Speaker 1: Perhaps the greatest question facing the human race is to
discover where we came from and to find out what
is our ultimate fate.
Speaker 2: Every culture, every age has asked that question and tried
to answer it.
Speaker 3: It's one of the greatest adventures of the human mind
to find out where we came from, where we are,
and of course, in the end, where we're going.
Speaker 4: Astronomy provides the basic information that each person needs to
understand where he or she came from and where the
human race is going.
Speaker 1: Now, at the dawn of a new millennium, we are
on the threshold of understanding how our universe began and
how it will end. Cosmologists around the world are trying
to unlock the origin and destiny of everything we see
around us. One of this elite group is Bob Keshner.
He's on a journey to Sero to Lolo in Chile
to measure if there's enough gravity to hold the universe together.
Speaker 5: We've known for a long time that the universe is
expanding and coasting along since the Big Bang. One of
the questions has been how much gravity has been slowing
down the expansion of the universe. Just like when you
drive a car up a hill. You can slow down
if you don't apply power, because gravity is pulling back
on you. We think that the expanding universe would be
slowed down by the gravity by all the stuff that's.
Speaker 6: In the universe.
Speaker 5: One of the interesting things is that we've been able
to do some work to try to measure that, and
we found a surprising result, not the one that we
expected to find, but one that really turns the whole problem.
Speaker 6: On its head.
Speaker 1: Kirshner's team may have discovered answers that seal the fate
of our universe. They've discovered that it's not just expanding,
it's speeding up. Cosmologists now realize that to understand what
the future may hold, they first have to unravel what
happened at the beginning of the universe, at the start
of time itself. In our daily lives, time is constant
and dependable. It's almost impossible for us to imagine. But
before the creation of the universe, there was no time.
Speaker 7: We can trace back cosmic history to a stage when
everything was very dense, very compressed, very hot. But the
further we go back, conditions were so extreme that we
can't really rely on any of our common sense intuitions.
We can say that time in the sense we understand
it didn't really exist before that.
Speaker 1: So when did the clock start ticking twelve billion years ago?
There was absolutely nothing, no matter, no space, no time.
We may never know how or why it happened, but
a seething mass of energy smaller than an atom grew
from nothing your inside The Big Bang, the birth of
our universe, a violent fireball of unimaginable heat. For England's astronomer,
Royal Martin Reece, understanding the Big Bang is the key
to the universe.
Speaker 7: Something that was literally originally only the size of a
single atom or smaller, expanded to be large enough to
encompass everything in our present universe.
Speaker 1: Only the minutest fraction of a second had passed, But
all of this was puny compared to what was about
to happen. Propelled by a new surge of internal energy,
the universe suddenly entered an incredible period of inflation. It
expanded one hundred trillion trillion, trillion trillion times to the
size of a grapefruit. Einstein's famous equation E equals mc
squared told us that energy and mass were interchangeable. It
gave us the knowledge to build weapons of mass destruction,
and the knowledge to understand how our universe was born.
When a nuclear bomb explodes, a tiny amount of matter
is completely annihilated and converted into energy. But in the
Big Bang, the exact opposite it happened. Pure energy was
converted into matter. Approaching a millionth of a second old,
the universe was brimming with energy so intense that it
was spontaneously converted into lumps of matter and its arch rival, antimatter.
A titanic battle ensued. Some atomic particles annihilated each other,
blow for blow, particle for particle. When matter and antimatter meat,
they mutually destruct. This is the most powerful release of
energy known.
Speaker 7: If our universe started off with equal amounts of matter
and antimatter, all the atoms were denihilate with anti atoms,
and we'd end up with universe consisting just of heat
and radiation, but nothing from which we and the stars
could have been made.
Speaker 1: But somewhere in this tiny, blazing inferno, the process was
slightly imperfect. There was more matter than antimatter. At the
end of the battle, matter had won, and the universe
was far from empty. Every time a particle of antimatter
had been annihilated. The energy was converted into radiation, and
that radiation is right before our very eyes. Don't adjust
your set. Hidden in the interference on a badly tuned
TV set is the energy signal left from the first
second of the universe. The discovery of the Big Bang
was one of the greatest scientific discoveries of all time,
even though it was an accident. This is the Horn
antenna the Bell Research Labs in New Jersey. Its unusual
funnel shape was designed to collect faint radio waves from
early communication satellites. It was being used for an entirely
different experiment when it detected something truly remarkable, a discovery
that would win two American scientists the Nobel Prize.
Speaker 8: When I visit the Horn antenna, I'm always reminded of
the days back in the sixties when hornaut and I
were using it. Seriously, if it's amazing to think about
just doing your experiment and discovering the beginning of the universe,
But there it is.
Speaker 1: In nineteen sixty four, Bob Wilson and his colleague are
No Penziers were using the Horn antenna to search for
natural radio emissions from our own galaxy. But as soon
as they switched their giant earps on, it started humming.
It was picking up weak but constant background interference. Wilson
and Penziers had no idea where the signal was coming from.
At first, they suspected nearby New York, but when they
ruled that out, their suspicions turned on the local bird population.
Speaker 8: There were a pair of pigeons living in the antenna.
Once a week we'd come up and disturb them. They'd
fly away, but the next day, when we were gone,
they'd come back. So the inside of the horn was
covered with white pigeon droppings. We got up in the
horn reflector the broom and swept it all out.
Speaker 1: With the pigeons evicted, The two scientists were disappointed to
find the interference was still there.
Speaker 8: We looked in various directions. Sometimes we looked at specific objects,
other times we looked at random parts of the sky,
And every time we did that, we saw the same level,
the same amount of excess noise, and it was the
same in all directions.
Speaker 1: They began to realize that it could have a more
dramatic origin. What Wilson and Prenzius had stumbled across was
a background of microwave radiation, a faint afterglow of the
battle that defeated antimatter twelve billion years before.
Speaker 8: The microwave background comes from the initial, very dense and
hot state stage of the universe, and as the universe expands,
the radiation expands with it, and just like anything else
that expands, it tends to cool off. It came from
the early stages of the universe, and it's just out there.
If you go outside, it'll hit you on the head.
You won't notice it because it's so weak. It's at
such a low level that it's almost undetectable.
Speaker 1: Every television set on Earth can detect the radiation from
the Big Bang. Antimata had been defeated and the universe
was still only a second old. Over the next three minutes,
the explosions created the kind of matter we would recognize today,
hydrogen and helium. It was still too early for the
universe to shine. In the dark ages that followed the
Big Bang, these elements would combine together and provide the
building blocks of the first generation of stars and galaxies.
The atoms created twelve billion years ago are still with
us today. Every time you take a sip of water,
you're swallowing hydrogen atoms that were created at the very
beginning of the universe. Most of the atoms in our
bodies were created in the first moments of the Big Bang.
Speaker 9: We tend to often associate ourselves from the universe. We
tend to think of asking questions about it versus us,
But of course that's not really true. We're a part
of the universe, and when we ask about the origin
and evolution of the universe itself, we're really asking questions
about the origin and evolution of ourselves.
Speaker 1: Since the Big Bang, the universe has continued to grow
and expand. To understand just how big it has grown,
we need to take an imaginary spaceship ride from the
Earth to the edge of the visible universe. Our nearest
neighbor is the Moon, just a quarter of a million
miles away at the center of our solar system. Ninety
three million miles away is our Sun. After crossing the
center of our solar system, we continue our flight beyond
the orbit of the Earth. The next planet out is Mars.
Beyond the orbit of Mars is the asteroid belt. A
billion miles away is the giant outer planet Saturn, almost
a thousand times the size of Earth. As we leave
the Solar System, we would pass one of our our
earliest interplanetary explorers, Voyager one, launched in nineteen seventy seven
and traveling at a mere forty thousand miles per hour.
Proxima Centauri and Alpha Centauri A and b our nearest
stars are twenty five million million miles away. Our Solar
system sits in the quiet suburbs of a spiral galaxy,
the Milky Way, a star city containing over one hundred
billion stars. Every star we can see in the night
sky lies within our own galaxy.
Speaker 10: This is deep space.
Speaker 1: Out beyond the Milky Way, ten million, million million miles
from Earth is the next spiral galaxy, Andromeda. Even traveling
at the speed of light, it would take two million
years to reach here. Andromeda and the Milky Way form
part of a small cluster of galaxies called the Local Group,
But stretching out way beyond the Local Group are much greater.
Speaker 10: Clusters of galaxies.
Speaker 1: If it were possible to travel fast enough for long
enough and reach the edge of the known universe, this
is what we would see uneven clusters of galaxies, a
pattern that was predetermined in the very first second of
the Big Bang.
Speaker 11: This is as far as our spaceship can take us.
Speaker 1: We are now fifty billion trillion miles from Earth. This
is where science ends and speculation begins. Astronomers may never
see what lies beyond here. This is where the secrets
of the universe are hidden. For centuries, astronomers have been
trying to locate our exact position by looking further and
further across the vast expanses of deep space. For four
hundred years, since Galileo first pointed his telescope at the sky,
astronomers have not only been looking across the far reaches
of space, but back in time. Because the light from
distant objects it takes so long to reach us, every
telescope is a time machine. Even traveling at an unbelievable
one hundred and eighty six thousand miles per second, light
takes a long time to cross space. Light reflected off
the surface of the Moon is already over a second
old by the time it reaches us on Earth. Look
up at Saturn and you're seeing it as it was
one and a half hours ago. And we see Andromeda
as it was when the first humans walk the Earth.
Speaker 11: Its light has been traveling across space for over two
million years.
Speaker 1: Here at the lick ofservatory soundra Faber spent her early
career unraveling the mysteries of the most distant galaxies.
Speaker 4: The biggest telescopes on Earth now are taking us back
billions of years into the past, ninety percent of the
way back to the beginning.
Speaker 12: Of the universe.
Speaker 1: View light from the furthest visible galaxies, and you're seeing
them as they were over eleven billion years ago.
Speaker 4: A galaxy is really like a city of stars. Just
as there are billions of people on Earth or millions
of people in a city, there are hundreds of billions
of stars in a typical galaxy.
Speaker 1: The universe contains over one hundred billion galaxies. Like giant
hurricanes in space, their resident stars spin around a giant
central core. To see into the heart of them, the
most distant galaxies would require a very special telescope. In
nineteen ninety, the launch of the Hubble Space telescope promised
astronomers a view of the early universe they had only
dared dream of. High above the Earth's atmosphere, this billion
dollar looking glass would have a totally clear view of
the most distant galaxies, But the dream turned into a nightmare.
Soon after it was launched, they discovered that the mirror
was misshapen. It saw everything out of focus. One of
the repair men sent up to fix the stricken telescope
was astronaut Jeff Hoffman.
Speaker 13: It was unbelievably embarrassing from Nasen and for the astronomical community.
I mean, I had astronomer friends who that summer when
they were on holiday and people asked, well, you know,
what do you do for a living. They didn't even
want to say I'm an astronomer because the first thing
everybody would say, oh, the Hubble telescope.
Speaker 6: Ha, you know, it was a big joke.
Speaker 1: First, the crew of the rescue mission had to capture
the crippled telescope, helloaed Yeah, then execute a repair mission
unprecedented in the history of spaceflight, spread over five days
of spacewalks. They repaired the faulty optics. The replacement parts
fitted perfectly. The problems came when Hoffman attempted to close
the huge access doors.
