Finding Life Beyond Earth Page #9

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process has to happen first,

a process that, according to

the most widely accepted theory,

took place on early Earth

and ultimately produced us.

In this scenario,

the raw ingredients of life--

organic molecules--

dissolved in water.

And once in this liquid,

they came together and reacted

to form bigger,

more complex molecules

that would eventually

somehow become living things.

For life to have a chance

on Titan,

the building blocks would have

to dissolve in liquid methane.

Chris is now trying to find out

if this is possible.

He first has to replicate

the organic building blocks

that Cassini's instruments

detected

high in Titan's atmosphere.

Simulating an energy source,

Chris fires an electric spark

that hits gases

inside the test tube that

are known to exist on Titan.

This creates organic molecules

similar to those

in Titan's atmosphere,

the brown residue

at the bottom of the tube.

And we trigger the same

reactions in the flask,

and as a result we produce

the same kind of solid organic

material in the flask

that is being produced

in Titan's atmosphere.

NARRATOR:

Then Chris recreates Titan's

remarkable lakes.

He fills the test tube

with methane gas

and then cools it

below minus-290 degrees

using liquid nitrogen.

Now the methane liquefies,

just as it does

on Titan's frigid surface.

So in the flask we'll have

a miniature little lake,

a little puddle

of liquid methane,

swirling around in that

organic material.

Will anything dissolve

in that organic material?

That's the question.

And will that over time

build up organic complexity?

Could it be the start of what

could be another type of life?

NARRATOR:

No one knows exactly

how life gets started.

But the question Chris

is interested in

is can organic compounds

dissolve in liquids

like methane?

If so, it would suggest

that even at extremely cold

temperatures,

the chemistry needed for life

could be possible

in liquids other than water.

McKAY:

We know that there's

conditions there

that maintain liquid,

there's energy sources,

there's organic material,

there's nutrients,

there's an environment that

may be suitable for life.

But if there's life there, it's

going to be completely different

than anything we have on Earth.

NARRATOR:

Chris's experiment is one step

toward understanding

whether there could be

life on Titan.

McKAY:

To me the most exciting

possibility

is that there's life on Titan

because then that would show

not just that life

started twice,

but it's started twice

in very different conditions.

It would show us that life

is a natural process

that's going to pop up

on many different worlds,

many different planets

around many different stars.

NARRATOR:

Titan, Enceladus,

Europa, and Io

show that even

within our solar system

there are places where some

scientists believe

life could potentially

gain a foothold.

GREEN:

Might be extreme life,

might be life

that we've never seen before

in terms of its structure

and its composition.

But we're now realizing

that those environments

could harbor life.

NARRATOR:

The three vital factors--

energy, liquids

and chemical building blocks--

are more widespread

than has ever been realized.

And if it's possible here,

then could the right conditions

also exist

beyond the boundaries

of our own solar system?

GREEN:

By understanding

our own solar system,

I believe we'll then

be well on our way

to understanding the conditions

that could occur

around other stars

and throughout our galaxy.

It really changes our view

of this universe.

NARRATOR:

Is there somewhere out there,

a star like our sun, orbited

by habitable planets

that are teeming with life?

There are billions of stars just

like our sun within our galaxy.

And the odds suggest that

tens of billions of planets

are orbiting around them.

If there is life out there,

can we find it?

Astronomer Mario Livio is

at the forefront of the search.

He's using the Hubble

space telescope

to look deep into space

to where new stars, like our

sun, are bursting into life.

This is the Orion nebula

as seen by Hubble.

Here, 1 ,500 light years

beyond our solar system,

new stars are being born inside

a vast cloud of dust and gas.

LIVIO:

So when we look

at the nebula now,

it's almost like looking

into a cave.

We see this hollow part where

gas and dust has been blown away

and inside where these stars

are being born.

NARRATOR:

And right inside,

among all the shining stars,

is what looks like

a small, dark smudge.

In fact, it is a young sun

surrounded by a dense disk

of dust and gas more than

50 billion miles across.

This smudge represents

the dawn of a new solar system.

In this case we see the disk

edge on, and therefore the disk

completely obscures the light

from the star,

and this is why you don't see

the star.

NARRATOR:

Other images show similar disks

tilted to reveal the star

at the center.

These spinning clouds of matter

may one day

form planets and moons,

as particles of dust, ice and

gas collide and clump together.

This is the same process

that is thought to have created

the planets of our solar system.

Hubble has revealed that

swirling disks like this

are extremely common.

The fact that

we see these very often

tells us that these

raw materials

from which planets form

are very, very common.

And so that planetary systems

form probably around most stars.

NARRATOR:

But do these young solar systems

produce Earth-like planets

containing the right ingredients

needed to sustain life?

Astronomer Josh Eisner

wants to find out.

He has come to Mauna Kea,

Hawaii,

to look at the clouds of gas

and dust in more detail.

EISNER:

We'd really like to understand

are there building blocks

of life there?

Are things that we associate

with at least life on our planet

available for planet formation

around other stars?

NARRATOR:

Analyzing gas

and tiny bits of dust

from hundreds of light years

away is no simple feat.

It requires instruments of great

sensitivity and precision:

the Keck telescopes.

1 4,000 feet up on the summit

of a dormant volcano,

these twin telescopes are among

the most powerful on Earth.

Josh uses both of them together.

And with a spectroscope

to analyze infrared light

emitted from inside

the early solar systems,

he can tell what

they're made of.

EISNER:

We're actually trying to map

a detailed picture

of the dust and what

that hot gas is made of.

Is there water vapor there

that might get incorporated

into an atmosphere one day,

or into an ocean one day?

NARRATOR:

His findings are encouraging.

In some of the distant

solar systems,

Josh is detecting evidence

of carbon, oxygen, and hydrogen,

three key elements needed

to produce the chemical building

blocks on which life depends.

Even more intriguing

is that in some disks

those ingredients also appear

to be at the right distance

from their stars to form planets

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