All language subtitles for Netflix - Alien Worlds 1x02 - Janus (2020)_Track04

The Earth, home to millions of species.

But what might live... beyond?

Astronomers have
discovered thousands of planets

outside our solar system.

They believe there are trillions more.

If life exists on only
a fraction of them,

then the universe must be... alive.

All living things have the same needs.

To feed...

reproduce...

and evolve.

By applying the laws of life on Earth

to the rest of the universe...

it's possible to imagine

what could live...

on alien worlds.

Most planets we know of are so hellish,

it seems impossible
that anything could live.

But it's amazing
where life can take hold.

For as long as I can remember, my
mom always told me I was an alien,

because I just had my mind on
outer space from the beginning.

I just had always known that I wanted to
get out there and explore the universe.

Oh, my God.

This is the most incredible
place I think I've ever seen.

This is what I dream
other planets looking like.

It's... it's incredible.

So, yeah.

The Danakil Depression is known
locally as "The Gateway to Hell."

120 meters below
sea level and volcanic...

it's the hottest place on Earth.

We're at 79C. 82C.

This one's topping out at 87.

If life can exist here...

it could exist on any number
of worlds in the universe.

Life on other planets, they're
gonna have, uh, chemistry.

Whether it looks exactly
like ours, we don't know,

but they're gonna have
chemistry that helps them live.

And that chemistry is
going to be subject to limits.

For example, all life
is made up of cells.

Inside these cells
they have biomolecules

that allow the cells to
function and live and work.

That's our machinery that runs
and makes this chemistry happen,

that keeps life living.

And so we really wanna
understand how that machinery works

and what's gonna make
that machinery break down.

Until recently, it was assumed

that Danakil was too
extreme to support life.

But astrobiologists come here to
look for simple single-celled microbes...

known as extremophiles.

Microbes are too small
to see with the naked eye,

so it's not going to be as simple as
taking a little bit of water out of a lake

and putting it under a microscope
and seeing lots of teeming bugs.

The only way to detect the
presence of extremophiles

is to find traces of their DNA,

using a portable genetic sequencer.

This is a very small device and
it's very sensitive to temperature,

and we're in one of the hottest
places on the planet Earth.

So, here in the field right
now, we do... a cool block,

to kind of keep it cool, and
we have our channels running.

And we have...

We have sequencing!

We actually have sequencing happening.

We have DNA in here.

Excellent.

Sequencing of DNA is proof

that extremophiles can survive
in the acidic waters of Danakil.

These guys are like the superheroes
of microbes, and it's just amazing,

as we learn more and more about
the different strategies and mechanisms

that they come up with to survive
these kinds of environments.

Finding things alive here
opens up an intriguing possibility.

But some life forms are tough
enough to survive anywhere...

even in the deepest reaches of space.

A red dwarf star.

The most common
type of star in our galaxy.

Imagine a planet in such a close orbit,

its rotation is locked
by the star's gravity,

so it always shows
the same face to its sun.

This is Janus.

How would life adapt on
such an extreme world?

On one side of the
planet, it's always daytime,

a searing desert.

On the other side, it's forever night,

a frozen shadowland.

Squeezed between the two,
a sliver of perpetual twilight.

Freezing meltwater
flows from the cold side,

carving canyons through the landscape.

Even here, where the
planet's most hospitable,

there's little vegetation.

But deep in these canyons

lives an extraordinary
five-legged creature...

a pentapod.

No bigger than a cat,

it's the dominant life form on Janus,

capable of adapting to any conditions.

On the cold side,

it's stocky and hairy.

On the hot side, it's
shiny, slender and skittish.

Pentapods can become
whatever they need to be

in order to survive.

On Earth, all animals
adapt to fit their environment.

But some are more adaptable than others.

This trail that I just came across here,

it's a beautifully manicured trail,

and you would think it was made by
some bigger animal or maybe even a human.

But it's actually made by ants.

The leaf-cutter ant, in particular.

All looks quiet right now,

but if we come back at night, this will
actually turn into an ant super-highway,

with leaves just streaming
up, like, towards their nest.

Oh, wow.

Look at that.

This is the ant nest.

