Somewhere not far from Earth, a star enters its death throes...
and explodes in a violent supernova
Leaving in its wake is the strangest phenomenon in the cosmos
a black hole.
Our galaxy may be infested with millions of them.
But now, there's evidence of something even more ominous...
Black holes - of unfathomable size and power.
That's a big galaxy and right down in the centre, we can't see it,
a black hole that's got a mass of a billion suns.
Astronomers are now studying them in unprecedented detail...
and finding they are bigger... stronger... and more destructive than anyone imagined.
We'd like to think black holes are far, far away.
But what if there's one on our cosmic doorstep?
A team from Europe; and another from the United States
are in a high tech race to be first to see into the very heart of the galaxy
Now an extraordinary new experiment
is giving astronomers a first ever glimpse inside a black hole,
to see what's in the lair of the Monster of the Milky Way.
A new era in astronomy has begun...
High-tech instruments in space
are now revealing a universe rocked by violent events.
JPL com, Chandra OC...
In the distant galaxies,
astronomers have witnessed space and time shattered by eruptions
so vast they boggle the mind.
To put this on sort of an Earth scale,
that is equivalent to about a trillion, trillion trillion atomic explosions.
But what could produce such awesome power?
Whatever it is, it lives at the centre of our own Milky Way.
Scientists now believe it is the largest and most powerful object in the universe
and yet it emits no light.
It is called a Black Hole.
First suggested by Albert Einstein's equations,
a black hole is space and time twisted into a furious knot
But the great scientist believed it could never exist in nature.
Albert never really liked the idea of black holes, himself.
He thought they were anathema - this was something that nature should avoid.
The places where space and time became infinitely twisted up
he thought no, nature shouldn't allow that.
Black holes are certainly odd beasts in the universe.
And they were thought to be peculiar,
so peculiar as to perhaps not even really exist in the real world.
Simply because your equations show that they can exist
doesn't require that the real universe has them.
That there is something strange and powerful
lurking in the centre of our galaxy first became clear 75 years ago.
Early radio telescopes recorded a hiss, like the sound of steam.
As a young astronomer,
Eric Becklin was determined to get to the bottom of this mysterious energy source
First, he had to find it.
There was a radio source called Sagittarius A, a very strong radio source
but there was even debate about whether that was really the centre or not
Astronomers knew that the centres of other galaxies are tightly packed with stars.
But when they tried to see into the centre of our galaxy,
those stars were obscured behind a thick veil of dust.
There is so much dust, between us and the galactic centre,
it is completely opaque.
You do not see the stars in the galactic centre.
The most powerful telescopes cannot see it.
Becklin knew that some kinds of light, invisible to our eyes,
can make it through the dust.
Infrared for example, travels in slightly longer wavelengths
Infrared radiation gets through the dust
because its wavelengths are longer
and the dust just kind of rides on the infrared wave.
In the 1960's,
Becklin bought an infrared detector from a military contractor
and attached it to the end of a telescope
It was August of 1966.
It was a beautiful night.
As we were looking with the Infrared detector,
we were seeing more and more stars.
And the signal increased,
and each star gives you more signal.
And we were building up,
as we were getting closer to the centre, more and more stars,
and we were actually seeing through the dust for the first time
and then came to a peak -
and then back down again,
and I knew immediately that that was the centre of our Milky Way
and that I was the first person to actually see the stars in the very core of our galaxy.
Eric Becklin had discovered the very heart of the Milky Way...
the exact location of the mysterious energy source.
But its staggering power meant that this was no ordinary star
Scientists believed the only one thing that could explain the mystery
was the very idea that Einstein had rejected an object that defies explanation...
What's a black hole? It's a monstrous, mysterious thing.
It is a point of infinite density.
We don't know how to wrap our brains around that.
It's a region where space and time have closed in on itself.
A black hole is a region of space where the pull of gravity is so immense
that not even light can escape it.
And you reach the point where light cannot even come out.
And if light can't come out, you are not coming out.
And if light, plus you're not coming out, it is a black hole -
there is no other phrase we can possibly use to describe it
Welcome to the strange world of extreme physics...
where space and time literally cascade into the abyss.
