> 02:05:41,640
the massive moon we see today.

1451
02:05:41,840 --> 02:05:43,720
Speaker 36: There's no other planet that we know of that has

1452
02:05:43,760 --> 02:05:46,439
a moon as large as ours in comparison to the

1453
02:05:46,520 --> 02:05:49,159
size of the planet. We're almost a binary planet, two

1454
02:05:49,199 --> 02:05:50,560
worlds going around each other.

1455
02:05:52,680 --> 02:05:57,159
Speaker 6: Without this large moon, we might not even be here.

1456
02:06:00,119 --> 02:06:04,119
Speaker 37: Is a key role in the survival of life here

1457
02:06:04,159 --> 02:06:06,640
on the Earth, and the reason is that the Moon,

1458
02:06:06,760 --> 02:06:09,359
in its orbit stabilizes the Earth.

1459
02:06:11,239 --> 02:06:15,000
Speaker 6: The Moon keeps the Earth spinning at the same angle

1460
02:06:16,520 --> 02:06:18,399
that steadies our climate.

1461
02:06:19,840 --> 02:06:22,199
Speaker 9: The fact that the Earth's axis stays in the same

1462
02:06:22,239 --> 02:06:25,079
direction as it goes around the Sun produces the seasons,

1463
02:06:25,600 --> 02:06:29,239
but regular seasons, things that life can depend upon as

1464
02:06:29,279 --> 02:06:29,880
it evolves.

1465
02:06:31,159 --> 02:06:36,159
Speaker 6: Earth is neither too hot nor too cold for life.

1466
02:06:37,359 --> 02:06:42,119
Thanks to our distance from the Sun and our massive Moon,

1467
02:06:47,920 --> 02:06:52,279
the Earth is not covered in ice or steam, but

1468
02:06:52,399 --> 02:06:59,880
in liquid water. Yet that water must come from Sun.

1469
02:07:00,000 --> 02:07:09,479
Some the newly formed Earth is dry. To get water,

1470
02:07:10,039 --> 02:07:19,560
our planet must once again face disaster. And it's half

1471
02:07:19,600 --> 02:07:25,640
a billion years since the Sun first ignited. Four billion

1472
02:07:25,720 --> 02:07:30,359
years from now, the first humans will set foot on Earth.

1473
02:07:33,199 --> 02:07:41,359
The Moon is just formed, and the Earth is a desert.

1474
02:07:43,800 --> 02:07:46,159
Speaker 36: One of the more amazing ideas in astronomy is that

1475
02:07:46,239 --> 02:07:48,880
the Earth started out hot and dry. There was no

1476
02:07:49,000 --> 02:07:52,119
water here Originally, As.

1477
02:07:51,920 --> 02:07:58,159
Speaker 6: The planets formed, the Sun's intense radiation vaporized the water.

1478
02:07:58,399 --> 02:08:03,800
In the inner Solar System, farther from the Sun, temperatures

1479
02:08:03,840 --> 02:08:08,800
were cooler, so in the outer Solar system, ice and

1480
02:08:08,960 --> 02:08:17,520
water collected on comets and asteroids, while closer to the Sun,

1481
02:08:18,119 --> 02:08:20,720
the young Earth was dry.

1482
02:08:21,840 --> 02:08:23,319
Speaker 26: So things changed.

1483
02:08:23,399 --> 02:08:24,119
Speaker 12: What happened?

1484
02:08:24,319 --> 02:08:27,720
Speaker 36: How is it that now we have this wonderful water cycle. Well,

1485
02:08:27,760 --> 02:08:29,880
the water probably came from somewhere else.

1486
02:08:31,439 --> 02:08:33,279
Speaker 12: If you want to have a solar system that has

1487
02:08:33,319 --> 02:08:35,159
a lot of water in it, you have to bring

1488
02:08:35,199 --> 02:08:38,520
it from the outer parts down into the inner parts,

1489
02:08:38,520 --> 02:08:41,399
and you can do that through comets and asteroids.

1490
02:08:43,640 --> 02:08:50,159
Speaker 6: Comets and icy asteroids contain huge reserves of water, but

1491
02:08:50,239 --> 02:08:54,479
there are hundreds of millions of miles from the young Earth.

1492
02:08:55,560 --> 02:09:02,920
Then something changes, an event that tosses the asteroids and

1493
02:09:03,000 --> 02:09:13,479
comets right across the Solar System. Jupiter, Saturn, Neptune, Uranus

1494
02:09:14,319 --> 02:09:19,880
take a cosmic roller coaster ride.

1495
02:09:20,439 --> 02:09:23,159
Speaker 27: So this isn't an event that happened when the Solar

1496
02:09:23,199 --> 02:09:25,199
System is young, thinking of it as more of its

1497
02:09:25,239 --> 02:09:29,079
teenage or breakout years, where it just started the party.

1498
02:09:29,119 --> 02:09:33,960
Speaker 6: For a while, the young planets have not yet settled

1499
02:09:34,119 --> 02:09:41,199
into stable orbits. As their orbits shift, Jupiter and Saturn

1500
02:09:41,640 --> 02:09:47,960
fall into an intricate dance. Every time Saturn orbits the

1501
02:09:48,039 --> 02:09:54,479
Sun once, Jupiter orbits twice, so they always line up

1502
02:09:54,520 --> 02:09:59,359
at the same spot each time gravity tugs them in

1503
02:09:59,439 --> 02:10:05,239
the same direction. First they destabilize each other, and then

1504
02:10:05,319 --> 02:10:08,880
the entire Solar System, the.

1505
02:10:08,840 --> 02:10:11,800
Speaker 27: Whole thing just goes KLUEI. The analogy I like to

1506
02:10:11,880 --> 02:10:14,720
use is when a bowling ball hits pins, just goes

1507
02:10:14,800 --> 02:10:17,239
bam all over the place. That's what this would have

1508
02:10:17,239 --> 02:10:17,600
looked like.

1509
02:10:18,800 --> 02:10:27,840
Speaker 6: Planetary pandemonium. Neptune and Uranus switched places. Saturn races outwards.

1510
02:10:29,159 --> 02:10:34,279
The giant planets scatter billions of asteroids and comets onto

1511
02:10:34,439 --> 02:10:38,960
new paths. Many head for Earth.

1512
02:10:40,960 --> 02:10:43,359
Speaker 27: These asteroids and comets would have been scattered all over

1513
02:10:43,399 --> 02:10:46,119
the place right, some of them hitting the Earth and Moon.

1514
02:10:47,840 --> 02:10:50,760
Speaker 6: Cosmic missiles bombard the Earth.

