Original subtitles

This is Big Bear Lake in California, USA.

An observatory stands in the middle of the lake.

It houses the largest solar telescope in the world,

completed in 2011.

When the sun surface is observed through this telescope,

a strange pattern can be seen.

The heat generated within is making the gas

on the surface bubble up and boil.

This is the sun as seen from space by a satellite.

With surface temperatures exceeding 6,000 degrees Celsius,

the sun glows red hot.

The dark shadows that can be seen are called sunspots.

Violent explosions occur around these spots

from time to time.

This erupting loop of gas is known as a prominence.

At 15 times the size of the Earth,

it is of a magnitude hard to fathom.

It's thanks to the light and heat emitted by the sun

that life on Earth can thrive.

However, experts believe the sun is undergoing

some unusual changes.

Up to now, changes in the intensity of the suns activity

have occurred in regular cycles.

However, the cycles are beginning to lose

their clockwork regularity.

This change comes at a golden age for solar observation,

with several satellites currently watching the sun

from space.

Now scientists have reached a surprising conclusion.

They say that some time in the near future,

the temperature of the Earth may drop.

What is now happening to the sun

and how will this effect life on Earth?

Cosmic Front delves into the mystery

of how our sun is changing.

Coming up, going into close loop control in LSPU.

The field of solar observation

is entering an unprecedented golden age.

In the last decade, countries around the world

have launched solar observation satellites

one after another.

There are now more satellites than ever observing the sun

from space, with six currently in orbit.

The footage captured by the satellites is sent here

to the Solar and Astrophysics laboratory in California.

The laboratory has been developing solar observation

satellites since the 1970s.

This is the laborites imaging server room.

The images captured by five of the satellites

are collated here, and then sent out to researchers

around the world.

Dr. Ted Tarbell has spent the last 30 years researching

the sun using satellite observations.

Today we have SDO, Hinode, Stereo, and SOHO.

As the fixed star closest to the Earth

the sun has always been of particular interest

to astronomers.

Of the satellites currently observing the sun,

the newest is SDO, which was launched

in February 2010.

The satellite can observe the sun in its entirety

in both visible and ultraviolet light.

When observed in various types of light,

the sun appears in totally different guises.

In normal light, the sunspots appear as small dots,

but when seen in ultraviolet light,

in stark contrast to the quiet, still image,

the sun appears as a glowing orb of swirling activity.

Sunspots are where the activity on the sun's surface

is at the most intense.

It follows, therefore, that the more sunspots there are,

the more active the sun is.

Hinode was launched in 2006.

Its on board telescope boasts images

of unprecedented resolution.

What do sunspots look like under Hinode's gaze?

What looks simply like a dot

now looks like a moving, living organism.

This sunspot is known among researchers as Nippon,

as it resembles the islands of Japan.

Thanks to the clarity of Hinode's images,

various phenomenon have been revealed to be occurring

around the sunspots.

This sunspot is 20,000 kilometers wide.

Flames reaching 10,000 degrees Celsius erupt and flicker

around the sunspot.

The dark ring that frames the sunspot is called a penumbra.

When closely examined, the stripes of the penumbra

can be seen to flow alternately in opposite directions.

The lighter stripes flow towards the sunspot center,

while the darker parts flow out.

Professor Saku Tsuneta heads up an observation project

that uses Hinode.

He spent 11 years developing the satellite.

He says he will never forget the first image

sent from Hinode.

In April 2008,

Hinode captured the greatest explosion in the solar system.

Between the two black sunspots

small sparks of light start to appear until

a band of white light suddenly erupts.

This is a massive explosion known as a solar flare.

The phenomenal amount of energy it emits

is equivalent to 100 million hydrogen bombs.

Furthermore, a strange phenomenon was also observed

where swirls of gas were sucked into the sunspots.

Sunspots do not necessarily stay in the same place.

They can appear and disappear

and are constantly changing.

This footage shows the surface of the sun

captured repeatedly over a period of more than 10 years.

The lighter, glowing patches are the sunspots.

When observed over several years,

it becomes evident that the number of sunspots

varies with time.

This is proof that the sun's activity changes in intensity.

For a long time, the fluctuations in the number of sunspots

and therefore the level of solar activity,

occurred in fixed 11 year cycles.

The sun, however, is now facing a change

in its patterns of activity.

Having hither two marked regular cycles

of 11 years, the sun was due for a peak in activity

in 2011.

However, the number of sunspots is yet

to noticeably increase.

In short, the suns regular cycles have started to go awry.

And it's believed this sudden change

may have a major impact on Earth.