Speaker 14: Law and behold they did not close.
Speaker 15: And I worked.
Speaker 14: I went up to the top of the doors, I
went to the bottom of the doors. But what we
figured out was that we could use an extra tool
which had a little strap and wrap that around and
bolts to gradually winch the door close. We ended up
spending over eight hours outside, which is the second one
the space what has ever been done.
Speaker 1: At one point in the mission, they even had to
dump a damaged solar panel overboard.
Speaker 11: With all the repairs.
Speaker 1: Completed, the cosmological community held its collective breath to see
if the most expensive telescope ever built would finally deliver
what its designers originally promised. This is what Hubble saw.
The images they received were beyond anyone's wildest imagination.
Speaker 11: Free from the.
Speaker 1: Distortion of the Earth's atmosphere, images captured by the Space
Telescope left even the most hardened of cosmologists in awe.
Hubble captured the final moments of a star's life, when
it explodes and blows off layers of gas and dust.
It also captured interstellar nurseries of newly born stars, each
one as varied and unique as a human fingerprint, and
dark pillars of cosmic dust more than a million million
miles long, ready to spawn a new generation of stars
and planets. But Hubble's true moment of glory was still
to come. The mission controllers pointed the telescope at a distant,
empty patch of deep space and waited over a period
of ten days in nineteen ninety five. Emerging across the
coldness of space, the Hubble Deep Field Image revealed a
tapestry of distant galaxies. This was the furthest back in
space and time we had ever seen.
Speaker 2: To point the telescope for hundreds of hours and let
this light that has traveled for ten billion years slowly
dribble in and accumulate. When you see so far back
and see so many galaxies, and imagine that the sky
is filled with them, billions of galaxies, that's like ten
galaxies for every person on Earth, something like fifty to
one hundred billion galaxies, and each one of them containing
fifty to one hundred billion stars. Say, that's an enormous
number of places where there might be planets and life
and very interesting things going on in the universe.
Speaker 1: Powerful computers have turned the real galaxies of the deep
Field image into a remarkable three D journey to the
edge of the universe. In the foreground, our mature galaxies
like our own, further back in time, our younger, energetic galaxies.
But beyond here the structures begin to thin out. This
is as far as we can see. This is the
edge of the visible universe, over ninety percent of the
way back to the beginning of everything, faint galaxies that
will formed just a billion years after the Big Bang.
Beyond these galaxies, we can see nothing. We're entering the
universe's dark.
Speaker 2: Ages, sometime a few hundred million years after the Big Bang.
This dark age must have ended when the first stars
were born, and so the universe lit up for the
first time perhaps half a billion years after the Big Bang,
and it's been lit by stars ever since.
Speaker 1: The universe is so vast, some astronomers have decided to
make a map of exactly where we are, just as
Galileo tried to make sense of our place in the heavens.
Here at Apache Point, New Mexico, a group of astronomers
are trying to locate our position by constructing the biggest
map that anyone has ever seen, built specifically to map
over a million galaxies. This is the home of the
Sloan Sky Survey. Over a period of five years, astronomer
Jim Gunn and his colleagues are about to start mapping
our exact position in the universe.
Speaker 3: We're in a galaxy which is not a particularly remarkable galaxy.
But this three D picture that we will make of
the nearby universe tells us how we fit into this
vast scheme of things that is the universe. And I
think we'll give us a much better idea of our place.
Speaker 1: By systematically scanning the entire night sky from a site
high above the desert floor. The results will be plotted
not as a two dimensional route map, but a fully
interactive three dimensional guide to the universe.
Speaker 3: If you think about that from a kind of cinematic
point of view, one could take this map very easily,
put this map on a computer and enable you to
rotate the map to fly through space if you like,
to look at our galaxy from outside, to look at
the other galaxies around us from the other side, and
take not only from any angle you want, but from
any place in this map, and look out and see
what it's like to be somewhere else in the universe
and what we are, which is of course what you
see in science fiction films all the time, but you
will actually be able to do it with the galaxies
that are there.
Speaker 1: Gym Gunn Survey is an ambientious project, and it's only
just beginning. This is how the final map may look.
It's a computer simulation of superclusters of galaxies massed together
in giant blobs.
Speaker 11: You are here.
Speaker 1: This would be the position of our planet, our Solar System,
and our own Milky Way. But on this scale it
would be impossible to see us or even any of
our neighboring galaxies. This is a map of everything. We
can see everything in the universe. All the visible stars
and galaxies were born in the same furnace.
Speaker 16: The Big Bang.
Speaker 6: A ball of.
Speaker 1: Intense heat, still cooling as it continues to expand. Cosmologists
are not only confident that they have unearthed the universe's past,
but that they can also predict its future. Space, like
the surface of hot blown glass, cools as it expands,
just as flecks of color embedded in the glass move
further apart the more it stretches sow to the galaxies.
Space is expanding in all directions at once. Modern cosmologists
are now trying to measure if this expansion will continue forever,
how will the universe end? The key to the future
of the universe was discovered long before modern astronomers built
their giant telescopes. Back in the sixteen sixties, when Sir
Isaac Newton had an encounter with a falling apple and
discovered gravity, Newton formulated laws of physics, which form the
basis of modern science.
Speaker 9: You realized that the same force that takes an apple
and pulls it down from a tree towards the Earth,
pulls the Moon towards the Earth, and in fact pulls
the Earth towards the Sun and pulls the Sun towards
the center of our galaxy.
Speaker 15: But in fact, gravity is the weakest force in nature.
Speaker 9: If you want to show someone how weak gravity is,
just take a friend to the top of a tall
building and push them off, and it may take twelve
stories for them to fall, and gravity to accelerate them
all the way down to the ground. But electricity and
magnetism in a fraction of a second and a fraction
of an inch will stop them. Because the reason you
don't go through things is not that the atoms in
your body hit the atoms in the table, but rather
it's the electric fields between those atoms that stop you.
So electricity and magnetism stops you in a fraction of
a second, even though it takes gravity all that time
to accelerate you.
Speaker 1: Gravity may be the weakest force, but it's the force
that holds the planets and the stars together. After Newton,
perhaps the greatest scientists and mathematician of all time was
Albert Einstein. Einstein had been an unremarkable student, and his
first job was as a clerk in the local patent office.
His General Theory of Relativity, announced in nineteen fifteen, explain
for the very first time how everything within the universe
interacts space, matter, even time. His calculations told him that
the stars and galaxies should exert a gravitational pull on
each other and should eventually collapse together in a catastrophic fireball.
But they hadn't collapsed. So to make his equations work,
he invented a special repulsive force. But it was a
makeshift solution, and deep down Einstein knew it. Then a
decade later, along came a man with the solution to
Einstein's puzzle. Here at the Mount Wilson Observatory in California,
Edwin Hubble took the first steps towards forecasting the fate
of our entire universe. Hubble was a World War One
veteran and a brilliant lawyer. When he turned his renowned
skills to astronomy, he came up with a remarkable discovery
that would change the way we view the universe forever.
He made the astronomical discovery of the century that the
universe was expanding.
Speaker 11: Seventy five years on.
Speaker 1: Measuring the precise speed of that expansion is the job
of astronomer Wendy Friedman.
Speaker 17: What Hubble found was that almost all galaxies appeared to
be moving away from us, and this led to the
idea that the universe is expanding. Here was evidence for
the first time that the universe was actually in motion,
that galaxies are moving apart. What that means is that
you can essentially extrapolate backwards in time. It's like running
a film in reverse. If galaxies are expanding now, then
as sometime in the past, they must have been closer
and closer together. And what that implies is that sometime
early in the history of the universe, galaxies would have
been much closer together the matter in the universe it
would have been much denser and much hotter, and this
gave rise to the idea of a Big Bang.
Speaker 11: Universe.
Speaker 1: Hubble's revelation stood the astronomical communities understanding of the cosmos
on its head. He'd use the same technique that police
forces around the world used today to catch speeding motorists.
Hubble used the astronomical equivalent of a police radar. Instead
of using radar signals, Hubble measured the light that came
from distant galaxies. He knew that their color would be
slightly altered if they were traveling towards or away from us.
Speaker 17: If an object is moving away from us, then the
light from that object will be shifted toward the red
part of the spectrum. If an object is coming towards us,
the light will be shifted toward the blue.
Speaker 10: Part of the spectrum.
Speaker 1: By determining just how much the color had been changed,
Hubble could work out how fast a galaxy was traveling.
It's an effect known as the Doppler shift, and it
applies to both light and radar. Hubble found that all
the light from all the galaxies was shifted towards the
red part of the spectrum. They were traveling away from
us at an incredible speed.
Speaker 17: There have been dramatic improvements in the technology since Hubble's day,
and we now have the advantage for the first time
of being able to get outside of the Earth's atmosphere.
That is, we can go to space use the Hubble
Space telescope named after Edwin Hubble, to measure distances to galaxies.
Speaker 1: Modern astronomers have calculated that we, along with all the
contents of our own galaxy, are traveling away from the
nearest cluster of galaxies at a.
Speaker 11: Million miles an hour.
Speaker 1: By the end of this program, the whole universe will
have expanded a billion miles in all directions. Cosmologists need
to find out if there's enough matter in the universe
for gravity to stop it expanding and flying apart.
Speaker 9: There isn't enough matter normal matter to count for all
the matter we can weigh in the universe. We can
actually weigh the galaxy the same way we weigh the
Sun and the Earth using Newton's laws. We watch the
Sun go around the galaxy and we use gravity to
determine how heavy the galaxy really is. And when we
do that, we find there's a lot more out there
than meets the eye.
Speaker 1: Wondering if there is enough matter in the universe to
stop it expanding is a prime concern of Professor Stephen Hawking,
born three hundred years after Newton. Hawking now holds Newton's
old job at Cambridge University. Hawking already knows that the
visible galaxies do not produce enough gravity.
Speaker 11: He now suspects that the universe is full of invisible
dark matter.
Speaker 18: If the universe continues to expand forever, everything will burn
out and decay. The amount of matter we observe in
stars and gas clouds is only about ten percent of
what is required to stop the expansion of the universe
and cause it to collapse again. However, there might be
other dark matter that we can see but which can
still affect the expansion of the universe.
Speaker 1: Dark matter is everywhere. The reason we can't see it
is because of its signs. Particles of dark matter are
so tiny they can pass through anything. Neil Spooner and
a dedicated band of astrophysicists are attempting to trap dark
matter particles called WIMPs weekly interacting massive particles a mile
underground at Bulby Mine in England.
Speaker 19: That it just makes up so much matter, so much
of the universe. It's at least ninety percent, probably ninety
nine percent. If it wasn't for this material, our galaxies
would just fly apart. We believe that not much was
composed of elementary particles that arose in the Big Bang,
and they're around us all the time, and they're passing
through us all the time.
Speaker 1: Neil Spooner and his team feel sure that any particles
that could penetrate through five thousand feet of solid rock
would be dark matter. The team are attempting to record
collisions between particles of dark matter and the atoms in
a light emitting crystal, but it's a long vigil that
requires an unusual level of patience.
Speaker 19: Occasionally, like about once a day, you might get one interaction.
Other words, the particle comes in, strikes an atom, it recoils,
and it produced a little burst of light, ordinary visible light,
which we can detect with our instruments and then amplify
and record into our computers.
