NOVA

Earth.

You may think you know it well.

But a startling new picture is emerging

of a world shaped by forces

more dynamic and intertwined than we ever imagined,

raising possibilities that defy common sense.

How can sandstorms in the Sahara Desert

transform the Amazon rainforest over 5,000 miles away?

In the frigid ocean beneath Antarctica,

how can a vast undersea waterfall

500 times bigger than Niagara Falls

lead to a gigantic feeding frenzy near the equator?

And how can warm water streaming past the coast of Africa

trigger a weather catastrophe

half a world away in the southern United States?

Scientists have begun to find surprising answers

to these and other profound questions

thanks to a network of satellites

orbiting high above the earth.

Ever watchful,

their senses extend far beyond what our eyes can see.

It's really the last bastion of human discovery.

We're discovering new things every day.

What are these hidden forces that rule our world?

How are the oceans, the continents, the atmosphere

and even the sun bound together,

and how do they affect all living things?

For the first time, we can understand

how earth, fire, wind and water join together

to create the dynamic environments

that shape life in all its forms.

Their interaction

is what has created the environment, the diversity,

the kind of life we see on earth today.

With astonishing images

created from a wealth of new information from satellites,

this is our planet as never seen before.

"Earth from Space," right now on NOVA.

Major funding for NOVA is provided by the following:

Since humans first ventured into space,

some of the greatest gifts of exploration

have been the new views of our home.

Who can forget the iconic "earthrise" images

of the Apollo era?

And now from the International Space Station,

we have these spectacular vistas.

The blue marble is finally revealing its secrets.

It's a planet alive with activity and constant change,

its surface transformed by humans

yet still ruled by powerful natural forces

that we are only beginning to understand.

It's just spectacular when you view it from space.

It's teeming with diversity, with beauty.

Amazing colors, you know,

the blues and the greens and the whites.

You see the world

as one huge system

all linked through the atmosphere and the oceans,

rolling its way around the sun.

So what is it that shapes Earth's dynamic face?

What are the essential ingredients,

and how do they combine to generate and sustain all life?

How do the natural forces that surround us work together

to create an engine powerful enough

to nourish and drive life forward in all its diversity?

Our best hope for answers may come from above.

Orbiting over our heads are 120 satellites

keeping watch from space.

Most operate at altitudes

ranging from a few hundred miles above the surface of the planet

to as high as 25,000 miles.

Each one of these Earth-observing satellites

reveals a different piece of the puzzle.

Each carries an array of exquisitely sensitive detectors,

designed to reveal what would otherwise

be hidden from our view.

The satellites are absolutely amazing

because not only can we see visible things from space,

but also we can see things that aren't visible to the human eye.

So satellites are enabling us

to turn what are invisible processes

into visible things we can see and then understand.

To see how our world works, in this program

we have taken information provided by satellites,

combined it with computer models,

and rendered the results

in these scientifically accurate graphics.

With the invisible now revealed,

we can see Earth as an endlessly changing system.

These images will show in great detail

how sunlight, moisture, land and atmosphere interact

in unexpected ways,

with seemingly local events

often triggered by forces far away in space and time.

And with these new insights, for the first time,

scientists can begin to understand

the intimate relationship between the planet

and all the living things it supports.

It's really the thrill,

because it matters so much,

of piecing together the story of what the earth is doing,

how it's changing, why it's changing

and how ultimately that affects humans.

The first piece of the puzzle

is in understanding the massive influence the sun,

from 93 million miles away, has on our planet.

The world's continuously bathed

in a flow of energy from the sun.

That warms the earth.

Everything that you can see that lives and breathes

and moves on the earth is pushed by the sun.

Now an electronic eye in space

can measure the impact of the sun's energy

all around the earth.

One of NASA's newest satellites,

named for a meteorologist, polar-orbiting Suomi,

launched in 2011, provides the view.

The spacecraft is the size of a small school bus.

It orbits 500 miles up, circling the planet 14 times a day.

On board, it carries five separate sensors

that enable it to see things invisible to human eyes.

The light that we can see

is confined to a narrow band of electromagnetic radiation,

just a tiny portion of what the satellite can pick up.

Electromagnetic radiation spans a spectrum

that goes far beyond the familiar colors of the rainbow.

If you were to consider the full spectrum to be a line

that stretched from New York City to Los Angeles,

the piece that our eyes could see

would be about the size of a dime.

There is so much other information out there

available to us,

and that's in large part what these satellites do.

One of this satellite's key instruments is called CERES,

an acronym for Clouds and Earth's Radiant Energy System.

It detects a broad range of the spectrum,

including the very short and very long wavelengths of light

in the ultraviolet and infrared that we can't see.

This is a CERES-eye view of the planet.

Anything that emits heat gives off infrared radiation,

so the CERES data shows the earth in shades of heat,

accurate to a fraction of a degree.

It reveals how the planet as a whole reacts to sunlight,

both absorbing and reflecting the radiation

coming from our local star.

At the poles, the sun strikes at an oblique angle,

and what little light there is

gets reflected back out to space by the ice and clouds.

These are the primary reasons why the poles remain cool.

At the equator, it's a very different story.

Not only does the planet receive more direct sunlight here,

the lack of ice means that

less of the sun's energy is reflected back into space.

And at the equator,

the sun's concentrated energy fuels a heat engine

that can trigger weather events around the world.

Perhaps the best place to see the impact of the sun's heat

is an area in the Atlantic

just north of the equator and west of Africa:

the coastal waters of the Cape Verde islands.

Here, the sea provides a living.

The local fishermen keep a careful eye on the weather.

They know that storms can bring a good catch.

Turbulent weather stirs up nutrients from the deep,

attracting great shoals of fish.

It's the hottest time of the year,

and the sun beats down relentlessly.

By late afternoon, the huge inflow of heat energy

has led to the buildup of large cloud formations.

Sometimes, these formations develop into massive storms.

It's a process that satellites are revealing in fine detail.

Circling above the fishermen is a NASA satellite called Aqua...

Latin for "water."

It orbits the poles.

One of its key tasks is to monitor the complex interaction

between sunlight and water.

Aqua satellite is one of NASA's flagship satellites.

Its primary function is to study the hydrologic cycle on Earth:

vapor in the atmosphere, liquid ocean,

the temperature of that ocean and the ice.

One of Aqua's instruments

looks down at the sea around Cape Verde,

again in infrared, sensing heat.

Highlighted here in yellow,

over one million square miles of ocean

reaches a critical temperature: 80 degrees.

At this temperature, the sea is evaporating fast,

producing an invisible gas: water vapor.

By looking at the infrared, the Aqua satellite

is able to measure the amount of water vapor evaporating

from the surface of the ocean.

Aqua shows that this area

is producing millions of tons of water vapor every hour.

Based on that data, it's possible to create an image

of what the vapor might look like

if these fishermen could actually see it

in the air around them.

Water vapor is much lighter than air,

and vast columns rise upward,

directly from the surface of the sea.