The first person to ever record sunspots

was Galileo Galilei.

These are sunspots sketched by Galileo.

In the 400 years since, the number of sunspots

has continued to be observed.

Looking at the records, there's a period of 70 years

when there were no sunspots.

This period is known as the Maunder Minimum,

named after the man who made the discovery.

How did this period of no sunspots and low solar activity

effect life on Earth?

It's impossible to know at first hand how things were

at the time, but clues can be found in an unexpected place.

This is Kyoto, the ancient capital of Japan.

Dr. Yasuyuki Aono is an associate professor

at Osaka Prefecture University.

He has come to the Yomei Bunko Library.

It is here that he read some ancient texts

passed down through the Konoe family of court nobility.

The timing of when cherry trees bloom

is determined by the temperatures at the start of Spring.

With this in mind, Aono looked for diary entries

that would provide clues to the temperatures at the time.

The research showed that in the early 1600s

cherry trees were in full bloom about 100 days

after January 1st.

But by the late 1600s,

the day of full bloom came more than 10 days later

than this.

Using this data, Aono was able to compute the temperatures

at the time.

This showed that during the 70 year Maunder Minimum

period, the average temperatures were nearly

two degrees lower.

During the period of low solar activity and fewer sunspots,

it is thought that Kyoto went through a cooling phase.

In fact, Japan was not the only place that experienced

cooling.

The River Thames flows through the center of London.

This painting from the late 1600s

shows a frozen Thames.

During this time, poor crop harvests were recorded

across Europe.

The Maunder Minimum, when sunspots disappeared

and solar activity plummeted,

was a period of global cooling.

The Earth is warmed by the sun's light.

When sunspots were scarce and activity levels low,

how much weaker was the sun's light?

An American solar observation satellite

has been making accurate measurements

of the levels of light given off by the sun

for more then 40 years.

These are the results.

What is surprising is that whether the sun is

at its most active with lots of sunspots

or whether its activity levels and number of sunspots

are low,

the level of light it emits varies by a mere 0.15%.

It is practically constant.

But if the levels of light from the sun did not decrease

during this period of fewer sunspots,

why then did the Earth's temperature drop?

The answer lies not in the sun's light, but elsewhere.

Big Bear Lake in California, USA.

A narrow road stretches out into the lake.

A white dome stands at the end of it

as if it's floating on the water.

This is Big Bear Solar Observatory,

operated by the New Jersey Institute of Technology.

The observatory was rebuilt in February 2010.

It houses the world's largest solar telescope.

Professor Phil Goode is the director of the observatory.

He has spent the past 40 years studying the sun.

Good, good.

This is the observatory's state of the art

telescope.

It stands eight meters high.

It is painted white all over

so as not to absorb the sun's heat.

This mirror is the largest aperture mirror

for any solar telescope in the world

and makes it the most powerful solar telescope.

Collecting the light coming in from the dome window

is a 1.5 meter wide reflecting mirror.

Compared to artificial satellites,

the advantage of ground-based observation

is that large telescopes like this can be used.

The major disadvantage, however,

is the presence of air.

The turbulence in the heated up air

causes the images to be blurred.

There are two ways in which the observatory combats

this problem.

Three kilometers of open water to the West

and so we have nice, smooth air

coming in and that enables us to correct our images

with adaptive optics all day long.

By placing the telescope on water,

which is less likely to warm up than the ground,

there is less turbulence in the air around the observatory.

The second way to solve the problem can be found in the room

where the light gathered by the telescope is analyzed.

An observation room lies directly under the telescope.

The light from the sun captured by the telescope

is guided down from the ceiling.

The light passes through several mirrors and lenses

into the observation equipment.

The mirror in the middle is specially designed

to minimize the atmospheric distortion.

Amazingly, it can change shape in an instant.

A high speed camera detects turbulence in the air

which prompts the mirror to change shape

in order to correct any distortion,

producing a pristine image.

This special technology is called adaptive optics.

Here is how the technology works.

A 30,000 kilometer square area of the sun's surface

is magnified.

It shows hot gas bubbling up from the interior.

The image is in focus,

but because of the turbulence in the air, it is blurred.

This is where the adaptive optics equipment comes into play.

At once, a crystal clear image is revealed.

The telescope can be employed to observe the sun

using a special type of light known as H-Alpha.

Several curved lines can be seen.

This in fact shows the source of the sun's activity.

These curved lines may look strangely familiar.

They are identical to the magnetic field lines

that appear when iron filings are poured over a magnet.

The curved lines show that there is magnetism everywhere

around the sun.

