Space's Deepest Secrets (2016–…): Season 1, Episode 7 - Attack of the Space Junk - full transcript

narrator: in the beginning,
the universe...

was a bit of a letdown,

abel: for millions of years
after the big bang,

things were actually
rather boring.

it's just this soup.

loeb: the big bang was not
the moment of creation.

the real moment of creation

came 100 million years later.

there was this magical, if you
like, metaphysical moment.

narrator: the cosmic dawn.

the moment of first light.

it wasn't really our univers

until the first star was born.

the first stars are
fundamental to how

abel: they're like
the rock stars in the

they live fast and die young.

narrator: the first star
lit up the universe...

bromm: for the first time
in cosmic history,

the universe really is
getting interesting.

narrator: ...and began forging
the ingredients

that made you, me,
and everything around us.

it was the starting point

that led to
the appearance of life.

narrator: astronomers
are now trying to witness

and understand
this moment of creation.

dunlop: i guess what we're
trying to achieve is

see the beginning of things.

loeb: we are dealing
with a scientific version

of the story of genesis.

"let there be light."

captions paid for by
discovery communications

our story started with a hot,

...the big bang, often
as being the moment of

loeb: the big bang

arranged the initial
of the universe.

early on, the universe
was very bright.

the temperature of the
was very high,

much higher than we find at
the centers of stars nowadays.

but as the universe expanded,
it cooled off.

and as it cooled,

the universe became darker
and darker.

the lights went out, and
our universe was nothing more

than a vast, black fog
of hydrogen.

welcome to the dark ages.

loeb: several million years
after the big bang,

the universe
was dark and boring,

filled with cold hydrogen
floating through space.

all the things we treasure
did not exist.

the big bang was not
the moment of creation.

narrator: the big bang
gets all the credit,

but in reality,
it merely set the stage.

it created space and time,

a brief flash of light,
and some hydrogen fog,

but nothing that you or i
would recognize

as our present-day universe.

but somehow the universe
transformed itself

from dark and boring

to a place filled with stars

and, eventually,
planets and life.

figuring out
the almost 14-billion year

history of our universe

is like researching
your ancestry,

when no ancestors
left any records,

and some relatives
are in hiding.

our cosmic family book.

that's an image of the earth
from the moon,

a quite beautiful image.

this is our home.

and, of course, we would like
to trace our cosmic roots

all the way back
to where we started.

we have some brilliant
of our universe as it is to

our solar system...

...our milky way galaxy...

and our galactic neighbors.

and if we go to
the very beginning of the

we also have
one spectacular image.

where it all began.

narrator: this picture shows
the cosmic microwave

from a mere 400,000 years
after the big bang.

loeb: this is an image
of the infant universe,

and that image shows us

the conditions
in the very early universe.

but after that image,

there is a gap,
a period of darkness and fog

the dark ages.

we don't have photos of those.

these are the missing pages
in our photo album.

"the universe --
the cosmic photo album."

yep, that's worth a blow-up.

[ laughs ]

i guess this is the famous
cosmic dark ages.

[ laughs, mutters ]

narrator: astronomers are
desperate to fill in the

somewhere in these
missing pages,

the first star was born...

[ both laughing ]

still blank.

...a moment of transformation

when the dark fog gave way
to a universe of light...

these are the bits
that we want to fill in.

how dark is it?

...the real moment of

when light and matter
came into being.

the first star probably formed
about here.

somewhere in these pages.

astronomers around the world

are devising
a variety of ingenious methods

to capture an image of that
first light in the universe.

at the edinburgh
royal observatory,

jim dunlop and ross mclure
are tunneling deep into space

to see the true dawn
of the universe.

what we're trying to achieve
is see the begin

see when the first structures
in the universe formed,

first stars, first galaxies.

narrator: they have been using
the hubble space telescope

to take one of its most
important pictures ever.

they arranged
for the hubble space telescope

to spend almost 44 days taking
one very ambitious photograph.

we're looking at
an ordinary patch of sky.

in this case, a little bit
to the right of orion.

but it's a tiny, tiny area
smaller than my fingernail

that looks blank
to the human eye.

narrator: it may look blank
with the naked eye,

but hubble is allowing
jim and ross

to tunnel deeper
into the distant universe

than ever before.

dunlop: we're trying
to look back as far as we can

to the beginning of time,

as close to the big bang
as we can manage.

here, we have orion,

a constellation
that many people will

and we're zooming in,
tunneling in.