Space itself is falling inside a black hole.
It's rather like a river falling over a waterfall
except its space itself that's falling over the cliff.
It's rather like a kayaker trying to make their way upstream
on a river that is going too fast.
They get dragged down to the centre of the black hole.
Gravity becomes a riptide.
The closer you get, the stronger the current.
Eventually you reach the Event Horizon - the point of no return.
The matter goes inside the surface of the black hole
shrinks down to the very centre where it gets destroyed
in a region of infinite warped space and time.
And it's gone.
The gravity at your feet if they're close to the black hole
is a little bit stronger than the gravity at your head
and you feel that as something that is tearing you apart.
The tidal forces unrelentingly getting stronger,
as they exceed the molecular forces that bind your flesh.
And so you end up moving through space-time like toothpaste through a tube.
And ultimately will pull your atoms apart
You will be, as we say, spaghetti-fied.
As strange as they are,
black holes are a product of the familiar universe of stars and gravity.
They have their genesis in a type of enormous star called a 'Red Super-giant'
It is 10 times heavier than our Sun
yet it will burn itself out in a fraction of the Sun's lifetime.
Deep inside -
the crush of gravity sends temperatures roaring above a billion degrees.
Helium and carbon fuse into heavier elements - oxygen, silicon, sulphur
Then - the star implodes under its own immense gravity,
sending a shock wave roaring out.
The star digs itself deeper into space travel
and now goes Supernova in a violent explosion.
What's left is a dense core of subatomic particles -
a neutron star - only about 16 Kilometres across.
It's so dense
that a teaspoonful of neutron star matter would weigh about a billion tons.
Eventually the gravitational pressure will be so large
that the neutrons themselves will be crushed
and there will be nothing left to stop the collapse.
A black hole is born...
it's a million times the mass of the Earth,
but compressed so tightly it literally exits the known universe
Now the effect of that mass is still in our universe.
The mass is still here in that it's causing this fold in space,
that goes all the way down.
It has become a hole.
The best way to look at it is
if you stick your finger down in there, you ain't getting it back.
We know exactly what effect a black hole is going to have on its environment
on the stars in its vicinity. On the gas that wanders a little too close
So will we ever see a black hole?
No.
But that's not what's important here.
What's important here is we can see its paw print.
In search of a black hole's paw print,
Eric Becklin is on a life-long quest to probe the centre of our galaxy.
The Milky Way is a giant spiraling disc of over a hundred billion stars.
Our sun is about halfway out, in the peaceful suburbs.
Becklin is headed to the galaxy's most exciting and most violent zones.
But to make the final leg of the journey, he would need help.
So he turned to a rising star in astronomy.
Andrea Ghez believes that the key to finding a black hole at the centre of our galaxy
lies in tracking the stars that buzz around it.
For about three decades or so
there has been this question of whether or not
our galaxy harbours a super-massive black hole at its centre.
And the key to answering this most definitively
is to watch stars at the centre of the galaxy orbiting.
Ghez's team set up at the newly built Keck telescope
on the summit of Hawaii's Mauna Kea Volcano,
the largest telescope ever built.
Our view to the centre of the galaxy is absolutely superb.
Our ability to position stars at the centre of the galaxy
is like somebody in Los Angeles seeing somebody in New York
be able to move their fingers like this, okay, just two centimetres.
That is the precision with which we can measure something that is
twenty-six thousand light years away from us.
Madeline, we're ready to go.
The conclusive experiment to be done
that really demonstrated that there was a black hole
was to follow the orbits of individual stars very, very accurately
and with the highest precision possible
But the stars in the centre of the galaxy
were not the only thing Ghez and Becklin had to keep track of
Another group working in the mountains of Chile
was hot on the same trail, led by Reinhard Genzel from Germany
This guy here
is a little too dense to be just a random collection.
We suspected in the galactic centre,
there may be hiding very massive black holes.
To really be sure that they are black holes,
we have to go in there as close as we can.
We can make measurements really good now to prove it must be a black hole.
