All language subtitles for Cosmic Front 07of18 Illuminating The Magellanic Clouds 720p

The large and small Magellanic Clouds.

Nebulous bodies in the heavens,

they have intrigued
humankind for centuries.

They acquired their name

after Ferdinand Magellan's expedition

circumnavigating the globe
in the 16th century,

and his crew used these cloud-like objects

as aids to navigation.

During the Age of Discovery,

sailors relied on celestial bodies

to reckon their own locations.

The two heavenly clouds

that attracted the attention

of Magellan and his crew

have fascinated people ever since.

Recently, thanks to observations

in the Southern Hemisphere,

using the most advanced telescopes,

research on the Magellanic Clouds

has taken a giant leap forward.

The Magellanic Clouds turn out to be

astonishing records of the very birth

of the universe.

They provide a unique opportunity

for studying what happens close to us

in the universe, and that actually tells us

all the things about how
the universe formed,

and how galaxies formed.

Astronomers throughout the world

are eager to shed light
on the Magellanic Clouds,

hoping to reveal secrets
about the earliest days

of the universe.

This program follows these stars

on a journey of amazement and discovery.

What is the true character
of the Magellanic Clouds?

This has been a huge mystery
since the Age of Discovery.

By the 17th century, 100 years
after Magellan's expedition

circumnavigated the globe,
Europe was producing

numerous star charts of
the Southern Hemisphere.

The constellations were
pictured as various creatures.

A flying fish,

a chameleon,

a resplendent peacock,

a big billed toucan.

The constellations all had exotic names.

And then, there was Nubecula Maior,

Latin for "large cloud",

meaning the large Magellanic Cloud.

That was paired with Nubecula Minor,

or "small cloud", the
small Magellanic Cloud.

Since they move together with the stars,

they were clearly no earthly clouds,

they were heavenly bodies.

But exactly what they
were remained a mystery.

The first detailed research
into the Magellanic Clouds

began in the 1830s.

To conduct research into stars
of the Southern Hemisphere,

England had established a royal observatory

at the Cape of Good Hope
in southernmost Africa.

Astronomer John Herschel

worked there for over four years.

He pioneered the study of celestial objects

in the Southern Hemisphere.

In 1847, Herschel published his findings

in a 450 page report.

This is the catalog of
objects Herschel found

in the Magellanic Clouds.

Some 1,000 items are listed.

There are numerous records of
nebulae and star clusters,

similar to those visible
within the Milky Way galaxy.

Herschel clearly thought
of the Magellanic Clouds

as constituting a galaxy.

At the time, most astronomers
thought that all

celestial bodies lay within the
disc of our own Milky Way.

Herschel thought that
these rather indistinct

and nebulous objects must be extragalactic

celestial bodies.

To prove that, however, one would have

to calculate the distance
to the Magellanic Clouds.

Alas, Herschel did not possess
the means to do that.

Are the Magellanic Clouds
inside the Milky Way,

or outside?

An epoch making discovery
at Harvard University

finally solved the riddle.

The crucial evidence was supplied

by photographic plates stored here.

This is the world's largest archive

of astronomical photographs.

As you can see, we have cabinet

after cabinet, many plates,

525,000 plates in this collection.

That's 25% of the world's total

of astronomical photographs

just in this collection,
and what is remarkable

about that, is that it covers
more than 100 years of time

from 1885 to 1989, and
we began photographing

the southern skies early in the 1880s

so the Magellanic Clouds are covered

from that early time.

These photographic glass plates,

recorded light from the stars

over long periods of exposure.

They enabled astronomers
to capture not only

what Herschel could see directly,

but even far dimmer stars in the nebulae.

Around the turn of the 20th century,

the data etched on these glass plates

were processed by a team
of female analysts.

The position and brightness
of every single star

were meticulously recorded.

The analysts were actively seeking

variable stars, a popular
quarry at the time.

Variable stars are stars
whose brightness fluctuates.

Of particular interest were
those whose brightness

fluctuated in regular periods.

This was one of the very old ones.

