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Our universe is a place
of infinite variety.
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Two trillion galaxies...
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..billions and billions of stars...
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..and countless planets,
worlds beyond imagination.
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The universe is so vast,
so incomprehensible, so terrifying,
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that I think it's quite natural for
us to choose to live out our lives
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completely oblivious to it.
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Perhaps that's why there's a sense
of relief that rises with the dawn.
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The brightening sky hides the stars
and the questions that they pose.
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After all, they are
the biggest questions.
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How did the universe come to be?
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Why are we here?
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And how will it all end?
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We have to face those questions
if we're ever to acquire
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a truly deep understanding
of ourselves.
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You see, astronomy challenges us.
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From one perspective,
we're just grains of sand adrift
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in an infinite and
indifferent ocean.
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But from another perspective, we are
nature's most magnificent creation,
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collections of atoms that can think
and wonder about the universe
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and choose to explore it.
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OVERLAPPING LAUNCH COUNTDOWNS
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We have liftoff... Zero...
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In our quest for answers, we're
venturing ever further from home,
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far beyond the planets...
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..and out to the stars.
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Our spacecraft are sending back
a stream
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of extraordinary revelations...
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..visions of alien worlds...
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..with the ingredients
to create life.
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We've seen galaxies collide...
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..black holes devouring
star systems...
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..and we may have glimpsed
the origin of the cosmos itself.
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With every new observation,
every new piece of knowledge,
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there is the opportunity to acquire
a deeper understanding.
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And as we answer question
after question, we get ever closer
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to being able to tell what is surely
the greatest story ever told.
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# Take me away. #
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Nasa's Parker Solar Probe,
a daring mission to shed light...
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..on the mysteries of
our closest star.
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This is a journey into
never-never-land, you might say.
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Nasa's Parker Solar Probe is the
first spacecraft to touch a star.
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It's designed to fly through
the sun's atmosphere...
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..braving temperatures no spacecraft
has ever endured.
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The Parker Solar Probe
is allowing us to know our star
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as we've never known it before.
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And it's also helping us to tell
the story of all the stars.
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Our sun is from a long line of stars
dating back to the dawn of time...
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..from fierce blue giants...
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..which first lit up the universe...
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..to later generations...
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..whose deaths enriched the cosmos
with precious elements...
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..the building blocks of
our solar system...
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..and allowed our sun
to create the thing
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which brings meaning to
the cosmos...
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..life, you and me.
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We have a strange relationship
with the stars,
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somewhere between awe
and indifference.
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I think we take our star,
the sun, for granted,
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partly because of
its predictability.
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Every day, it rises in the east
and sets in the west...
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..without any help or reverence
from us.
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But many ancient cultures
deified the sun.
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They treated it as a god.
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And the sun gods were creators
and destroyers of worlds.
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So which is it?
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Well, I think that the modern story
of the stars, as told by science,
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which is indisputably an epic story,
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stretching back over 13 billion
years to the origin of the universe,
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places them firmly in the realm
of the gods.
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If we want to understand
where these gods came from...
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..we have to go back...
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..to a time before the stars.
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In the beginning,
the universe was dark.
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But it was not empty.
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Something was lurking in the void...
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..stretching out tendrils.
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The cosmic web grew to become
a vast structure...
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..crisscrossing the entire universe.
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It was formed by interlocking
filaments of dark matter.
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And it was at the places
where these filaments met...
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..the intersections...
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..that the first stars, our sun's
earliest ancestors, were born.
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The cosmic web is the scaffolding
of the universe,
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the vast and intricate structure
that spans the void.
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The web is made primarily
out of dark matter,
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a mysterious substance
that dominates the universe,
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although we don't know what it is.
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It's one of the great mysteries
in modern physics.
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It's probably some kind of particle
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that interacts very weakly
with itself and with light.
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It doesn't interact with light.
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You can't see it, which is why
it's called dark matter.
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But it does influence the universe
through its gravity.
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It was in the dark heart
of the cosmic web
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that gravity began to sculpt
the early universe...
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..drawing together the two simplest
elements - hydrogen and helium...
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..the raw material
for the very first stars.
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Hydrogen gas clings to
the filaments of the web,
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attracted there by the gravitational
pull of the dark matter.