Both teams wanted to be the first
to prove that our galaxy harbours a super-massive black hole,
but Genzel and his team had a three year head start.
The amazing precision of Keck is the 'ace in the hole' for Ghez and her team
Mark Morris is a veteran of the Galactic Centre Search.
The German group had already started to make headway on the galactic centre
even while we decided to pursue this.
We knew that in a head to head competition,
that as long as they were using the small 2.2 meter telescope
that they were using compared with our 10 meter telescope that we would blow them away.
That bright speck on the top of this insert.
That's the star which really has given us the essential clue for the black hole.
It was certainly high excitement,
but on the other hand... we would have to compile like
at least five years of data before we could see the stars move
But what kind of cosmic monster was pulling the stars along?
This is our road map,
and that's the centre of our galaxy
So, there's a large cluster of stars that are orbiting the centre of our galaxy
Basically the way this experiment works is you take an image,
you see where all the stars are
and then you come back some time later, and you take another image.
And you look to see if they have moved
And so the second time we took an image we knew we were golden
that those stars had clearly moved.
The first order of business was to see how large the object is,
to weigh it by measuring its gravity.
So we have the black hole here.
The more massive it is, the more pull there is.
The more pull there is, as it gets closer to the black hole, the faster it goes.
And we are measuring the speed of these stars.
That's the key to getting the mass is measuring the speed of those stars
Andrea's more advanced telescope made the difference.
The object weighed in at a staggering 3 million times that of our sun.
But that didn't prove it's a black hole...
It could still be a cluster of smaller objects.
For the Germans, it was time to even the playing field.
The VLT, Very Large Telescope, opened its doors on a mountain in Chile
Both the VLT and Keck were upgraded with revolutionary technology.
For years, the teams relied on computers
to pinpoint the location of stars through the turbulence of our atmosphere
Now they could cancel it out with a new system known as Adaptive Optics
It uses a powerful laser beam to read the turbulence.
Telescope operators can use those readings
to sharpen the image of distant stars and galaxies.
So this little animation shows you the benefit of adaptive optics.
So you see the stars without adaptive optics,
you turn the adaptive optics on, and all of a sudden, you see stars
And in particular, you see stars near the centre of the galaxy,
we track all of them, but these are the ones that are the key to the problem.
These new eyes were delivered just in time...
With both teams watching,
one of the stars made a dramatic hairpin turn around the centre.
In 2002, it made a huge jump to over here
So, whoop, all the way around.
The star was initially going very slowly and then moving around very quickly
and at that point coming very, very, close to the central black hole.
It is moving on order ten million miles per hour.
So it is just speeding away.
The star had come close enough for the teams to see
that it had to be circling a single massive object.
All other physical explanations of what was at the very centre were gone
The only thing left was a black hole.
To astronomers around the world, the evidence was impressive.
I have to say when I first saw Andrea's video I was stunned,
when I saw that star come out of the left side of the frame
and go zipping around
and go shooting off into the other end of the frame
and it move around a point in space and nothing was there.
That we could with our instruments, together with our minds,
effectively travel to the centre of the galaxy,
26 thousand light years away,
and collect the evidence for such an incredible object was really an amazing achievement.
The European and American teams
had confirmed that a black hole was there without actually seeing it
From our quiet corner at the far edge of our galaxy's spiral,
it's hard to imagine the violence at its centre.
The closer you draw toward the centre, the denser it gets.
Our destination: the galaxy's central hub, brimming with stars
known simply as "the Bulge"
Venture into the bulge and you enter a busy highway.
It's jammed with star traffic speeding in every direction
and it's always rush hour.
There is a lot of gas.
There is a lot of dust.
This is absolutely the most crowded place in our galaxy
There will be stars all around us. An incredible density of stars...
you couldn't exist there; there is lots of ultra violet radiation
X rays are floating around.
Gas clouds bash into each other...
So it is a very hostile environment really.
The black hole is surrounded by a cloud of super-hot gas that's falling in.
The space around the black hole is so warped -
it distorts the light that scatters across it.
