All language subtitles for 306844789C8E6E1C085DFA474A19D346_eng

- The night sky is a time machine.

The further we look out into the universe,

the further back in time we reach.

What we see in the night sky is only

a small percentage of the
contents of the universe.

Most is dark matter and dark energy.

We know it exists, but its
nature eludes us for the moment.

No longer hampered by a hazy,

often polluted atmosphere,

telescopes and other
sensors have been able

to obtain clearer images from orbit

thanks to advances in
technology and engineering.

In the 1960s, satellites began to

explore the cosmos surrounding us.

They saw beyond visible light

into ultraviolet, infrared,
X-ray and even gamma rays.

Like the universe itself,
our understanding of

its beginnings, construction,
evolution, and future

is evolving and constantly expanding.

In the last two decades
of the 20th century,

the United States and other nations

began to develop more
substantial research programs

utilizing larger and more
complex space based telescopes.

- For hundreds of years,
thousands of years,

humans have thought the
universe is a very static place.

If you go out at night and
look into the night sky

you will see that things
don't really change much.

The universe appeared very
static for a long time.

We now know this is not true.

The universe is a highly dynamic place

and things are happening all the time.

Every single second, a star explodes

in a gigantic supernova explosion
somewhere in the universe.

And we have to go and find it.

We have to build
instruments that are capable

of finding those unforeseen events.

- The Cosmic Background
Explorer, or COBE satellite

started crystallizing the
big picture of the universe

by mapping the microwave background

radiation leftover from
the early universe.

Its successor, WMAP, created the most

detailed portrait of the infant universe.

- Well because it takes the light

over 13 billion years to reach us,

we are seeing now what the universe looked

like then over 13
billion years ago so it's

a fossil remnant of
what the early universe

was like, and just like fossils
are used to study the past,

we use this light to
study what the universe

was like way back near the very beginning.

And you can see in there blue spots

and red spots, and what
those correspond to

are slightly hotter and
colder images of the sky.

That's a picture there,
those hot and cold spots,

that pattern, is really, it's
the afterglow of the big bang.

On a sort of deeper, long term level,

it's this amazing
consistency that the picture

we can put together of the universe is

relatively simple, that
the pieces fit together.

It's a stunning
confirmation of the study of

cosmology for many years now that

it's just built up and here it is.

In some ways, we're getting to know

the cosmos like we know our own backyards.

- ESA's Planck spacecraft joined the fleet

and expanded on their observations.

Together, they were able to map

vast regions in multiple wavelengths,

enabling astronomers to determine the

size, shape, and age
of the known universe.

- So we had it in 70,000 years after

the universe began in a
big bang, all that existed

was a hot plasma similar
to a candle flame.

Protons and electrons, seen
as the red and green balls,

were bouncing around,
scattering the light.

The particles of light, called photons,

shown in blue, couldn't go far

without colliding with an electron.

As the universe cooled, the protons

and electrons could pair
up forming hydrogen atoms

and the light was free to travel.

It's been traveling freely ever since.

Through the dark ages
before there were stars

then past the formation
of the first stars.

As the universe expanded,

protons lost energy, changing color.

They went past clusters of galaxies.

The path of the photon is slightly bent

by the gravity of the clusters.

Now and then, going through a cluster,

an electron, that green ball,

would collide with some of the photons,

they would change their path,

past more matter, more little

wiggles due to gravity and mass.

The photons traveled
for 13.8 billion years

before they reached the Planck detectors

and died a glorious death giving up

the information that they had gleaned

passing through the entire
universe to our instruments

and enabling us to make this
beautiful map of the universe.

The various satellite telescopes

have sensors designed for
use in multiple wavelengths

of the electromagnetic spectrum.

From near to far infrared light

through visible and
ultraviolet frequencies

to X-ray, gamma, and cosmic ray detectors.

Each can reveal unique aspects

of the construction of
stars, nebuli, galaxies,

and the exotic quasars and black holes.

However in the public's
eye, the poster pinup star

of the latest generation would undoubtedly

be the Hubble Space Telescope.

Over its 25 year lifespan, Hubble has

produced some of the most amazing imagery

of the cosmos as it delves back in time

through visible and infrared light.

Another advantage of Hubble
is its long lifespan,

thanks to several maintenance missions,

which allows it to study
objects over a long

period of time with some amazing results.

Newborn stars eject strings of matter

into the surrounding star forming region.

Known as Herbig–Haro
objects, these supersonic

jets can be seen to change
over a very short time span.

- If you see just a
single picture from Hubble

you can interpret it
in many different ways,

but the fact that Hubble has been around

for as long as it has been means by taking

multiple images you can
actually stitch them together

and watch how the material moves

and so that really gives you,

the only way to get true
insight into the physics

of the dynamics of what's going on.

- The Horsehead Nebula in
the Orion constellation,

silhouetted by glowing
gas, is a good example.

Infrared can see right through
revealing its dark secrets.

The Spitzer Telescope is one
of NASA's great observatories.

- Spitzer is an infrared telescope,

which means it sees through
the dust that's out in space

and by seeing through the dust we get

to pinpoint these stellar nurseries that

are out there where stars are being born.