Speaker 1: It will take years, but if their equipment successfully detects
dark matter, Spooner's team will have discovered the invisible ninety
percent of our universe. But this may not be enough.
There may still be too little gravity to stop the
universe expanding for eternity.
Speaker 19: It could be that the universe will basically expand forever
and simply dissipate and eventually will end up with a
like a soup of rather boring atoms and dark matter
diffused around, and it will be a sort of slow
death and on into infinity in the.
Speaker 1: For some, the challenge of predicting the fate of our
universe is compulsive. Their passion for cosmology often turns into
a lifelong obsession.
Speaker 5: There are a lot of people engaged in trying to
find out what the universe is, and I think it's
mostly the same kind of curiosity that kids have when
they're six years old or eight years old. It seems
to get beaten out of them in school, But we're
sort of the ones.
Speaker 20: That I don't know, the schools didn't affect.
Speaker 5: Or something like that. We're still asking those same questions
and still trying to get answers to them.
Speaker 1: Here at Cero Tololo, cosmologists have made a startling new discovery.
Bob Kirshner believes that dark matter may not be holding
the universe.
Speaker 11: Together at all.
Speaker 1: They're forecasting how the universe will end by observing one
of the most violent cosmic events, stars that explode in
distant galaxies with unbelievable ferocity when they reach the end
of their life supernovae. From the brightness of these explosions,
Kirshner and his team can tell if a galaxy is
near or far away. They measure the distant supernovae as
markers to help them work out how fast the universe
is expanding.
Speaker 5: This is a very sensitive system that we're using.
Speaker 21: It has an electronic detector and of course it's connected
to a gigantic telescope. It lets you see objects which
are about one hundred million times fainter than you can
see with your dark adapted eye.
Speaker 1: Like Edwin Hubble, they're using the light from distant galaxies
to get an accurate fix on the universe's rate of
excit pansion. They thought they would be measuring how much
the gravitational pull from dark matter was slowing the expansion
rate down, but what they have found has stunned the
cosmological community.
Speaker 5: Well, maybe it's the other galaxy.
Speaker 1: Rather than slowing down, the universe is speeding up. The
galaxies are moving apart faster than ever before. Dark matter
is not powerful enough.
Speaker 21: See what it looks to me like, there's still something
there at the location that.
Speaker 13: Is the right there.
Speaker 1: Scientists now believe that the universe will not collapse in
a catastrophic fireball, nor will it coast on serenely. Instead,
its contents will speed apart, faster and faster, until lost
in the vast blackness of space.
Speaker 5: So if the picture that is coming from the supernob
is really right, the universe will expect and forever, in fact,
faster and faster on into the future. Now, this is
really not anything to worry about, even though it is
a kind of obleak future of an empty, cold, dark universe.
Speaker 1: What Kirshner may have discovered as a remnant of the
original Big Bang, the inflation that started in the very
first second of the universe, is taking off again.
Speaker 9: What makes cosmology at the end of the twentieth century
so exciting is that, in fact we understand that the
largest things in the universe are really determined by the
smallest things in the universe. That there's this connection because
the very early Big Bang, the fundamental forces governing the
microscopic structure matter really determined the structures we see today
on scales as large as galaxies and superglusters.
Speaker 1: The shape of our universe, everything we see around us
was determined when the universe was smaller than an atom
and only a fraction of a second order. Our universe
is cooling and dying. In a billion years from now,
our first unmanned spacecraft like Voyager one, will leave the
Milky Way and drift unhindered through the universe. As the
universe reaches middle age, even the longest lived stars will
start to burn out.
Speaker 18: Our sun has about five billion years of life clift,
and very few stars will still be shining ten billion
years from now. The dead stars will still orbit around
the center of the galaxy, but your delisiens will gradually
cause most of them to fall into a giant legged
hole at the center.
Speaker 7: Suppose we look ahead to when universe is one hundred
billion years old, Then it would be a rather dull
and dark place because all but the faintest and most
slow burning stars would have died. So the universe will
not only disperse, but all the galaxies will get fainter.
Speaker 1: As the universe expands with age, gravity will lose its
precarious grip. If you could be there to witness it,
you would see absolutely nothing. Is there anything that human
race could do to flee from such a dark fate.
Could we escape into another dimension, into another universe?
Speaker 7: The best ideas that people have come up with do
suggest that maybe our big Bang was not the only one,
and that the inflation which led to our universe may
have happened elsewhere, maybe anifer a number of times in
some grand eternal cosmos.
Speaker 1: If other universes do exist, could we ever find a
way of traveling into one.
Speaker 9: It's incredibly interesting that there's a lot more we don't
know about the universe than we do in spite of
all we've learned up to day, and therefore some of
the wild ideas from science fiction, including things like even wormholes,
might or might not be possible.
Speaker 15: We just don't know at this point.
Speaker 1: Wormholes are another prediction of Einstein's theories. Here space is
so twisted that it forms a tunnel from one universe
to another. Even if these hypothetical holes in space and
time do exist, entering a neighboring universe could be on
wives travel into one where the laws of physics are
even slightly different from our own, and you'd cease to
exist at all.
Speaker 5: Even though we have very small brains and we lead
very brief lives and so on, the fact is we're
able to understand where we are. And because we can,
we use instruments like the big telescopes, the physics that
we learn on the surface of the Earth, and the
ideas that people have had over the last few centuries
to build up a coherent picture. And I think we
should be proud of that We've done pretty well.
Speaker 4: I feel it's been a great privilege and a huge
amount of luck to be present to witness an important
science like cosmology hit its peak.
Speaker 2: In some way, creatures like us, and there probably are
many are the consciousness or the intelligence of the universe.
It's almost as if the universe invented a way to
know itself.
Speaker 1: After centuries of gazing at the heavens, scientists now know
that everything in our universe was born twelve billion years ago.
Speaker 11: Before the Big Bang, there was nothing.
Speaker 1: This violent explosion gave birth to everything we can see,
countless galaxies, stars and planets, even life itself. Our universe
is alive with the shimmering of countless stars, but our
vision from beneath the Earth's protective atmosphere shields us from
the real dangers. These are the most violent objects in
the universe. Bob Kirshner is a Harvard professor the passion
for the stars. He spent a lifetime studying them from
their cradle to their grave.
Speaker 5: I remember as a kid going out and seeing the
stars at night, and I lie on the snow a
flashlight and a star map and try to dope out
what things were where in the sky. And my mother
used to call at the back door and she said, Bobby,
come in, get off that snow.
Speaker 1: Today, instead of lying in the snow, Kirshner comes to
Kick Peak Observatory.
Speaker 5: Kin Peak is at about seven thousand feet, so it's
not a particularly high mountain, but it is considerably above
the valley floor, so it's a good site for astronomy. Also,
the weather is very good down here in Arizona, so
we get a lot of clear nights.
Speaker 1: He has a date with the night sky to look
for one of the most dramatic and beautiful events in
the universe, the birth of a new star, as the
sun sets over the Arizona Desert. The observatory is open
for work. This mountaintop gives astronomers an unrivaled view of
the sky, high above the clouds and obscuring lower atmosphere.
Kirshner is looking for giant clouds of gas inside our
galaxy in the Milky Way that may give birth to
new stars.
Speaker 5: Okay, ready, let's go to the first one man, all right,
there are catalogs of regions where stars have been forming
or where there are big clouds of gas that people
have compiled over the years, And so by looking at
some of these things from the catalog, we can begin
to investigate into areas where there really are stars forming
and where we look deep into them to see what's
going on.
Speaker 1: With their high power telescopes, Kirshner and his colleagues have
been peering into enormous gas clouds inside our own galaxy.
This is the Lagoon Nebula, an interstellar nursery which is
giving birth to hundreds of new stars. The clouds are
mostly made of hydrogen, the most abundant element in the universe.
They are so dense they begin spiraling inwards under their
own gravity. The matter collects and begins to form a
fledgling star, a protostar with a disk of gas and
dust falling inwards. It spins faster and faster. This was
probably how our sun and the Solar System was born.
Speaker 5: After a while, the material that is in orbit around
the protostar starts bumping into itself, and so it builds
up bigger particles out of smaller ones, eventually makes dust
and makes gravel, and then very quickly probably builds up
things as big as planets.
Speaker 1: This is the moment of birth of a new star,
With a new sun spawning a disc of orbiting planets.
Speaker 5: The star shrinks down more and more until it becomes
hot enough and dense enough for the nuclear reactions in
the center to get going that turn it from being
a glowing ball of gas into a real star, something
that has a nuclear fire down in the center.
Speaker 1: The same nuclear reactions that take place in a hydrogen bomb,
converting hydrogen into helium produces the energy that causes stars
to shine. When the nuclear fires ignite, a new star
is born. Since the birth of our Solar system, the
closest and most familiar star of all our sun has
bathed our planet in heat and light. At the heart
of the Sun, six hundred million tons of hydrogen are
converted into helium every second in a nuclear reaction that
fired up four and a half billion years ago. For generations,
the only way astronomers could study the Sun's fiery atmosphere
was during a total solar eclipse, for a few fleeting minutes,
the Sun drops its guard, allowing us a glimpse of
its awesome power. Francisco Diego, a professional eclipse chaser, saw
his first eclipse as a teenager in Mexico. It began
a lifelong fascination with the Sun.
Speaker 22: The total solar eclipse is an event that when you
see it, you will never forget. The day of the
eclipse is very special. When you look at the Sun,
you see this beautiful, complete, perfect disk. But the day
of the eclipse exactly at the time that has been
predicted for many, many years. In the bands, you see
how the moon starts eating into it.
Speaker 1: At total eclipse, the Moon will align itself perfectly between
the Sun and the Earth.
Speaker 11: The Moon is four.
Speaker 1: Hundred times closer to the Earth than the Sun, and
by extraordinary cosmological coincidence, also exactly four hundred times smaller.
Diego and his astronomical colleagues will travel anywhere on Earth
to study this rare celestial event. Each eclipse will last
just a few precious minutes.
Speaker 22: The temperature starts dropping and he drops up to about
ten or fifteen degrees. In some cases, he's very noticeable.
You feel this wind, this atmosphere is agitating, and it
is very very tense moment. Then you look at the west,
because the shadow of the moon is coming towards you
very fast, at three thousand kilometers per hour. The landscape
looses its colors.
Speaker 1: One hundred miles wide. Shadow will pass over the surface
of the Earth. The brightness of the midday sun will
slowly turn tonight.
Speaker 22: The sky gets so dark that the corona, which is
very faint, is now visible.
Speaker 15: It really flourishes.
Speaker 22: It's like a flower, a white flower that opens its
petals in the sky.
Speaker 1: This is the Sun's corona, a glowing atmosphere normally obscured
by the intense clare. It burns at over a million degrees.
Giant prominences irrupt from its surface. They could swallow the
Earth dozens of times over like giant fingers. They stretch
for millions of miles into the vacuum of space. But
for solar astronomers like Diego, a total eclipse is over
all too soon. After just a few minutes, the alignment
is lost. The Sun's brilliant light bursts out from behind
the Moon, a magical sight that eclipse watches have named
the diamond Ring.
Speaker 22: When you finish looking at the diamond ring and you
see the shard of the Moon rushing away from you
now towards the east, then you see that was it.
Those two or three minutes are gone. You have been
waiting for that for years, and suddenly it is gone.
You feel like a vacuum and you say, this is
not enough. I want more.