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And where those filaments cross,
the gas can become dense enough
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to collapse under its own gravity
to form great clusters of galaxies,
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each filled with billions of stars.
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The universe was approaching
a turning point.
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Hydrogen and helium
poured into the regions
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where the filaments crossed...
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..gathering into ever denser clouds.
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Gravity asserted its grip...
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..and the clouds of gas
began to collapse...
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..becoming denser and denser.
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And in the densest regions,
the gas became so hot...
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..that nuclear fusion
reactions began.
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And out of the maelstrom...
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..the first gods emerged.
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And there was light.
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The stars illuminate the universe.
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But that is the least interesting
thing that they do.
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The thing that makes
the universe interesting,
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that brings meaning to the universe
is that -
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life, you and me.
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And life is just chemistry.
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And chemistry requires
complex chemical elements.
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The only thing that existed
in the universe before the stars
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was hydrogen and helium.
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Life requires carbon and oxygen
and iron.
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All those things were made
in a process called nuclear fusion,
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in the cores of stars or even,
for the heavier elements like gold,
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in the collisions of stars.
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So, without the stars, the universe
would be uninteresting.
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It would be meaningless.
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It would be just an infinite
box of gas.
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The first stars were monsters...
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..hundreds of times as massive
as our sun.
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They burnt with such ferocity
that they shone blue...
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..with surface temperatures
in excess of 100,000 degrees.
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They were the largest stars
ever to have lived...
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..violent and volatile giants.
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A star is essentially
a balancing act.
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The force of gravity
is constantly trying to collapse it,
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and that pushes its ingredients -
primarily hydrogen, single protons -
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closer and closer together.
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Now, when those protons
get close enough together,
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another of the fundamental forces
of nature, the strong nuclear force,
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takes over and it can stick
the protons together.
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That releases energy, which creates
a pressure which holds the star up.
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Now, the more massive the star, the
stronger the inward pull of gravity,
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and the more energy has to be
released to maintain the balance,
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and so the faster the ingredients
are used up.
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These giant stars were in a struggle
for survival...
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..fighting the relentless
pull of gravity...
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..consuming more and more
hydrogen fuel
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to maintain their
precarious equilibrium.
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For most of its life,
a star burns hydrogen -
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the simplest chemical element,
with one proton in its nucleus -
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into helium, with two protons.
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Now, when it runs out of hydrogen
in the core,
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the core starts to collapse
and heat up,
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and the star responds by building
ever more complex elements.
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So it makes carbon,
with six protons,
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and oxygen, with eight protons,
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releasing more and more energy
as it goes.
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But when the star has assembled iron
in its core,
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with 26 protons in its nucleus,
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no more energy can be released.
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The star loses its battle
against gravity.
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It collapses
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and in a final moment
of creation,
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salvaged, if you like,
from its destruction,
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it distributes those newly minted
heavy chemical elements
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out into the universe.
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Imagine we could journey back
in time
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and watch the first star live
out its brief, luminous life.
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After only a million years,
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the star used up all of its fuel...
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..the core collapsed...
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..the star imploded...
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..and then rebounded
in a colossal explosion -
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a supernova.
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In death, the first stars began
to transform the cosmos,
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enriching the ocean of hydrogen
and helium,
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which filled the
universe with heavy elements,
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to build new generations
of more complex stars.
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Over time, these elements
gathered together...
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..creating rich clouds of gas
and dust.
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Nurseries where new generations
of stars were born.
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And not just stars,
but families of stars -
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the first galaxies.
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And around this time,
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some of the early star systems
formed
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in our own galaxy,
the Milky Way.
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A new age of complexity
was dawning in the universe.
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Now there were stars of
different sizes...
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..and different colours...
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..and, crucially,
new bodies had appeared...
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..planets.
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Places where the rich chemical
elements
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built by previous generations of
stars could finally find a home.
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Countless billions of stars
have come and gone
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since those first giants illuminated
the darkness,
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each enriching the universe
with the material
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out of which the next generation
formed.
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Blue stars and white stars,
single stars,
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double stars, even triple star
systems orbiting around each other.
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The conditions were now right for
those stars to drive the universe
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into a new and profound
age of complexity.
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Our Sun was formed from the ashes
of generations of ancestors.