- We've been flying for about ten years,

that's about 3,600 days.

We have 5,000 published papers.

That means every day, a new
paper based on Spitzer data

announcing new results or
new discoveries is published

which to me is absolutely amazing.

- Spitzer has made several surprising

revelations within our
solar system, and beyond.

It helped pinpoint some of the

most distant galaxies in the universe.

And Spitzer's ultra high resolution map

of the Milky Way
substantially improved our

understanding of our
own galaxy's structure.

Japan and ESA had launched their own

infrared telescopes in
various infrared wavelengths.

The European Herschel, in particular,

focused on massive star formation regions.

- We are really happy to have new things

and trying to understand because

we are making a new step towards our

understanding of massive star formation.

So the idea is that Herschel can reveal

this population of highly embedded star

that are formed in gas and dust cocoon,

but that are not visible at
optical wavelength, for example.

So we need Herschel to detect all

this population of very young stars.

- The next great spaceborne
infrared telescope

is the James Webb
Telescope, which is nearing

test completion in preparation
for its launch in 2018.

It will have a 6.5 meter primary mirror.

Almost three times larger than Hubble.

However, ground based telescopes are

also working in the infrared spectrum.

- So there's a large complementarity

between space and ground.

From space, with the Hubble images,

you can characterize the images,

you see the images much better.

With the ground based telescopes

you then can take that light and look

at spectra, and then find the reference

for example for this galaxy,

or you could take infrared observations,

which Hubble couldn't do for a long time,

to then see how these
objects look in the infrared.

- Together they have delved
into the star forming nebuli

left over from exploding supernova

and witnessed the birth of stars.

Another observational tool in the

electromagnetic spectrum for astronomers

and cosmologists is the X-ray band.

- An amazing discovery
of the last 20 years

is that every galaxy,
like our own Milky Way,

has a massive black hole at its heart.

And as material from this galaxy,

dust and gas, falls onto this central

black hole it radiates
and we can see that.

So we look at the sky, in
visible light, we see stars.

If we look at the sky in
X-rays we see black holes.

- You can observe X-rays
from very distant objects.

So you can investigate
the cosmic structure

of the universe so you investigate

the metal distribution in the universe

while observing the galaxies, the active

black holes in the center of the galaxies

to very far distances and this is

very important for cosmology and

to learn about the origin and
the evolution of our universe.

- X-rays are absorbed in our atmosphere,

so X-ray detectors must
be placed at either

high altitudes by balloon, or into orbit.

NASA's flagship X-ray telescope, and one

of their great observatories is Chandra.

- You want to find black holes,

you want to use an X-ray telescope.

- What we're tending to find is that

a cluster of galaxies has a bright,

central galaxy in the middle.

It's often an active galaxy or a quasar.

So a supermassive black hole
in the middle of a big galaxy.

Because, when the cluster is forming,

a lot of the material
tends to fall to the middle

so you get the biggest
galaxy in the middle.

- So you see the power of an observatory.

An observatory like Chandra with a

state-of-the-art telescope and these

imaging spectroscopic capabilities

that its science instruments can do things

that maybe weren't even things that

you planned on doing because you

didn't know about them at the time.

And a lot of the science of
Chandra falls in that category.

- The most recent telescope launched

is NuSTAR, which has the ability to focus

X-rays for a much sharper image.

One of NuSTAR's main scientific goals

is to make a full census of
black holes in the universe.

X-rays have also revealed
the explosive processes

of nova seen only at these wavelengths.

ESA have their XMM-Newton
studying cosmic evolution

and INTEGRAL, the International

Gamma Ray Astrophysics Laboratory

looking at gamma ray frequencies

revealing unseen structures
and new sources of gamma rays.

- So INTEGRAL is important because

it's one of the few satellites
which look in gamma rays.

Together with other
satellites and observatories

around Earth can get a complete

picture of how these stars evolve.

And without INTEGRAL you're missing

a large piece of the puzzle.

We want to know, how did they produce

the elements which we are made of?

These are the objects which,

throw all the different kinds
of material into the universe

and they wander off into space

and we are made of all these elements

which are produced by the supernova.

So it is important for us to know,

where does life originate?

And how does it originate?

- Gamma rays are at the top of
the electromagnetic spectrum.

The most energetic and powerful photons

which stream from black
holes, exploding stars,

and even from our own star, the sun.

Originally called GLAST, the
Fermi Gamma Ray Space Telescope

observes the entire sky in high energy

gamma rays every three hours, creating

the most detailed map of the universe

ever known at these energies.

When it detects a new gamma ray burst

it works in conjunction
with the Swift satellite.

Then, Swift is able to
spin rapidly across the sky

and point an X-ray telescope and an

optical ultraviolet telescope at the

possible location of the gamma ray burst.

- GLAST is primarily devoted to

seeing in a new energy range.

It's designed to pick up at the other end

of the swift energy range and carry it on

up to much higher energies.

- And it allows you to just see stranger

and more exotic things the
further up in energy that you go.

- GLAST and Swift are very different.

Swift is like a nimble
small satellite that points

here and there, but it isn't
surveying the whole sky.