Speaker 1: As the Sun breaks out from behind the Moon once again,
the Earth is bathed in its light. We rely on
the Sun's constant energy to breathe life into our planet.
It gives us free energy, its heat evaporates water to
produce the clouds and rain. The slightest change in its
behavior could put the world and even the human.
Speaker 10: Race at risk.
Speaker 1: To keep a constant vigil on the Sun's enormous power
from above the Earth's shimmering atmosphere, a new satellite, SOHO,
was designed and built by NASA and the European Space Agency.
Launched in nineteen ninety five, SOHO was to promise a
breakthrough in Sun observations and give astronomers a front row
view of our nearest star. Douglas Goff a solar astronomer
at Cambridge University, was one of the members of the
SOHO team.
Speaker 23: The satellite has gone to a position between the Earth
and the Sun where the gravitational pull of the two cancils,
so it sits there, looking at the Sun continuously and
beaming back the information to Earth.
Speaker 1: The images as it beam back were beyond their wildest dreams.
The Sun's raging surface is a turbulent world, its eruptions
ripped and torn by enormous magnetic fields. SOHO revealed that,
like the Earth, the Sun has weather. Gigantic solar tornadoes
twist through its atmosphere and gigantic shockwaves rip across its surface.
The surface of the Sun is heaving. Every five minutes,
the entire star breathes in and out. Our Sun is pulsating.
This is the real sound of it, vibrating, speeded up
thousands of times.
Speaker 23: The outside of the Sun is in a very dynamical
turbulent motion, just like the turbulence behind the back of
a jet engine. The jet engine creates a lot of noise. Similarly,
this motion creates a lot of noise inside the Sun,
which reverberates around and makes the Sun sing and By
listening to those tones, we can learn about the structure
of the Sun.
Speaker 11: Inside.
Speaker 1: Below its churning surface, there's a nuclear furnace that will
burn for billions of years from its nuclear heart, trillions
and trillions of time, any particles of radiation photons make
their arduous journey from the core to the surface. The
photons collide with super dense gas. They take so many
hits that a trip that should take just a few
seconds takes millions of years. But after the photons escape
from the surface's light, they take only eight and a
third minutes to travel from the Sun to the Earth.
Every summer, millions of people go out of their way
to worship their local star, even ninety three million miles away.
We can feel the Sun's enormous destructive power, but not
all of us are nowatually protected against the Sun's lethal rays.
Fair skinned people have weak defenses. The result is sunburn
from the Sun's deadly ultraviolet radiation. This anti burn patrol
is on the lookout for unprotected babies. The greater the
exposure to the Sun, the greater the risk of getting
skin cancer, especially deadly malignant melanomas. Even greater dangers are
whipped up when the Sun's surfaces twisted and contorted by
powerful magnetic fields. These fields can puncture the surface and
create dark areas called sunspots. Each one is big enough
to swallow the entire Earth, and their presence is a warning.
The magnetic disturbances cause enormous eruptions, blasting huge amounts of
radiation billions of tons of charged particles into space. Every
eleven years, the sun spots increase in number and size,
a mass of intense energy can head our way, engulfing
the entire Earth. When this happens, is not just the
sun bathers who need to head for cover. March nineteen
eighty nine, the Sun was about to give Eastern Canada
an early wake up call. It was the height of
the Sun's eleven year cycle, the solar maximum. Out in space,
a cloud of incandescent matter over one million miles long
was heading straight for Earth. Night workers at the National
Grid Control Center had no idea what was in store.
At a quarter three in the morning, engineers noticed an
enormous surge in their power system. When the cloud hit
the Earth, it induced a massive surge of electricity inside
the power cables. Engineers struggled to reduce the load, but
in a matter of minutes they'd lost control of the
whole system. Power plants over half a min million square
miles of Quebec were swamped with excess current. Moments later,
the whole grid blew the city was plummeted into darkness.
Power was lost to eight million homes. Further north, the
same cloud that had plunged Quebec into darkness was lighting
up the night sky in a massive celestial fireworks display.
This is the Aurora Borealis. Some of the particles from
the cloud had become trapped inside the Earth's magnetic field.
As they passed through the atmosphere, they reacted with the
air like a giant neon light. The solar radiation lit
up the night sky. Our Sun is not the only
star that threatens our existence. Space is filled with harmful
particles and radiation. Traveling above the Earth's protective atmosphere is
extremely dangerous. Despite the dangers of traveling above the atmosphere,
our desire to conquer space is so great that we
are prepared to risk the consequences. In nineteen sixty nine,
US Aldrin, Neil Armstrong and Mike Collins began their historic
Quarter of a million mile journey to the Moon.
Speaker 24: Hello, Neil and Burse, I'm talking to you by telephone
from the over room at the White House, and this
certainly has to be the most historic telephone call made.
Speaker 1: Celebrations ran high as Aldron and Armstrong stepped onto the
lunar surface for the first time, but behind the euphoria,
the pair were keeping a secret from mission control in Houston.
They'd seen more than just the dust of the Moon's surface.
It was only when they returned to Earth that Armstrong
and Oldering revealed their secret. They reported seeing strange, white
streaks of light flashing in their eyes. NASA decided to
run tests on future missions to discover exactly what the
light flashes might be. Astronaut Chinlie Duke was that guinea
pig on board upon O sixteen. He was asked to
watch out for the mysterious flashes.
Speaker 25: We're on our way to the Moon, and uh, all
of a sudden, I closed my eyes and I saw one.
It was like a The first one was like a
flashbulb exploding inside your eye.
Speaker 26: Uh.
Speaker 25: It was very bright, very white.
Speaker 18: Uh.
Speaker 26: And uh, I said, hey.
Speaker 5: I saw my first one.
Speaker 25: It was just this streak of light very fast and
just as white as it could be.
Speaker 11: Uh uh in very bright.
Speaker 1: A young researcher, Larry Pinski, was assigned to work with
Duke and find out what was causing the flashes.
Speaker 27: White in the right eye upper center.
Speaker 1: He recorded Duke's comments back in Houston and eventually realized
the flashes could only be one thing.
Speaker 24: Faint white and the.
Speaker 11: Left dye were well.
Speaker 28: It turns out that they were seeing cosmic rays. They
were seeing these elementary particles that permeate space, that penetrate
the spacecraft, actually penetrate the body and in this case,
penetrate the eye.
Speaker 24: We're feeling gooding, How about an expansion? You got?
Speaker 1: What Pinsky had worked out was the Duke and the
other astronauts were seeing high energy particles produced from one
of the universe's most violent acts of destruction, when a
massive star trillions of miles away explodes as a supernova.
As a heavyweight star nears the end of its life,
it incinerates all the fuel in its core. The heavier
star is, the more catastrophic it's death. The core becomes unstable,
it loses energy and starts a headlong collapse that for
one second gives off as much energy as all the
stars in all the galaxies in the universe.
Speaker 28: Cosmic rays are actually particles, They're actually little pieces of matter.
They are the nuclei of atoms. The atoms come from supernovae,
and they're just the bare nucleus accelerated to very very
high velocities.
Speaker 25: I'm sure they were there all the time, but the
only time you'd ever noticed them is when you sort
of got quiet, closed your eyes and thought about it,
and then you see them going.
Speaker 24: Off faint, faint white butt and then left eye.
Speaker 25: There wasn't any pain associated with it.
Speaker 26: It's just sort of like a.
Speaker 25: Very spectacular fireworks display going off inside your eyeball.
Speaker 1: When the astronauts returned to Earth, Penske took a closer
look at Duke's space helmet. He found hundreds of microscopic
tracks where the cosmic rays had tunneled right through.
Speaker 28: They are tremendously penetrating and do considerable damage to the
molecular structure of whatever they passed through, and this is
the reason why they're a hazard to people.
Speaker 6: When they passed through you.
Speaker 25: The thought occurred to me, you know, if I was
out here maybe a couple of years, these little things.
Burning a hole through my head might cause me some
problems in the future, but we didn't worry about it,
of course, on a short mission like we were on.
Speaker 1: But if a supernova is too close, it won't be
only astronauts who will at risk. It could kill everything
down here on Earth. Our galaxy is packed with over
one hundred billion stars, many of them near the end
of their natural life. At least one or two supernovas
explode in our galaxy every century. Two young astronomers from
Caltech have now come up with a new theory of
life on Earth that has shaken our scientific beliefs, a
theory that links the death of stars to mass extinctions
on Earth.
Speaker 29: The fossil record of the last five hundred million years
shows five or six huge extinction events in which anywhere
from sixty to ninety five percent of species on Earth dinosaurs, reptiles,
et cetera, were wiped out. And so I really set
out to do was to come up with some sort
of model that would explain why the major extinctions happen.
Speaker 11: When they do.
Speaker 1: Eric Lych and Gautam Vasish have calculated exactly when the
Earth may have been close to ancient supernovas.
Speaker 26: The key to.
Speaker 1: Their model was understanding the rotation of the Milky Way.
Like a giant spinning wheel. The Milky Way is circled
by spiral arms packed with billions of stars.
Speaker 30: Spiral arms are really disturbances that sweep through the disk
of the galaxy, and the gas and dust tends to
accumulate along these disturbances.
Speaker 29: If you imagine looking at our galaxy face on, the
spiral arms appear like swirls going out from the center
to the outer edge, rather like the kind of whirlpool
you see when water goes down and drain.
Speaker 1: The spiral arms are wherein supernovas are most likely to explode.
Our solar system passes in and out of the arms
once every fifty million years.
Speaker 30: We know the location of the spiral arms fairly well,
so we could trace the orbit of the Earth back
into time. The hope was to find a link between
the times of occurrences of the extinctions and the timing
of the passage of the Earth through the spiral arms.
Speaker 1: Their calculations revealed that the biggest mass extinctions correspond exactly
with the dates when the Earth had passed through the
spiral arms. If a supernova exploded nearby, the surface of
the Earth would have been swamped by deadly radiation.
Speaker 29: If the Solar system happens to be passing through a
spiral arm, your chances of care entering a supernov explosion
at close enough range to do serious damage to the
Earth or quite high. In fact, we estimated something like
fifty to fifty.
Speaker 1: Understanding the mystery of just how massive stars die has
taken astronomers centuries to unravel. Modern astronomers picked up their
first clues from an unusual source during the Second World
War in occupied Holland, Ian Duvand, a scholar of ancient
Chinese manuscripts, discovered a document written in China nearly nine
hundred years earlier.
Speaker 31: It reported on the twenty second day of the seventh
month of the first year of the period Chiwe said,
frustrating myself, I have observed the appearance of a guest
star in the fifth moon in the eastern heavens in Taurus.
It was visible by day like Venus ponting Rates shut
out from it on all sides.
Speaker 1: The account told of a bright star that had appeared
in the heavens in the summer of ten fifty four,
which shone for twenty two months and then disappeared. Du
and that realized the significance of his discovery. Through contacts
in the Dutch underground, he smuggled a paper through enemy
lines and across the Atlantic to astronomers in the United States.
Twenty years earlier, American astronomers had discovered that a distant
cloud of gas called the crab Nebula at the fringes
of our galaxy was expanding. By working backwards, they had
calculated that it originated from a single point some nine
hundred years earlier, exactly the time of the Chinese Star.
Astronomers believed that the crab Nebula was the debris from
an exploding star a supernova, but at the time they
had no proof. The Chinese Star was so bright it
could be seen in daylight, and for a time it
was even possible to write by its light. What's more,
the star had appeared in exactly the same part of
the sky as the crab Nebula. It clinched the argument
it had to be the remains of an exploding star.