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Just one small star in a galaxy
of billions of brilliant gods.
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For the first million years
of its life,
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the Sun was virtually alone,
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wreathed in clouds of gas and dust.
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The dust slowly clumped together...
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..forming clusters,
the size of pebbles,
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then boulders...
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..and finally...
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..planets.
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But the planets were lifeless rocks.
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Only the Sun had the power to turn
them into worlds.
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Some were too far away from the Sun.
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Ice giants -
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frozen, seemingly, into infertility.
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Others formed too close to the
Sun,
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seared by a relentless light.
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They became scorched desert worlds,
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but there was a planet in the Sun's
family
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that quite by chance formed neither
too close nor too far away.
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An arcadia, where our star could
breathe life into dust.
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The planets are just the leftovers
from the formation of stars.
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The sort of debris, if you like.
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It's just little specks orbiting
around those magnificent flames,
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but the planets are also the
places in the universe
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where gravity has concentrated the
heavy elements
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built by previous generations of
stars.
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And that makes the planets
the canvas
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on which the stars can create.
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The canvas on which the stars
can create,
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what do I mean by that?
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Well, just look around.
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Everywhere you look on Earth,
there is complexity.
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Not only mountains and rivers,
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but living things, animals and
plants, human beings,
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human civilisation,
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the most complex thing we know of
anywhere in the universe.
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So you have to ask yourself,
how can it be that such complexity
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can emerge completely naturally
in the universe?
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Well, the answer, in fact, was known
in the 19th century,
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and it comes from the science of
thermodynamics.
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In the 19th century,
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people were interested in the
efficiency of steam engines,
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and steam engines are, after all,
the machines that powered
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the factories that allowed people to
build increasingly complex things.
251
00:31:18,640 --> 00:31:23,320
And it turns out that the only thing
that matters for a steam engine,
252
00:31:23,320 --> 00:31:25,520
the thing that determines its
efficiency,
253
00:31:25,520 --> 00:31:28,880
the thing that allows it to do work
and build things
254
00:31:28,880 --> 00:31:32,960
is the temperature difference
between the fire,
255
00:31:32,960 --> 00:31:35,440
the furnace
and the heart of the steam engine
256
00:31:35,440 --> 00:31:38,320
and the cold environment
surrounding it.
257
00:31:40,960 --> 00:31:45,840
In the universe, the stars
are hot spots in a cold sky.
258
00:31:45,840 --> 00:31:48,720
We are sitting, in a very real
sense,
259
00:31:48,720 --> 00:31:55,200
inside a giant steam engine, powered
by the furnace of the Sun.
260
00:31:55,200 --> 00:31:59,920
And it's in that sense that the
stars are the creators
261
00:31:59,920 --> 00:32:02,760
of complexity in the universe.
262
00:32:06,560 --> 00:32:11,080
But creating complexity
is a subtle art.
263
00:32:12,720 --> 00:32:14,400
You need an engine -
264
00:32:14,400 --> 00:32:18,840
in this case, a star
that's not too wild and flashy.
265
00:32:22,720 --> 00:32:27,880
A star which is consistent enough
for long enough
266
00:32:27,880 --> 00:32:30,680
to kindle
the sparks of life...
267
00:32:36,320 --> 00:32:40,000
..and allow those sparks to flicker
and flourish.
268
00:32:53,360 --> 00:32:56,400
The most important property
of a star,
269
00:32:56,400 --> 00:33:00,840
if it's to nurture a civilisation,
270
00:33:00,840 --> 00:33:04,000
is magnificent dependability.
271
00:33:29,080 --> 00:33:33,120
No-one knows exactly how life
on Earth emerged...
272
00:33:39,640 --> 00:33:43,400
..but what we do know is that at
some point,
273
00:33:43,400 --> 00:33:49,160
primitive cells living in the ocean
began using the Sun's energy
274
00:33:49,160 --> 00:33:52,800
to power life-giving chemical
reactions.
275
00:33:54,880 --> 00:34:02,520
These cells formed a bridge
between Earth and Sun,
276
00:34:02,520 --> 00:34:08,360
delicate engines which harness the
fires of our star,
277
00:34:08,360 --> 00:34:14,120
using sunlight to turn carbon
dioxide and water into food.