Those jets are plasma that's excited and sent up

and attracts along magnetic field lines,

so you can see an outline

of the magnetic field of the sun

and on the smallest scale, it's everywhere.

So that's a surprise.

The sun is truly a magnetic star.

The sun is covered in magnetism.

The surface may appear quiet and still,

yet it's 100 times more magnetic than the Earth.

Where the intensely active sunspots lie,

it can be as much as 10,000 times more.

The sun is covered all over by distinctive loops

of magnetic field lines produced by the strong magnetism.

This magnetism is generated in the sun's interior.

There is a 400,000 kilometer deep layer

under the surface of the sun

where hot gases circulate in convection currents.

It is thought that the sun's magnetism

is generated by the energy of the moving gases

at the bottom of this layer.

The sun's magnetism can be seen in its full glory

during a total solar eclipse.

The sun's atmosphere, called the corona,

only appears at the moment the moon obscures

the intensely bright sun.

Examined closely, a streaky pattern can be seen.

These streaks are the magnetic field lines that the sun,

the magnetic star, emits into space.

It is this magnetism that causes the various phenomena

on the sun.

The flames that flicker on the surface of the sun

are prominences.

These prominences are eruptions of gas

caused by magnetism.

This phenomenon can be recreated using a magnetic toy.

When a magnetic top is spun on top of a stand,

the magnetism causes the top to float in the air.

Similarly, prominences are plasma gases

that float up through the power of the sun's magnetic force.

Solar flares are the largest explosive events

in our solar system.

They are also caused by the sun's strong magnetic force.

Magnetic field lines shoot out from inside the sun

onto the surface.

When the lines are pulled together at their base

by convection currents,

the two sets of lines connect.

At this point, the magnetic field lines recombine.

The newly reconnected lines contract

like an elastic band.

They snap back and force gas down onto the surface

of the sun, leading to a violent explosion.

The intense activity seen on the sun

is the product of the massive magnetic energy

that is constantly generated inside the star.

In fact, the sun's strong magnetic field extends so far

that it envelopes the whole solar system.

This magnetism lies at the root of the various activities

seen on the sun's surface.

The Earth, too, has a magnetic field.

It's field lines extend neatly from North to South.

In the sun's case, however, the magnetic field lines

are arranged in a complex tangle.

The sun's secret lies here.

The sun rotates on its own axis

once every 27 days or so.

Being made up of gas,

it's rotational speed can vary.

It rotates faster near the equator

and more slowly at its poles.

This means that the magnetic field lines

that run from North to South in its interior

are gradually pulled sideways

and end up wrapped around the sun.

The magnetic field lines vary in density

and where they are lighter, they float up to the surface.

When these field lines break through,

they form sunspots.

Sunspots are areas where the strong magnetic force

created inside the sun shoots out of the surface.

What happens then to the strength of the magnetic force

when there are changes in the suns activity?

As previously seen, light levels stay fairly constant

even with changes in number of sunspots

and levels of solar activity.

Here, the strength of the suns magnetic force

is added to the graph.

The magnetic force varies greatly.

Furthermore, the changes correlate perfectly

with the levels of solar activity.

The sun's magnetic force fluctuates wildly

with the changes in solar activity levels.

A hitherto unimagined possibility has emerged

that it is in fact this magnetic force

that has a major influence

on the Earth's changing temperature.

In the late 1600s.

When sunspots disappeared and solar activity dropped,

the Earth experienced global cooling.

Why did the Earth's temperature fall

when solar activity levels decreased

and the sun's magnetic force weakened?

In 1997, a paper written in Denmark

caused shockwaves around the world.

It claimed that the sun's magnetic force

effects the Earth's clouds.

The author of the paper lives in Denmark.

Yes, hello.

Professor Henrik Svensmark

is based at the National Space Institute,

otherwise known as DTU Space.

Since publishing his paper

Svensmark has continued to research the relationship

between the sun and the Earth's climate.

This is

what we call our sky experiment.

We are testing

how clouds are

forming or some of the processes that are important

for cloud formation.

Svensmark noticed a strong correlation

between cloud cover and something rather unexpected.

This graph shows levels of cloud cover

as measured by satellites.

Svensmark discovered something else

that fluctuates in the same way as levels of cloud cover.

It was cosmic rays,

the radiation that showers down from space.

Cosmic rays are a type of radiation generated in outer space

when a star reaches the end of its life and explodes.

Some of the rays travel across space over a long period

of time and reach Earth.