to tunnel through space a

from the most distant objects
in the university,

they used what may be

the longest exposure
in cosmic history.

during the course of 650
they pointed hubble

at the same tiny thumbnail
of dark sky for 100 hours.

dunlop: we go deeper,
tunneling into deep space,

and we start to see
very faint galaxies appear.

narrator: as they tunnel,

they are reaching further
and further back in time,

because the further away
something is,

the longer its light
has taken to reach us.

and what we see
of a distant object

is how it looked
in the distant past.

one of the simplest ways
to look at is to realize

that even the sun is seen
as it was eight minutes ago.

so, if the sun disappeared,

we wouldn't know
for eight minutes.

and if jupiter disappeared,
we wouldn't know

for about an hour,
or something like that.

what's really staggering

is that once you get
to the nearest galaxy,

that delay is already
several million years.

narrator: which means that
we are seeing these galaxies

as they were
millions of years in the past.

deeper down the tunnel,
there are galaxies

that we see as they were
many billions of years ago.

dunlop: and here, we start
to come into this image

of what's called
the hubble ultra-deep field.

and these galaxies now,
we're seeing back

to within a billion years or
of the big bang.

dunlop: so, this here
is the deepest ever image

of the night sky ever taken.

narrator: the hubble
deepest, most distant image,

shows us galaxies as they were
over 13 billion years ago.

that tiny, if you like, bore
hole that we made into the

so, it is a window
into a very different time.

mclure: we're the first people
to look at this data.

there's just one object
in there

from the thousands
that are in that image

that we identified
as being potentially the most

the most distant object
ever been seen by anyone.

this one here is the most
distant of all.

sort of zoomed in, it's just
literally a faint blob.

and there's only
a few photons of light

being collected
to see this object,

which we're seeing

only 500 million years
after the big bang.

narrator: this faint blob
out to be an entire galaxy.

dunlop: see, it's not a star.
it's not point-like.

you can see
it's slightly extended,

which proves it's a galaxy.

and about 20 times smaller
than our milky way.

but that's about all we have
on this galaxy.

we can't even measure
its color very well.

it's only just
detected by hubble

in its very reddest

there's a certain excitement

to being the first person
to ever look at that image,

and from that image,

see this object
that nobody's ever seen

let's put it
in the right place.

ross and jim have identified

it's more than
13 billion years old.

you can do the sticking.
why not?

this image shows
one of the first galaxies,

billions of stars
gathered together.

which way up is it?

but the first individual star
is not in this galaxy.

we will need other tools
to see that.

at siding spring observatory
in australia,

stefan keller is trying to see

the very first star
to ever light up the universe.

he's not staring at
the furthest reaches of space.

he's looking
much closer to home.

the star we're most familiar
with is, of course, our own

keller: here we are
on top of the mountains

catching the last rays
of the sun.

and the sun
is very special for us,

but it's a very average
sort of star.

it's been around
for about 4.6 billion years --

1/3 of the lifetime
of the universe.

that may sound like a long

but it's pretty typical
for stars in our galaxy.

keller: what we're looking for
are those very rare stars

that are amongst the oldest
stars that are out there.

narrator: stars can be
100,000 times bigger than

but all stefan has
available for study

is a pinprick of light.

keller: light is all
that we have to work with.

we need special ways

of dissecting the starlight
that is coming to us

so that we can understand
where they've come from,

how old they are.

when we decode that,
we can uniquely identify

some of the oldest stars
that remain with us today.

by analyzing starlight,

stefan can see
what the star is made of.

and if he knows that,
he can estimate the star's

stars are fundamental to life,

that have created everything
that we need on earth.

the rocks that we see have
formed inside a stellar

and then thrown back
out into the universe.

the gold and the silver
in the rings on my finger,

they've all been made
in a supernova.

there's no other place
in the universe

that you can create elements
like that.

after a lifetime forging

a star will eventually
run out of fuel.

many then explode
in a massive supernova,

spewing out a cloud of debris
into interstellar space.

this rich cloud is then

into the next generation
of stars.

again and again and again,

this cosmic recycling
has taken place.

in a star like the sun,

there have been about 1,000
generations of stars before

narrator: each generation has
a richer and richer

of heavier and heavier

and particularly noticeable
is the buildup of iron.

keller: so, the amount of iron
is an arrow of time.

it shows us how old the star

narrator: if you want to find
a very old star,

you need to find one
with very little iron.

the way to do that

is to look for a specific
but minute variation in color.

