All language subtitles for Alien Worlds S01E01 1080p WEB-DL

The Earth,
home to millions of species.

But what might live... beyond?

There are countless planets
throughout the universe.

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.

All life forms need a planet to live on.

But how many planets
are there in the universe?

Think about our star,

the Sun,

with Earth, Mars, Jupiter orbiting it.

For centuries,

people have asked themselves,
"What about the other stars?

Uh, do they have planets as well?"

And 24 years ago,

I found one!

Didier Queloz
is a superstar astrophysicist.

He has won the Nobel Prize
for discovering the first planet

beyond our solar system.

I was 28 years old
when I found the planet.

I was about to finish my PhD,

and my PhD adviser
gave me the key of the equipment.

And after observing a couple of times,
the star 51 Peg,

I realized that something was going on
on that star.

And frankly, I just panicked at that time.

I thought something was really wrong
with my equipment.

And the more I wanted to understand this,
the less it made sense.

Until the point I got convinced
it must be a planet.

That's likely to be a planet over there.

Could be Jupiter over there.

It's pretty cool.

Distant planets are invisible
to telescopes

because they don't emit any light.

But if a planet passes in front of a star,

it casts a tiny shadow,

and there's a minuscule dimming
of the star's brightness.

When astronomers detect
this dip in light level,

they have found a new planet.

Hello, guys.

Uh... Oh, hey.
Here is what the telescope is looking at.

This is a picture
of the telescope right now.

Uh, in the middle, you have the...
the target we're observing.

So, you analyze this whole field,
you process the data,

and, um, if you're lucky enough,
you detect this.

There's a little bit of a decrease
of the flux,

and this tells me
that there is a planet orbiting that star.

We know there are a huge number
of planets in the universe.

There must be a zillion kinds
of different life.

Let's imagine
that this is the Earth, here...

Right?

So, imagine that one meter
is 20 light-years.

So, I've made two meters
as 40 light-years.

This is where you have 51 Peg,
where the first planet was detected.

Each of these tiny lights
represents a star

where a planet has been found.

Over the next few years,

planets were turning up everywhere.

♪ Planets, planets everywhere ♪

It looks pretty cool right now.

A horizon of stars and planets...

all around.

Planets beyond our solar system
are called exoplanets.

Astronomers have found
over 4,000 of them.

And they keep finding more.

They now believe there's at least
one planet for every star in the universe.

That means over
a million, billion, trillion exoplanets.

More than all
the grains of sand on Earth.

A vast canvas for the evolution of life.

The distances are mind-boggling.

The nearest exoplanets
are trillions of miles from us.

But they're all subject to the same force
that holds the Earth in place.

Gravity.

Imagine a world double the size of Earth,

with twice as much gravity.

This is Atlas.

How would life adapt on such a world?

Gravity pulls vegetation
to the planet's surface.

And yet, seeds can float in the sky.

That's because gravity here is so strong.

Air molecules are
densely packed together...

creating a thick, buoyant atmosphere
for seeds to drift through.

And where there are seeds...

there are sky grazers.

Giant herbivores with six wings

to ride on the dense pillow of air.

Because of the extra gravity,

they weigh twice as much
as they would on Earth.

But they don't fall from the sky.

The atmosphere is thick enough
to keep them airborne.

Whether on Atlas or on Earth,

flying is always a battle
to overcome gravity.

You might say I have a pretty
complicated relationship with gravity.

And you can really feel that gravity
is a force pulling you down

as you struggle your way up.

But ultimately, my dream
has always been to be able to fly.

Whoo-hoo-hoo!

The thing I love most about paragliding
is that it's so simple and intuitive.

It's just you and the air.

Like the sky grazers on Atlas,

paragliders use their wings
to generate lift.

But the atmosphere
is less dense on Earth...

so it takes more effort
to stay airborne.

Most people
don't see air as a substance.

But for me, when I'm flying,

I really see it as a fluid
that's moving up and down the valleys

and along the ridges.

It would be really weird
to fly in a very dense atmosphere.

You could just be gliding around
the whole time, effortlessly.

The best way to gain altitude
is to find an updraft,

known as a "thermal."

When you hit the thermal,
it's very similar

to when you're in an elevator
and it starts.

You feel a push upwards.

Yeah, there we go!

Just the power of nature
to pull me up.

When I'm flying
and I see a bird circling up,

it means there must be a thermal there.

So we're always
constantly looking at them.

You can really feel the balance
between the gravity pulling you down

and the air lifting you up.

You can then use your bodyweight
to gain speed,

and use that speed
to generate more energy

and feel that you're moving
through the air.

Gravity may be weaker
on Earth than on Atlas...

but the thinner atmosphere
means there's less buoyancy.

So, eventually, everything falls.

On Atlas, the sky grazers
never need to land.

Their front and back wings
are for direction and thrust.

Their long middle wings
are for catching thermals.