This type of star could help prove

whether the Magellanic Clouds lay inside

or outside the Milky Way.

With the...

Wow, it's a 240 minute exposure.

Here we have a glass plate

of the small Magellanic Cloud,

a long exposure which is taken.

Some of the stars will be variable stars,

but you get them at only one moment

on this plate, so this is a negative plate,

and we also can then make, from one

of these plates, a positive plate,

and this one can then
be used as a master.

When you put them on top of each other...

Superimposing an image of a given area,

on top of another, taken
at a different time,

reveals any change.

If the star's brightness is constant,

it should be a perfect match.

What happens when the brightness changes?

Since brightness is
translated optically as size,

any variability is immediately apparent.

This comparative method,

done plate by plate, is a way of detecting

which stars are variable.

One of Harvard's female star analysts,

was Henrietta Leavitt,

an astronomer later
recognized for her analyses

of variable stars.

This is one of the photographic plates

of the Magellanic Clouds
that Leavitt analyzed.

Out of 100,000 stars
recorded on a single plate,

she endeavored to identify
the variable ones.

Harvard still has her handwritten logbook.

She assigned numbers to each variable star,

comparing readings at fixed intervals,

and determining the periodicity

of its variations in brightness.

To prevent any mistaken attributions

among the countless stars in the sky,

she drew detailed star charts.

After four years of research,

Leavitt published her study
of 1,777 variable stars

in the Magellanic Clouds.

In the course of compiling these data,

she made a vital discovery.

She noticed that variable stars
in the Magellanic Clouds

with the same period had
the same brightness,

or luminosity.

Compared with variable stars
of the same periodicity

within the Milky Way, the
ones in the Magellanic Clouds

appeared fainter.

The fainter the star, the
farther away it must be.

In the late 1920s, after
Leavitt had passed away,

detailed analyses revealed
that the Magellanic Clouds

lie far outside the Milky Way.

Precise observations determine
that the Magellanic Clouds

are 200,000 light years away.

That's twice the diameter
of the entire Milky Way.

The Magellanic Clouds were
definitely other galaxies

lying outside the Milky Way.

A large telescope subsequently revealed

a deep relationship between the Milky Way

and the Magellanic Clouds.

This is the 2.5 meter Hooker
Telescope at Mount Wilson.

This telescope enabled measurement

of the distances to many
galaxies outside our own.

It revealed features of
the Magellanic Clouds

that differentiated them definitively

from other galaxies.

This is the galactic distribution,

as currently understood.

The two Magellanic Clouds lie approximately

200,000 light years away
from our own Milky Way.

The larger one is
approximately 1/10th the size

of our galaxy.

The nearest spiral galaxy
to our own Milky Way

is the Andromeda Galaxy,

some 2.3 million light years away.

That's 10 times farther away

than the Magellanic Clouds.

So the Magellanic Clouds
are two small galaxies

very near our own.

Edwin Hubble, the leading
astronomer of his day

described the Magellanic System thus,

"The Cloud is an independent
stellar system,"

"and a close neighbor,
actually, a satellite,"

"of the galactic system."

A satellite is a space object

that is gravitationally
attracted to another,

and orbits it as the moon does the earth.

Hubble thought that the Magellanic Clouds

similarly, orbit the Milky Way galaxy.

This concept of a satellite galaxy

eventually became the standard view

among astronomers.

A major discovery was made
in the Southern Hemisphere

in Australia.

The two Magellanic Clouds together make up

a single, gigantic space object.

The discoverer was an Australian astronomer

named Don Mathewson.

If this object I discovered

was actually visible,
everyone would be astounded.

It's an enormous arc of gas stretching

right across the sky.

In fact, it's more outstanding
than the Milky Way galaxy.

Mathewson's starting point

was a research paper written by astronomers

at Bell Laboratories in the United States.

Their measurements of
intergalactic radio waves

revealed filaments of gas in the skies

over the Northern Hemisphere.

It was a rainy Sunday afternoon,

and it was quite late,

and I was just turning the pages

of an astrophysical journal.