each night, stefan's robotic
skymapper telescope

captures the light
from nearly a million stars.

it automatically analyzes
the color of each one

and arranges them
on a graph for stefan

according to iron content.

so, we see most stars like the
sun have quite a lot of iron.

but then there's
this tail of objects

that don't have
much iron in them at all.

and they're the potential
needles in the haystack.

narrator: in 2013, skymapper
presented stefan with a star

that stood apart from all
on stefan's graph.

here you see about 100 or so
ordinary stars

scattered around the field,

and in the center
is the star that we

narrator: this star had
incredibly low iron content.

at first, we thought we
done something wrong here.

but we confirmed it
the next night.

and that's when things
really got exciting.

narrator: the next step
was to take a much closer look

with a much bigger telescope.

we were lucky enough

to find some telescope time
over in chile,

and we stared at this one star
the entire night,

building up a very detailed
spectrum of the star.

there are a number of things
that we saw

that we just hadn't
ever seen before.

what we see here
is a spectrum of light

from a star
that's similar to the sun.

this is like a fingerprint
from the star,

and it tells us how much iron,
magnesium, and calcium

is inside that star.

and you can see that there's
quite a lot of lines here.

in the case of our star,
which is at the top here,

all we see
are the lines of hydrogen,

and a little bit here,
which is carbon.

and, so, it's quite
a different recipe.

and, indeed, we just don't see

any iron detectable
in this star.

and we knew that we were
onto something very exciting,

'cause we had never seen
a star like this before.

a star with no detectable iron
must've been made very early

in the process
of cosmic recycling.

it's been around
for 13.6 billion years.

it's a very pristine star.

it formed very early on
in the history of the universe

before much stellar recycling
had taken place.

narrator: stefan had
the oldest star ever seen.

it's been burning
for 13.6 billion years --

not quite the first star,
but almost.

in fact, what we're able to do
with this star

is, for the first time, say

that there was only one star
that preceded it.

stefan's star had to have been
formed from the exploding d

of one of the very first stars
in the universe.

stefan's image
of a second-generation star

takes us closer to the dark
than ever before.

ah. here we are.

that looks like the right

this is a star that predates
the milky way galaxy itself.

but we must go even further,

because even before this

came the very first generation
of stars of the cosmic dawn.

the first stars came together
in a dark sea of hydrogen

bromm: as you go back
to this time of the dark ages,

the universe looked
completely different.

if you had a human observer
translated back in time,

you would see a completely
boring, featureless universe

an utterly alien place,
it would appear to us.

it was a universe
without any light.

there were no stars,
no galaxies.

narrator: just a collection
of lone hydrogen atoms

and the odd bit of helium
spread out in a diffuse fog.

bromm: hydrogen would be
in its most primitive state --

single hydrogen atoms.

and, basically,
we would have, say,

a volume of the size
of my stretched-out arms.

then in this volume,

you would particularly have
one hydrogen atom.

narrator: so diffuse
that if a hydrogen atom

was the size
of a ping pong ball,

the next closest one
would be halfway to the moon.

bromm: so, we have
this very diffuse universe.

how do we get stars out of

volker bromm decided

the only way to get a picture
of the first star

was to build one from scratch,

one hydrogen atom at a time.

it was time
to forget the telescopes

and use a supercomputer.

astronomer volker bromm

to create an image
of the first star ever formed.

bromm: we can input
into the supercomputers

all the laws of physics,

from, as we say,
first principle.

we can put in
the initial conditions,

because initial conditions
is what we see here.

there are no missing pieces.

we have all the laws of

that describe the behavior
of these basic ingredients,

and at that point,
we set up the computer,

and then we let it go.

[ operatic singing ]

narrator: the scale of the
calculation seems impossible

to model the behavior

of vast clouds
of primordial hydrogen gas,

trillions of hydrogen atoms,
one interaction at a time,

and to ask the question,
"will they form a star?"

bromm: at first, you might
this is hopeless.

how do we get things like
out of this?

but what really then kicks in
is the force of gravity.

the force of gravity
has an infinite reach.

it reaches over
far stretches of the universe,

millions of light-years.

so, the force of gravity, in
a way, is a very patient

narrator: tiny fluctuations
left over from the big bang

meant some regions were ever
slightly more dense than

allowing gravity
to work its magic.

bromm: gravity would very,
very slowly act

to clump matter together.

certain regions of space

where then the density
of primordial stuff

is larger than the rest.

and then what would happen is
millions of years,

million of years
would create and attract

more and more material.

