Wild Palms

Our universe is a place of infinite variety.

Two trillion galaxies.

Billions and billions of stars.

And countless planets.

Worlds beyond imagination.

The universe is so vast,

so incomprehensible, so terrifying,

that I think it's quite natural for us to choose

to live out our lives completely oblivious to it.

Perhaps that's why there's a sense of relief that rises with the dawn.

The brightening sky hides the stars and the questions that they pose.

After all, they are the biggest questions.

How did the universe come to be?

Why are we here?

And how will it all end?

We have to face those questions

if we 're ever to acquire a truly deep understanding of ourselves.

You see, astronomy challenges us.

From one perspective, we're just grains of sand adrift

in an infinite and indifferent ocean.

But from another perspective, we are nature's most magnificent creation.

Collections of atoms that can think and wonder about the universe

and choose to explore it.

Five, four, three, two, one.

We have lift-off. All systems go.

In our quest for answers, we 're venturing ever further from home,

far beyond the planets...

And out to the stars.

Our spacecraft are sending back a stream of extraordinary revelations.

Visions of alien worlds...

With the ingredients to create life.

We've seen galaxies collide,

black holes devouring star systems.

And we may have glimpsed the origin of the cosmos itself.

With every new observation, with every new piece of knowledge,

there is the opportunity to acquire a deeper understanding.

And, as we answer question after question

we get ever closer to being able to tell

what is surely the greatest story ever told.

Na sa '5 Parker solar probe,

a daring mission to shed light

on the mysteries of our closest star.

This is a journey into never-never land you might say.

NASA's Parker solar probe is the first spacecraft to touch a star.

It's designed to fly through the sun's atmosphere,

braving temperatures no spacecraft has ever endured.

The Parker solar probe is allowing us to know our star

as we've never known it before.

And it's also helping us to tell the story of all the stars.

Our sun is from a long line of stars dating back to the dawn of time.

From fierce blue giants

which first lit up the universe,

to later generations,

whose deaths enriched the cosmos with precious elements,

the building blocks of our solar system,

And allowed our sun to create the thing which brings meaning to the cosmos.

Life.

You and me.

We have a strange relationship with the stars,

somewhere between awe and indifference.

I think we take our star, the sun, for granted,

partly because of its predictability.

Every day it rises in the east and sets in the west,

without any help or reverence from us.

But many ancient cultures deified the sun.

They treated it as a god

and the sun gods were creators and destroyers of worlds.

So which is it?

Well, I think that the modern story of the stars as told by science,

which is indisputably an epic story

stretching back over 13 billion years to the origin of the universe,

places them firmly in the realm of the gods.

If we want to understand where these gods came from...

We have to go back...

To a time before the stars.

In the beginning the universe was dark.

But it was not empty.

Something was lurking in the void,

stretching out tendrils.

The cosmic web grew to become a vast structure,

Criss-crossing the entire universe.

It was formed by interlocking filaments of dark matter,

And it was at the places where these filaments met,

the intersections,

That the first stars, our sun's earliest ancestors, were born.

The cosmic web is the scaffolding of the universe,

the vast and intricate structure that spans the void.

The web is made primarily out of dark matter,

a mysterious substance that dominates the universe,

although we don't know what it is.

It's one of the great mysteries in modern physics.

It's probably some kind of particle that interacts very weakly with itself

and with light.

If it doesn't interact with light,

we can't see it, which is why it's called dark matter.

But it does influence the universe through its gravity.

It was in the dark heart of the cosmic web

that gravity began to sculpt the early universe,

drawing together the two simplest elements,

hydrogen and helium.

The raw material for the very first stars.

Hydrogen gas clings to the filaments of the web,

attracted there by the gravitational pull

of the dark matter.

And where those filaments cross,

the gas can become dense enough to collapse under its own gravity

to form great clusters of galaxies, each filled with billions of stars.

The universe was approaching a turning point.

Hydrogen and helium poured into the regions

where the filaments crossed,

gathering into ever denser clouds.

Gravity asserted its grip,

and the clouds of gas began to collapse,

becoming denser and denser.

And in the densest regions,

the gas became so hot...

That nuclear fusion reactions began.

And out of maelstrom,

the first gods emerged,

and there was light.

The stars illuminate the universe,

but that is the least interesting thing that they do.

The thing that makes the universe interesting,

that brings meaning to the universe is that, life. You and me.

And life is just chemistry.

And chemistry requires complex chemical elements.

The only thing that existed in the universe before the stars

was hydrogen and helium.

Life requires carbon and oxygen and iron.

All those things were made in a process called nuclear fusion

in the cores of stars,

or even the heavier elements, like gold, in the collisions of stars.

50, without the stars, the universe would be uninteresting.

It would be meaningless.

It would be just an infinite box of gas.

The first stars were monsters.

Hundreds of times as massive as our sun.

They burnt with such ferocity that they shone blue,

with surface temperatures in excess of 700, 000 degrees.

They were the largest stars ever to have lived.

I/iolent and volatile giants.

A star is essentially a balancing act.

The force of gravity is constantly trying to collapse it,

and that pushes its ingredients,

primarily hydrogen, single protons, closer and closer together.

Now, when those protons get close enough together,

another of the fundamental forces of nature,

the strong nuclear force, takes over,

and it can stick the protons together.

That releases energy which creates a pressure which holds the star up.

Now the more massive the star, the stronger the inward pull of gravity

and the more energy has to be released to maintain the balance,

and so the faster the ingredients are used up.

These giant stars were in a struggle for survival,

fighting the relentless pull of gravity,

consuming more and more hydrogen fuel

to maintain their precarious equilibrium.

For most of its life, a star burns hydrogen,

the simplest chemical element with one proton in its nucleus,

into helium with two protons.

Now, when it runs out of hydrogen in the core,

the core starts to collapse and heat up,

and the star responds by building ever more complex elements.

So it makes carbon with six protons and oxygen with eight protons,

releasing more and more energy as it goes.

But when the star has assembled iron in its core,

with 26 protons in its nucleus,

no more energy can be released.

The star loses its battle against gravity.

It collapses and in a final moment of creation,

salvaged if you like, from its destruction,

it distributes those newly minted heavy chemical elements

out into the universe.

Imagine we could journey back in time

and watch the first star live out its brief luminous life.

After only a million years the star used up all of its fuel.

The core collapsed.

The star imploded.

And then rebounded...

In a colossal explosion.

A supernova.

In death, the first stars began to transform the cosmos,

enriching the ocean of hydrogen and helium

which filled the universe with heavy elements...

To build new generations of more complex stars.

Over time, these elements gathered together,

Creating rich clouds of gas and dust.

Nurseries where new generations of stars were born.

And not just stars, but families of stars.

The first galaxies.

And around this time,

some of the earliest star systems formed in our own galaxy, the milky way.

A new age of complexity was dawning in the universe.

Now, there were stars of different sizes,

And different colours.

And crucially new bodies had appeared.

Planets.

Places where the rich chemical elements built by previous generations of stars

could finally find a home.

Countless billions of stars have come and gone