Despite their weight,

the air is thick enough
for them to live a life

in the sky.

But it's not always a peaceful life.

As on Earth, grazers attract predators.

Using hydrogen-producing bacteria
to inflate their air sacs,

they take to the skies.

Alone, they're no match for their prey...

so they hunt in a pack...

waiting for a sky grazer
to stray from the group.

Target sighted, they expel their gas...

and attack from above.

The fastest predator on Earth

uses the same tactic.

My interest in flying falcons is...

their predatory instinct
coupled with the speed factor...

and how they use that speed
to their advantage.

But just watching
a top predator do its thing...

is perfection.

I probably have 30-some birds
at this moment.

Each bird is a different personality.

What I love about falcons

is how evolution has made
the most perfect specimen.

I do have a relationship with these guys.

Certainly from my end, I do.

I don't think the falcons
see it that way,

but they certainly see me
as part of the team.

Vahe Alaverdian trains
captive-bred falcons how to hunt.

These birds are
genetically programmed

to be the top-notch
avian predators that they are.

What we do as falconers

is try to awaken
that predatorial nature in the bird.

Lure training is the very first step.

Come on, buddy! Hup, hup, hup, hup, hup!

I want to put that lure
in front of the bird,

and get the falcon
to coordinate eye to foot...

Hup, hup!

...and throw its feet out
as if it's gonna grab it.

As that happens,
I try to pull that away from the falcon

to get it to shoot up in the air
and repeat this process again.

I wanna see that bird drop down
as vertical as it can.

That's something that they later on
will apply to hunting game.

When the falcons are ready,
Vahe introduces a prey target...

a racing pigeon.

The falcon can't keep up with the pigeon
in a chase,

so its best bet is to drop on it...

using gravity.

When the bird thinks
that he's got the advantage,

that's when the wings will get tucked in.

They stoop into a little teardrop shape...

coming down from the heavens.

The kinetic energy
of a falcon hitting a pigeon

would be as if you were hit
by a cannonball.

In training,
the pigeon invariably gets away,

because the falcon is made to stoop
from less than a thousand feet.

When hunting for real,

it'll drop from a greater height...

to lethal effect.

The predators make their move.

They deploy their wings

to create drag...

destabilizing the sky grazer

to devour it on the ground.

But this pack is too small to take down
such a large beast.

Today, they'll go hungry.

The sky grazer climbs to a safe height...

to recuperate.

But as a fertile female,

she has company.

Male grazers,
competing to be chosen as a mate.

Their oversized tails are a handicap,

making it harder to fly.

But to the female,
they're a sign of vitality.

The first to reach her gets to mate

and pass on his genes.

The same principle applies on Earth,

whether up in the sky

or down in the dirt.

Males compete for the right to mate.

And running, set...

I think when people sit at home
watching insects on television,

they imagine the cameraman
sitting in the jungle,

in a river or in a hedge,

waiting for this beetle to come across

and reproduce or have a fight
in front of the camera.

It doesn't work that way.

This is a ramshackle old shed
which is attached to my parents' place,

which is just there.

Huge advantages to having a place
attached to your mum and dad's.

You get good dinners in the evening
and, uh, teas arriving during the day.

- Have a look and see what we're doing.
- Oh!

Oh, gosh.

Oh! What on Earth are they?

They are rhinoceros beetles.

The male's got these big horns.

The female doesn't.
It's a form of sexual selection,

because the females like males
with big horns.

So every time they mate,

they'll mate with a beetle
that has a slightly bigger horn

- than the one they've last seen before.
- Oh!

And, therefore,
that male passes its genes on.

So, over generations,
the horns will get bigger.

- Anywhere particular?
- Um, just on the...

on the log facing the other male.

Here they go.
They're going straight away.

The horns of a male rhinoceros beetle

are like the tail of a male sky grazer.

They've evolved for sexual competition.

- Ha-ha!
- That dominant one's done it again.

That's a good shot.
The shot we wanted.

- Yeah.
- Going into her, yeah.

One, two, three.

- That right?
- Yeah.

- Yep.
- That's it.

- Can I... Yes.
- You putting that in?

Male insects don't always fight
to snare a mate.

Sometimes it's enough just to show off
their physical prowess.

Right, I'm gonna bring the male
in front of you.

He's coming in from your right.

Now, uh... He's flown off.

These are stalk-eyed flies.

Stalk-eyed fly
is an amazing little thing.

It looks a little bit like an ant
with massive eyes on the ends of stalks.

Both the male and the female
have eyes on the end of stalks,

but the male has much longer eye stalks
than the female.

The males with the long stalks
will come up to one another,

and they will, kind of,
have a little dance.

And they will try and judge

which of the two of them
has the bigger stalks.

There they are. That's the standoff!

The winner of that will remain where they
are and the loser will then toddle off.