1515
02:10:53,399 --> 02:10:56,119
Speaker 27: We believe that every square inch of the Earth got

1516
02:10:56,199 --> 02:11:00,239
hit by a cometer an asteroid during this period. Not

1517
02:11:00,319 --> 02:11:01,680
have been a fun time to be here.

1518
02:11:03,760 --> 02:11:11,640
Speaker 6: The bombardment less hundreds of millions of years, until finally

1519
02:11:12,760 --> 02:11:17,239
the gas planets settle into the stable orbits we see today,

1520
02:11:19,319 --> 02:11:30,399
restoring order. But Earth itself has fundamentally changed. Those comets

1521
02:11:30,439 --> 02:11:35,439
and asteroids were not just made of rock, but of

1522
02:11:35,479 --> 02:11:37,960
ice frozen water.

1523
02:11:40,640 --> 02:11:43,119
Speaker 41: Commets we know are made out of ice. They're dirty,

1524
02:11:43,159 --> 02:11:46,720
snowballs are out of space, and even asteroids can bring

1525
02:11:46,920 --> 02:11:48,479
water and ice to the Earth.

1526
02:11:50,359 --> 02:11:55,560
Speaker 6: Our oceans are full thanks to the cosmic hailstorm.

1527
02:11:56,960 --> 02:11:59,960
Speaker 41: So next time you're drinking a glass of water, realize

1528
02:12:00,039 --> 02:12:03,960
said you're probably drinking comet and asteroid juice.

1529
02:12:05,439 --> 02:12:09,760
Speaker 6: The arrival of water is the final step to create

1530
02:12:09,880 --> 02:12:18,239
a habitable planet. A sequence of catastrophes has created a

1531
02:12:18,279 --> 02:12:24,760
world that's perfect for life. But has it happened elsewhere

1532
02:12:25,079 --> 02:12:38,239
among the stars? Or are we alone? How did we

1533
02:12:38,319 --> 02:12:44,359
get here? Planet Earth only exists because of a chain

1534
02:12:44,439 --> 02:12:52,159
of extraordinary events, a lucky throw of cosmic dice.

1535
02:12:54,359 --> 02:12:55,479
Speaker 15: Five billion years ago.

1536
02:12:55,680 --> 02:12:58,199
Speaker 9: The odds would have seemed extremely slim that a planet

1537
02:12:58,279 --> 02:13:01,039
like Earth would form in a rather unremarkable arm.

1538
02:13:00,960 --> 02:13:02,159
Speaker 15: In the Milky Way galaxy.

1539
02:13:02,920 --> 02:13:05,880
Speaker 9: It's like trying to throw two sixes, but with dice

1540
02:13:05,920 --> 02:13:11,319
that have thousands of size.

1541
02:13:12,399 --> 02:13:15,960
Speaker 6: We know it happened once. Else we wouldn't be here,

1542
02:13:17,119 --> 02:13:23,079
But what are the odds it happened elsewhere that other

1543
02:13:23,199 --> 02:13:29,880
planets have life? Life like ours needs a planet with

1544
02:13:30,000 --> 02:13:36,520
the right temperature and size, a stabilizing moon, a protective

1545
02:13:36,640 --> 02:13:42,720
magnetic field, and just the right amount of water. The

1546
02:13:42,760 --> 02:13:54,960
conditions must be perfect, Yet amazingly, there may be countless

1547
02:13:55,119 --> 02:14:01,960
Earth like planets out there waiting to be found. Thanks

1548
02:14:01,960 --> 02:14:07,239
to the sheer scale of the universe, we may find

1549
02:14:07,279 --> 02:14:14,760
one any day now with the Kepler Space Telescope. Jeff

1550
02:14:14,800 --> 02:14:17,680
Marcy is mission co investigator.

1551
02:14:18,760 --> 02:14:21,600
Speaker 37: It has only one goal, and that's to discover Earth

1552
02:14:21,680 --> 02:14:25,159
sized planets around other stars that you see in the

1553
02:14:25,239 --> 02:14:25,720
night sky.

1554
02:14:27,399 --> 02:14:33,920
Speaker 6: Earth sized planets are hard to spot. Before Kepler, astronomers

1555
02:14:33,960 --> 02:14:40,039
took twenty years to discover around five hundred planets, most

1556
02:14:40,279 --> 02:14:46,439
were gas giants hundreds of times bigger than Earth. Since Kepler,

1557
02:14:47,079 --> 02:14:48,720
that number has exploded.

1558
02:14:50,520 --> 02:14:56,960
Speaker 37: Kepler has already discovered a couple thousand planet candidates. Many

1559
02:14:57,000 --> 02:15:01,000
of them are members of multiplanet systems two, three, four, five,

1560
02:15:01,079 --> 02:15:05,000
and even six planets all orbiting the same star. So

1561
02:15:05,119 --> 02:15:09,680
we're finding an absolute avalanche of planets out there among

1562
02:15:09,720 --> 02:15:10,239
the stars.

1563
02:15:12,279 --> 02:15:16,159
Speaker 6: Keppelar is found one planet only twice the size of

1564
02:15:16,279 --> 02:15:22,600
Earth and the right temperature for life. We don't know

1565
02:15:22,720 --> 02:15:27,880
yet if this planet has other Earth like attributes like

1566
02:15:28,239 --> 02:15:33,640
liquid water, but even if it doesn't, there are many

1567
02:15:33,720 --> 02:15:40,079
more planets out there. Keppelar is found only a tiny

1568
02:15:40,239 --> 02:15:44,960
fraction of them, because it only looks at a small

1569
02:15:45,159 --> 02:15:46,319
part of the sky.

1570
02:15:48,000 --> 02:15:49,960
Speaker 12: It's not even looking at the whole sky. It's looking

1571
02:15:50,000 --> 02:15:53,079
at a very tiny slice of stars in the galaxy.

1572
02:15:53,439 --> 02:15:55,119
And in fact, if you were to look up, you

1573
02:15:55,159 --> 02:15:56,920
could cover it with just your thumb.

1574
02:15:58,279 --> 02:16:02,359
Speaker 6: In the hole of our galaxy there are two hundred

1575
02:16:02,520 --> 02:16:06,960
billion stars. Many will have planets.

1576
02:16:08,119 --> 02:16:11,800
Speaker 37: Based on our knowledge from Kepler and other searches, something

1577
02:16:11,920 --> 02:16:16,039
like half of those stars, perhaps even more harbor planets.