278
00:34:20,640 --> 00:34:24,640
This process,
known as photosynthesis,
279
00:34:24,640 --> 00:34:27,280
unleashed the Sun's creative
power...
280
00:34:41,800 --> 00:34:45,160
..and drove the evolution
of complexity...
281
00:34:53,760 --> 00:34:56,920
..from primitive bacteria,
282
00:34:56,920 --> 00:34:59,480
to plants and trees...
283
00:35:11,920 --> 00:35:14,840
..and,
ultimately,
284
00:35:14,840 --> 00:35:19,520
to you and me.
285
00:35:19,520 --> 00:35:24,720
Photosynthesis is a process that's
very easy to describe in words.
286
00:35:24,720 --> 00:35:27,520
The plants take energy from the Sun
287
00:35:27,520 --> 00:35:31,480
then use it to react carbon dioxide
and water together
288
00:35:31,480 --> 00:35:34,880
to make sugars and a waste product,
oxygen.
289
00:35:34,880 --> 00:35:36,560
Really easy to say.
290
00:35:36,560 --> 00:35:38,480
Very difficult to do.
291
00:35:38,480 --> 00:35:41,800
I mean, there's a part of
that photosynthetic machinery,
292
00:35:41,800 --> 00:35:43,400
everything you see here,
293
00:35:43,400 --> 00:35:46,640
every plant on the planet's
got a photosystem, too.
294
00:35:46,640 --> 00:35:52,400
It's comprised of 46,630 atoms,
295
00:35:52,400 --> 00:35:55,560
all working together in an intricate
machine.
296
00:35:55,560 --> 00:35:59,920
Very efficient. It took billions of
years of evolution.
297
00:35:59,920 --> 00:36:04,120
Then we eat the plants, or we eat
something that's eaten the plants
298
00:36:04,120 --> 00:36:06,840
and we do the reverse reaction.
299
00:36:06,840 --> 00:36:10,920
We take those sugars and we breathe
in that waste product, oxygen,
300
00:36:10,920 --> 00:36:13,800
react them together, release a bit
of energy,
301
00:36:13,800 --> 00:36:16,240
a bit of the stored sunlight,
if you like,
302
00:36:16,240 --> 00:36:19,440
and we use that energy to maintain
our structure,
303
00:36:19,440 --> 00:36:22,400
to grow, to live.
304
00:36:29,160 --> 00:36:32,920
Trillions of stars have existed
since the universe began...
305
00:36:37,920 --> 00:36:44,080
..but ours has nurtured that most
miraculous thing,
306
00:36:44,080 --> 00:36:46,920
life.
307
00:36:48,760 --> 00:36:52,920
And that makes the Sun
a truly remarkable star.
308
00:37:01,840 --> 00:37:03,680
That is the only star we know
of
309
00:37:03,680 --> 00:37:08,120
anywhere where there are collections
of atoms in orbits around it,
310
00:37:08,120 --> 00:37:09,760
you and me,
311
00:37:09,760 --> 00:37:11,880
that have named
it.
312
00:37:11,880 --> 00:37:13,800
The Sun, our Sun.
313
00:37:13,800 --> 00:37:17,960
We've worshipped it, deified it
since the dawn of history.
314
00:37:17,960 --> 00:37:21,320
In fact, it's been argued
that the Sun lies at the foundation
315
00:37:21,320 --> 00:37:25,760
of all religion, and there
may be some truth in that.
316
00:37:25,760 --> 00:37:29,000
In fact, I think there is a deep
truth in that,
317
00:37:29,000 --> 00:37:31,880
because we all owe our existence,
318
00:37:31,880 --> 00:37:34,400
this brief time we have in the
universe,
319
00:37:34,400 --> 00:37:36,080
to that star.
320
00:37:36,080 --> 00:37:39,440
In fact, in a deeper sense, to all
the stars.
321
00:37:39,440 --> 00:37:44,800
We don't need to invent imaginary
gods to explain the universe.
322
00:37:44,800 --> 00:37:47,680
We can replace them with
the real thing.
323
00:38:01,480 --> 00:38:03,680
Everyone we love...
324
00:38:08,960 --> 00:38:10,960
..everything we value...