The blue glow of the crab Nebula comes from escaping
cosmic rays. The colored pincers are the remnants spewed out
in the giant explosion. But for this star, the supernova
explosion wasn't the end. Left behind was a strange corpse.
Professor Anthony Huish from Cambridge University discovered there was life
beyond the grave for dead stars when he built an
unusual telescope in the nineteen sixties.
Speaker 32: We started building in nineteen sixty five. The thing was
we wanted a large radio telescope which was very sensitive,
but it had to be rather cheap, and I decided
on this construction of big dipole array. We all took
our turns in hammering the posts into the ground and
hanging up the wires and putting into the cables. It
was just very much a team effort.
Speaker 1: Over the next two years, Huish and a small team
of students built a jumble of wires and poles spread
over a four acre site. This strange looking telescope was
to discover the weirdest object in the universe and win
Hwish the Nobel Prize. The task of running it was
the responsibility of then research student Joscelyn Bell.
Speaker 33: That was producing miles of chart paper, ninety six feet
of chart paper every day, and we kept scanning the
sky over and over and over again. I ran it
for six months and generated several miles.
Speaker 12: Of chart paper.
Speaker 1: In August nineteen sixty seven, after just one month of operation,
an unusual signal caught her eye.
Speaker 33: As the pen ran over the chart paper went beep beep,
beep beep beep, regular poses about one and one third
seconds apart.
Speaker 32: Looked so artificial. It looks like an intelligent signal to
begin with, And intentional intelligent signals coming from out of space,
what are they? Well, you make a joke and say,
perhaps somebody is talking to us in some kind of
a code. So we call these things little Green Men LGM.
I mean, we didn't really believe it. On the other hand,
it was a possibility you couldn't immediately ignore.
Speaker 1: After months of analysis, Huish and Bell came to an
outstanding conclusion. Only a small, super dense spinning object could
be creating such a fast pulse. The only possibility was
the collect asked core of a super nova, a neutron star.
Here was the living courts.
Speaker 32: I really didn't know neutron stars existed until I started
talking to people and said, look, can you tell me
any sort of star that's but smaller than a thousand kilometers,
and up came the answer, neutron stars, and maybe we're
seeing the first one.
Speaker 33: Orthen the posts that come from one of these neutron
stars come to us because like a lighthouse, these stars
are spinning, and they have a beam that's focused by
the magnetic field of the star. And every time the
beam sweeps across us, across our radio telescope, we pick
up a Pultz.
Speaker 32: But for one year there are literally hundreds of theories
being published, and it was an absolutely open question, and
I think it only became generally accepted after about twelve
months that it had to be with Netles Bell.
Speaker 1: The revelation triggered a wave of activity. Radio telescopes all
over the world scanned the heavens looking for the mysterious pulses.
Less than a year later, the giant Aracibo dish in
Puerto Rico picked up a signal it was coming from
the heart of the crab nebula. They had found the
ticking corpse at the center of the Chinese supernova. The
spinning neutron star was not only giving off radio waves amazingly,
it was also visible. High speed television pictures revealed it
was flashing on and off thirty times a second. It
was the most powerful object that anyone.
Speaker 10: Had ever photographed.
Speaker 1: Neutron stars are like nothing else in the universe. They're
so dense a thimbleful would weigh over one hundred million tons.
Speaker 33: Supposing you somehow managed to land on a neutron star,
then you are experiencing phenomenal gravity, and the atmosphere, instead
of being five miles thick, is about five millimeters thick.
So if you stood on the neutron star, the atmosphere
would be sloshing around between your doors.
Speaker 1: But even a neutron star's phenomenal gravity is surpassed when
a real super heavyweight star dies. When a star a
hundred times heavier than our sun switches.
Speaker 16: Off, it goes with a bang.
Speaker 1: While we see the outward explosion is a supernova, this
masks the inward implosion. The core is collapsing into the
most dangerous.
Speaker 10: Object in the universe.
Speaker 1: The density becomes so great in the center that gravity
sucks in time and space itself from the outside universe.
A darkness forms at the heart of the collapsing star.
A black hole is born.
Speaker 34: If you have a massive star. Once the massive star
has exhausted its nuclear fuel, which is keeping it hot
and keeping it puffed up. Gravity becomes so strong that
it just overwhelms all pressure the material can provide, and
the star goes imploding inward in a and it's gone,
forming a black hole.
Speaker 1: Everyone has heard of black holes, no one has seen
them or be near one. At the center of a
black hole is a point called the singularity. Everything that
has ever fallen into a black hole is destroyed, crushed
into a pinpoint of infinite density and infinite smallness, evens
space and time are squelched out of existence.
Speaker 34: The singularity is a place where gravity is essentially infinitely strong.
It's a place where Madder gets destroyed. It's a place
where space and time as we know them get destroyed.
Speaker 1: At some time in the future, a spaceship from Earth
will be sent into the jaws of the most elusive
object in the universe. A spacecraft traveling towards a black
hole wouldn't see the singularity hidden deep inside. It would
only see the blackness around it its target as a
gravitational pull that is so great not even light can escape.
Speaker 34: As the spaceship goes flying into the core of the
black hole. I begin to feel my self being pulled
from head to foot and squeezed from the sides. My
body gives way. I die, the atoms of which I
may give way, and all is destroyed.
Speaker 16: In the singularity, all that remains is a perfect sphere
of absolute darkness, a gravitational ghost of the star that died.
Speaker 1: The perils of a black hole are thankfully remote. Even
the nearest is over five thousand like years from Earth.
Our nemesis lies much closer to home. Like every star
in the galaxy, our Sun has a finite lifespan. One
day it will run out of fuel and scorch the planets.
It's a terrible fate that astronomers have known for decades.
Speaker 5: We expect that the Sun will swell up in about
five billion years, and it will become a red giant star.
That's the beginning of the end for the Sun.
Speaker 1: In five billion years, our local star will have exhausted
its fuel supply. Without fuel, the Sun will die in
its death throes. The star that gave birth to life
will swell and engulf the Earth and Moon. Nothing will survive.
Speaker 5: The amount of energy would get from the Sun would
increase tremendously. The Earth would heat.
Speaker 18: Up, oceans would boil.
Speaker 5: Eventually, the mountains would melt and evaporate. The Earth would
be incinerated by our own friendly star, the Sun.
Speaker 1: The heat from this red giant will be so intense
the Earth will be scorched beyond recognition. The Earth's crust
will melt, the surface will become an ocean of molten rock.
Nothing will survive the ultimate catastrophe.
Speaker 5: And that's the end of the story for the Sun.
It will cool off, and as time passes, the Sun
will become a dimmer and dimmer, cooler and cooler clinker
of a leftover star.
Speaker 1: The Earth, devoid of all life, will sit in the
cold emptness of space. As ours Sun's brilliance dies somewhere
in the galaxy in an endless cycle of life and death,
a new star will be born, maybe it will spawn
its own solar system, even a new planet like Earth
and a new place where life can flourish.
Speaker 6: Our planet is extraordinary. It provides everything life needs, trillions
of creatures, plants, and us.
Speaker 20: Where you look down at the Earth from space, and
everything that we know of that's life is down there
on that planet, that beautiful planet that you now are
going around every hour and a half, and that's almost overwhelming,
just the beauty.
Speaker 27: Of the Earth.
Speaker 6: It's unique in our solar system, but is it unique
in the universe.
Speaker 35: It's important for us to understand the conditions that led
to the formation of the Earth, because then we can
look for those conditions around other stars. And if we
find those conditions there, then that would suggest that other
Earths could be forming elsewhere in the universe.
Speaker 6: Could there be other planets like ours among the stars?
To find out, we must travel back in time and
discover how the Earth was made. Rewind the clot four
and a half billion years and this is what you see.
This speck of dust will become the Earth by combining
with countless others. They're all part of a giant cloud
called a stellar nursery. The first step of planetary formation
is about to start, an event that will transform the
cloud into thousands of infant solar systems, including our own.
The same process is happening today seven thousand like years
away in the Eagle Nebula, our own solar system formed
inside clouds of gas and dust like these.
Speaker 12: There are these three trunks of gas and they're nicknamed
the pillars of Creation. And they're truly of miles long.
These are huge structures.
Speaker 6: The clouds look dense, but they're actually very sparse.
Speaker 12: These gas clouds are incredibly tenuous. You'd have to compress
basically a mountain's volume worth of the stuff squeeze it
down just to make a little tiny rock like this.
Speaker 6: To compress the gas and dust into dense stars and
planets takes a supremely powerful event, one that can only
follow the death of a giant star. In two thousand
and seven, the Spitzer space telescope captured this image a
ball of hot gas behind the Eagle nebula, evidence that
a huge star has exploded and sent a vast wall
of gas racing toward the pillars.
Speaker 36: There's a wave of hot material approaching the Pillars of Creation,
and this may be a shockwave from a supernova a
dying star.
Speaker 6: Supernovas briefly outshine entire galaxies. Superheated plasma blasts into space
at seventy million miles per hour. A mighty shockwave speeds
toward the Pillars of Creation. When it hits, it will
demolish them. It will also create new worlds. Supernova shockwaves
smash into the pillars compressing the thin gas and dust
into dim clumps. Each is a new star, a new
solar system.
Speaker 37: Molecular cloud minding its own business gets blasted by a
supernova explosion, crushing the cloud down into stars and planets.
Speaker 6: Wind back four and a half billion years, and our
solar system starts the same way. A supernova crushes a
massive dusty cloud into a protoplanetary disk. A thin, nebulous
cloud becomes a dense whirlpool of gas and dust, a
solar system in the making. One star is destroyed, a
new star is born, our Sun and its planets. This
is the first link in the long and unlikely chain
of events that made our world. For Earth to even
be here, we had to beat astronomical odds.
Speaker 9: A host of different factors have to line up to
get a planet, just like the Earth. You have to
have the right distance, the right size, the right kind
of moon.
Speaker 6: On Earth, all the conditions are just right for life.
Speaker 15: To get a world like ours, you need a lot of.
Speaker 9: Ass Somehow, our solar system hit the jackpot, But the
big question is did it happen anywhere else?
Speaker 6: One of the universe's most violent events triggered the birth
of our planet a sparse cloud crushed into a dense
swirl of dust. Some of this dust will become planet Earth.
But how do tiny dust grains create entire worlds? A
supernova explosion triggers a chain of events that will eventually
create the Earth, the formation of our solar system. A
hot ball of gas grows in the center. This will
become our Sun. The dust that swirls around it will
form the planets. But first the grains must stick together.
Speaker 27: So we have this interesting conundrum. Right, So this disconsists
of gas and dust parties. They're about the size of
let's say particles and smoke, right, Let's say cigarette smoke.
Speaker 13: Right.
Speaker 27: So these are small things, and somehow we have to
get from those little grains to what we see on
the Earth.
Speaker 6: Gravity is a powerful attractive force. It shapes galaxies and
solar systems. But specks of dust are far too small
to pull on each other. Somehow they clump together to
form planets. So if gravity doesn't bind them, what does.
In Germany, scientists are on the case. They can simulate
how dust behaves in space inside a huge tower.
