The Search for Life in Space

Hello from the children of planet Earth.

...extend the greetings of the government and the people of Canada

to the extraterrestrial inhabitants of outer space...

From my point of view, the search for extraterrestrial life,

and especially the search for extraterrestrial intelligence,

is one of the key philosophical, scientific and human questions

that have been posed, but we are at the very beginning of searching.

It was Carl Sagan's idea

to send a greeting card to our neighbors in the cosmos.

An idea ahead of its time,

since we haven't really met any neighbors out there

in the vastness of space.

We still haven't, but we're getting closer every day.

It was a greeting not only in words and images,

but full of the sights and sounds of our precious planet.

It's a message in a bottle

that we sent into the sea of interstellar space,

where it's still sailing

at 11 miles per second towards the unknown.

Sagan said that, "We make our world significant

by the courage of our questions,

and by the depth of our answers."

He wasn't afraid of making extraordinary claims,

as long as they were backed up by extraordinary evidence.

It might be a while before we hear

from an alien who's found our message in a bottle.

So today, instead of waiting to hear from life out there,

we're going to go looking for it.

Let's start here,

on the top of Mauna Kea in Hawaii,

where the W. M. Keck Observatory scans the clear night sky.

Carl Sagan knew what explorers have always known,

by understanding more about our neighbors,

we will understand more about ourselves

and our place in the universe.

No one knows Sagan's vision more than Lisa Kaltenegger,

the director of the Carl Sagan Institute at Cornell University.

Carl Sagan and his approach to science inspired me.

We are using many different fields of science,

astronomy, chemistry, biology, engineering and many more,

to make a forensic toolkit

to understand our place in this fascinating universe.

Before the Voyager spacecraft left our solar system,

it made some remarkable discoveries.

It proved that we need to be more open-minded

about where we search for alien life.

In 1980, Voyager first reached Saturn...

a raging ball of hydrogen and helium storms.

Not much chance of finding life there.

Voyager then turned to one of Saturn's 62 moons...

capturing the first close-up images

of Saturn's largest moon, Titan.

What it saw stunned astronomers.

Titan had a dense atmosphere, mostly made of nitrogen.

Twenty-four years later, the Cassini probe revealed even more.

On the surface are vast lakes of hydrocarbons,

the building blocks of amino acids, proteins.

Cassini continued on its celestial road trip,

where it found this frozen outpost, Enceladus.

This moon appeared to be frozen solid,

a dead ball of ice,

until something astounding was spotted near the south pole...

huge plumes of water,

spouting through cracks in the surface ice.

Beneath the frozen surface of Enceladus, was an ocean of liquid water.

It turns out that planet Earth

doesn't have a monopoly on water like we once thought.

On Earth, water is key to life.

It abounds on our planet and every animal, every plant,

every life-form depends on it for survival.

The seas are where life was born.

Water is the lifeblood of existence.

On Earth, liquid water is critical for life-forms that live in it...

as it is for those that live out of it.

When we search for alien worlds that might support life,

the presence of liquid water is a critical clue.

If a world has liquid water, there's a chance for life.

First discovered by Polynesian seafarers,

Hawaii is one of the most isolated string of islands in the Pacific.

These islands were formed when magma bubbled up

and cooled into mountains.

Each new outcropping of lava

is home to a dazzling variety of plants and animals, from above...

and below the surface of the sea.

More than 25,000 species

make this one of the most dynamic living habitats anywhere.

A living laboratory for the resilience of life.

Biologist Chris Johns

knows the fauna and flora of Hawaii really well,

including some amazing examples of the extremes

life will go to, to survive.

A stretch of barren lava rock.

It isn't the first place you'd expect to find life...

but that's exactly where nature has hidden a few surprises.

These lava tubes extend for miles.

They were created when lava drained out from an ancient volcanic eruption

beneath a crust that hardened above.

This is amazing, a whole new Hawaii I've never seen before.

A secret, hidden Hawaii.

Keep to your left.

It's just up ahead.

In this upside-down place,

you have to look up to see the roots of the remarkable Ohia tree.

They're beautiful,

hanging down into the caves like sparkling jewels.

Yeah, so we can actually check out some of these microstructures...

And they sparkle

because they're covered in water,

moisture that has condensed from the humid air.

Life needs liquid water to survive,

but the Ohia tree shows us that it can be very innovative

in the way it finds it.

-...for our data collection. -OK.

This is the Haleakala Valley on the island of Maui.

NASA uses alien landscapes like these to test their Mars rovers

before sending them off to the Red Planet.

The soil here is made of cinders,

the altitude is over a mile high

and the weather is dry, sunny,

windy and freezing.

It's the last place you'd expect Mother Nature to start gardening.

This is the Haleakala silversword.

Its fat leaves store water and are covered with tiny hairs

that pick up humidity in the dry air

and send it down as liquid water to the roots.

Water, as liquid, or carried on the wind,

or coursing across the landscape,

makes Earth a thriving paradise of life.

Water, with a dash of carbon

and a little energy from the sun,

are the simple ingredients for life to blossom.

In the canyons of this undersea world,

there is no sunlight and the water pressure is,

to put it simply, bone-crushing.

And yet, more than a mile down from the surface,

life flourishes.

These hydrothermal vents leak out heat and minerals

from the Earth's core.

They're called black smokers and ooze clouds of sulfur,

which is toxic and smelly to you and me,

but to the deep-sea bacteria that thrive here,

it's good, wholesome nutrition.

If life can thrive here in the dark, pressurized depths of Earth's oceans,

what about other oceans,

like the one on Enceladus?

For years, we have searched the planets

in our solar system for signs of alien life.

But perhaps it will be a moon that first confirms that we are not alone.

Some moons have all the key ingredients for life,

water, carbon and energy.

Energy not from the sun or from volcanoes,