As bizarre as it seems,
the gravity of a super-massive black hole is so spread out
that you might fall in and survive... for a moment.
During the final descent,
you would then go into the event horizon but you would actually not feel it
because you are a small body, compared to the large massive black hole
Now, thanks to a computer simulation,
based on Einstein's own equations - we can visualize the scene.
As you move toward the black hole's core
you hit an inner horizon, a log jam of trapped light and energy
At a certain moment as we hit the inner horizon,
there is this infinitely bright blinding flash of light.
That is the stuff that has been waiting there trying to get out,
it is just held there at the inner horizon
it would vaporize you.
Almost certainly if you fell into a real black hole,
you would simply, unfortunately die
But that's not the end of the journey
The computer storm can be turned off,
and the strange predictions of Einstein's equations allowed to play out
A passageway opens up -
a tunnel through space and time known as a wormhole.
We now leave through a strange door known as a white hole.
Here the twisted logic of extreme gravity goes into reverse.
Instead of being sucked in,
you'd be catapulted out to the far reaches of time and space.
But to where?
In science fiction, wormholes offer handy escape routes to other universes
In reality, the inside of a black hole
is probably too chaotic and violent for a wormhole ever to form.
The black hole at the centre of the Milky Way is strange enough as it is.
But is it the norm, or is our galaxy a freak of nature?
To find out, astronomers have mounted a major international project
to search galaxies throughout the universe for evidence of super-massive black holes.
From Apache Point in New Mexico,
astronomers are probing big galaxies out to a billion light years from Earth
They take a series of steel plates
and drill holes to exactly match the location of galaxies in the night sky
Then they plug fibre optic sensors into those holes,
and for the first time ever,
they can use the plates to capture the light of hundreds of galaxies per night
The astronomers are looking for a distinctive light signature coming from a galaxy's core.
It's a sign of hot gas swirling into a black hole.
The goal of the project, called the Sloan Digital Sky Survey,
is to map a quarter of the entire Northern sky,
to find out what kind of galaxies make up our universe
and how they are arranged.
Of the 125 billion galaxies that make up the visible universe,
more than a million have so far been analyzed.
Nearly all the large ones, circled in red,
bear the signature of a super-massive black hole.
The closer we look to the centres of galaxies,
the more we find these black holes, and the inventory is rising high.
So any idea for the formation of a galaxy
will now have to include some explanation for how you get a black hole in its centre.
But how did every big galaxy in the universe
end up with a giant black hole in the middle?
To understand, go back to the very beginning...
the Big Bang.
Matter and energy rush outward as the universe expands.
You have the big bang handing you your birth ingredients,
your hydrogen, your helium, your traces of some other elements
So it is kind of like this soup.
You put it together and stir it.
It's gravity that stirs the soup.
Over billions of years
it moulds the universe into a spider's web of gas and galaxies
Within this web gravity draws together wisps of hot primordial gas.
Over tens of millions of years, the clouds of hydrogen gas coalesce,
growing more and more dense.
Some grow hot enough to ignite.
The first stars are born...
giants, hundreds of times bigger than our Sun.
They burn out quickly and explode in the flash of a supernova
Billions of years later,
an orbiting satellite called Swift is in position to capture that flash of light.
Swift is the eyes of an international group of astronomers
Within 30 seconds of detecting a flash,
it sends out an alert via mobile phones, pagers, and emails
The astronomers scramble to their telescopes.
Speed is vital.
They have to catch the light beam
if they are to probe the dark secrets behind these distant disasters.
First they determine how far it has travelled,
give it a name and pinpoint its birth galaxy
By analyzing the light,
they have gleaned the distinctive signatures of black holes being born
The most distant are the earliest generation of primordial monsters.
We could be forming the seed of the super-massive Black Holes
that we see galaxies today,
very early on when the very first objects forming the universe.
We can now with our big telescopes look back in time.
And sure enough what we find is that at the same time when the galaxies formed
also the black holes formed...
it may very well be that they needed each other.
This computer simulation shows how our Milky Way galaxy was born
It grew over billions of years
from a swarm of smaller galaxies, smashing together, merging.