Speaker 38: Here we do free fall experiments. So the whole experimental setup,
including our dust aggregas are in perfect freefall. It is
simulation of space, but a very good one. Indeed, I
think this is the closest you can get a space
on Earth.
Speaker 6: Researchers place dust in a container and load it into
a launch capsule at the base of the tower. They
lower it into a super powerful catapult. This launches the
half ton capsule from zero to over one hundred miles
per hour in a quarter of the second. Four hundred
feet up, the capsule reaches the top of the tower,
then plunges back down. A drum of polystyrene balls thirty
feet deep breaks its fall. All this gives just ten
seconds of zero gravity, just enough time they hope for
the dust to stick three two, one and go. Moments
after the capsule launches, the dust inside becomes weightless. The
brains clump together, just like the early Solar system. These
images reveal how dust particles came together four and a
half billion years ago to form the Earth.
Speaker 38: The force that binds the aggregates together is not gravity.
They are too small for gravity to be efficient. We
think the force that binds the aggregates together is electrostatic force.
Speaker 37: It's the same reason that when you pull your clothes
out of the dryer. You know how the clothes sometimes
stick to you. That's the same effect that allows one
dust particle to stick to another.
Speaker 6: Dust particles joined to form balls of fluff.
Speaker 27: The little static charges that they have can make them
stick when they hit, and you get something sort of
like the dust bunnies that I have a lot of
underneath my bad.
Speaker 6: These cosmic dust bunnies are planets in the making. They
start out smaller than a pin head, then grow. The
dust is now in clumps, but it's still just balls
of dust. Turning dust balls into rocks takes a whole
new process. A comic electric storm space clouds build up charge,
just like clouds here on Earth, generating huge bolts of lightning.
Speaker 38: Balls of dust can turn into solid rocks by an
energetic event like lightning.
Speaker 6: The electric bolts smash through the dust balls and heat
them to three thousand degrees fahrenheit. In minutes, they cool
and fuse into solid rock. Meteorites today still carry these
ancient rock balls inside them. These tiny globules were once
the building blocks of planets. To form the Earth, these
tiny must collide, stick and grow.
Speaker 9: Rocks begin to build up by accidental collisions, which can
take a long time.
Speaker 37: Eventually, the proto planets, as we call them the baby planets,
get the size of asteroids kilometers across.
Speaker 6: The baby Earth is now the size of a few
city blocks, big enough for a new force to take
charge gravity.
Speaker 37: At that point, a single asteroid will gravitationally attract a
neighboring asteroid, and so those two asteroids that would have
passed in the night are gravitationally attracted and they hit
each other.
Speaker 12: Once gravity starts to rear its head, things really speed
up because instead of just randomly plowing through material and
getting bigger that way, now it's starting to draw material in.
Speaker 6: Gravity pulls rocks together, then holds them there to produce
bigger and bigger piles of rubble.
Speaker 12: So this formation process, which was taking a long time
to get to the size where gravity kicks in, suddenly
gets kicked into overdrive and the planet grows very rapidly.
Speaker 6: But planets are more than just overgrown rock piles. These
rocks are lumpy and inert. How did the Earth become
round and full of life? The early Solar System is
a construction site for planets. Dust sticks together to form rocks.
Rocks join to form asteroids. But most asteroids look nothing
like Earth, and when.
Speaker 37: You look at a toast up of an asteroid, it
looks like some kind of distorted peanut, like a potato
that's been sort of bassed. You can see giant craters
and oblong shapes.
Speaker 6: The young Earth is one of billions of misshapen space boulders.
To become a planet, it must first become round. That
process only starts when it's several hundred miles across, when
its own internal gravity begins to change its shape.
Speaker 36: Once you get enough material, enough mass, the gravitational force
becomes stronger. Any giant mountain will be crushed down by
the force of gravity.
Speaker 27: The gravity is so strong that can actually break rocks,
and the rocks itself can lackt like a fluid, making
an object.
Speaker 6: Huge outcrops of rock crumble and fall. The immense self
gravity of the early Earth crushes it into the most
efficient shape, a vast round ball of rock, a lopsided
pile of rubble transformed into a miniature world. The Earth
has a new shape, but it's still just a ball
of rock. Its structure will also soon change. Cosmic rocks
and boulders still rain down from space. Each collision heats
the ground.
Speaker 12: There's a huge amount of energy store in an object.
It's moving rapidly, and when that hits the Earth, all
that energy is dumped into the material, and that heats
it up and melts it. And the Earth became molten
and stayed that way for a long time.
Speaker 6: The young planet is no longer solid rock. It's a
seething molten mass, just like this blast furnace at the
Severstall plant in Detroit.
Speaker 39: Believe it or not, this process behind me makes life
on Earth possible.
Speaker 6: They feed in ground up iron ore, a mixture of
rock and metal, just like the early Earth. Put iron
ore in a furnace and the heat melts everything.
Speaker 39: This multon iron is at two thousand and seven hundred
degrees fahrenheit. That's about the temperature of the surface of
the Earth four and a half billion years ago. Imagine
an entire planet molten in the distance. You will see
thundering volcanoes spewing out lava.
Speaker 15: It would be a scene.
Speaker 39: Right out of Dante's Inferno.
Speaker 6: Iron is heavier than rock. Now molten they separate.
Speaker 15: This is amazing.
Speaker 39: We're witnessing a process which created the very crust of
the Earth billions of years ago, the crust that we
walk on every day.
Speaker 6: Molten rock rises to the surface and cools to form
the crust. Molten iron sinks underneath inside the Earth. It
sank all the way to the planet's core. The rocky
surface is where we live, but without Earth's molten iron core,
none of us could survive.
Speaker 39: This process separated the iron from the rocky minerals. As
the iron descended to the center of the Earth, it
eventually created a magnetic field, and that's why we're here today.
Speaker 6: The molten iron swirls inside the Earth's core and generates
a powerful magnetic field around the planet, a cosmic shield
against deadly radiation from space. But the young Earth is
still small, far smaller than the Moon. Today, this newly
formed world must grow. It must also avoid being blown
to pieces. Thousands of protoplanets are hurdling around the Solar System,
and some are heading straight for Earth. It's one hundred
thousand years since our Solar System formed. The young Earth
already looks like a planet. It's round, it has an
iron core and a rocky surface. Yet our baby planet
is just a few hundred miles across It has a
long way to go. It must grow four thousand times
more massive, and it has competition. Thousands of other protoplanets
shoot through the Solar System, often colliding at over twenty
thousand miles per hour. You can find proof of this
ancient destructive era in modern day Arizona. Not meteor Crater itself,
that's just fifty thousand years old, but the asteroid that
gouged it out, that was four and a half billion
years old. Mark Sykes and Marvin Hilgore think the asteroid
came from a violent event in the early Solar System.
Asteroid flew through space for billions of years, then it
hit Earth. They aimed to find a fragment of the asteroid,
a remnant from the period of planetary formation.
Speaker 40: About six miles from here's meteor crater, and that was
an impact fifty thousand years or so ago, and it
spewed a bunch of pieces out.
Speaker 6: They're convinced the original asteroid was rich in iron. So
they've come prepared with some impressive metal detectors.
Speaker 26: Does it work, Oh yeah, But.
Speaker 6: Even with a quad drawn metal detector, meteorites are hard
to find.
Speaker 26: Yeah. Are you pretty convinced there's nothing there.
Speaker 40: I yeah, I don't really, I'm not detecting anything.
Speaker 6: They find metal, but no meteorites.
Speaker 40: My great discovery of the afternoon has been this bolt.
Speaker 26: And this piece of wire.
Speaker 6: It takes hours of searching and many false alarms. Then
with the light fading, the detector sounds again.
Speaker 20: How about that success.
Speaker 6: At least this meteorite is over ninety percent iron and nickel.
It could only form right in the core of a
proto planet. The protoplanet that came from must have smashed
a part in a brutal collision.
Speaker 40: Well, in the early Solar System it was a pretty
violent place, and these protoplanetary embryos would smash into each other.
They would shatter each other, exposing the interior cores like this.
It's a very tumultuous time.
Speaker 6: Entire worlds reduced to chunks of rock and metal and
scattered into outer space. In the early Solar System, these
vast collisions are common. The young Earth is in danger.
The period's name is the Taidannomackian, literally the wool of
the Titans. All rocky planets, the Earth included, go through
this destructive phase. Sometimes they shatter completely. Sometimes one consumes
the other.
Speaker 27: All the big guys are sort of competing with one
another in a very violent way, actually, to see who
comes out on top by eating all their neighbors.
Speaker 6: The battle lasts over thirty million years. Finally, thousands of
protal planets have combined into a few full size planets Mercury, Venus, Earth, Mars,
and a fifth planet, THEA. It's racing toward Earth, our
planet's last giant impact. THEA is the size of Mars,
big enough to destroy the Earth.
Speaker 12: If that thing it hit us straight on, it could
have literally blown the Earth abits, and then we wouldn't
even have a planet today.
Speaker 41: If this Mars like object had a direct hit with
the Earth, perhaps there would have been another asteroid belt
where the Earth is today.
Speaker 6: But Earth is in luck. Instead of a head on crash,
THEA strikes a glancing blow. It's the most violent event
the Earth has ever known. The impact turns the Earth
back to a molten world of magma ocean six hundred
miles deep. The Earth barely survives, and the encounter changes
our world forever. Material blasts out into space, enough rock
to build a mountain as wide as America and ten
thousand miles high.
Speaker 12: It would have been so much energy, so much catastrophe.
Huge amounts of material blasted off and went into orbit
around the Earth.
Speaker 6: The debris forms a huge ring around the Earth. This
gathers together to form two rocky bodies, both orbiting the Earth.
Speaker 36: Something the size of Mars hit the Earth about four
billion years ago. Lots of material would have been thrown off.
We now think that it may form not only one moon,
but two.
Speaker 6: For millions of years, two moons dominate the Earth's sky.
Eventually they drift together and collide. Two moons merge into one,
the massive moon we see today.
Speaker 36: There's no other planet that we know of that has
a moon as large as ours in comparison to the
size of the planet. We're almost a binary planet, two
worlds going around each other.
Speaker 6: Without this large moon, we might not even be here.
Speaker 37: Is a key role in the survival of life here
on the Earth, and the reason is that the Moon,
in its orbit stabilizes the Earth.
Speaker 6: The Moon keeps the Earth spinning at the same angle
that steadies our climate.
Speaker 9: The fact that the Earth's axis stays in the same
direction as it goes around the Sun produces the seasons,
but regular seasons, things that life can depend upon as
it evolves.
Speaker 6: Earth is neither too hot nor too cold for life.
Thanks to our distance from the Sun and our massive Moon,
the Earth is not covered in ice or steam, but
in liquid water. Yet that water must come from Sun.
Some the newly formed Earth is dry. To get water,
our planet must once again face disaster. And it's half
a billion years since the Sun first ignited. Four billion
years from now, the first humans will set foot on Earth.
The Moon is just formed, and the Earth is a desert.
Speaker 36: One of the more amazing ideas in astronomy is that
the Earth started out hot and dry. There was no
water here Originally, As.
Speaker 6: The planets formed, the Sun's intense radiation vaporized the water.
In the inner Solar System, farther from the Sun, temperatures
were cooler, so in the outer Solar system, ice and
water collected on comets and asteroids, while closer to the Sun,
the young Earth was dry.
Speaker 26: So things changed.
Speaker 12: What happened?