It's pointing in at particular objects.

GLAST looks in the high
energy gamma ray sky,

looks over the whole sky at all times.

- So when we see something
interesting with GLAST

we can ask Swift to go look at it with our

other telescopes and gain
additional information on it.

- We don't know what will
happen over the next ten years.

Hoping that Swift will
still give us exciting data,

but what we do know is
that Swift will give

us exciting data because
of its pure nature.

This is what it was built for.

To study new unforeseen unexpected events

and they will inevitably be happening.

- There is one more type of radiation

being studied in orbit: cosmic rays.

The eight ton cosmic
ray particle detector,

called the Alpha Magnetic
Spectrometer, or AMS Instrument,

is attached to the
International Space Station.

Cosmic rays consist of
protons, alpha particles,

atomic nuclei of heavier
elements, electrons,

their antimatter partner
positrons, and gamma rays.

Studying these particles
may answer some fundamental

questions like the unexplained
absence of antimatter

and the nature of dark
matter in the universe.

- Calibration of positron is important

because when you have

dark matter,

collision with another dark matter

you produce excess positrons.

So, the characteristics
of the excess positron

tells you what's the
origin of dark matter.

- About 80% of the matter in the universe

is invisible to telescopes.

This dark matter neither reflects,
absorbs, nor emits light,

yet it interacts with matter
by a gravitational influence

which can be seen in the orbital speeds

of stars around galaxies and

in the motions of clusters of galaxies.

Yet, despite decades of effort, no one

knows what this dark matter really is.

This visualization shows galaxies composed

of gas, stars, and dark matter colliding

and forming filaments in
the large scale universe,

providing a view of the cosmic web.

It is believed that dark matter provides

the framework for this web.

Galaxy clusters are the
largest gravitationally

bound structures in the universe.

It is also believed
that after the big bang,

the universe originally
decelerated in its expansion,

but then changed gears
and began to accelerate.

- Important discoveries in
astronomy and astrophysics

was the discovery of dark energy

and that is that the universe
is accelerating apart.

What people are trying to do using various

different techniques, and again

in all the different wavelength bands

is to measure the parameters

to characterize the dark energy.

- With a launch date set for 2020,

ESA is building Euclid, a space telescope

which, it is hoped, will chart dark matter

and dark energy's effect on the universe.

- I'm working on Euclid.

This mission to map the universe.

And for that we built a
highly precise telescope

in which we can map dark matter structures

as well as the derivative
properties of the dark energy.

- Understanding dark energy will allow

us to understand the
future of the universe.

- The interesting thing is, we get

more and more dark energy, why?

Because our universe is expanding

and with our expanding universe,

we get more dark energy in our universe.

Now the ordinary matters of dark matter

and normal matter is not
expanding, it's diluting,

so the fraction of dark energy compared

to normal matter is increasing in time.

When the universe expands more and more,

we get more volume of our universe,

we get more space, and
we get more dark energy.

- The leading particle physics model

for dark matter is called weakly

interacting massive particles.

They're also known as WIMPS.

These guys just fly through the universe

without even bumping into
anything or each other.

The idea of two WIMPS coming together,

annihilating and forming gamma rays

is kind of like two bullets
hitting head on in a crossfire.

It's very rare.

But when you go to the area around

a supermassive black hole,

we expect the density to be much higher

so the probability of
annihilation is much higher

and thus, detection with
a gamma ray telescope.

- In his theoretical process, Schnittman's

computer simulation shows particles of

dark matter around a
massive spinning black hole.

All of the action takes place close

to the black hole's event horizon,

the boundary beyond
which nothing can escape,

in a flattened region
called the ergosphere.

Within the ergosphere,
the black hole's rotation

drags space time along with it,

and everything is forced to move in the

same direction at nearly
the speed of light.

Concentrated fast moving
dark matter particles

collide and make gamma
rays, but only some of this

high energy light can
escape the black hole.

In this case, from the left side

where the black hole
is spinning towards us,

giving us a lopsided glow
of high powered gamma rays.

The simulation tells
astronomers that there

is an astrophysically interesting signal

we may be able to detect as
gamma ray telescopes improve.

Schnittman believes this would be

conclusive evidence of the WIMP model.

- To me, dark matter, black holes,

two of the most elusive
things in the universe

coming together to help explain
each other is quite poetic.

- Future missions will see a gravitational

wave observatory to study gravity waves

and test Einstein's theory
of general relativity.

The Athena mission,
mapping hot gas structures,

and searching for supermassive

black holes, due to launch in 2028.

The Sloan Digital Sky
Survey, the most ambitious

astronomical survey ever undertaken,

will provide a three dimensional map

of about a million galaxies and quasars.

The recently refurbished and upscaled

CERN large hadron collider is one of the

tools in search of WIMPS
and other exotic particles

that may help explain
the fabric of the cosmos.

Then perhaps, the scientists, astronomers,

and engineers can turn their attention

to other mysterious theories brought

about by particle physics
such as multiple dimensions,

entire universes beyond our own,

and what lies beyond the event horizon.

These, in time, will
become the new frontier.