I caught an air filament,
of gas, asausage of gas,

and I thought well, let's
extend that sausage

a little bit, spread it out a little bit,

so I drew a line on this polygraph paper,

and I thought, gee, it
passes through the large

and small Magellanic Cloud.

The line Mathewson extended into

the Southern Hemisphere
from the mystery gas

mentioned in the article,

went right between the Magellanic Clouds.

And Australia had a radio telescope

well suited to confirming the presence

or absence of gases.

It was the park's observatory.

Mathewson couldn't contain his excitement.

He telephoned the observatory right away.

The very next morning, Mathewson jumped

into his car and drove to the observatory.

The director had told
him that the telescope

would be offline for maintenance that day,

so Mathewson thought that at night,

there might be a chance for
some brief observations.

It took him four hours to drive
to the park's observatory.

At the time, this giant, 64 meter diameter

parabolic antenna made Parks

the largest radiotelescope
in the Southern Hemisphere.

When Mathewson arrived,

he asked the maintenance workers

if he might borrow some
time on the telescope.

So all the memories come flooding back.

It was a most emotionally charged episode

in my life, really,

the discovery of the Magellanic Stream.

Past 10PM, it was only after
the maintenance staff

had left for a late supper,

that Mathewson was able
to use the telescope.

I had it all plotted out,

what I thought would happen,

but of course, in science,

things never happen the
way you want them to.

Nature is a teaser.

It teases you, and then all of a sudden

drops you flat on your face.

But tonight was completely different.

For the rest of the three or four hours,

that it took, every
position that I looked at

with the telescope came out
to be the right velocity

and the right intensity.

When the telescope was pointed along

the extrapolated path of the gas stream

first noticed in the Northern Hemisphere

further traces of gas
were found along the way.

The gas trail seemed to be headed

for the Magellanic Clouds.

That's how Mathewson was
the first in the world

to actually establish a
link between the gas trail

and the Magellanic Clouds.

Subsequent detailed observations confirmed

that their distributions were aligned.

This intergalactic belt of gas

was named the Magellanic Stream.

The Magellanic Stream is an
extension of the same nebulae

spotted by Ferdinand Magellan.

It's a huge belt of gas, stretched out,

as if to curve around the Milky Way galaxy.

It's one million light years in length,

that's 10 times the
diameter of the Milky Way.

Like the contrail of a jet plane,

the Magellanic Stream is proof that

the Magellanic Clouds have passed that way.

The gas is distributed
as if it were encircling

the Milky Way, so astronomers believe

that the Magellanic Clouds

are spewing out gas as
they orbit our galaxy.

The Magellanic Clouds,

galaxies with a gas trail
longer than the diameter

of our own galaxy.

To people of the Northern Hemisphere,

the night sky of the Southern Hemisphere

presents a strange spectacle.

There's the constellation Orion.

But it's upside down.

And the Milky Way looks huge.

The exceptionally bright area,

is our galaxy's nucleus.

In the Southern Hemisphere,

the mysteries of the universe
seem all the closer.

This is Santiago, the capital of Chile.

It's surrounded by 5,000
meter-high mountains.

Still bearing traces of its
Spanish colonial past,

Santiago is today, at the forefront

of astronomical research.

On the way to a green grocer's,

in a new part of town.

The shopper is Valentine Ivanov,

an astronomer who was born in Bulgaria.

Recently, he has been
analyzing observations

of the Magellanic Clouds

made with one of the world's
most advanced telescopes.

He is affiliated with the
European Southern Observatory

known as ESO.

ESO has established three
observatories in Chile

from which to survey the stars

of the Southern Hemisphere.

With his telescopic observations,

Ivanov has been creating the
most detailed picture yet,

of the Magellanic Clouds.

This is one of the newest projects

of ESO, and it aims at creating

large uniform maps of the sky.

These are called surveys.

One of the most important surveys

that this telescope is producing now

is the survey of the Magellanic Clouds,

these green squares over here.