In a cosmic dance of death,
the infant galaxies swirl around and orbit one another,
gravity pulling them closer.
If another galaxy comes too close
they will each feel each other's gravity
What started out as a stately ballet of stellar orbits,
moving around the centre of their galaxy, has now become this maelstrom.
There is no other way to say it: galactic cannibalism.
That is what they are doing.
They are dining on their neighbours, eating entire galaxies.
Well for every galaxy you eat,
if that galaxy has a black hole in its centre it is going to eat the black hole
And the black hole will work its way down to the centre of the large galaxy
making the centre of the galaxy bigger, as well as the galaxy itself.
As galaxies swallow each other,
the black holes at their centres merge and grow.
There was an epoch once about one two three billion years after the Big Bang
when in fact galaxies were forming or at least they were tremendously more active than now
And at the same time black holes already existed, had formed,
and were feeding at tremendous rates,
producing very powerful quasars.
Quasars are bright beacons of light at the centres of distant galaxies,
where feeding black holes shine brighter than anything else in the universe.
The Hubble Space Telescope peered into a dormant quasar
in a nearby galaxy called M87.
It found a tiny central region where gas is heated to tens of millions of degrees
and whipped by gravity to millions of kilometres per hour.
So what had become obvious was that
there was a tremendous amount of mass and a very small volume,
but that mass was very unlikely to be stars
like those that we see in our galaxy.
Astronomer Brian McNamara believes giant ravenous black holes
can have a profound effect on the surrounding galaxy and beyond
Can we get an offset?
180. 180, 180, same direction.
We are setting at 360, 360.
The guider is locked up.
McNamara is studying a trail of devastation left in their wake.
It's not amazing.
All of these other galaxies are gravitationally bound to this galaxy cluster.
So they're all buzzing around this giant galaxy like bees buzzing around a hive
These clusters are the product of galactic cannibalism on a cosmic scale
This computer simulation shows how a galaxy cluster evolves
in a dense region of the universe,
tens of millions of light years across
Hundreds of galaxies form then swarm toward a common centre.
A central galaxy swallows them up.
As it grows, so does the black hole.
McNamara is searching for the monster's paw print.
So that's a giant galaxy sitting in the middle of a cluster galaxies
And so the idea is that's a big galaxy and right down in the centre you can't see it
and we think there's probably a black hole that's got a mass that approaches a billion suns.
It very recently in the last several tens of millions of years gobbled up a lot of matter
and it caused a huge eruption.
McNamara zeros in on a distant galaxy cluster 2.5 billion light years away
Called MS07, it's hidden in a vast cloud of hot gas.
There is an atmosphere of gas that pervades the entire galaxy cluster
And it is an atmosphere like our atmosphere except that it is far less dense
and it is it is much much hotter.
McNamara noticed that two immense cavities in this cloud
had been hollowed out.
So between this cavity here and that cavity there,
we could stuff 600 Milky Ways in there.
It's just astonishing.
The energy involved is huge.
McNamara believes this eruption of energy
is the most powerful since the big bang itself.
He traces its source to the core of the giant central galaxy,
a super-massive black hole.
But how does a black hole,
a creature famous for devouring everything within its grasp,
spew energy across the universe?
As matter falls in
what we know now is that it spirals around in a disk,
ok very much the way when water goes down the drain.
And the speeds that matter can achieve around that black hole
approach the speed of light.
And when matter travels at that speed
it gets a tremendous amount of energy.
Matter falling into a black hole
is a lot of stuff trying to get into a very small place.
And so it is like trying to fill a dog dish with a fire hose.
Most isn't going to get in.
A high-speed whirlpool of matter coils around the black hole,
creating a powerful magnetic field
that hurls enormous volumes of gas outward.
It produces a powerful jet of matter-
hundreds of millions of times the power of the Sun-
that blasts right out of the galaxy.
There is no question that black holes at the centres of galaxies
have a profound influence on their surrounding,
they send out these huge jets, moving at almost the speed of light,
and those jets can send shock waves into the surrounding medium,
change their surroundings completely.