1578
02:16:17,119 --> 02:16:21,880
Speaker 6: That means at least one hundred billion planets have formed

1579
02:16:22,439 --> 02:16:27,680
in the Milky Way. Earth Like worlds may be rare,

1580
02:16:28,920 --> 02:16:33,040
but it seems a safe bet they're out there somewhere.

1581
02:16:34,000 --> 02:16:36,040
Speaker 9: So the odds of getting an Earth like planet are

1582
02:16:36,079 --> 02:16:40,280
extremely small, much smaller than getting a double six at crafts.

1583
02:16:41,680 --> 02:16:44,639
But if you have a lot of dice, you're guaranteed

1584
02:16:44,639 --> 02:16:48,200
to get sixes, and if you.

1585
02:16:48,319 --> 02:16:53,399
Speaker 6: Have a lot of planets, you're guaranteed to get earths.

1586
02:16:56,239 --> 02:17:00,440
There are so many planets in our galaxy. Even if

1587
02:17:00,440 --> 02:17:04,360
the chances are one in a million, there should be

1588
02:17:04,559 --> 02:17:07,479
thousands of Earth like worlds.

1589
02:17:10,120 --> 02:17:14,200
Speaker 37: Our universe at large has hundreds of billions of galaxies,

1590
02:17:14,440 --> 02:17:17,280
each of which is more or less like our Milky Way.

1591
02:17:17,719 --> 02:17:21,520
So the number of planets in our universe is virtually uncountable.

1592
02:17:22,639 --> 02:17:26,799
Speaker 6: Alien earths must be everywhere.

1593
02:17:27,319 --> 02:17:30,159
Speaker 12: Now we haven't discovered even one of them yet, but

1594
02:17:30,239 --> 02:17:34,319
statistically speaking, it is a rock solid certainty. There are

1595
02:17:34,440 --> 02:17:38,520
millions of billions of planets like the Earth out there.

1596
02:17:39,639 --> 02:17:43,879
Speaker 6: And with that many Earth like planets, surely some of

1597
02:17:43,920 --> 02:17:46,680
them will have intelligent life.

1598
02:17:47,799 --> 02:17:50,639
Speaker 12: I would bet everything. I would bet my house that

1599
02:17:50,680 --> 02:17:53,280
there is another Earth out there somewhere.

1600
02:17:55,319 --> 02:17:57,920
Speaker 37: There really can be no doubt that elsewhere in our

1601
02:17:58,040 --> 02:18:02,680
universe there are other smart critters who are asking themselves, Gee,

1602
02:18:02,879 --> 02:18:05,719
I wonder if there are any other intelligent species out

1603
02:18:05,760 --> 02:18:06,760
there in the universe.

1604
02:18:17,520 --> 02:18:21,440
Speaker 6: An ordinary starfield, but home to one of the most

1605
02:18:21,600 --> 02:18:26,520
extraordinary stars in our galaxy, eight point seven light years

1606
02:18:26,559 --> 02:18:36,959
from Earth. This is uv Setti. This mysterious object can

1607
02:18:37,000 --> 02:18:49,600
grow five times brighter in less than a minute. Any

1608
02:18:49,680 --> 02:18:53,680
planet circling this star would be blasted by the heat,

1609
02:18:54,399 --> 02:19:11,520
quickly melting its frozen surface. Then just seconds later, the

1610
02:19:11,559 --> 02:19:26,520
sun dims the planet retreats into icy darkness, but uv

1611
02:19:26,639 --> 02:19:33,959
Seti is about to go way further. The star begins

1612
02:19:34,000 --> 02:19:40,840
to brighten, but this time it doesn't stop a runaway infernit.

1613
02:19:41,360 --> 02:19:45,440
In just twenty seconds, it gets seventy five times brighter

1614
02:19:45,479 --> 02:20:02,040
than normal. Uv Seti has unleashed a megaflare, an immense

1615
02:20:02,120 --> 02:20:12,719
explosion of energy on the star's surface. If our sun

1616
02:20:12,879 --> 02:20:18,639
fired off on make a flare like this weep the toast.

1617
02:20:21,639 --> 02:20:23,319
Speaker 12: If you were standing on the surface of the Earth

1618
02:20:23,639 --> 02:20:26,559
and the Sun were to get seventy five times brightery,

1619
02:20:26,680 --> 02:20:29,479
even for only a minute or two, it would really

1620
02:20:29,799 --> 02:20:32,680
probably be the last thing you'd ever seen. The temperature

1621
02:20:32,680 --> 02:20:35,360
on Earth would rise up, and we'd have huge fires.

1622
02:20:35,360 --> 02:20:36,719
It would just basically cook.

1623
02:20:36,879 --> 02:20:51,280
Speaker 6: Every Earth is a long way from uv SETI. We're

1624
02:20:51,399 --> 02:20:56,239
safe from that particular star. But the more stars we studied,

1625
02:20:58,719 --> 02:21:18,440
the more flares bind. They fire in all directions, sometimes

1626
02:21:18,840 --> 02:21:39,959
directly at us. The closer star is to Earth, the

1627
02:21:40,040 --> 02:21:45,360
greater the danger. And one star is way closer than

1628
02:21:45,399 --> 02:21:56,040
all the others. Our Son looks stable and calm, but

1629
02:21:56,120 --> 02:22:11,760
behind the glare, the Sun is a monster. Solar observatories

1630
02:22:12,479 --> 02:22:27,719
capture the violins flares erupt across its surface, gigantic explosions

1631
02:22:27,760 --> 02:22:30,760
on an unimaginable scale.

1632
02:22:31,760 --> 02:22:34,200
Speaker 42: One flare, one of the most energetic flares on the

1633
02:22:34,239 --> 02:22:36,319
surface of the Sun, would be equivalent to over two

1634
02:22:36,440 --> 02:22:43,959
hundred million hydrogen atomic bombs. It's enough energy to power

1635
02:22:44,399 --> 02:22:48,920
the entire human race's energy consumption for something like two

1636
02:22:48,959 --> 02:22:49,799
million years.

1637
02:22:58,600 --> 02:23:02,200
Speaker 6: Each flares as bright it is four hundred billion trillion

1638
02:23:02,319 --> 02:23:08,280
light bulbs. But the visible light is just a fraction

1639
02:23:08,440 --> 02:23:19,840
of the energy it emits. Radio waves, infrared heat, ultraviolet light,

1640
02:23:21,600 --> 02:23:29,920
even X rays unleashed in every flare at incredible intensities.