325
00:38:14,040 --> 00:38:18,160
..our supreme accomplishments
as a civilisation...
326
00:38:22,560 --> 00:38:25,560
..were created and crafted...
327
00:38:29,000 --> 00:38:31,480
..by stars.
328
00:38:50,560 --> 00:38:54,200
There are over 200 billion
stars in our galaxy...
329
00:38:59,280 --> 00:39:04,120
..and there are two trillion
galaxies in the observable universe.
330
00:39:13,240 --> 00:39:15,880
We're living in the Age of Stars...
331
00:39:26,720 --> 00:39:30,240
..an era of light and life
in the cosmos.
332
00:39:36,240 --> 00:39:41,480
From our fleeting human
perspective, stars seem eternal...
333
00:40:01,720 --> 00:40:05,320
..but even gods are not immortal.
334
00:40:09,440 --> 00:40:14,120
Where there is light,
335
00:40:14,120 --> 00:40:17,880
there is darkness.
336
00:40:20,480 --> 00:40:23,080
Stars are creators...
337
00:40:28,600 --> 00:40:32,040
..but they can be jealous
guardians of their creations.
338
00:40:36,960 --> 00:40:43,520
Many smaller stars don't die
in spectacular explosions,
339
00:40:43,520 --> 00:40:50,200
instead, they slowly.
fade away.
340
00:40:50,200 --> 00:40:56,240
They hang on to the precious
elements they made,
341
00:40:56,240 --> 00:41:02,680
becoming fossil stars...
342
00:41:02,680 --> 00:41:08,360
..and as more fossils
litter the universe,
343
00:41:08,360 --> 00:41:14,800
more life-giving elements
remain locked away,
344
00:41:14,800 --> 00:41:18,480
starving the cosmos of the material
needed
345
00:41:18,480 --> 00:41:21,920
to make new generations of stars.
346
00:41:38,880 --> 00:41:43,480
The Age of Stars may seem infinite,
347
00:41:43,480 --> 00:41:47,400
but it had a beginning
348
00:41:47,400 --> 00:41:49,520
and it will also have an end.
349
00:41:53,000 --> 00:41:56,680
Imagine a timeline of the universe
350
00:41:56,680 --> 00:42:00,000
and imagine that this is the origin
of the universe,
351
00:42:00,000 --> 00:42:03,320
the Big Bang,
13.8 billion years ago.
352
00:42:03,320 --> 00:42:07,120
After 100 million years
or so, the first stars formed.
353
00:42:07,120 --> 00:42:11,920
On this scale, one centimetre
is about 20 million years.
354
00:42:11,920 --> 00:42:16,880
After four billion years, the peak
rate of star formation occurred.
355
00:42:16,880 --> 00:42:20,480
The maximum number of new stars
were born.
356
00:42:20,480 --> 00:42:23,320
After nine billion years,
357
00:42:23,320 --> 00:42:25,840
our Sun was born.
358
00:42:25,840 --> 00:42:27,640
And today we stand,
359
00:42:27,640 --> 00:42:30,440
13.8 billion years later,
360
00:42:30,440 --> 00:42:34,320
about halfway
through the lifetime of our Sun.
361
00:42:34,320 --> 00:42:37,360
Now, in about five billion years'
time,
362
00:42:37,360 --> 00:42:40,840
our Sun will die, but new stars
will be born
363
00:42:40,840 --> 00:42:43,560
and many of the oldest
stars in the universe,
364
00:42:43,560 --> 00:42:46,920
the smallest stars,
will continue to shine.
365
00:42:46,920 --> 00:42:51,480
In fact, we think that the last
star will cease to shine,
366
00:42:51,480 --> 00:42:53,320
the universe will go dark,
367
00:42:53,320 --> 00:42:56,200
in around ten trillion years.
368
00:42:57,600 --> 00:43:03,040
On this scale, that's about 5,000
metres away from the Big Bang.
369
00:43:03,040 --> 00:43:04,760
But that's not
the end of the universe.
370
00:43:04,760 --> 00:43:10,640
As far as we know, the universe
will continue expanding forever.
371
00:43:10,640 --> 00:43:15,720
And so the Age of Starlight
is the briefest moment of time
372
00:43:15,720 --> 00:43:18,040
in the infinite history
of the universe.