They have a dramatic influence.
These jets can literally sterilize the galaxy,
by halting the formation of new stars
In principle galaxies can grow to very, very large sizes
and what we see in the universe is that they don't.
And we think that the supermassive black holes at the centre may be the culprit.
They may be responsible for preventing runaway growth of galaxies
In smaller galaxies,
all this violence can have a creative impact.
Black hole blast waves spread heavy elements generated in the core of the galaxy,
setting the stage for the formation of new solar systems.
We usually think of black holes as god's dumpster,
but they really are actors on the galactic stage.
The Monster of the Milky Way may have helped create our solar system
but what's to stop it from wiping us out?
It all depends on the Monster's diet.
One of the key differences between galaxies with super-massive black holes
is whether or not the black holes are lit up,
because they are basically binging on a lot of material in its surroundings
For years, our own black hole has probably been fasting.
But in 1999, the Chandra Space Telescope
detected a powerful signal from the galactic centre.
Station 34, Chandra OC.
Just to let you know we have about 18 minutes remaining at the playback
An explosion just outside the Event Horizon...
For the Galactic Centre teams, the blast is a wakeup call.
It was a hot piece of news at the time
A remarkable fact for all of us was for many years
how inactive the black hole was.
The big puzzle is there are so many blue stars that side and...
Now, both Reinhardt Genzel and Andrea Ghez
race to their telescopes.
They will try to see whether the black hole's about to binge.
The two teams join in a worldwide effort
Five major observatories will probe the black hole.
From space, the Chandra X-ray Observatory
will watch for high-energy light.
Reinhard Genzel heads to Europe's Very Large Telescope
set in the high desert of Chile.
Andrea Ghez climbs Hawaii's Mauna Kea volcano,
to the legendary Keck Observatory.
When you are there it is an incredible rush,
I mean you are very much on for the few nights
that you are there, hoping that that your experiment works
Hoping that the weather cooperates.
Telescope time is precious, there's no room for mistakes.
Madeline, we're ready to go.
The teams have five short nights to find out how much the black hole is eating
by measuring the energy that flares out
Night one - the Chandra headquarters in Cambridge Massachusetts.
Zoom in a little more.
Alright, so, first night, it doesn't look like there are any flares.
The telescope turns up only noise,
x-ray flashes from small black holes roaming through the galactic centre
Four more chances, guys.
Night two - the telescope in Chile has problems.
Can I see the monitor the correction?
There's still not very much there.
Well we do need to sacrifice now someone to the gods or something like this.
Should I volunteer?
Even if there are flares,
the Very Large Telescope can't see them
We have to redo the acquisition.
The correction was unstable.
A patch of humidity is warping the delicate optics
everything's a blur.
Look at the guide star.
Alright now we have a problem with the main mirror,
the eight meter mirror, seems to be deformed.
In Hawaii, it's not much better.
The Galactic Centre is playing hide and seek behind overcast skies.
We're fighting with clouds.
It looked better just a moment ago.
It looked like we were just ready to go But now it's looking like.
Finally on night three.
Look at this, it's really flaring.
The German team's luck changes... in Chile they spot an outburst.
That's the best flare event that we saw in this run.
A new point of light appears in the star field - one that wasn't there before.
Here clearly we see there's basically no source at that position.
Just those two blobs.
On the other side in the same region,
and we clearly see those same two sources
And now in between we see an additional source.
So this is the flaring stage...
When the Chandra team receive their data from space -
they can see it too.
Oh! Alright... Here we go.
Oh, yeah, that's huge...
It's a least a factor of 15 or so.
The x-rays show a spike
that coincides with the flash of light captured by the Germans.
News from our colleagues.
Of course telling us they are a few hours further west,
so the sun hasn't even set yet.
The stars of the Galactic Centre haven't yet risen above the Hawaiian horizon
Ghez has missed the flare.
This part kills me, waiting.
But the next night the team gets what it's looking for
Well I like that image a whole lot better
This is it! Really? Yeah! Really!