1641
02:23:34,280 --> 02:23:44,959
These are the biggest explosions in the Solar System, Yet

1642
02:23:45,000 --> 02:24:01,120
the force behind them is simple magnetism. The Sun has

1643
02:24:01,159 --> 02:24:07,479
an immense magnetic field. The energy stored in this field

1644
02:24:07,840 --> 02:24:20,399
powers solar flares. Vast loops of magnetic force push toward

1645
02:24:20,440 --> 02:24:44,120
the surface. Huge magnetic arches rise out into space. When

1646
02:24:44,159 --> 02:24:48,520
two field lines cross, it triggers a magnetic short circuit.

1647
02:24:51,959 --> 02:24:57,639
This is a solar flare. All the energy trapped in

1648
02:24:57,680 --> 02:25:02,079
the magnetic field blasts out At one hundred million degrees.

1649
02:25:05,479 --> 02:25:09,360
It can hurl hot gas a billion miles out into space,

1650
02:25:15,280 --> 02:25:33,920
an eruption ten million times more powerful than a volcano. Magnetism,

1651
02:25:33,959 --> 02:25:37,680
the same force that powers a simple compass, fuels the

1652
02:25:37,719 --> 02:25:45,879
biggest explosions in the Solar System. Yet by cosmic standards,

1653
02:25:46,360 --> 02:25:48,319
our Sun is puny.

1654
02:25:51,920 --> 02:25:54,600
Speaker 36: As we look out into space, we see even more

1655
02:25:54,680 --> 02:25:58,120
active stars, even more intense magnetism, and then things really

1656
02:25:58,159 --> 02:25:59,079
start to get wild.

1657
02:26:06,840 --> 02:26:09,680
Speaker 9: There are stars and objects in our galaxy and in

1658
02:26:09,680 --> 02:26:14,639
other galaxies that produce flares and great intensity, so great

1659
02:26:14,879 --> 02:26:17,079
they would literally destroy all life on Earth if they

1660
02:26:17,079 --> 02:26:19,000
were nearby.

1661
02:26:21,680 --> 02:26:28,840
Speaker 6: Outside our Solar system. Titanic explosions rock the cosmos on

1662
02:26:28,879 --> 02:26:34,360
a scale we can barely imagine. Far beyond the Sun,

1663
02:26:34,920 --> 02:26:44,239
we entered the realm of mega flares. Our Sun is violent.

1664
02:26:47,600 --> 02:26:51,559
Flares explode with the force of billions of atomic bombs,

1665
02:26:56,719 --> 02:27:01,760
but travel out into the cosmos and the explosions get bigger.

1666
02:27:05,879 --> 02:27:23,879
Other stars have flares so huge they're planet killers. Ev

1667
02:27:24,040 --> 02:27:36,920
Lacerti is sixteen point five light years from Earth. Every

1668
02:27:37,000 --> 02:27:43,840
day flares erupt on its surface, but one megaflare smashed

1669
02:27:43,959 --> 02:27:55,280
every record. The star blasted out ten thousand times more

1670
02:27:55,479 --> 02:28:00,680
X rays than the Sun's most powerful flare. The ultra

1671
02:28:00,799 --> 02:28:08,920
violet light was so intense the star turned blue. This

1672
02:28:09,120 --> 02:28:14,239
stellar firestorm, one hundred trillion miles away, was visible from

1673
02:28:14,280 --> 02:28:23,120
Earth with a naked eye. If our Sun flared like this,

1674
02:28:23,840 --> 02:28:30,479
we'd be incinerated. But Evi Lacerti is a very different

1675
02:28:30,600 --> 02:28:40,559
kind of star compared to our Sun. It is tiny.

1676
02:28:48,920 --> 02:28:50,520
This is a red dwarf.

1677
02:28:51,639 --> 02:28:54,559
Speaker 12: Red dwarfs are stars that have much less mass than

1678
02:28:54,600 --> 02:28:56,799
the Sun. They can be a tenth to about four

1679
02:28:56,879 --> 02:29:00,159
tenths the mass of the Sun. They're smaller, they're cool.

1680
02:29:00,440 --> 02:29:01,719
These are dinky stars.

1681
02:29:09,760 --> 02:29:13,079
Speaker 9: They burn so slowly that Unlike our Sun, which will

1682
02:29:13,159 --> 02:29:15,479
last ten billion years, some of them will last ten

1683
02:29:15,559 --> 02:29:16,360
trillion years.

1684
02:29:21,559 --> 02:29:27,520
Speaker 6: They're also relatively cold. Their surface is just five thousand

1685
02:29:27,559 --> 02:29:32,840
degrees fahrenheit, half the temperature of our Sun, and ten

1686
02:29:32,959 --> 02:29:40,680
thousand times dimmer. Yet somehow they're capable of staggering violence.

1687
02:29:49,559 --> 02:29:55,600
That's because red dwarfs are immensely magnetic. The fields which

1688
02:29:55,719 --> 02:30:00,559
form inside them are enormous, much more powerful than our suns.

1689
02:30:01,159 --> 02:30:04,040
Speaker 9: That means the magnetic field energy that could be released

1690
02:30:04,319 --> 02:30:07,639
when those fields get twisted up is incredibly intense. And

1691
02:30:07,680 --> 02:30:10,120
even though these objects are very dim and visible light,

1692
02:30:10,479 --> 02:30:13,879
they can produce flares that are thousands of times more

1693
02:30:14,000 --> 02:30:16,639
energetic than those released by the Sun. You wouldn't want

1694
02:30:16,680 --> 02:30:18,959
to be near one of those when it went off.

1695
02:30:21,600 --> 02:30:29,079
Speaker 6: All red dwarfs flare violently, but ev Lacerd's flares are

1696
02:30:29,120 --> 02:30:34,239
off the chart. That's because it's young, just three hundred

1697
02:30:34,319 --> 02:30:40,840
million years old, fifteen times younger than our sun.

1698
02:30:43,680 --> 02:30:45,520
Speaker 12: In one way, stars are a little bit like people.

1699
02:30:46,000 --> 02:30:49,120
They're hot heads when they're younger. When stars are first born,

1700
02:30:49,200 --> 02:30:52,840
they're spinning very rapidly, and that actually helps generate magnetic

1701
02:30:52,879 --> 02:30:53,559
fields as well.

1702
02:30:56,360 --> 02:31:01,520
Speaker 6: The result a star one hundred times more magnetic than

1703
02:31:01,559 --> 02:31:07,520
the Sun. When its giant loops cross the megaflare is colossal,

1704
02:31:13,120 --> 02:31:26,719
a torrent of radiation lasting eight hours. Big flares on

1705
02:31:26,840 --> 02:31:30,319
our Sun have the energy of billions of atomic bombs.