Svensmark noticed that when there are more cosmic rays,

the Earth's cloud cover increases

and when cosmic rays decrease, cloud cover falls.

That is

you know, it's a big surprise,

and the agreement was

fairly good even though it was very a short period

that we had data.

The agreement was very good,

but the mere idea that there could be such a connection

I thought was very

exciting.

Up until then,

no one had ever imagined a relationship

between cloud formation and cosmic rays.

This idea first occurred to Svensmark

when he thought of an experiment he had seen

at high school.

Of course, the cloud chamber at that time

was much, much smaller,

but it's the same principle.

It works fine.

This is a cloud chamber,

an apparatus filled with vapor.

There's one there.

But it lasts only maybe a second

and then it's gone.

From time to time, white streaks appear.

These streaks are the tracks of the cosmic rays

that fall onto Earth from space.

When cosmic rays pass through the vapor,

cloud-like forms appear.

I thought immediately that

if cosmic rays are important,

it might be clouds.

Sorry, yes, it might be clouds that they are

effecting, so that was the basic idea.

Svensmark believes that the cosmic rays

that fall from afar cause clouds to form.

It is widely known that the sun's magnetic force

effects the levels of galactic cosmic rays.

Cosmic rays fly down towards Earth.

The suns strong magnetic field, however,

extends all the way across the solar system.

This acts as a barrier, making it difficult for cosmic rays

to break through.

But when solar activity levels drop,

the magnetic shield weakens

allowing more cosmic rays to enter the solar system.

The cosmic rays can then reach the Earth's atmosphere.

In short, the volume of cosmic rays that reaches Earth

is determined by solar activity levels.

Here, solar activity levels are added to the earlier graph.

It is evident that when solar activity is low

and the magnetic shield weakened,

more cosmic rays fall on Earth

and there is greater cloud coverage.

What is important is the sun's magnetic field,

which shields against the cosmic rays

and when this shield changes,

it changes the Earth's cloudiness

and thereby the temperature of the Earth.

So the solar activity

and the plasma that comes from the sun

or the magnetic field

is really what controls the climate.

Clouds are not formed by water vapor alone.

They can only form with the presence of tiny particles

that act as seeds around which water vapor gathers.

In this photo taken above the Pacific Ocean,

white streaks can be seen.

These are clouds created by ships

travelling across the ocean.

Water vapor gathers around the tiny particles

found in the ships exhaust forming clouds.

Svensmark theorizes that cosmic rays

effect the formation of these particles.

When cosmic rays reach Earth,

they collide with molecules in the air.

The molecules then become charged with electricity

and are drawn to each other

growing bigger and bigger.

This gives rise to the tiny particles necessary

in cloud formation.

According to this theory,

the particles become cloud seeds

for water vapor to gather around

and clouds are formed.

Svensmark's theory of climate change on Earth

can be summarized thus:

The Earth is protected by the sun's magnetic field,

but when this is weakened, higher levels of cosmic rays

can reach Earth.

This creates more particles up in the air

giving rise to clouds.

As a result, sunlight is blocked,

and the Earth cools.

What is happening in the space surrounding us

is very important and the solar activity can change

the number of particles which changes the cloudiness

of the Earth, which changes the climate.

So that is the

connection that it's very surprising,

but that is how things look now.

Svensmark's claim that the Earth's climate

is influenced by space sparked a heated debate worldwide.

His theory is now being verified around the world.

The most extensive verification of the theory

is being carried out just outside Geneva in Switzerland

at the European Organization for Nuclear Research

known as CERN.

Large-scale research, such as studies into the origins

of the universe, is being carried out using the world's

largest particle accelerator,

which is 27 kilometers long.

One of the projects being carried out here

is the cloud experiment,

which investigates the relationship between cosmic rays

and clouds.

Consisting of an airtight chamber three meters in diameter

and four meters high, it is the only facility in the world

which can recreate the conditions of the atmosphere

anywhere on Earth.

Using this, scientists can test whether cosmic rays

really do cause clouds.

So this is the

cloud chamber where we

create the atmosphere

and investigate the effective cosmic rays from the beam

on the cloud processes.

Dr. Jasper Kirkby uses this chamber

to run the cloud experiment.

He started the project three years ago

as a result of Svensmark's research.

26,000 liters of air can be trapped

inside this airtight chamber.

The ceiling is fitted with lights that irradiate the same

strong ultraviolet light that comes down from the sky.

The experiment simulates the composition of the air,

the temperatures, humidity, and light levels

to recreate the exact same conditions

as the atmosphere where clouds are formed.

The chamber is then showered with cosmic rays

artificially created by the accelerator.