Speaker 36: How is it that now we have this wonderful water cycle. Well,
the water probably came from somewhere else.
Speaker 12: If you want to have a solar system that has
a lot of water in it, you have to bring
it from the outer parts down into the inner parts,
and you can do that through comets and asteroids.
Speaker 6: Comets and icy asteroids contain huge reserves of water, but
there are hundreds of millions of miles from the young Earth.
Then something changes, an event that tosses the asteroids and
comets right across the Solar System. Jupiter, Saturn, Neptune, Uranus
take a cosmic roller coaster ride.
Speaker 27: So this isn't an event that happened when the Solar
System is young, thinking of it as more of its
teenage or breakout years, where it just started the party.
Speaker 6: For a while, the young planets have not yet settled
into stable orbits. As their orbits shift, Jupiter and Saturn
fall into an intricate dance. Every time Saturn orbits the
Sun once, Jupiter orbits twice, so they always line up
at the same spot each time gravity tugs them in
the same direction. First they destabilize each other, and then
the entire Solar System, the.
Speaker 27: Whole thing just goes KLUEI. The analogy I like to
use is when a bowling ball hits pins, just goes
bam all over the place. That's what this would have
looked like.
Speaker 6: Planetary pandemonium. Neptune and Uranus switched places. Saturn races outwards.
The giant planets scatter billions of asteroids and comets onto
new paths. Many head for Earth.
Speaker 27: These asteroids and comets would have been scattered all over
the place right, some of them hitting the Earth and Moon.
Speaker 6: Cosmic missiles bombard the Earth.
Speaker 27: We believe that every square inch of the Earth got
hit by a cometer an asteroid during this period. Not
have been a fun time to be here.
Speaker 6: The bombardment less hundreds of millions of years, until finally
the gas planets settle into the stable orbits we see today,
restoring order. But Earth itself has fundamentally changed. Those comets
and asteroids were not just made of rock, but of
ice frozen water.
Speaker 41: Commets we know are made out of ice. They're dirty,
snowballs are out of space, and even asteroids can bring
water and ice to the Earth.
Speaker 6: Our oceans are full thanks to the cosmic hailstorm.
Speaker 41: So next time you're drinking a glass of water, realize
said you're probably drinking comet and asteroid juice.
Speaker 6: The arrival of water is the final step to create
a habitable planet. A sequence of catastrophes has created a
world that's perfect for life. But has it happened elsewhere
among the stars? Or are we alone? How did we
get here? Planet Earth only exists because of a chain
of extraordinary events, a lucky throw of cosmic dice.
Speaker 15: Five billion years ago.
Speaker 9: The odds would have seemed extremely slim that a planet
like Earth would form in a rather unremarkable arm.
Speaker 15: In the Milky Way galaxy.
Speaker 9: It's like trying to throw two sixes, but with dice
that have thousands of size.
Speaker 6: We know it happened once. Else we wouldn't be here,
But what are the odds it happened elsewhere that other
planets have life? Life like ours needs a planet with
the right temperature and size, a stabilizing moon, a protective
magnetic field, and just the right amount of water. The
conditions must be perfect, Yet amazingly, there may be countless
Earth like planets out there waiting to be found. Thanks
to the sheer scale of the universe, we may find
one any day now with the Kepler Space Telescope. Jeff
Marcy is mission co investigator.
Speaker 37: It has only one goal, and that's to discover Earth
sized planets around other stars that you see in the
night sky.
Speaker 6: Earth sized planets are hard to spot. Before Kepler, astronomers
took twenty years to discover around five hundred planets, most
were gas giants hundreds of times bigger than Earth. Since Kepler,
that number has exploded.
Speaker 37: Kepler has already discovered a couple thousand planet candidates. Many
of them are members of multiplanet systems two, three, four, five,
and even six planets all orbiting the same star. So
we're finding an absolute avalanche of planets out there among
the stars.
Speaker 6: Keppelar is found one planet only twice the size of
Earth and the right temperature for life. We don't know
yet if this planet has other Earth like attributes like
liquid water, but even if it doesn't, there are many
more planets out there. Keppelar is found only a tiny
fraction of them, because it only looks at a small
part of the sky.
Speaker 12: It's not even looking at the whole sky. It's looking
at a very tiny slice of stars in the galaxy.
And in fact, if you were to look up, you
could cover it with just your thumb.
Speaker 6: In the hole of our galaxy there are two hundred
billion stars. Many will have planets.
Speaker 37: Based on our knowledge from Kepler and other searches, something
like half of those stars, perhaps even more harbor planets.
Speaker 6: That means at least one hundred billion planets have formed
in the Milky Way. Earth Like worlds may be rare,
but it seems a safe bet they're out there somewhere.
Speaker 9: So the odds of getting an Earth like planet are
extremely small, much smaller than getting a double six at crafts.
But if you have a lot of dice, you're guaranteed
to get sixes, and if you.
Speaker 6: Have a lot of planets, you're guaranteed to get earths.
There are so many planets in our galaxy. Even if
the chances are one in a million, there should be
thousands of Earth like worlds.
Speaker 37: Our universe at large has hundreds of billions of galaxies,
each of which is more or less like our Milky Way.
So the number of planets in our universe is virtually uncountable.
Speaker 6: Alien earths must be everywhere.
Speaker 12: Now we haven't discovered even one of them yet, but
statistically speaking, it is a rock solid certainty. There are
millions of billions of planets like the Earth out there.
Speaker 6: And with that many Earth like planets, surely some of
them will have intelligent life.
Speaker 12: I would bet everything. I would bet my house that
there is another Earth out there somewhere.
Speaker 37: There really can be no doubt that elsewhere in our
universe there are other smart critters who are asking themselves, Gee,
I wonder if there are any other intelligent species out
there in the universe.
Speaker 6: An ordinary starfield, but home to one of the most
extraordinary stars in our galaxy, eight point seven light years
from Earth. This is uv Setti. This mysterious object can
grow five times brighter in less than a minute. Any
planet circling this star would be blasted by the heat,
quickly melting its frozen surface. Then just seconds later, the
sun dims the planet retreats into icy darkness, but uv
Seti is about to go way further. The star begins
to brighten, but this time it doesn't stop a runaway infernit.
In just twenty seconds, it gets seventy five times brighter
than normal. Uv Seti has unleashed a megaflare, an immense
explosion of energy on the star's surface. If our sun
fired off on make a flare like this weep the toast.
Speaker 12: If you were standing on the surface of the Earth
and the Sun were to get seventy five times brightery,
even for only a minute or two, it would really
probably be the last thing you'd ever seen. The temperature
on Earth would rise up, and we'd have huge fires.
It would just basically cook.
Speaker 6: Every Earth is a long way from uv SETI. We're
safe from that particular star. But the more stars we studied,
the more flares bind. They fire in all directions, sometimes
directly at us. The closer star is to Earth, the
greater the danger. And one star is way closer than
all the others. Our Son looks stable and calm, but
behind the glare, the Sun is a monster. Solar observatories
capture the violins flares erupt across its surface, gigantic explosions
on an unimaginable scale.
Speaker 42: One flare, one of the most energetic flares on the
surface of the Sun, would be equivalent to over two
hundred million hydrogen atomic bombs. It's enough energy to power
the entire human race's energy consumption for something like two
million years.
Speaker 6: Each flares as bright it is four hundred billion trillion
light bulbs. But the visible light is just a fraction
of the energy it emits. Radio waves, infrared heat, ultraviolet light,
even X rays unleashed in every flare at incredible intensities.
These are the biggest explosions in the Solar System, Yet
the force behind them is simple magnetism. The Sun has
an immense magnetic field. The energy stored in this field
powers solar flares. Vast loops of magnetic force push toward
the surface. Huge magnetic arches rise out into space. When
two field lines cross, it triggers a magnetic short circuit.
This is a solar flare. All the energy trapped in
the magnetic field blasts out At one hundred million degrees.
It can hurl hot gas a billion miles out into space,
an eruption ten million times more powerful than a volcano. Magnetism,
the same force that powers a simple compass, fuels the
biggest explosions in the Solar System. Yet by cosmic standards,
our Sun is puny.
Speaker 36: As we look out into space, we see even more
active stars, even more intense magnetism, and then things really
start to get wild.
Speaker 9: There are stars and objects in our galaxy and in
other galaxies that produce flares and great intensity, so great
they would literally destroy all life on Earth if they
were nearby.
Speaker 6: Outside our Solar system. Titanic explosions rock the cosmos on
a scale we can barely imagine. Far beyond the Sun,
we entered the realm of mega flares. Our Sun is violent.
Flares explode with the force of billions of atomic bombs,
but travel out into the cosmos and the explosions get bigger.
Other stars have flares so huge they're planet killers. Ev
Lacerti is sixteen point five light years from Earth. Every
day flares erupt on its surface, but one megaflare smashed
every record. The star blasted out ten thousand times more
X rays than the Sun's most powerful flare. The ultra
violet light was so intense the star turned blue. This
stellar firestorm, one hundred trillion miles away, was visible from
Earth with a naked eye. If our Sun flared like this,
we'd be incinerated. But Evi Lacerti is a very different
kind of star compared to our Sun. It is tiny.
This is a red dwarf.
Speaker 12: Red dwarfs are stars that have much less mass than
the Sun. They can be a tenth to about four
tenths the mass of the Sun. They're smaller, they're cool.
These are dinky stars.
Speaker 9: They burn so slowly that Unlike our Sun, which will
last ten billion years, some of them will last ten
trillion years.
Speaker 6: They're also relatively cold. Their surface is just five thousand
degrees fahrenheit, half the temperature of our Sun, and ten
thousand times dimmer. Yet somehow they're capable of staggering violence.
That's because red dwarfs are immensely magnetic. The fields which
form inside them are enormous, much more powerful than our suns.
Speaker 9: That means the magnetic field energy that could be released
when those fields get twisted up is incredibly intense. And
even though these objects are very dim and visible light,
they can produce flares that are thousands of times more
energetic than those released by the Sun. You wouldn't want
to be near one of those when it went off.
Speaker 6: All red dwarfs flare violently, but ev Lacerd's flares are
off the chart. That's because it's young, just three hundred
million years old, fifteen times younger than our sun.
Speaker 12: In one way, stars are a little bit like people.
They're hot heads when they're younger. When stars are first born,
they're spinning very rapidly, and that actually helps generate magnetic
fields as well.
Speaker 6: The result a star one hundred times more magnetic than
the Sun. When its giant loops cross the megaflare is colossal,
a torrent of radiation lasting eight hours. Big flares on
our Sun have the energy of billions of atomic bombs.
Ebie Lacert's monster flare was ten thousand times more powerful. Incredibly,
even these massive flares are just a flicker on the
cosmic scale. There are eruptions millions of times explosions that
can light up a whole galaxy from a tiny star
with unimaginable power. This is the Australia Telescope Compact Array,
a network of five radio dishes constantly listening to the cosmos.
In two thousand and four they were struck by a
massive blast of energy, evidence of a megaflare. But this
was bigger than any we had witnessed before, the largest
burst of power ever recorded from our galaxy. The object
behind it is truly bizarre, a kind of star we
didn't even know existed until a megaflare gave it away.
Speaker 12: I've studied black holes, I've studied stars that explode.
Speaker 6: I've talked about.
Speaker 12: Rogue planets wandering the galaxy. For my money, the scariest
single object in the galaxy is a magnetar.