You can really see into
the heart of this colony.

There's a lot going on.

There's actually, for leaf-cutter
ants, there's different castes.

There is the soldiers,
there are different workers.

There's also the queen.

She's the only one who's laying
eggs, and there's only a single queen.

Without her, none of this would be here.

An ant colony depends
on the division of labor.

Different castes have different jobs,
and they come in all shapes and sizes.

I just grabbed one of the soldiers,

and I also grabbed the
really, really small worker.

And it's not the smallest
worker in this colony,

but it's... it's pretty close.

And I mean, the soldiers,
I barely can hold her.

It's really hard. I can feel her power.

I can feel she's trying to get
out. Her jaws are wide open.

But, I mean, the
difference is incredible.

And to think that they all started
from the same... the same larva.

All ants in a colony
are closely related.

They share most of the same genes.

But as they grow up, some genes
are switched on, others switched off,

depending on the food they are fed.

Any of them can become
workers, foragers or soldiers.

So, this ability to create such different
shapes and forms from the same blueprint,

this is actually called polyphenism.

And "poly" just means "many,"
and "phenism" would be "shapes."

Oh, the spider just did exactly
what I was trying to avoid all night.

She walked exactly into one of
these trails of these leaf-cutters here.

And that's not good news.

So here, you really see the power
of these soldiers and their jaws.

If something disturbs the colony,

it's their job to come in and get
it, and that's exactly what they did.

But wow.

Aaah!

All right, I'm already being attacked.

Ooh, that's gonna hurt.

They are now coming for me.

So, any creature that
has this ability to morph

and react to changes in its
environment as quickly as ants can do,

has an amazing
advantage to not just survive,

but actually dominate its world.

On Janus, pentapods are
masters of polyphenism.

Like ants, they're able to
develop into different forms.

But they all begin life
in the same place...

the Twilight Zone.

A pair of adults is ready to breed.

They're both male and female.

Hermaphrodites.

Each can produce offspring,

doubling their chances of success.

Having mated, a pentapod
leaves the shelter of the canyon.

It climbs to high ground,

ready to spawn.

At the top, a constant wind blows between
the cold and hot sides of the planet.

But the wind provides an
opportunity to scatter their larvae.

This way, they can colonize the planet.

On the hot side, water is scarce...

condensing only in shaded areas.

If there's nothing to eat, they move on.

With five legs, they can
skitter in any direction.

And with ten eyes,

not much escapes their attention.

If they sense a meal,

they use feelers to root it out.

They need to make the
most of every opportunity.

Life in any desert is an ordeal.

Only the tough survive.

And in the natural world,

there's nothing much tougher...

than a scorpion.

- Oh. Anything?
- Here?

I don't think so.

My first childhood
memory of the scorpion,

I was, uh, ten years old
and I see this big scorpion.

I screamed "Mom!"

Uh, so she came to my aid

and she was like, "What? What happened?"

And I point to the
scorpion, uh, on the ceiling,

I said, "That's gonna eat me."

And she was just like, "No, come
on. Be cool. This is just a scorpion."

So, as a cute Mexican mother,

she took, uh... her sandal

and just smashed the, uh,
little bastard on the ceiling.

Carlos Santibáñez-López is
now an expert on scorpions,

specializing in the
study of their venom.

I go at night and I use the UV light,

because UV light makes scorpions glow.

They have a special
protein in their shell.

Yeah, let's... Let's
take a look at this one.

- Oh, look at this!
- There's a lot of them.

Yeah, this is great.

Scorpions have barely
changed in 400 million years.

Perfectly adapted
for life in the desert.

Scorpions have a very slow metabolism.

They can spend long
periods without food or water.

We have records of some
species lasting one year

without eating anything.

And they have just enough energy

to sustain essential
functions to keep them alive.

They need to ensure that
the next time food is available,

they catch it.

So, scorpions have developed a lot of
weapons that they can use to hunt prey,

including the most important weapon...

venom.

To study scorpion venom,

Carlos needs to extract
it from glands in the tail.

Venom is a powerful cocktail
that contains minerals, salts

and hundreds of proteins
with a different function.

Try to be as fast as you can.