373
00:43:18,040 --> 00:43:23,400
The Age of Darkness will go
on and on and on.
374
00:43:29,760 --> 00:43:35,600
Stars won't just disappear,
of course.
375
00:43:35,600 --> 00:43:39,800
They'll be here for aeons to come.
376
00:43:41,360 --> 00:43:47,960
But over time, the universe,
will grow darker,
377
00:43:47,960 --> 00:43:50,960
colder
and emptier.
378
00:44:01,240 --> 00:44:03,920
There are stars around today
that existed
379
00:44:03,920 --> 00:44:06,840
close to the beginning
of the Age of Stars...
380
00:44:15,560 --> 00:44:19,360
..and some of them
will also witness the end.
381
00:44:23,680 --> 00:44:29,080
They're the longest lived
stars in the universe,
382
00:44:29,080 --> 00:44:31,720
red dwarfs.
383
00:44:38,920 --> 00:44:41,880
TRAPPIST-1 is one
of these ancients.
384
00:44:48,960 --> 00:44:53,440
It's already more than seven billion
years old,
385
00:44:53,440 --> 00:44:55,920
almost twice as old as our Sun...
386
00:45:05,680 --> 00:45:08,360
..but only around a tenth
of the size...
387
00:45:14,560 --> 00:45:18,320
..and less than 1% as bright.
388
00:45:21,320 --> 00:45:27,120
It's a cool star,
slow-burning...
389
00:45:32,720 --> 00:45:36,040
..and that is the secret
of its longevity.
390
00:45:40,800 --> 00:45:43,680
Because they burn slowly,
391
00:45:43,680 --> 00:45:46,640
red dwarfs live
for a very long time...
392
00:45:53,560 --> 00:45:57,640
..far longer than any other star.
393
00:46:03,080 --> 00:46:08,640
Like the Sun, TRAPPIST-1
has its own planets -
394
00:46:08,640 --> 00:46:13,800
seven rocky worlds,
395
00:46:13,800 --> 00:46:16,040
each roughly the size of Earth.
396
00:46:20,680 --> 00:46:23,680
Some may have atmospheres
397
00:46:23,680 --> 00:46:25,920
and even oceans...
398
00:46:33,800 --> 00:46:38,000
..but there the similarity ends...
399
00:46:48,800 --> 00:46:51,160
..because these are strange worlds.
400
00:46:54,280 --> 00:47:00,240
Every one of these planets
is locked in its orbit,
401
00:47:00,240 --> 00:47:04,720
one side facing TRAPPIST-1,
402
00:47:04,720 --> 00:47:06,400
the other side frozen,
403
00:47:06,400 --> 00:47:10,720
permanently exposed to the cold void
of space.
404
00:47:23,040 --> 00:47:30,960
If you could stand on the surface
of one of these ancient worlds...
405
00:47:30,960 --> 00:47:38,840
..as the aeons passed...
406
00:47:38,840 --> 00:47:46,160
..you could watch the future
of the cosmos slowly unfold.
407
00:47:55,280 --> 00:48:02,120
And one day,
five billion years from now,
408
00:48:02,120 --> 00:48:10,120
you'd see our Sun flicker
and fade away forever.
409
00:48:38,520 --> 00:48:42,720
The death of our Sun will
probably go unremarked.
410
00:48:44,480 --> 00:48:47,160
We had hope that we'll be
around to see it.
411
00:48:47,160 --> 00:48:50,720
Maybe some alien astronomer
on a world far away
412
00:48:50,720 --> 00:48:55,000
across the Milky Way will see it
through the end of their telescope,
413
00:48:55,000 --> 00:48:57,160
but I don't think they'll give
it a second thought.
414
00:48:57,160 --> 00:48:59,320
We've seen hundreds of stars
die
415
00:48:59,320 --> 00:49:01,600
and we don't give them
a second thought.
416
00:49:01,600 --> 00:49:06,640
But I think the death of our Sun
will matter here locally
417
00:49:06,640 --> 00:49:09,120
in this little corner of the galaxy,
418
00:49:09,120 --> 00:49:12,400
because it will mark the end
of a glorious time
419
00:49:12,400 --> 00:49:14,440
in the history
of our galaxy,
420
00:49:14,440 --> 00:49:18,240
where meaning, where science and
literature
421
00:49:18,240 --> 00:49:21,880
and art and poetry and
music existed here.