1706
02:31:33,639 --> 02:31:50,120
Ebie Lacert's monster flare was ten thousand times more powerful. Incredibly,

1707
02:31:50,479 --> 02:31:53,840
even these massive flares are just a flicker on the

1708
02:31:53,920 --> 02:32:04,600
cosmic scale. There are eruptions millions of times explosions that

1709
02:32:04,639 --> 02:32:08,440
can light up a whole galaxy from a tiny star

1710
02:32:08,959 --> 02:32:19,399
with unimaginable power. This is the Australia Telescope Compact Array,

1711
02:32:20,200 --> 02:32:25,520
a network of five radio dishes constantly listening to the cosmos.

1712
02:32:29,040 --> 02:32:32,399
In two thousand and four they were struck by a

1713
02:32:32,440 --> 02:32:45,760
massive blast of energy, evidence of a megaflare. But this

1714
02:32:45,959 --> 02:32:52,840
was bigger than any we had witnessed before, the largest

1715
02:32:53,000 --> 02:33:05,479
burst of power ever recorded from our galaxy. The object

1716
02:33:05,600 --> 02:33:10,159
behind it is truly bizarre, a kind of star we

1717
02:33:10,280 --> 02:33:15,040
didn't even know existed until a megaflare gave it away.

1718
02:33:16,760 --> 02:33:19,680
Speaker 12: I've studied black holes, I've studied stars that explode.

1719
02:33:20,040 --> 02:33:21,120
Speaker 6: I've talked about.

1720
02:33:20,920 --> 02:33:26,120
Speaker 12: Rogue planets wandering the galaxy. For my money, the scariest

1721
02:33:26,280 --> 02:33:29,520
single object in the galaxy is a magnetar.

1722
02:33:36,040 --> 02:33:43,440
Speaker 6: Magnetars are the most magnetic objects in the universe, and

1723
02:33:43,520 --> 02:33:56,680
this one beats them all. Its magnetic field is one

1724
02:33:56,760 --> 02:34:01,680
thousand trillion times stronger than our suns. If it came

1725
02:34:01,760 --> 02:34:05,520
near our solar system, the effects would be devastating.

1726
02:34:06,680 --> 02:34:09,280
Speaker 43: The first thing you would notice is its magnetism would

1727
02:34:09,280 --> 02:34:11,440
wipe every credit card in your pocket. As you start

1728
02:34:11,440 --> 02:34:13,920
to get closer, anything metal on you would be ripped away,

1729
02:34:13,959 --> 02:34:16,639
your earrings, your jewelry. Once you got within a few

1730
02:34:16,719 --> 02:34:19,399
million miles of the magnetar, its magnetism would be so

1731
02:34:19,440 --> 02:34:21,959
intense it would actually disrupt the electrical signals in your

1732
02:34:21,959 --> 02:34:24,639
nerves and your heart would stop beating. Get even closer,

1733
02:34:24,719 --> 02:34:27,000
and the magnetism would be so intense it would rip

1734
02:34:27,000 --> 02:34:32,479
apart every atom in your body.

1735
02:34:38,079 --> 02:34:42,760
Speaker 6: Amazingly, this vast magnetic field comes from an object no

1736
02:34:42,920 --> 02:34:51,159
bigger than an asteroid. Our sum is close to a

1737
02:34:51,200 --> 02:34:58,959
million miles across. The magnetar just ten, but it's unimaginably dense.

1738
02:35:05,920 --> 02:35:11,159
Speaker 41: It weighs more than the Sun. This is incredible. Take

1739
02:35:11,200 --> 02:35:14,280
the Sun and squeeze it down not just to the

1740
02:35:14,280 --> 02:35:17,479
sides of the Earth, but down to the size of Manhattan.

1741
02:35:20,079 --> 02:35:23,639
Speaker 6: The entire mass of a gigantic star packed into a

1742
02:35:23,719 --> 02:35:27,600
space the size of a city.

1743
02:35:30,840 --> 02:35:33,479
Speaker 9: You could almost walk around the star in a day,

1744
02:35:33,559 --> 02:35:36,399
except you couldn't because the gravitational field is so intense.

1745
02:35:36,959 --> 02:35:40,120
The density of material on these stars is so great

1746
02:35:40,360 --> 02:35:44,799
that a tea spoonful of material weighs several thousand billion tons.

1747
02:35:45,239 --> 02:35:48,360
You would be crushed beyond recognition in a moment.

1748
02:35:53,680 --> 02:35:57,920
Speaker 6: Dense and compacted, the iron rich crust is under incredible

1749
02:35:57,959 --> 02:36:10,799
magnetic pressure. Something has to give. Fissures rip across the surface.

1750
02:36:16,879 --> 02:36:21,280
The crust splits open a star quake.

1751
02:36:24,120 --> 02:36:27,120
Speaker 12: It's like an earthquake on Earth, except the crust literally

1752
02:36:27,159 --> 02:36:30,239
moves half an inch. It's just a little tiny shift,

1753
02:36:30,280 --> 02:36:32,520
but that is a huge amount of energy because of

1754
02:36:32,559 --> 02:36:36,440
this intense gravity. It's like a magnitude thirty earthquake.

1755
02:36:41,680 --> 02:36:51,680
Speaker 6: A flar erupts from the fracture. A trillion tongue cloud

1756
02:36:51,760 --> 02:37:00,239
of ultra dense matter lasts into space. It lasts to

1757
02:37:00,360 --> 02:37:10,239
tenth of a second, but it unleashes more energy than

1758
02:37:10,280 --> 02:37:14,360
the Sun emits over two hundred and fifty thousand years.

1759
02:37:18,360 --> 02:37:21,200
Speaker 9: The energy emitted when one of these flares from the

1760
02:37:21,280 --> 02:37:24,120
magnetar is released, in some cases more than a billion

1761
02:37:24,120 --> 02:37:25,559
times the energy emitted by the Sun.

1762
02:37:32,120 --> 02:37:36,760
Speaker 6: Mega flares are time machines. They show us events from

1763
02:37:36,799 --> 02:37:43,840
long ago. This magnetar is fifty thousand light years from Earth.

1764
02:37:44,840 --> 02:37:48,479
The flare we observed in two thousand and four actually

1765
02:37:48,600 --> 02:37:56,840
happened fifty thousand years ago. It took that long for

1766
02:37:56,920 --> 02:38:01,239
the light to travel halfway across the galaxy and slam

1767
02:38:01,319 --> 02:38:14,600
into our atmosphere. If a similar megaflare exploded near Earth,

1768
02:38:17,360 --> 02:38:19,079
we wouldn't even see it coming.