The researchers then carefully check for the tiny particles

necessary for cloud formation.

The results can be seen here.

When the chamber is irradiated with artificial cosmic rays

from the large-scale accelerator,

the chamber quickly begins to fill up

with tiny particles.

When these particles grow,

they form the seeds that give rise to clouds.

We've run for three so-called campaigns

and we're finiding a very strong effect

when the beam goes through the chamber,

these particles, these seeds,

for cloud droplets or at least the embryonic form,

the very small version of them, do form

much more abundantly when the beam goes through.

Furthermore, it has been found

that when the number of tiny particles increases

the nature of the clouds themselves changes.

Research has been carried out using Japan's earth simulator

super computer.

Professor Kanya Kusano of Nagoya University

studied the effect the number of tiny particles has

on cloud formation

when the amount of water vapor is fixed.

In this simulation,

air containing water vapor is warmed up on the ground

and rises.

The water vapor gathers together up in the air

and forms clouds.

In time, rain falls from the clouds

and the clouds disappear.

The number of tiny particles that form the cloud seeds

is then varied.

When there are fewer tiny particles,

the water vapor that rises does form clouds,

but it quickly leads to rainfall and the clouds disperse.

With a large number of tiny particles, however,

there is hardly any rainfall

and the clouds remain for longer.

Kusano has a theory of what causes this difference.

The amount of water vapor is kept constant.

When there are fewer tiny particles,

more water is concentrated on each particle

creating big droplets that fall as rain.

With lots of tiny particles, however,

each particle attracts less water

creating droplets that are too small and light

to fall as rain.

The number of tiny particles

determines whether the droplets turn into rain

or stay as clouds,

and this has major repercussions on the amount of light

that reaches Earth.

When solar activity drops

and the suns magnetic field weakens

more clouds are formed,

which may lead to a cooling of the Earth.

Will the present lowering of solar activity levels continue

or will it return to previous levels?

Researchers are looking to the past for clues to the future.

The island of Yakushima,

a natural world heritage site, offers an answer.

Dr. Hiroko Miyahara from the

University of Tokyo's Institute for Cosmic Ray Research

is investigating trends in solar activity levels

from the past thousand years.

She's here to study the Yakusugi cedar trees

aged 1,000 years or more.

A growth ring sample from a fallen Yakusugi tree

is carefully extracted.

This sample contains a special substance

that provides valuable clues

to the sun's activity in the past.

That substance is carbon.

When cosmic rays hit the atmosphere,

carbon dioxide containing a special kind of carbon,

called C-14, is produced in varying amounts

depending on the number of cosmic rays.

The Yakusugi trees absorb this carbon dioxide

through photosynthesis.

As a result, in the years when the Earth's atmosphere

saw a high volume of cosmic rays,

the growth rings contain a greater quantity of C-14.

This means that by measuring the quantity of C-14

in each growth ring, the amount of cosmic rays

that fell on Earth that year can be ascertained.

Miyahara carefully peeled apart each growth ring

of the Yakusugi and collected around 1,000 years

worth of samples.

By looking at the changes in volume of cosmic rays

over 1,000 years,

she can calculate the solar activity level of each year.

She also noticed something interesting

before the Maunder Minimum.

That was the period in the 1600s

of low solar activity and global cooling.

It has been discovered that immediately prior to this

the sun's cycle was 13 years

instead of the usual 11.

Furthermore, there have been dips in solar activity levels

three times in the past 1,000 years,

and before each one, the sun's cycle had lengthened.

In other words, a pattern emerged where each time

the sun cycle lengthens, a period of several decades

of low solar activity follows.

Nobody even knows what the

upcoming solar maximum's going to look like

or when it will be, so everything is a surprise.

So you need to have as many eyes on the sun as possible.

The importance of solar observation

is greater than ever before.

In the U.S., a mission is being planned

to send a solar probe directly into the sun's atmosphere.

In Japan, too, preparations are under way

to launch another solar observation satellite in 2018.

At the National Astronomical Observatory of Japan,

Professor Tsuneta of the Hinode project

is leading the development of this new satellite.

And I think the sun

is very likely having a very strong effect on our climate,

but we don't understand it scientifically.

So I think it's our duty as scientists, all of us,

the climate scientists, the solar scientists,

satellite, physics, everybody

to really pull their capabilities

and understand our star,

which is controlling our lives.

The sun is mother of all life on Earth.

Scientists around the world are researching

what will happen to Earth

when the sun's activity falls.

What they discover will have important repercussions

for all of us here on Earth.