eventually, gravity would pull
such a vast collection of a

so incredibly close together
under such extreme pressure,

that it could trigger
nuclear fusion,

and a star could be born.

but even as gravity is pulling
the gas atoms closer together,

there's another force
trying to push them apart.

and it comes together.

when we compress gas,
then it also is heated up.

and at some point, the heat --
we basically have random

and the random motion will
basically prevent gravity

from condensing the gas
any further.

narrator: the more
that gravity squeezes inwards,

the more the gas heats up
and pushes outwards.

it's a stalemate.

and then the important
is, "can this gas,

this primordial gas,
can this get rid of the heat?"

narrator: what tipped
the balance in favor of

were a few chance encounters
between hydrogen atoms.

bromm: very rarely, something
very dramatically happened.

you have the two hydrogen

and they meet, and they form
hydrogen molecules.

and, crucially, a pair like

are able to absorb
a tiny bit of heat

in a way that a lone atom

this is the key process

for the entire end
of the cosmic dark ages.

the gas can cool.

gravity can take over
and eventually create

that are so extreme in terms
of temperature and density

that you can trigger
nuclear fusion.

you can eventually form,
out of this material, stars.

[ operatic singing ]

the first star is born.

the first light of the
is created.

the gas has collapsed
for millions of years

into the center of the system,

and now, for the first time
in cosmic history,

we see the moment
of first light,

the moment
that the first star formed.

after 100 million years,

this was how the dark ages
finally came to an end.

the first stars were giants --

100 times or more
the mass of the sun.

that has dramatic

because massive stars
have a very different life,

a much more violent life

than the kind of low-mass star
that the sun is.

they would be 20 times

...shining ultraviolet blue...

...10 million times
more luminous than the sun.

volker bromm's supercomputer

of the first stars ever to
in the darkness of space.

bromm: the one picture
that really captures

this metaphysical moment
of first light

would be like this,

a supercomputer frame
that shows the very first

it's a realistic image

of the first light
from the first-ever star.

let's patch it in

just at the end
of the cosmic dark ages,

because this is
when it happened.

it shows the moment when,

from the impenetrable fog
of the dark ages,

light finally dawned
on the universe.

loeb: soon after
the first star formed,

a few million years later,

another star formed
somewhere else.

and then the process

narrator: after 100 million
years of darkness,

lights were coming on
across the universe.

it grew up exponentially.

very quickly, within tens
of millions of years,

there were plenty of stars
filling up the universe.

this was the era that so many
astronomers have searched for

the cosmic dawn.

loeb: the cosmic dawn
would've been spectacular.

new galaxies were forming
out of darkness.

this age of enlightenment was
a very dynamic period of time.

narrator: these great furnaces
start forging

the more useful ingredients
of the universe.

abel: all of a sudden,
it gets interesting.

for the first time,
new elements are being made.

they take hydrogen,
turn it into helium.

helium gets combined
to make carbon,

and we go to oxygen, and so

narrator: deep in their
the first giant stars

began the transformation
of matter,

producing the heavy elements
necessary for life.

they were huge

but so hot that they burned
through their fuel quickly.

abel: they can only live
for a very short time --

only a few million years.

that's really nothing.

we often say they're like
the rock stars in the

they live fast and die young.

and so, by the time
you make another one,

over here, this one
may already be ready to die.

when they died, they died in

a hypernova --

the biggest explosions
ever seen in the universe.

stars were appearing
and disappearing.

it's like fireworks.

it's very dynamic.

these were the very first

that spewed out
the heavy elements

and led to the formation of
the second generation of

narrator: for the first time,
stars were made,

light was produced,
and heavy elements were

and yet, the dramatic events
of the cosmic dawn

were still shrouded
behind a veil of fog.

abel: those first stars --
very bright, you know?

they could be a million times
as bright as our own sun,

giving off tons and tons
of light.

but the light's not getting
very far yet.

actually, most of it
gets sort of stopped

by all this fog of hydrogen.

atoms of neutral hydrogen

filled the space
between the giant first stars.

as the light leaves the
surface of the st

it gets stopped,
so it couldn't get to us yet.

so the universe at this point
is still opaque.

narrator: tom abel uses
supercomputer simulations

to model these first stars
and the fog

to see how the universe
became transparent.

abel: what we'd like to do
is try and predict the past.

what we have here is
one of the first stars

there's a whole filament of
that was all that hydrogen

now, see, everything that gets
blue here gets really hot.

that's the ultraviolet
from this star

affecting everything

up to thousands of light-years
away from that star.

the radiation that they give
off, as it's trying to escape,

ionizes hydrogen gas.

but as a consequence,

you actually make things

radiation hits the fog.

fog gets transparent.

now my boundary to the fog
is further away.

radiation in the next little
can go a little further.

so, i make these bubbles.

each star created a clearing

blowing a bubble
of transparent space.

abel: the simplest way to
about it is some swiss cheese.

as their light travels out,
it changes the "cheese."

our air bubbles are growing,
and we make ever larger ones.

in this way
of thinking about it,

at the end, we end up
with no cheese at all.