422
00:49:21,880 --> 00:49:23,920
And that does matter.
423
00:49:26,880 --> 00:49:29,600
Why does meaning
have to be eternal?
424
00:49:29,600 --> 00:49:33,600
It's the fragility of our lives
that makes them valuable.
425
00:49:39,040 --> 00:49:42,360
I think the wonderful thing
is that our star
426
00:49:42,360 --> 00:49:46,680
has taken the laws of nature here on
this planet
427
00:49:46,680 --> 00:49:50,840
and crafted such a
magnificent expression of them.
428
00:49:50,840 --> 00:49:55,720
You, me and all this.
429
00:50:23,760 --> 00:50:28,840
Stars like TRAPPIST-1 will linger on
long after the death of our Sun.
430
00:50:36,720 --> 00:50:40,280
We will never know the name
of the last star...
431
00:50:48,000 --> 00:50:54,400
..but we know that the last star to
shine...
432
00:50:54,400 --> 00:50:57,080
..will be a red dwarf.
433
00:51:03,280 --> 00:51:09,280
The last star will slowly cool
434
00:51:09,280 --> 00:51:14,960
and fade away.
435
00:51:25,080 --> 00:51:29,880
With its passing, the universe
will become, once again,
436
00:51:29,880 --> 00:51:36,360
a void,
437
00:51:36,360 --> 00:51:39,240
without light
438
00:51:39,240 --> 00:51:43,920
or life
439
00:51:43,920 --> 00:51:47,800
or meaning.
440
00:52:04,640 --> 00:52:06,560
The stars illuminate the universe
441
00:52:06,560 --> 00:52:13,640
and create its most intricate
structures,
442
00:52:13,640 --> 00:52:16,920
and one day they will all be gone.
443
00:52:20,360 --> 00:52:24,320
The stars are gods,
but they are mortal gods.
444
00:52:24,320 --> 00:52:27,680
And when that time comes when
the last stars have faded
445
00:52:27,680 --> 00:52:32,080
and all possibility of life
and meaning in the universe
446
00:52:32,080 --> 00:52:33,320
has faded with them,
447
00:52:33,320 --> 00:52:36,720
they will have left the most
profound legacy
448
00:52:36,720 --> 00:52:40,880
because for a moment in the long
history of the universe,
449
00:52:40,880 --> 00:52:44,440
the stars illuminated the dark
450
00:52:44,440 --> 00:52:47,320
and allowed us
to illuminate it, too.
451
00:52:47,320 --> 00:52:50,080
MUSIC:
Who Knows Where The Time Goes?
by Fairport Convention
452
00:52:50,080 --> 00:52:58,040
# For who knows
where the time goes?
453
00:53:00,240 --> 00:53:07,680
# Who knows where the time goes? #
454
00:53:21,360 --> 00:53:25,880
We want to study the Sun because it
teaches us a lot about stars.
455
00:53:25,880 --> 00:53:29,520
It teaches us a lot about all
the other millions and billions
456
00:53:29,520 --> 00:53:32,000
of stars in our galaxy and beyond.
457
00:53:39,920 --> 00:53:43,040
There was a moment when we were
putting the spacecraft together
458
00:53:43,040 --> 00:53:45,680
that I just took a moment and looked
at the spacecraft
459
00:53:45,680 --> 00:53:50,160
and realised
this is going into a star.
460
00:53:50,160 --> 00:53:52,880
And to realise how special
it was
461
00:53:52,880 --> 00:53:55,960
to be able to have worked on this
462
00:53:55,960 --> 00:54:00,440
and that humanity decided this was
something we wanted to do.
463
00:54:00,440 --> 00:54:02,680
Status check.
464
00:54:02,680 --> 00:54:05,680
Go, Delta.
Go, PSP.
465
00:54:05,680 --> 00:54:07,000
Minus 15.
466
00:54:07,000 --> 00:54:10,080
Launch night,
I was sick to my stomach.
467
00:54:10,080 --> 00:54:12,920
Five, four, three,
468
00:54:12,920 --> 00:54:14,240
two, one,
469
00:54:14,240 --> 00:54:16,640
zero.