1769
02:38:20,440 --> 02:38:22,799
Speaker 12: We would have no warning if a magnetar were to

1770
02:38:22,799 --> 02:38:25,639
have another flare like this. The event is so sudden

1771
02:38:25,639 --> 02:38:27,879
on the surface, and it creates so much energy. It

1772
02:38:27,920 --> 02:38:30,399
blasts out at the speed of light, and nothing can

1773
02:38:30,399 --> 02:38:34,799
travel faster than light, So basically this just happens and

1774
02:38:35,120 --> 02:38:35,559
that's it.

1775
02:38:36,920 --> 02:38:40,200
Speaker 6: Any life within ten light years of the blast would

1776
02:38:40,239 --> 02:38:56,879
be vaporized. Thankfully, even the closest magnetar is too distant

1777
02:38:56,920 --> 02:39:01,200
to threaten us. We can't see them even with the

1778
02:39:01,280 --> 02:39:07,079
strongest telescope. We've only detected these stars in the flash

1779
02:39:07,159 --> 02:39:11,959
of a megaflare. Yet these explosions are dwarfed by an

1780
02:39:12,040 --> 02:39:25,520
even more powerful monster, second only to the big Bang

1781
02:39:25,559 --> 02:39:44,280
and scale. This is the ultimate megaflare. Seven and a

1782
02:39:44,319 --> 02:39:55,399
half billion years ago, many galaxies away, a super giant

1783
02:39:55,479 --> 02:40:06,840
star is in trouble. Its nuclear core has run out

1784
02:40:06,879 --> 02:40:26,280
of energy. It's about to implode. For a few seconds,

1785
02:40:26,680 --> 02:40:30,920
the colossal blast shines a million times brighter than our

1786
02:40:31,120 --> 02:40:53,360
entire galaxy. This is the most extreme explosion in the universe.

1787
02:40:57,280 --> 02:40:58,719
A gamma ray burster.

1788
02:41:01,680 --> 02:41:05,000
Speaker 41: Gamma ray bursters are so powerful that they can be

1789
02:41:05,079 --> 02:41:11,319
seen across the entire universe, second only to creation itself.

1790
02:41:14,639 --> 02:41:27,200
Speaker 6: Two intense jets of energy shootout. These two beams of

1791
02:41:27,280 --> 02:41:30,159
gamma rays are the ultimate megaflare.

1792
02:41:31,719 --> 02:41:35,040
Speaker 12: The energy of these things is just unimaginable. It's the

1793
02:41:35,239 --> 02:41:37,799
entire power that the Sun puts out over its entire

1794
02:41:37,920 --> 02:41:41,600
ten billionaire lifetime, focused into just these two things that

1795
02:41:41,680 --> 02:41:44,239
last for maybe a few seconds. It's like a cosmic

1796
02:41:44,319 --> 02:41:47,799
blow torch of gamma rays and matter that march across

1797
02:41:47,840 --> 02:41:48,479
the universe.

1798
02:41:50,360 --> 02:41:54,479
Speaker 36: The most high energy intense light is gamma rays. Gamma

1799
02:41:54,520 --> 02:41:57,159
rays are naturally produced by things that are billions of

1800
02:41:57,200 --> 02:42:03,040
degrees hot. There will never be a hotter type of flare.

1801
02:42:03,159 --> 02:42:05,360
This is where it stops. Gamma raises it.

1802
02:42:13,239 --> 02:42:17,440
Speaker 6: Seven and a half billion years after the explosion actually happened.

1803
02:42:19,799 --> 02:42:24,879
We see it in our skies. March two thousand and eight,

1804
02:42:30,200 --> 02:42:35,000
a flare from halfway across the entire universe shines even

1805
02:42:35,040 --> 02:42:37,280
more brightly than the closest star.

1806
02:42:40,520 --> 02:42:43,879
Speaker 36: Something blew up seven billion light years away that you

1807
02:42:43,879 --> 02:42:46,319
could see with your unaided eye on a dark night.

1808
02:42:47,239 --> 02:42:51,639
That should tell you something.

1809
02:42:54,840 --> 02:43:00,520
Speaker 6: It is the biggest flair ever witnessed. But it is

1810
02:43:00,600 --> 02:43:07,120
also a sign of the birth of the most destructive

1811
02:43:07,280 --> 02:43:19,559
entity in the universe. A black hole has formed in

1812
02:43:19,600 --> 02:43:26,440
the core of the collapsing star. It consumes the star

1813
02:43:26,959 --> 02:43:41,719
from the inside out. When the star finally explodes in

1814
02:43:41,799 --> 02:43:48,239
a catastrophic supernova, all that remains is a newborn black hole.

1815
02:43:53,920 --> 02:43:56,120
Speaker 41: Usually when we looking out of space, we see all

1816
02:43:56,239 --> 02:43:59,159
black holes, black holes that have been around for millions

1817
02:43:59,200 --> 02:44:03,040
of years. But to see a baby black hole being born,

1818
02:44:03,680 --> 02:44:06,639
that is an incredible event, and that's what we think

1819
02:44:06,840 --> 02:44:07,920
is a gamma ray burster.

1820
02:44:11,280 --> 02:44:23,120
Speaker 6: Amazingly, these gigantic explosions are common. We see more than

1821
02:44:23,200 --> 02:44:24,959
three hundred and fifty a year.

1822
02:44:27,159 --> 02:44:28,520
Speaker 15: We see them every day.

1823
02:44:29,040 --> 02:44:32,760
Speaker 41: Our satellites attect them every few hours in all directions

1824
02:44:33,079 --> 02:44:34,879
outside the milky way.

1825
02:44:34,760 --> 02:44:43,040
Speaker 6: Galaxy, gamma ray megaflares reveal one of the universe's most

1826
02:44:43,200 --> 02:44:49,559
awesome secrets. A new black hole is born every single day.

1827
02:44:53,520 --> 02:44:57,719
Most of these explosions happened a long time ago, far

1828
02:44:57,799 --> 02:45:08,639
away from Earth, but if one went off inside our galaxy,

1829
02:45:14,719 --> 02:45:16,600
it could be catastrophic.

