Hidden Universe Page #2

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A supernova explosion that

scattered gas and dust particles

60 billion miles

into the cosmos,

forming this.

The Crab Nebula.

Sometimes, astronomers

look deep into the sky

and see the cosmos

looking right back at them.

This magnificent

eye in the sky

is just the remnants

of a burned-out star

that has shed its outer layers

back into the universe.

By studying

formations like this,

we now know that stars

come and go from the universe.

Just like life begins

and ends here on Earth.

Beyond our Milky Way,

you'll find stars,

gas and dust

clumped together in huge

structures called galaxies.

Galaxies come in

all shapes and sizes,

but what I love

most about them

is that the light that I'm seeing

was created way back in time.

Light from even

the closest large galaxy

takes two and a half million

years to reach us.

And the deeper I

look into space,

the older the light I see.

This means that galaxies

are like fossil records

of how the universe

used to look and act.

So in a way,

my work is a little bit

time travel

and a little bit

cosmic archeology.

I'm trying to help decipher

these distant records

so that we may one day

better understand

the story of our universe.

Since these

objects are so far away,

a new challenge faces

optical astronomers.

Like the heat distortion

you see on a road,

the atmosphere distorts and blurs

light coming in from the universe.

It's what makes the stars

appear to twinkle at night.

To counter this problem,

the VLT has a trick

up its sleeve.

It fires a laser beam 60 miles

up in to the night sky

to create a fixed point.

Almost like a fake star

for the telescope to focus on.

On the ground,

the VLT compensates

by warping the telescope's mirror

hundreds of times per second,

allowing us to capture

the sharpest of images.

If you want

to see what I'm looking for,

don't look at the main

part of these pictures.

Look further, deeper,

into the details of the image.

My work takes me beyond all

these close celestial objects

and out into the vast

universe that lies beyond.

Highlighted here

are distant galaxies.

They're similar in size and

structure to the closer ones,

but they are so far away

that even with the VLT,

you can barely make them out.

These are the galaxies

that I study.

Out here are the frontiers

of our knowledge.

This image is as far back

in time as we can see

with an optical telescope.

It is the edge of

the visible universe.

I chose

to become an astronomer

when I learned that

our sun is a star.

You know, we have looked over

13 billion years into the cosmos,

and everywhere we look,

we find stars like our sun

and galaxies

like our Milky Way.

When you see all

of these galaxies,

you can't help but feel a profound

connection to the universe.

Here in our cities,

the digital world is producing

a new breed of astronomer,

using telescopes and supercomputers

to create detailed simulations.

They see the world

differently.

Dr. Greg Poole is one

of those astronomers.

He is a universe-builder.

But the glow of bright

city lights of technology

drowns out our universe.

When we look for the heavens,

we can't see them anymore.

That's why when Greg gathers his

data for his cosmic simulations,

he too has had

to pack his bags

and head for the

Atacama Desert.

Greg has come to use the most

powerful telescope ever built,

but his passion

for photography

won't let him pass

up an opportunity

to capture the

Atacama's night sky.

I love this place.

It has a peacefulness

that clears your mind.

The ancient

Incas who lived here

organized their lives

by the night sky.

The movement and position of

the stars told them when to

plant and harvest their crops.

They must have felt a kind

of kinship with the stars.

And when you see the night sky

as they would have,

it's not hard to see why.

Greg isn't the only one that

sees the world differently.

This mosquito is on the prowl

for its next meal.

As it hunts,

it sees the world in a very

different way than we do.

It doesn't just

see visible light.

It also has

an array of sensors

that detect infrared

heat signatures.

That's how it can

find you in the dark.

And it will.

Like the mosquito,

a new telescope called "ALMA"

is being built to detect

signals outside of visible light.

ALMA is an extraordinary

collaboration

between the European

Southern Observatory,

North America and East Asia.

A decade of work

is almost complete.

If you're thinking this looks

more like a construction site

than a telescope,

you'd be right.

This is base camp.

ALMA has a completely different

design from optical telescopes,

because it's looking

for microwave signals.

And the best place for

a microwave telescope

is high and dry

at over 16,000 feet

on the top of a mountain.

But 16,000 feet is not a place

you can work for very long.

The thin air and dryness

make it hard to breathe

and altitude sickness

can lead to unconsciousness

or even death.

So engineers here have come up

with a creative solution.

They're building

each individual antenna

at a low-altitude base camp.

And then each hundred-ton dish

is driven up the mountain,

one giant piece at a time.

Normal vehicles

aren't up to the task,

so engineers have built

the world's biggest

remote-control truck.

An operator can guide each

antenna into its place in the array

by using laser-guided steering

and collision detectors.

These safely guide the dish

onto a concrete pad,

where it will be ready to

power up and get to work.

Every time

I see ALMA,

I think of how far we've come.

This isn't just

a big telescope.

It's an array of 66 dishes

that are connected by

a giant supercomputer

to make these separate dishes

act as one huge "eye in the sky".

It makes ALMA the most

powerful telescope ever built.

Bathed in its eerie,

green light,

ALMA lets us peer into the

farthest corners of the universe.

These are the Antennae galaxies

when viewed by normal, optical light.

But ALMA sees so much more.

One of her first images

was a revelation.

A huge, dense cloud

of hydrogen gas

hidden within the galaxies.

Enough gas to form

more than a billion stars.

Centaurus A was the first

galaxy I ever studied.

Using telescopes like ALMA,

we can see a massive black hole

at the center of this galaxy.

It's spewing out plasma at

almost half the speed of light.

Every galaxy, nebula

and star in the sky

has secrets hidden from us.

Take the Crab Nebula.

We know that it was once a star that

blew up in a supernova explosion.

We know this because when

we look with X-ray vision,

we can see the compact remains

of that exploded star.

A pulsar.

But there is still

more to the story.

Because infrared observations

penetrate deep

into the dusty

clouds of this nebula,

revealing elements like hydrogen,

carbon, silicon and iron.

All of these observations

reveal an incredible truth.

That stars are the factories

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