That winner then will gain access
to the female,

and be able to reproduce with her,

and that way can pass on
the genetics that he has,

which will include
that of a longer eye stalk.

- Yes! Got it.
- Are... are you on it?

Oh, It's fantastic.

Normally, it's a second and they're gone.
This is fantastic.

Why would the male stalk-eyed fly
go to the effort

of having these enormous eye stalks?

Well, the idea is that you are
conspicuously signaling to the female

that you can have this incredible
investment of energy into this resource

that is completely needless.

And if you can still survive,

if you can carry on flying and living
and not getting predated upon,

and still have this... wasteful
extravagance coming out of your head,

then you're gonna be a pretty good bet
to reproduce with.

On Atlas,

the long tail of the male sky grazer
shows he's an ideal choice...

to father the next generation.

But the mother can't lay her eggs
in the sky.

So she's come down to land.

Because of the gravity, she's too heavy
to launch herself back into the sky.

To create new life,
she must surrender her own.

The babies grow up close
to where their mothers die.

Now they need to get off the ground
and into the air.

But scavengers lie in wait.

Boneless creatures

with no skeleton to give them form.

They kill by enveloping
and dissolving their prey.

The sky grazers have only just hatched,
but already they're in grave danger.

And now, there's no going back.

Every day on Earth,

young animals have to overcome
terrible odds,

if they're to survive.

Sixty percent of meerkats don't make it
to their first birthday.

For a young meerkat,
in their early life,

there's a lot of danger here.

They're vulnerable for many months
after they're born...

but particularly in the first month or two
after they emerge from the burrow.

Predators are everywhere,
and a constant danger.

There are snakes in this area

that will eat a young meerkat.

A young meerkat is safe within a group,

but if it lags behind, it's vulnerable.

Scorpions are a constant threat.

The young are really
completely incompetent,

and totally ignorant when it comes
to dealing with scorpions, initially.

But they can't avoid
this danger forever.

They're going to eventually have to learn
how to neutralize the threat.

The first time that a young meerkat
faces a scorpion

and it has to deal with it itself

is probably a terrifying encounter.

This is a real moment of truth.

It's a real rite of passage, because once
they've managed to do that themselves,

then they really are at a stage where
they can start to forage by themselves

and become independent
and be a useful group member.

So, they've really managed to escape
the vulnerability of being a pup

and made that transition
into being an adult.

It's one step on the road to adulthood,

but it's by no means plain sailing
after that.

There are a lot of threats out there,

and it will have to continue to learn
in order to reach adulthood.

If the young sky grazers are to grow up,

they have no choice.

It's time to fly.

Even in the air, they're still not safe.

On Atlas, survival is a game of chance.

Life goes on
from one generation to the next.

At least for now.

The strong gravity of Atlas
pulls asteroids onto a collision course.

Most burn up in the atmosphere.

But there's a constant threat
something big will get through...

and reset the course of life
on the planet.

Because gravity is weaker
on Earth than Atlas,

asteroid strikes are less frequent.

But when they do occur,
they can be catastrophic.

This is the Yucatán Peninsula.

27,000 square miles of tropical jungle.

But hidden within the jungle
are numerous sinkholes called cenotes.

These are entrances
to vast underground cave systems.

There's no surface rivers or streams
in the peninsula,

so the only source of water
is underground in caves.

But the really interesting thing
is the location of these cenotes.

Although there's probably 10,000
or more cenotes across the peninsula,

in the northwest corner...

they occur in a very well-defined
semicircle.

If we follow that semicircle
out into the Gulf of Mexico...

we now have a complete circle
that marks what one would expect

from the edge
of an asteroid impact crater.

65 million years ago,

gravity pulled an asteroid
into our solar system.

It smashed into our planet,

causing the extinction
of 75 percent of life on Earth.

The asteroid strike generated
enough debris

to block out sunlight for two years.

A world plunged into darkness.

Nothing could grow.

This would happen on Atlas

if a big enough asteroid
hit the planet.

Cenotes
are difficult places to survive...

just like the Earth was
65 million years ago.

What are the characteristics that
a species needs to survive an extinction?

Somebody's in here.

So, crocodiles are very resilient animals.

They live both in the water and on land.

They're generalists.
They don't require a specific diet.

They'll eat almost anything.

Whatever is available is good enough,

they'll take it.

Here in this cenote,

one's fallen in, gotten trapped,
no way out...

Somehow, some way...

he's succeeded.

They're survivors.

In a changing world,
it pays to be a generalist,

not a specialist.

If a big enough asteroid hits Atlas,

the sky grazers and predators
would be doomed.

They're too specialized
to cope with change.

The generalists
are the boneless scavengers.

Like crocodiles, they eat anything...

and live anywhere.

On this imagined high-gravity world,

they could be the great survivors.

How might life adapt

on a different world,

where creatures are trapped

between a searing desert

and a frozen shadowland?

A world of extremes.