1830
02:45:19,559 --> 02:45:20,920
Speaker 12: If you were to put a gamm ray burst a

1831
02:45:21,040 --> 02:45:28,200
hundred light years from the Europe, it would be like igniting

1832
02:45:28,280 --> 02:45:32,159
a one megaton nuclear bomb over every square mile of

1833
02:45:32,239 --> 02:45:43,159
the surface of the Earth. Facing that event, you would

1834
02:45:43,159 --> 02:45:46,680
be blowing up millions and millions of nuclear weapons over

1835
02:45:46,680 --> 02:45:48,959
the planet. It would be the end of all life

1836
02:45:49,200 --> 02:45:51,239
on Earth as we know it forever.

1837
02:45:56,200 --> 02:46:00,799
Speaker 6: Gamma ray bursts are the most powerful mega flares in existence,

1838
02:46:01,639 --> 02:46:07,639
but not the most dangerous for us. The greatest threat

1839
02:46:07,680 --> 02:46:12,639
to Earth sits terrifyingly close right at the heart of

1840
02:46:12,680 --> 02:46:27,920
our own solar system. We were once blissfully ignorant, safe

1841
02:46:28,200 --> 02:46:35,360
in our solar system. Now we know Earth sits in

1842
02:46:35,440 --> 02:46:45,479
a cosmic firing range. Monster megaflares are everywhere we look,

1843
02:46:50,920 --> 02:46:54,200
but the deadliest cosmic weapon of all is right on

1844
02:46:54,280 --> 02:46:58,840
our doorstep, our Sun.

1845
02:47:07,239 --> 02:47:10,760
Speaker 41: We're lulled into thinking that the Sun is static, is

1846
02:47:10,799 --> 02:47:20,920
benevolent and is our friend wrong. The Sun is dynamic

1847
02:47:21,200 --> 02:47:25,200
in some sense, It's alive. It creates magnetism on a

1848
02:47:25,239 --> 02:47:27,840
scale that we can only begin to comprehend.

1849
02:47:30,600 --> 02:47:36,959
Speaker 6: And its most powerful weapon is this a coronal mass

1850
02:47:37,120 --> 02:47:44,399
ejection or CME. A colossal solar explosion rips a chunk

1851
02:47:44,440 --> 02:47:48,719
of the star away and torpedoes it out into space.

1852
02:47:51,159 --> 02:47:54,639
Speaker 36: Coronal mass ejections are related to flares, but they're even larger.

1853
02:47:55,120 --> 02:47:57,239
Speaker 12: You can sort of think of it as a solar

1854
02:47:57,239 --> 02:48:00,200
flare being like a tornado, very powerful, very into It's

1855
02:48:00,280 --> 02:48:02,799
very short lived, and a coronal mass ejection is like

1856
02:48:02,840 --> 02:48:05,799
a hurricane, much more energy, much bigger, and can last

1857
02:48:05,840 --> 02:48:06,639
for days and days.

1858
02:48:12,200 --> 02:48:18,280
Speaker 6: CMEs start with a magnetic short circuit. Magnetic arcs emerge

1859
02:48:18,360 --> 02:48:28,920
from the surface, glowing with trapped solar matter. The loops cross,

1860
02:48:29,440 --> 02:48:36,559
triggering a firestorm of energy. The Sun erupts, solar matter

1861
02:48:36,680 --> 02:48:43,239
explodes from the surface out into space, a monstrous cloud

1862
02:48:43,319 --> 02:48:46,559
of super hot gas and electric particles.

1863
02:48:48,559 --> 02:48:52,120
Speaker 15: When one of these huge prominences is shot out, an

1864
02:48:52,200 --> 02:48:56,200
energy equivalent of about ten percent of the entire luminosity

1865
02:48:56,200 --> 02:48:58,920
of the Sun for a second is released towards the Earth.

1866
02:49:04,959 --> 02:49:06,959
Over ten billion tons of.

1867
02:49:06,920 --> 02:49:09,399
Speaker 9: Material is shot out at a speed of over a

1868
02:49:09,479 --> 02:49:10,600
million miles an hour.

1869
02:49:17,360 --> 02:49:19,920
Speaker 12: The power of a chronal mass ejection is sort of

1870
02:49:20,079 --> 02:49:22,920
mind numbing. It takes our probes years to get from

1871
02:49:22,920 --> 02:49:25,559
the Earth to the Sun. A coronal mass ejection can

1872
02:49:25,600 --> 02:49:28,360
cross that distance in a couple of days, sometimes in

1873
02:49:28,440 --> 02:49:30,920
only a couple of hours, or even faster than that.

1874
02:49:31,319 --> 02:49:33,680
So these are tremendously powerful events.

1875
02:49:38,879 --> 02:49:45,079
Speaker 6: Powerful but also deadly. Because sometimes the Sun shoots a

1876
02:49:45,159 --> 02:49:52,440
CME straight toward the Earth. The crackling charged cloud plays

1877
02:49:52,559 --> 02:49:57,840
havoc with our electronics. It melts power grids, blows fuses,

1878
02:49:58,239 --> 02:50:06,159
and disrupts communication. But that's nothing compared to the damage

1879
02:50:06,600 --> 02:50:08,959
that a really big CME could do.

1880
02:50:20,280 --> 02:50:24,319
Speaker 41: They can wipe out satellites, GPS, the Internet, all sorts

1881
02:50:24,319 --> 02:50:28,440
of have it can take place when this huge tsunami

1882
02:50:28,799 --> 02:50:29,479
hits the Earth.

1883
02:50:36,040 --> 02:50:41,399
Speaker 6: The damage to satellites alone with total one hundred billion dollars.

1884
02:50:44,120 --> 02:50:46,559
Speaker 41: Think of a blackout that hits not just one city,

1885
02:50:47,079 --> 02:50:50,399
but hundreds of cities around the planet Earth.

1886
02:50:57,200 --> 02:50:59,959
Speaker 15: Property damage would be about two trillion.

1887
02:51:01,120 --> 02:51:05,200
Speaker 41: We're talking about perhaps a collapse of modern day civilization.

1888
02:51:05,719 --> 02:51:08,479
We're going to be thrown back perhaps fifty one hundred

1889
02:51:08,559 --> 02:51:12,280
years into the past into a world without electricity.

1890
02:51:16,760 --> 02:51:24,719
Speaker 6: Big solar storms are rare. On average, a massive CME

1891
02:51:24,959 --> 02:51:30,879
strikes Earth every five hundred years, but it's happened before

1892
02:51:32,440 --> 02:51:34,360
and it will happen again.

1893
02:51:37,440 --> 02:51:40,000
Speaker 41: In two thousand and three, we had one of the

1894
02:51:40,280 --> 02:51:45,760
largest coronal mass ejections ever recorded, but fortunately it missed

1895
02:51:45,799 --> 02:51:49,920
the Earth. One of these days is going to hit

1896
02:51:49,959 --> 02:51:52,239
the Earth. One of these days, one of these rifle

1897
02:51:52,239 --> 02:51:55,040
bullets will be aimed right at the Earth, and at

1898
02:51:55,040 --> 02:51:56,719
that point watch out.