To produce a complete map
of the Magellanic Clouds

Ivanov spends a total of one third

of every year at a
mountain top observatory.

He has already taken
over 100 of these trips.

His destination is about
1,000 kilometers north

of Santiago.

It's in an arid zone that
sees less than 10 millimeters

of precipitation annually.

This is the European Southern Observatory's

largest site.

Seven telescopes are located
on the mountain top here,

at an elevation of some 2,600 meters.

This is the one Ivanov uses.

It's a four meter aperture
telescope called Vista.

Installation was completed toward the end

of 2009, its technology is cutting edge.

Vista is a special purpose built telescope,

unlike other telescopes, Vista is designed

to cover extremely large fields of view

in a single pointing.

The filter of your Vista is about a degree

by degree and a half.

How does Vista compare in this regard

to the Hubble Space Telescope?

Vista's field of view is
about 500 times greater

than Hubble's.

In a single pointing, Vista
can take in a region

much broader than a full moon.

Ivanov and his Vista team are attempting

an exhaustive survey of the entire region

containing both the small

and large Magellanic Clouds.

And the bridge linking them.

It's sundown.

Vista can now be engaged.

In the control room, Ivanov
will conduct observations

all night long.

The display shows stars within
the Magellanic Cloud system.

The Vista Magellanic Cloud survey

already completed the number of tiles,

and the data publicly available.

This data contain a lot
of interesting projects

like this giant H2 region called Tarantula.

The Tarantula nebula

is an expanse of gas located within

the large Magellanic Cloud.

It's 1,000 light years across.

Its name derives from the
hairy, spidery appearance

of its gases.

This image that we see here

actually is built from
three different images,

each of them in the near infrared.

The advantage of the near infrared,

and the advantage of the kind of data

that Vista delivers to us

is that we can actually
see through the dust.

If you look at this area
in the sky in optical,

you will see almost no stars,

because the dust absorbs

the optical light much
more than infrared light.

Vista captured this image
of the Tarantula nebula.

Compare it to an optical image

showing ordinary visible light.

It's clear that the VISTA image

reveals the stars hidden
beyond the gas and dust.

The large Magellanic Cloud

is said to contain as
many as 20 billion stars.

VISTA captures them in stunning detail.

Innumerable stars, nebulae,

star clusters, countless points of light,

beyond the reach of ordinary
optical telescopes,

rendered here, vividly, and distinctly.

VISTA is continuing to
survey the Magellanic Clouds

at a level of detail unmatched
by any other telescope.

The Hubble Space Telescope has shown us

how different in shape as well

the Magellanic Clouds are from our own

Milky Way galaxy.

This nebula, in a remote part

of the large Magellanic Cloud

shines with extraordinary luminosity.

It's gigantic, more than 30 times

the size of the great Orion nebula.

And out of the dark gas and dust,

it is birthing countless new stars.

One region in the large Magellanic Cloud

is giving birth to more stars

than any other region in the Milky Way.

Here is just one portion,

newly born stars illuminate
the surrounding gas.

It looks like a cocoon.

Here, an accretion of gas and dust

is displayed in silhouette, lit from behind

by young stars.

The largest mass looks like a seahorse,

it's a huge object, some
20 light years in length.

The small Magellanic Cloud also boasts

magnificent nebulae and star clusters.

The explosive birth of 100,000 stars,

the energy they put out
is said to be 60 times

that of the great Orion nebula.

Or look at the outskirts of
the small Magellanic Cloud.

Innumerable young stars,
born all in a group.

And this sparking,
multicolored open cluster,

has been called the Jewels of Magellan.

Even today, the Magellanic Clouds

are far more prolific than the Milky Way

in the production of new stars.

The Magellanic Clouds had been thought

to be orbiting the Milky Way.

But recently, a great discovery was made

in that regard.

The discovery was made by
Roeland van der Marel.

Hey guys.

Van der Marel spent four years

directing observations of the Milky Way

by the Hubble Space Telescope.

So we could do that... His
goal was to determine

the mass of our galaxy,

and he found a way to use
the Magellanic Clouds

to do so.