Speaker 6: Magnetars are the most magnetic objects in the universe, and
this one beats them all. Its magnetic field is one
thousand trillion times stronger than our suns. If it came
near our solar system, the effects would be devastating.
Speaker 43: The first thing you would notice is its magnetism would
wipe every credit card in your pocket. As you start
to get closer, anything metal on you would be ripped away,
your earrings, your jewelry. Once you got within a few
million miles of the magnetar, its magnetism would be so
intense it would actually disrupt the electrical signals in your
nerves and your heart would stop beating. Get even closer,
and the magnetism would be so intense it would rip
apart every atom in your body.
Speaker 6: Amazingly, this vast magnetic field comes from an object no
bigger than an asteroid. Our sum is close to a
million miles across. The magnetar just ten, but it's unimaginably dense.
Speaker 41: It weighs more than the Sun. This is incredible. Take
the Sun and squeeze it down not just to the
sides of the Earth, but down to the size of Manhattan.
Speaker 6: The entire mass of a gigantic star packed into a
space the size of a city.
Speaker 9: You could almost walk around the star in a day,
except you couldn't because the gravitational field is so intense.
The density of material on these stars is so great
that a tea spoonful of material weighs several thousand billion tons.
You would be crushed beyond recognition in a moment.
Speaker 6: Dense and compacted, the iron rich crust is under incredible
magnetic pressure. Something has to give. Fissures rip across the surface.
The crust splits open a star quake.
Speaker 12: It's like an earthquake on Earth, except the crust literally
moves half an inch. It's just a little tiny shift,
but that is a huge amount of energy because of
this intense gravity. It's like a magnitude thirty earthquake.
Speaker 6: A flar erupts from the fracture. A trillion tongue cloud
of ultra dense matter lasts into space. It lasts to
tenth of a second, but it unleashes more energy than
the Sun emits over two hundred and fifty thousand years.
Speaker 9: The energy emitted when one of these flares from the
magnetar is released, in some cases more than a billion
times the energy emitted by the Sun.
Speaker 6: Mega flares are time machines. They show us events from
long ago. This magnetar is fifty thousand light years from Earth.
The flare we observed in two thousand and four actually
happened fifty thousand years ago. It took that long for
the light to travel halfway across the galaxy and slam
into our atmosphere. If a similar megaflare exploded near Earth,
we wouldn't even see it coming.
Speaker 12: We would have no warning if a magnetar were to
have another flare like this. The event is so sudden
on the surface, and it creates so much energy. It
blasts out at the speed of light, and nothing can
travel faster than light, So basically this just happens and
that's it.
Speaker 6: Any life within ten light years of the blast would
be vaporized. Thankfully, even the closest magnetar is too distant
to threaten us. We can't see them even with the
strongest telescope. We've only detected these stars in the flash
of a megaflare. Yet these explosions are dwarfed by an
even more powerful monster, second only to the big Bang
and scale. This is the ultimate megaflare. Seven and a
half billion years ago, many galaxies away, a super giant
star is in trouble. Its nuclear core has run out
of energy. It's about to implode. For a few seconds,
the colossal blast shines a million times brighter than our
entire galaxy. This is the most extreme explosion in the universe.
A gamma ray burster.
Speaker 41: Gamma ray bursters are so powerful that they can be
seen across the entire universe, second only to creation itself.
Speaker 6: Two intense jets of energy shootout. These two beams of
gamma rays are the ultimate megaflare.
Speaker 12: The energy of these things is just unimaginable. It's the
entire power that the Sun puts out over its entire
ten billionaire lifetime, focused into just these two things that
last for maybe a few seconds. It's like a cosmic
blow torch of gamma rays and matter that march across
the universe.
Speaker 36: The most high energy intense light is gamma rays. Gamma
rays are naturally produced by things that are billions of
degrees hot. There will never be a hotter type of flare.
This is where it stops. Gamma raises it.
Speaker 6: Seven and a half billion years after the explosion actually happened.
We see it in our skies. March two thousand and eight,
a flare from halfway across the entire universe shines even
more brightly than the closest star.
Speaker 36: Something blew up seven billion light years away that you
could see with your unaided eye on a dark night.
That should tell you something.
Speaker 6: It is the biggest flair ever witnessed. But it is
also a sign of the birth of the most destructive
entity in the universe. A black hole has formed in
the core of the collapsing star. It consumes the star
from the inside out. When the star finally explodes in
a catastrophic supernova, all that remains is a newborn black hole.
Speaker 41: Usually when we looking out of space, we see all
black holes, black holes that have been around for millions
of years. But to see a baby black hole being born,
that is an incredible event, and that's what we think
is a gamma ray burster.
Speaker 6: Amazingly, these gigantic explosions are common. We see more than
three hundred and fifty a year.
Speaker 15: We see them every day.
Speaker 41: Our satellites attect them every few hours in all directions
outside the milky way.
Speaker 6: Galaxy, gamma ray megaflares reveal one of the universe's most
awesome secrets. A new black hole is born every single day.
Most of these explosions happened a long time ago, far
away from Earth, but if one went off inside our galaxy,
it could be catastrophic.
Speaker 12: If you were to put a gamm ray burst a
hundred light years from the Europe, it would be like igniting
a one megaton nuclear bomb over every square mile of
the surface of the Earth. Facing that event, you would
be blowing up millions and millions of nuclear weapons over
the planet. It would be the end of all life
on Earth as we know it forever.
Speaker 6: Gamma ray bursts are the most powerful mega flares in existence,
but not the most dangerous for us. The greatest threat
to Earth sits terrifyingly close right at the heart of
our own solar system. We were once blissfully ignorant, safe
in our solar system. Now we know Earth sits in
a cosmic firing range. Monster megaflares are everywhere we look,
but the deadliest cosmic weapon of all is right on
our doorstep, our Sun.
Speaker 41: We're lulled into thinking that the Sun is static, is
benevolent and is our friend wrong. The Sun is dynamic
in some sense, It's alive. It creates magnetism on a
scale that we can only begin to comprehend.
Speaker 6: And its most powerful weapon is this a coronal mass
ejection or CME. A colossal solar explosion rips a chunk
of the star away and torpedoes it out into space.
Speaker 36: Coronal mass ejections are related to flares, but they're even larger.
Speaker 12: You can sort of think of it as a solar
flare being like a tornado, very powerful, very into It's
very short lived, and a coronal mass ejection is like
a hurricane, much more energy, much bigger, and can last
for days and days.
Speaker 6: CMEs start with a magnetic short circuit. Magnetic arcs emerge
from the surface, glowing with trapped solar matter. The loops cross,
triggering a firestorm of energy. The Sun erupts, solar matter
explodes from the surface out into space, a monstrous cloud
of super hot gas and electric particles.
Speaker 15: When one of these huge prominences is shot out, an
energy equivalent of about ten percent of the entire luminosity
of the Sun for a second is released towards the Earth.
Over ten billion tons of.
Speaker 9: Material is shot out at a speed of over a
million miles an hour.
Speaker 12: The power of a chronal mass ejection is sort of
mind numbing. It takes our probes years to get from
the Earth to the Sun. A coronal mass ejection can
cross that distance in a couple of days, sometimes in
only a couple of hours, or even faster than that.
So these are tremendously powerful events.
Speaker 6: Powerful but also deadly. Because sometimes the Sun shoots a
CME straight toward the Earth. The crackling charged cloud plays
havoc with our electronics. It melts power grids, blows fuses,
and disrupts communication. But that's nothing compared to the damage
that a really big CME could do.
Speaker 41: They can wipe out satellites, GPS, the Internet, all sorts
of have it can take place when this huge tsunami
hits the Earth.
Speaker 6: The damage to satellites alone with total one hundred billion dollars.
Speaker 41: Think of a blackout that hits not just one city,
but hundreds of cities around the planet Earth.
Speaker 15: Property damage would be about two trillion.
Speaker 41: We're talking about perhaps a collapse of modern day civilization.
We're going to be thrown back perhaps fifty one hundred
years into the past into a world without electricity.
Speaker 6: Big solar storms are rare. On average, a massive CME
strikes Earth every five hundred years, but it's happened before
and it will happen again.
Speaker 41: In two thousand and three, we had one of the
largest coronal mass ejections ever recorded, but fortunately it missed
the Earth. One of these days is going to hit
the Earth. One of these days, one of these rifle
bullets will be aimed right at the Earth, and at
that point watch out.
Speaker 6: Our planet is under attack, not just from megaflares in
deep space, but from our own star. The Sun fires
billions of tons of hot gas and electric particles into
space every day, deadly solar weapons, sometimes pointing straight at us.
Speaker 41: What I find amazing is the fact that the Earth
is in the middle of a shooting gallery.
Speaker 6: We have survived this onslaught. We are protected. The Earth
has a magnetic field. It's incredibly weak, but enough to
keep us safe.
Speaker 41: Think of an ordinary magnet that you use on your
refrigerator that has more magnetism than the Earth's magnetic field.
Speaker 6: Without our magnetic shield, every CME would strip away Earth's
atmosphere and we be fried. By solar radiation. How do
we know because it happened to one of our neighbors.
Speaker 10: Look at Mars.
Speaker 41: Mars is an example of what happens to a planet
without a magnetic field. Mars is a frozen desert with
an atmosphere only one percent the atmosphere density of the Earth.
It's because it lacks a magnetic field.
Speaker 12: Over billions of years, these particles have actually stripped away
Mars' air and that's why it has very thin atmosphere.
Now Here on Earth, we have a magnetic field and
we have air. This is not a coincidence. So we
can breathe because of our magnetic field.
Speaker 6: From Earth's surface safe beneath our magnetic umbrella. We see
the power of our violent sun in the northern and
southern lights. Trillions upon trillions of electric particles strike the
Earth every second. The magnetic shield funnels them to the poles.
They energize gas molecules in our atmosphere, making them glow
a chemical light show. Oxygen shines green, nitrogen blue or red.
The aurory are evidence of a battle between magnetic fields.
The Sun's field creates cmese, Earth's field shields us from them.
Magnetism is nature's most mysterious force. Only now are we
beginning to understand how it shapes the cosmos. Mega flares
make magnetism visible. They shine a light on the incredible
power of magnetic fields, fields that play a fundamental role
in the universe. They impose order on chaos. They weave
their way through the spiral shapes of galaxies. Fields hundreds
of thousands of light years across, yet one hundred thousand
times weaker than Earth's smaller Magnetic fields exist inside galaxies.
They organize matter into clouds of molecules spectacular nebulae. These
stellar nurseries are where new stars are born. Now we've
discovered magnetic fields even permeate empty space fields created in
the Big Bang with just one quadrillianth the strength of earths.
This is a magnetic universe.
Speaker 9: What's amazing is this thing that's invisible. Magnetic fields play
such an important role in every aspect of the universe,
protecting us from the radiation from the Sun, to the
explosions in red dwarfs, to the magnetars, and to the
most energetic violent processes in the entire universe, gamma ray burst.
Speaker 15: Magnetism plays a role on every scale of.
Speaker 9: The universe, changing the dynamics of objects and making universe
a violent and interesting place.
Speaker 6: Mega Flares light up the cosmos. They show us things
we can't otherwise see from the other side of the universe,
or from billions of years in the past. A black
hole is born, a star dies, Distant events and hidden
mysteries in a flash flares reveal them, illuminating the awesome
secrets of the universe.