1899
02:52:10,159 --> 02:52:17,159
Speaker 6: Our planet is under attack, not just from megaflares in

1900
02:52:17,280 --> 02:52:28,360
deep space, but from our own star. The Sun fires

1901
02:52:28,479 --> 02:52:32,120
billions of tons of hot gas and electric particles into

1902
02:52:32,159 --> 02:52:48,959
space every day, deadly solar weapons, sometimes pointing straight at us.

1903
02:52:51,559 --> 02:52:54,200
Speaker 41: What I find amazing is the fact that the Earth

1904
02:52:54,280 --> 02:52:56,239
is in the middle of a shooting gallery.

1905
02:53:00,120 --> 02:53:09,840
Speaker 6: We have survived this onslaught. We are protected. The Earth

1906
02:53:09,920 --> 02:53:17,959
has a magnetic field. It's incredibly weak, but enough to

1907
02:53:18,120 --> 02:53:21,879
keep us safe.

1908
02:53:23,200 --> 02:53:25,799
Speaker 41: Think of an ordinary magnet that you use on your

1909
02:53:25,840 --> 02:53:30,319
refrigerator that has more magnetism than the Earth's magnetic field.

1910
02:53:39,159 --> 02:53:44,159
Speaker 6: Without our magnetic shield, every CME would strip away Earth's

1911
02:53:44,200 --> 02:53:54,440
atmosphere and we be fried. By solar radiation. How do

1912
02:53:54,520 --> 02:53:59,840
we know because it happened to one of our neighbors.

1913
02:54:01,120 --> 02:54:01,920
Speaker 10: Look at Mars.

1914
02:54:02,600 --> 02:54:05,440
Speaker 41: Mars is an example of what happens to a planet

1915
02:54:05,719 --> 02:54:14,719
without a magnetic field. Mars is a frozen desert with

1916
02:54:14,840 --> 02:54:19,120
an atmosphere only one percent the atmosphere density of the Earth.

1917
02:54:22,760 --> 02:54:25,079
It's because it lacks a magnetic field.

1918
02:54:31,239 --> 02:54:34,239
Speaker 12: Over billions of years, these particles have actually stripped away

1919
02:54:34,360 --> 02:54:37,520
Mars' air and that's why it has very thin atmosphere.

1920
02:54:37,559 --> 02:54:43,200
Now Here on Earth, we have a magnetic field and

1921
02:54:43,319 --> 02:54:46,840
we have air. This is not a coincidence. So we

1922
02:54:46,920 --> 02:54:49,079
can breathe because of our magnetic field.

1923
02:54:53,920 --> 02:55:00,879
Speaker 6: From Earth's surface safe beneath our magnetic umbrella. We see

1924
02:55:00,920 --> 02:55:04,079
the power of our violent sun in the northern and

1925
02:55:04,280 --> 02:55:17,200
southern lights. Trillions upon trillions of electric particles strike the

1926
02:55:17,280 --> 02:55:23,040
Earth every second. The magnetic shield funnels them to the poles.

1927
02:55:25,520 --> 02:55:32,639
They energize gas molecules in our atmosphere, making them glow

1928
02:55:33,639 --> 02:55:45,040
a chemical light show. Oxygen shines green, nitrogen blue or red.

1929
02:55:49,360 --> 02:55:53,360
The aurory are evidence of a battle between magnetic fields.

1930
02:55:55,840 --> 02:56:08,319
The Sun's field creates cmese, Earth's field shields us from them.

1931
02:56:08,360 --> 02:56:16,479
Magnetism is nature's most mysterious force. Only now are we

1932
02:56:16,600 --> 02:56:25,639
beginning to understand how it shapes the cosmos. Mega flares

1933
02:56:25,760 --> 02:56:31,000
make magnetism visible. They shine a light on the incredible

1934
02:56:31,079 --> 02:56:38,680
power of magnetic fields, fields that play a fundamental role

1935
02:56:38,799 --> 02:56:49,079
in the universe. They impose order on chaos. They weave

1936
02:56:49,159 --> 02:56:58,280
their way through the spiral shapes of galaxies. Fields hundreds

1937
02:56:58,280 --> 02:57:02,360
of thousands of light years across, yet one hundred thousand

1938
02:57:02,479 --> 02:57:11,319
times weaker than Earth's smaller Magnetic fields exist inside galaxies.

1939
02:57:14,840 --> 02:57:24,760
They organize matter into clouds of molecules spectacular nebulae. These

1940
02:57:24,799 --> 02:57:32,479
stellar nurseries are where new stars are born. Now we've

1941
02:57:32,520 --> 02:57:42,120
discovered magnetic fields even permeate empty space fields created in

1942
02:57:42,200 --> 02:57:46,799
the Big Bang with just one quadrillianth the strength of earths.

1943
02:57:48,959 --> 02:57:51,440
This is a magnetic universe.

1944
02:57:54,799 --> 02:57:58,719
Speaker 9: What's amazing is this thing that's invisible. Magnetic fields play

1945
02:57:58,799 --> 02:58:01,559
such an important role in every aspect of the universe,

1946
02:58:02,000 --> 02:58:05,079
protecting us from the radiation from the Sun, to the

1947
02:58:05,079 --> 02:58:07,840
explosions in red dwarfs, to the magnetars, and to the

1948
02:58:07,959 --> 02:58:12,840
most energetic violent processes in the entire universe, gamma ray burst.

1949
02:58:13,200 --> 02:58:15,920
Speaker 15: Magnetism plays a role on every scale of.

1950
02:58:15,840 --> 02:58:20,079
Speaker 9: The universe, changing the dynamics of objects and making universe

1951
02:58:20,319 --> 02:58:22,239
a violent and interesting place.

1952
02:58:25,159 --> 02:58:30,280
Speaker 6: Mega Flares light up the cosmos. They show us things

1953
02:58:30,440 --> 02:58:34,840
we can't otherwise see from the other side of the universe,

1954
02:58:38,040 --> 02:58:42,200
or from billions of years in the past. A black

1955
02:58:42,239 --> 02:58:56,639
hole is born, a star dies, Distant events and hidden

1956
02:58:56,680 --> 02:59:11,360
mysteries in a flash flares reveal them, illuminating the awesome

1957
02:59:11,639 --> 02:59:13,200
secrets of the universe.