Space's Deepest Secrets

The Sun.

The star at the center of our solar system.

Its surface rages with violent eruptions,

magnetic tornadoes,

and mysterious dark spots.

The Sun is essentially a big, giant ball of plasma.

And it's just pouring out energy.

Where does the Sun's vast power come from?

How was our star born?

And could its immense energy one day consume our planet?

The Sun is both the bringer of life and the ultimate destroyer.

To find out, we will strip the Sun...

Peeling open its searing layers,

diving deep into its core,

revealing the secrets

that lie at the heart of our closest star.

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90 million miles from planet earth,

a cosmic powerhouse shapes our world.

The Sun, a giant nuclear reactor

1 million times bigger than earth.

Its influence extends

to the furthest regions of the solar system.

It supports all life

and protects us from a harsh galaxy.

The basic building block of the universe is a star.

And the Sun is a star.

The more we know about the Sun,

the more we could learn about the universe itself.

All of the energy in my body

that I'm using to speak and to move

originally comes from the Sun.

The Sun giveth and the Sun taketh away.

So, the Sun gives us life, it sustains us, it protects us,

but it can also wipe us out in an instant.

The Sun is more than a ball of gas.

It's a complex engine.

The outside is an ocean of roiling plasma.

Below that...

Is a bright layer dotted with dark and violent Sunspots.

120,000 miles deeper, plasma swirls in giant vortices,

pushing the Sun's heat to the surface.

Down in the core,

a nuclear furnace produces the energy

of 100 billion tons of dynamite every second.

All these layers work together

to make a colossal cosmic engine that powers life on earth.

But there's a dark side to all this energy.

These real-time satellite images

show lethal solar storms raging on the surface of the Sun.

At its most active, it can spew out 20 of them every day.

These energy surges blasting our planet

can damage power grids and cause city-wide blackouts.

These aren't made-up science fiction movies

coming out of Hollywood.

We get solar storms all the time,

but a really big one

could actually bring our civilization to its knees.

The U.S. air force is right in the firing line of the Sun.

Solar storms can fry communication satellites,

endangering the life of anyone on board an aircraft.

That's why the air force has eyes on the Sun day and night.

The men and women of the second weather squadron

scrutinize the Sun's activity 24/7.

The man with his finger on the solar pulse

is staff sergeant Erin O'Connell.

So, my job, in a simple way to phrase it,

is watch the Sun and report any activity that might occur on it.

The Sun can brew up a storm without any warning.

The surface of the Sun

is a highly volatile layer of plasma

1,500 miles deep.

Violent magnetic fields force their way up

through this roiling mass.

The fields rip off

loops of solar matter thousands of miles high.

Some of them collapse into solar flares

releasing bursts of radiation.

Others erupt as huge fire storms,

ejecting billions of tons of super-heated plasma

at millions of miles an hour.

These Sun storms take just a few days to reach the earth.

But the radiation from a flare can hit us within minutes,

creating a deadly threat to airborne flights.

So sergeant O'Connell's telescope

constantly monitors the Sun's surface

for solar flares.

We do have a region

that looks like it's getting bright enough

to possibly produce a flare.

Right now, it is bright enough for a flare,

but it's not quite big enough.

So, we can go ahead and continue to watch it, monitor it.

The air force isn't the only organization

watching the action unfold.

Millions of miles from earth,

a fleet of NASA satellites zooms in on the bright region.

This volatile area could erupt at any time,

shooting deadly radiation towards aircraft on earth.

It's wildly caught up.

If I hear that three alarm burst,

then I'm very worried.

The alarm tells sergeant O'Connell

that the flare has begun to erupt on the surface of the Sun.

So, that's the start of our flare.

The cause of this brewing flare

lies buried deep within the Sun.

Magnetism.

The Sun's magnetic field

originates 120,000 miles below the surface.

Here, one layer moves faster than the layer below it,

shearing the highly charged plasma in between.

This generates massive magnetic fields throughout the Sun.

These powerful fields Pierce the outer layers,

pushing up towering loops of plasma

that can erupt without warning.

That's our end flare alarm.

This region's no longer flare bright.

And that's the end of our flare.

This time, we're lucky.

The flare died down

before it could escape the Sun and hit the earth.

Our Sun demands constant vigilance.

But other stars have an even more violent temper.

The cosmos seethes with magnetic ferocity.

When we consider the danger that the Sun poses,

one of the big dangers has to do with its magnetic fields.

It has strong fields.

And the size and strength of the field

is related to a star's rotation rate.

So, when stars are young, they rotate much more quickly

and they have much more powerful magnetic fields,

which means more powerful explosions on their surface.

One of the most explosive young stars lies 16 light years away,

Ev Lacertae.

It's three times smaller than our Sun

and 100 times less bright.

But this tiny stellar infant packs a bunch.

Spinning six times faster than our Sun,

its magnetic field is 100 times stronger.

In 2008, ev lacertae

produced the largest star storm ever recorded,

thousands of times more powerful than any storm from our Sun.

Thankfully, our planet was too far away to be hit.

While the Sun isn't nearly as violent

it's much closer to earth.

The next big solar storm could arrive at any time.

A direct hit could wipe out power

across an entire continent.

So, how can we survive the next big strike?

Violent and volatile,

our 4 1/2 billion-year-old Sun

becomes more dangerous as it ages.

The Sun's chaotic behavior

threatens technology across the planet.

Weather forecasting, communication,

banking, the Internet...

All of that would be damaged, if not destroyed,

by a big solar storm.

The warning system that we have in place now

is better than nothing, certainly.

Is it enough?

I would say no.

But the Sun offers clues

that can help us predict its behavior.

Pulling away the loose gases of the Sun's atmosphere

reveals black disks the size of a planet

that drift on a layer of boiling plasma.

Sunspots.

Slicing through them reveals they are more than skin deep.

Areas of darkened plasma extend far below,

stretching thousands of miles into the Sun's interior.

Whenever you see these spots,

you know that the magnetic field is very intense

and very violent in those areas.

So, when you see lots of Sunspots,

you will also see flares and prominences of things

being thrown off the Sun.

But by the time we see Sunspots from earth,

we can already be under attack.

How these dark patches form

could be the missing link in predicting solar storms.

At the university of Birmingham,

bill Chaplin is on a mission

to increase solar warning times from minutes to days.

Bill thinks the key is not just watching the Sun,

but also listening to it.

Just below the visible surface of the Sun,

then the gas is very turbulent,

so there are lots of very rapid changes in pressure.

The gas is whizzing everywhere.

And what that does is it makes sound.

And what we're doing is,

we're actually measuring the effects

of these sound waves inside the Sun.

Bill's network of six observatories around the world

detects the Sun's surface moving back and force

and records the sound this motion creates.

These real-time sounds

reveal what's happening below the surface.