There you go.

We use electricity to
stimulate the muscles.

We're only gonna get
small... very small amounts,

a teeny, tiny drop of it.

But this drop is so valuable
that we don't wanna lose it.

Give him a nice massage.

Yeah. There's a tiny droplet.

- There.
- Oh, yes, it's... Okay, so it's working.

Uh, we have venom.

It is right there, but
it's a teeny, tiny drop.

- Uh... do you see it?
- That's right. Yeah.

I mean, it's... it's like
a... a drop of water.

Venom is such an effective weapon,

it's used by reptiles, insects and fish.

It has evolved, separately,
at least 30 times.

The more often a trait like
venom has evolved on Earth,

the more likely it is to
exist on other planets.

On the hot side of Janus,

pentapods use venom to catch their prey.

But hunting alone is risky.

Even a venomous predator is powerless

against a swarm.

On the cold side of the
planet, things are just as tough.

In perpetual darkness and
with no energy from the sun...

how can anything survive?

On Earth, nearly all
life depends on sunlight.

Plants convert solar energy into food,

which feeds other life forms.

But there are some
extraordinary places on Earth

where life has evolved
without any light.

When I contemplate
going in a cave like this,

one of the things I know
is it's an alien environment.

- It's fogging up a little bit.
- Yeah.

It is full of good ways to die.

One of the big risks in this cave
is there is a lot of hydrogen sulfide.

Hydrogen sulfide can kill you.

- Okay. You ready?
- Yeah.

And so my husband comes
along to act as a safety officer.

He's not afraid to pull us out and
say, "Time to go, you've had enough."

Cueva de Villa Luz is a
maze of limestone chambers.

Hydrogen sulfide bubbles
up from the Earth's crust.

Mixing with oxygen, it forms sulfuric
acid and turns the water milky white.

And yet, some life forms survive,

and even thrive in these conditions.

Snottites...

dripping colonies of bacteria.

There are a lot of
organisms in one snottite.

Instead of relying on photosynthesis,

they are eating hydrogen sulfide

and are using it as their energy source.

- Okay, ready to flame?
- Yep.

So, make it nice and sterile.

Okay, cap that, please.

Okay, let's go for this one.

Okay.

Okay. One snottite.

These are some of the
best snottites in the world.

So acidic.

More acidic than car battery acid.

An entire ecosystem has evolved

to feed off the snottites.

Creatures that have never seen daylight.

Can you see those?

Yes, I do.

So, there's some really big
ones over here to the right.

So, whenever you see one of
those white streamers of bacteria,

you'll see a fish go after it.

Okay, here comes some more over
there. See? Here comes a big one, see?

It's coming. There, it got it!

Studying life in total darkness

has expanded how we look for
life in other places in the universe.

It's made us think about the fact

that we could find life in
places we never considered.

- Yep, there we go.
- 25.

25. It's getting pretty high.

All right.

You think we ought to get out of here?

Yeah.

All life needs some form of energy.

On the hot face of Janus,
it comes from starlight.

On the cold face, it
comes from deep within.

Geothermal activity.

When volcanic pressure
forces water to the surface,

there's a flurry of new life...

which stirs pentapods into action.

They're after grubs that
emerge around geothermal pools.

But it's not so easy.

The grubs have evolved a defense.

They jump and flash a
warning signal to others...

acting as one to stay alive.

On Earth, some animals
use light in the same way...

to send signals.

Every single point of light that
you see out there is a firefly.

Right as the sun sets, you'll
start to see them come up,

like little sparks rising from a fire.

It's just spectacular, and it only
gets better as the night gets darker.

Fireflies flash as a
form of communication.

They are among the only land animals

that communicate with
light of their own making.

Bioluminescence evolved among fireflies

as a warning to predators

that they're packed with toxins
and should be given a wide berth.

Now the same mechanism

is used for finding a mate.

So, the firefly produces light from an
organ on its abdomen called the lantern.

And this organ has an enzyme

that produces one photon of light.

This chemical reaction involves oxygen.

So, by controlling the flow
of oxygen to their lantern,

they can produce, uh, flashes.

They can turn the
chemical reaction on and off,

and use these flashes to
communicate with each other.