We thought if we could measure exactly

how the clouds are moving
in the sideways direction,

we could learn more about the mass

of the Milky Way, and
about the distribution

of the Mass in the Milky Way.

Van der Marel's group thus observed

the Magellanic Clouds directly,
in order to ascertain

the speed of that sideways motion relative

to the Milky Way.

As a reference point, they
chose to use a quasar,

celestial bodies that are very far away,

and so, essentially motionless.

By using a quasar located beyond

the Magellanic Clouds, as seen from earth,

they could measure the
clouds' relative motion.

They pointed the Hubble Space Telescope

in that direction.

The anticipated motion
of the Magellanic Clouds

was minute.

It is the equivalent of observing
a one millimeter movement,

from 100 kilometers away.

That was close to the limit

of Hubble's powers of resolution.

And then if you try this
with a telescope on earh,

you run into several realistic problems

with telescopes on earth.

For example, telescopes
are subject to gravity.

As the telescope moves,

the gravity on the telescope is different,

and the instrument distorts a little bit,

and you see this in your images.

The observations with Hubble

continued for four years.

Now, you cannot actually measure

the motions of the stars in the...

Van der Marel's group succeeded

in obtaining data on 25 of the regions

into which the Magellanic
Clouds had been divided.

After analyzing the
results for a full year,

they calculated that the Magellanic Clouds

are moving at an incredible
378 kilometers per second,

1.36 million kilometers per hour.

This was 300,000 kilometers per hour faster

than anticipated.

Initially, we were just very happy

we were getting any results out that said,

hey, we can actually measure the motion

of the Magellanic Clouds.

So that was our initial
excitement for quite awhile,

and it was clear we were doing it better

than anyone else had done it before,

but it wasn't immediately obvious

what we were learning.

To extract meaning from these speed

calculations, computer
simulations were conducted

of the relative motion
of the Milky Way galaxy

and the Magellanic Clouds.

The simulations were carried
out at Harvard University.

The movements of the Magellanic Clouds

were minutely calculated,

using the latest data on the size and mass

of the Milky Way.

This is the result.

Contrary to expectations,

the Magellanic Clouds do
not orbit the Milky Way.

Assuming the Milky Way is
not unnaturally massive,

the Magellanic Clouds
will eventually fly off

into deep space.

I basically computed things like

the escape speed, which refers to

the speed that an object would need to have

to escape the potential of the Milky Way

at its distance and separation
from the Milky Way,

and for the basic model I had
initially started off with

for the Milky Way, the LMC was sitting

at the escape speed.

So the orbit couldn't be anywhere close

to what we thought before.

So it was very normal for people to think

for years that the Magellanic
Clouds had been going

around the Milky Way many times.

Gutina realized that that
couldn't be at that speed,

they were going too fast,

they were basically flying away

from the Milky Way too fast,

which means that, probably,

they were just coming into the Milky Way

for the very first time,

and this is a very revolutionary thought.

So the Magellanic Clouds are not

satellite galaxies of
the Milky Way after all

they are visitors from afar,

merely enjoying a chance encounter

with our own galaxy.

In a few billion years,
they are fated to disappear

into the furthest reaches of space,

never to return.

The true nature of the Magellanic Clouds

is gradually emerging,

and astronomical observations indicate

that the clouds hold the
key to understanding

what the universe looked like

right after the Big Bang.

Paul Crowther is one of the scientists

fascinated by the Magellanic Clouds.

For 15 years, he's been
studying one of the clouds

features in particular.

What's attracted his attention

is the Tarantula nebula.

At its center, there's a
place estimated to shine

with the luminosity of a
hundred million of our suns.

R136 is its scientific designation.

It was thought to contain a mystery object.

Crowther set out to find out what that was.

He conducted his observations
with what's called

the VLT, or Very Large
Telescope located in Chile.

He pointed the VLT and its
8.2 meter diameter mirrors

straight at R136 in the middle
of the Magellanic Clouds.

This is the very center of R136.

