The Sights of Space: A Voyage to Spectacular Alien Worlds

This is the NAVIS III,

an imaginary ship that can take you anywhere in the Milky Way.

Its maiden voyage will take you on a tour

of the wildest planets we have yet discovered.

Worlds of burning ice,

planets hotter than stars,

with clouds made of metal,

zombie worlds born from the ashes of dead ones,

and hundreds of billions more are waiting for us in our galaxy alone.

These worlds will give us a glimpse

into how deep nature's imagination goes

and create a map for future pioneers

who may one day plant their flags on landscapes

we can hardly imagine.

As our journey to new worlds begins,

we set sail for the closest alien planet,

40 trillion kilometers away.

But the long road to our cosmic neighbor

is paved with strange sights of its own.

Past the distant orbit of Neptune,

we slip into a no man's land

of icy cosmic debris that surrounds our solar system:

The Kuiper belt.

This massive disc of frozen material

contains hundreds of millions of icy scraps,

leftovers from the formation of our solar system.

Out here, among the scattered bits of rock and ice,

live something strange...

Haumea.

A tumbling dwarf planet shaped like an egg.

Carrying two moons and an icy ring, this bizarre Pluto-sized world

is the fastest-spinning object in our Solar system.

Splashed across its surface is a mysterious red spot,

possibly a scar from a recent impact.

And Haumea is not alone.

There is a whole eccentric family of mini-worlds lurking out here.

Dwarf planets like Makemake

and Gonggong, a red-tinted mini-Pluto

with a thin atmosphere of methane.

The Kuiper belt could hold as many as 200 dwarf planets,

and thousands more could be floating in the space beyond.

Someday, these tiny worlds may serve as

a cosmic base camp for interstellar voyagers.

A final outpost still bound to our Sun.

And, when we finally outgrow our home system,

the one nearest to Earth will be waiting:

Alpha Centauri.

In this triple star system, a tiny red dwarf star

known as Proxima Centauri, orbits around a pair of Sun-like stars:

Alpha Centauri A and B.

As we approach Proxima, the closets of the stellar trio,

we are greeted by two huge dust belts that circle the star.

But further in, we come to the real gem of this system:

Welcome to Proxima Centauri B, the closest exoplanet to home.

With a mass almost identical to Earth's,

and a density that suggests a rocky composition,

this distant Earth cousin orbits right inside its star's habitable zone,

giving it potential to hold liquid water.

Given how near and similar it is to Earth,

perhaps this will be the first outpost

for mankind around another star.

Visitors can gaze up to see Proxima Centauri

and its two sister suns.

And on a clear night, our own Sun,

a distant glimpse of home.

But there is still a lot we don't know about our cosmic neighbor.

And its star is so volatile,

that stellar flares could shock the planet into a lifeless state.

The only way to know for sure is to go there ourselves.

Missions are now being proposed

that can reach this system in as little as 20 years.

Using nanoprobes powered by light sails.

If humans ever touch down on Proxima Centauri B,

it will become the sight of the most

transformative event in human history.

The moment mankind became an interstellar species.

As we push farther into space, we leave the familiar behind

and come across a world beyond all human comprehension.

GLIESE 436-B is about as different from Earth as you can get.

Orbiting extremely close to its star,

its surface is a scorching 438 °C.

On a planet this hot, you might expect to find vast seas of magma,

but this Neptune-sized world is something else entirely.

A world of burning ice.

Its massive gravity compresses water vapor in the atmosphere

into an exotic form of ice called Ice-VII.

The pressures here are so intense that

the ice can withstand burning temperatures without evaporating.

But the atmosphere is another story.

It's been blasted into space by the star's immense heat

and as the starlight pushes on the escaping gas,

it's leaving behind a comet-like tail... nine million miles long.

Most planets in the universe will be hostile to humans.

But 39 light years away,

a tiny red dwarf star is home to a potential planetary oasis.

This is the TRAPPIST-1 system.

A family of seven rocky planets huddled closely around their sun.

These Earth-sized worlds orbit so closely together

that the whole system would fit easily inside the orbit of Mercury.

The inner two are suspected to be Venus-like.

Searing hot and covered in dense clouds.

And the outer planet Trappist-1H

is thought to be as cold as the South pole.

But four of the middle worlds orbit in the star's habitable zone,

making this system a possible bonanza for life.

Trappist-1E is one of the single most promising candidates

for habitability that we know of.

And each of these worlds is far older than Earth,

giving potential life forms here a 3 billion year head start.

But this system has a catch:

Each of the planets are theorized to be tidally locked

with one side stuck facing their sun

and the other side permanently exposed to the cold void of space.

Such temperature extremes could make it hard

for life to find a foothold.

But in the right conditions,

one of these worlds could hold vast oceans on the sun-facing side

where the star's heat is just enough for liquid water.

An eyeball Earth.

Appearing like a glistening watery iris staring into space.

Others could have a habitable strip of land between dark and light:

The terminator line, where the temperature is just right.

A haven for life between scorched earth and eternal winter.

The Trappist planets are now

a prime target of the James Webb Space Telescope,

which will gaze into their atmospheres in search of bio-signatures.

If our descendants ever reach this system,

they will look up to see the sibling planets decorating the sky.

Each clinging to the heat of their dim red star,

like campers around a fire.

Further beyond, 64 light years away,

lies a world that looks deceptively peaceful.

A world where pasty white clouds