We were taking measurements
and you didn't see anything from the black hole,
all you saw was a star and then bam it was there.
And bright. And fifteen minutes later, it was gone
So that was our moment to make the measurement
and it was extremely exciting to know that we had actually been able to catch it
One day, not long from now,
these scientists hope to see the monster directly...
by linking observatories around the world
in a giant telescope powerful enough to peer deep into the centre of the galaxy
What they will see is a dark spectre framed by flashes of light.
These are just flares compared with the monumental eruptions of its past.
Our black hole had a wild teenage life, I am pretty sure of that.
It probably had jets. It threw lots of matter out.
It had a grand old time.
And now it has decayed into the Old Folks Home of the galaxy.
But what would it take for the Monster of the Milky Way to awaken?
Could explosive jets of energy once again blast across our galaxy?
The watch is on at the very ends of the Earth.
Astronomers have come to the South Pole
to monitor radio signals from the Galactic centre.
They can see signs of a disaster in the making.
A vast ring of gas is looming just beyond the Milky Way's central black hole.
In time, it will accumulate 300 million Suns' worth.
When the ring reaches a tipping point,
it will begin to funnel into a second ring that orbits close to the centre.
The inner ring will condense into a giant cloud.
Within it a storm of new stars will be born.
Then the gas cloud will begin to spiral down into the grasp of the black hole.
When the feasting starts,
the eruption will be visible far beyond our galaxy.
Our galaxy will survive its black hole's upcoming feast.
But it isn't likely to survive a threat further down the road...
Galactic Cannibalism.
Our galaxy, the Milky Way,
is not immune from these colliding galaxy scenarios.
We've got neighbours.
We are falling towards each other.
And one day we will collide.
Even now, the end of our galaxy is approaching.
Our giant neighbour, the Andromeda Galaxy, is charging toward us.
Knowing the galaxies' dimensions, flight paths and the laws of gravity,
scientists can predict how the clash of titans will unfold.
What our simulations show is what could happen
basically in quite a few billion years from now,
when the two galaxies will actually approach each other and merge.
First the galaxies will circle and entwine, ripping each other apart.
Imagine what that might look like from another galaxy.
They will see two grand, beautiful, spiral galaxies moving towards each other
slowly losing their shape.
They'll see new avenues where stars and gas
can funnel down towards this newly formed centre.
Feeding this reborn monster.
The collision will send a blizzard of stars and gas
billions of kilometres into space.
Some will shoot toward the crowded core of the new galaxy,
spurring even more massive explosions.
Amid the turmoil, our little solar system will be flung into the voids of space,
or driven into the black hole's jaws.
In the process of merging there will be a very strong star burst event,
occurring at the time of the merger,
as all of the gases being funnelled and towards the centre.
As well as the two black holes that are likely to merge
will also swallow a lot of this gas.
So the black hole in our Milky Way will ignite emitting so much energy
that all of the gas around it will again be blown away
in this very substantial wind, and very substantial outflow.
The Milky Way will be destroyed...
but what about the black hole at the centre?
It will merge with Andromeda's.
Stars and galaxies may come and go,
but super-massive black holes just keep getting bigger.
Once considered freaks of the cosmos,
black holes may simply be the workings of a restless universe.
As we forge ahead in trying to understand how we came into being,
and how all of the matter got put down in the universe,
we can't leave black holes out of the picture
because it seems they play a fundamental role on very, very large scales.
Black holes not only actively shape the landscape in which they are invented,
they wreak havoc upon it.
You throw in a hungry beast in the middle of it all
and it distorts the gas clouds. It flings stars hither and yon.
It creates energy fields that would fry any life in its vicinity.
That kind of makes the centre of galaxies interesting places.
So, black holes are kind of the spice of the universe.
They are a major player
in the evolution of the things that light up our night sky.
Even though we can't see them,
they are in a sense the secret shadows behind the waltz of the galaxies.
Scientists today are bringing us closer to a shadowy presence
that long ago erupted across our galaxy
and shaped the universe we know.
For the moment the monster is resting quietly...
but how long will we have to wait for it to rise again?
www.mvgroup.org