The detailed view provided by the VLT

reveals that what looked
like one bright clump

at its center is comprised of many stars,

the brightest of which has
been designated R136a1.

With a luminosity of 10 million suns,

it is, so far as we now know,

the brightest star in the universe.

Crowther performed a spectral
analysis of its light.

The spectrum is kind of like a fingerprint

of an object, it tells
us what it's made of,

it tells us how hot the gas is in the star,

and so this actually is
an infrared spectrum

taken with the Very Large Telescope

of R136a1, and it reveals the presence of,

for example, this is a line of helium two,

ionized helium, and this means the star

is incredibly hot.

Thanks to this analysis,

Crowther was able to start profiling

his mystery object.

This is how Crowther envisions

R136a1 in the center of
the Tarantula nebula.

With surface temperatures
reaching 55,000 degrees celsius

it burns bright blue.

When it was born, it had the
mass of 300 of our suns.

To date, nothing comparable has been found

in the Milky Way.

These first generation stars
of the early universe

born right after the Big Bang

were unlike most of the stars we see today.

They were formed directly out of hydrogen

and helium gases, and they
were all blue giants.

In the Magellanic Clouds,
there are many such stars.

The Hubble Space Telescope
has captured a number

of ancient galaxies that contain
these blue giant stars.

All these galaxies are more than 13 billion

light years away, so what we see now,

is how they looked 13 billion years ago.

In other words, just moments after

the universe was born.

Ancient galaxies, glowing bright blue.

The sheer number of blue giant stars,

similar to the one
Crowther has been studying

is enough to impart a blue color

to the galaxy as a whole.

These galaxies, born
just after the creation

of the universe, are a mere tenth the size

of the Milky Way, and
have irregular shapes.

In size and shape, they
resemble the Magellanic Clouds.

That is why scientists
believe that studying

the Magellanic Clouds will provide insights

into the evolution of our own galaxy.

Well, so the interesting thing here

is that we've learned a lot
about structure formation

in the universe over the
years, and in particular

what has been learned
is that structure forms

by smaller units coming together.

So if you're a big galaxy
like the Milky Way,

you really started out
as lots of little clumps

that fell together over time.

One scenario for the growth

of the galaxy, would go as follows,

in the earliest stage of the universe,

there were only small, irregular galaxies

like the Magellanic Clouds.

These small galaxies collided
and merged repeatedly.

In this way, so the theory goes,

over the course of billions of years,

larger galaxies like our
Milky Way were formed.

Van der Marel believes
that the Magellanic Clouds

are in fact holdovers
from the earliest days

of the universe, small galaxies

that only now are brushing
past our own, larger galaxy.

In the early universe,
soon after the Big Bang,

we believe this happened all the time.

There were bits and pieces
of galaxies falling together

to form the first real
galaxies that then later grew

over time.

Nowadays, in our current universe,

this is actually a pretty rare occurrence.

So the effect that we're seeing

Magellanic Clouds pass
the Milky Way right now

is very unusual at some level,

but it really gives us a glimpse

of what the universe was
like more typically

when it was much younger,

when galaxies were falling onto each other

and merging together all the time.

The Magellanic Clouds

had been thought of as satellite galaxies,

but it turns out that they
are actually leftovers

from the very beginnings of the universe.

Small galaxies linked together,

spewing a plume of gasses behind them

as they rush past us.

At the VISTA telescope in Chile,

observations of the Magellanic
Clouds are ongoing.

The detailed mapping of
the Magellanic Clouds,

based on the Vista surveys

is expected to be completed in 2017.

Vista is continuing observations

of the Magellanic Clouds,

and we are extremely lucky
to have this exciting,

and mysterious galaxy next to us,

because it has been a wonderful playground

for astronomers for more
than a century now.

A couple of centuries.

And I'm sure it will help us

to reveal many more secrets.

The origins of the universe,

the birth of the galaxies.

These are the mysteries to
which the Magellanic Clouds

hold the keys.

As humanity peers into the
southern night skies,

that quest will continue.