The males are flying around, and
they're doing little advertisements,

little flashes that say, "Here I
am. This is me, check me out."

And then the females are waiting on
the ground below and they're looking up.

And when they see a guy
that they like, they flash back.

And then the male will
come over, he'll flash again.

She flashes back and they
come together and mate.

So, this is actually
one big flirtatious dance

that we're seeing right here behind us.

Each species creates
its own little language

that they can use to find
each other in the dark.

But using light to
communicate is inherently risky.

Some species have
evolved to emit fake signals.

What we have here is a
predatory Photuris female,

also called femmes fatales,
because they have a reputation

for luring in males of
other species to eat them.

They can hack in to the communication
between a male and a female

and use that to her advantage.

So, you can tell this
is a predatory firefly

because her lantern
has a different shape to it.

Only two... two little lines light
up, almost like an equals sign.

So, basically, a male will be
flying around looking for a mate

and then when the males
flash, they flash back,

just as if they were a
female of that species.

So, they're imitating the
females of that other species

to get the male to come over,

but they don't wanna
mate with that male...

she wants to eat that male.

And she proceeds to do so
in an extremely violent way.

This is a classic example
of a predator using mimicry.

One species copying
the behavior of another...

in order to kill it.

Lying and deceit is...

is pretty widespread in the
animal kingdom, I would say.

And I think it would be on any planet.

On Janus, the grubs
use light to stay alive.

But their system is about to be hacked.

By catching a few grubs, the
pentapods absorb their bioluminescence...

and mimic their warning signals.

The grubs instinctively jump
away from flashing lights.

But this time, it's a trap.

The pentapods have
them where they want them.

Again, adaptability is
the secret to their survival.

But for all creatures on Janus,

existence depends
on one key ingredient...

whether in the hot,
cold or twilight worlds.

Water.

Everybody knows the story of
Goldilocks and the Three Bears.

She sneaks into their house
and tries to eat their porridge.

The first bowl is too hot.

The second bowl is freezing cold.

It's only when she tries the
third bowl that she's happy.

"This one," Goldilocks
says, "is just right."

When we look around the
universe in the search for life,

we are looking for
conditions that are "just right."

And "just right," in this case,

is defined by the
presence of this stuff.

Water.

Water transports the essentials
for life around the planet

and around every living body.

It's the most important
substance in the universe.

Because water is so familiar to us,

it's not until you really stop and think
about it that you realize how weird it is.

Water is made up by one oxygen atom...

and two hydrogen atoms.

And because of the nature of the
elements and the way they're bound,

we have a net negative
charge at the oxygen side

and positive on the two hydrogens.

This means that every
hydrogen in a molecule

can interact with the oxygen on
the other molecules neighboring.

Replicate this attraction for
billions of neighboring molecules

and you get a substance
that is very sticky.

And water molecules
don't just attract each other,

they attract almost any other
molecule they come in contact with.

They pull other substances apart,

break them down, and dissolve them.

Water is the universal solvent

because of its unique ability to
dissolve nutrients and chemicals.

It seems certain the first spark of
life on Earth happened not on land...

but in water.

Deep underwater, in
the primordial oceans,

the chemical ingredients
for life were swirling around.

What was needed was a place
to concentrate these ingredients...

to allow the chemical reaction
that would eventually lead to life.

That place could have
been a hydrothermal vent.

Water interacts with hot
rocks deep underground.

It comes gushing back up
into the freezing seawater

carrying nutrients and chemicals...

little bubbles of life.

The link between water
and life is so strong,

it's hard to imagine any
life anywhere in the universe

existing without it.

It's mind-boggling to think,

you know, how life can find
a way in very extreme places.

Very hot, very cold.

And at the end, it's
all about the water.

If there's liquid
water, you'll find life.

Water on Janus is scarce.

It either freezes as ice...

or evaporates into the wind.

But there's just enough liquid water

for life to take hold...

and for the toughest of creatures

to adapt and survive.

At NASA, they have a saying.

"If you want to find life...

follow the water."

How might life adapt
on a different world?

One with two stars,

where there's more energy than on Earth.

A planet perfect for life.