[ laughs ]
all the bubbles are so big

that the light from those
objects really travel freely.

this image shows the cosmic

as the first light clears a
through the universe.

we're not even complete yet.

some parts of the universe
are still neutral and opaque.

but there it goes.
the whole fog lifts,

and all the galaxies
are revealed.

re-ionization would be
somewhere in these pages.

narrator: tom's models
offer an explanation

for how our universe
finally became transparent.

shall we glue it in?
maybe with a light glue.

[ laughs ]

in case we have to correct it.

narrator: the theories and
computer models are valid,

but there's still testing
to be done in the real world.

steven tingay is trying to see

but he's doing it
in an unexpected way.

he's trying to tune in
to radio hydrogen.

[ rock music playing ]

first light tonight

first light tomorrow

first light this morning

well, in the early universe,

there were vast amounts
of hydrogen,

and each one
of those hydrogen atoms

can randomly give off
a radio wave.

and, so, we can tune
our telescope

to that radio frequency,

and then we're tuning in
to the hydrogen gas.

first light this morning

first light this evening

first light tonight

been looking back

unfortunately, the band of
radio where hyd

is already filled with music
and news here on earth.

first, i was an ancient

hydrogen gas
produces radio waves

at a very specific frequency.

that's similar
to sort of f.m. radio

by the time they get to us.

so, it means that we've got to
build our telescopes

in areas where
there's no human interference.

so, you can't have f.m. radio.
you can't have tv.

you can't have mobile phones,
traffic on the road,

or anything like that.

first light tonight

first light this evening

first light this morning

distance is the only cure,

so we need to be in the middle
of nowhere, basically.

narrator: murchison county,
western australia,

is bigger than massachusetts
and rhode island combined,

but with less than
150 residents.

then i found it

i did it finally, oh

it's a terrible place

if you want radio, television,
or cellphone service.

i prayed till it was gone

my all in light

but it's the perfect place

to hear radio
from the beginning of time.

this is steven's telescope,

the murchison widefield array,
or mwa.

tingay: so, what we've got
are the antennas.

we have a cluster
of 16 of them here.

so, you can build
a lot of antennas

and get a very
sensitive telescope.

narrator: 2,000 antennas
out over 1/3 of a square mile

are sensitive enough
to receive radio waves

that have traveled more than
13 billion light-years.

tingay: so, that gas outside
bubble produces the radio

no radio waves from the

and so, for us,
we're sort of looking

for this swiss-cheese pattern
of bubbles and holes

in the hydrogen gas

narrator: although it's not
possible to see the first

it should be possible
with this radio telescope

to find clues about the way
they cleared the hydrogen fog.

tingay: we don't actually see
the stars themselves.

we see the effect of the star
on its environment.

this is an actual image
made from the mwa data.

this is a patch of the sky

that's around about
30 degrees across,

so it's quite a big
chunk of sky.

so, we're looking through
our atmosphere.

we're looking
through our galaxy.

we're looking through
most of the universe.

if you look carefully down
you can see many, many specks,

and these are all
galaxies or quasars,

millions, billions
of light-years away.

so, we need to remove
each of these signals one by

in order to peel back
those layers.

and, hopefully,
what we're left with

is just the signature of the
and the first stars forming

13 billion years ago.

narrator: this radio signal
will be our first direct

with the very first stars
in the universe.

it's incredible to think

that in this very image
that i'm looking at right now,

that signal exists.

what's really special for me
is being able to look at this

while sort of sitting
in an ancient landscape

where we've actually built the
telescope and collected the

from these signals
that have traversed

billions of light-years
throughout the universe.

so, it's just astonishing

on a number of different
for me.

loeb: we are all curious
where we came from.

we are now at a special time

that allows us to explore
these questions

we are able to peer
deep into space

and see those very early
sources of light

that tell us
how we came into existence.