470
00:54:16,640 --> 00:54:20,120
Liftoff of the mighty Delta IV
Heavy rocket
471
00:54:20,120 --> 00:54:22,760
with Nasa's Parker
Solar Probe.
472
00:54:22,760 --> 00:54:24,640
There we go.
473
00:54:24,640 --> 00:54:27,600
The spacecraft is the first that
NASA has named after a living
474
00:54:27,600 --> 00:54:31,080
person because Eugene Parker is
really such, you know,
475
00:54:31,080 --> 00:54:33,600
an eminent physicist in our field.
476
00:54:35,000 --> 00:54:37,600
The Delta IV Heavy is a very
slow rocket
477
00:54:37,600 --> 00:54:40,640
compared to the other launches I've
seen,
478
00:54:40,640 --> 00:54:45,200
so I just saw fireballs and was
very, very frightened for a while.
479
00:54:45,200 --> 00:54:47,160
25 seconds into flight.
480
00:54:48,960 --> 00:54:51,880
Temp pressures continue to
look good on all three boosters.
481
00:54:51,880 --> 00:54:54,040
Then realising that this was all
OK,
482
00:54:54,040 --> 00:54:57,880
as it slowly made its way
up into the sky.
483
00:54:57,880 --> 00:55:00,240
Now, 50 seconds into flight.
484
00:55:06,360 --> 00:55:08,800
Parker Solar Probe is so
revolutionary
485
00:55:08,800 --> 00:55:12,040
because it's the first time that
we're actually going in
486
00:55:12,040 --> 00:55:14,560
to touch the Sun.
487
00:55:14,560 --> 00:55:18,320
We're going 94% of the way from the
Earth to the Sun
488
00:55:18,320 --> 00:55:23,440
to actually experience the
solar corona, the Sun's atmosphere.
489
00:55:23,440 --> 00:55:25,960
I think at closest approach,
490
00:55:25,960 --> 00:55:29,440
it'll be about eight solar
radii from the Sun,
491
00:55:29,440 --> 00:55:32,400
which is just mind-blowingly
close.
492
00:55:35,640 --> 00:55:39,440
So we were expecting things
to be very hot,
493
00:55:39,440 --> 00:55:41,520
over 2,500
Fahrenheit,
494
00:55:41,520 --> 00:55:44,640
but in a soup of a million
degree plasma.
495
00:55:49,120 --> 00:55:51,080
That's a real challenge
for the spacecraft
496
00:55:51,080 --> 00:55:52,800
to survive that environment.
497
00:55:52,800 --> 00:55:55,360
So in order to do that, there's
a very large heat shield
498
00:55:55,360 --> 00:55:56,960
on the front of the spacecraft,
499
00:55:56,960 --> 00:55:59,480
which protects the majority of the
instruments
500
00:55:59,480 --> 00:56:02,080
which are sat
behind on the spacecraft body.
501
00:56:04,080 --> 00:56:07,840
What makes Parker so great
is the fact that it has a set
502
00:56:07,840 --> 00:56:11,720
of instruments that work together
in order to look in all directions,
503
00:56:11,720 --> 00:56:15,160
in order to solve those big
mysteries about the solar wind.
504
00:56:22,080 --> 00:56:26,160
The solar corona has been mysterious
to us since we've known about it,
505
00:56:26,160 --> 00:56:27,800
so it's a very strange thing.
506
00:56:27,800 --> 00:56:31,360
The surface of the Sun is sort
of 6,000 degrees,
507
00:56:31,360 --> 00:56:34,080
and then above that, you have this
very thin atmosphere
508
00:56:34,080 --> 00:56:36,800
that's a million degrees,
super hot.
509
00:56:36,800 --> 00:56:39,880
And the way that's heated, we know
it has something to do
510
00:56:39,880 --> 00:56:43,480
with magnetic fields, but we don't
know exactly how it works.
511
00:56:43,480 --> 00:56:45,640
That's where the solar wind
is generated.
512
00:56:45,640 --> 00:56:48,240
We don't know quite exactly
how that works, either.
513
00:56:49,880 --> 00:56:55,480
Other things that have come out of
this are coronal mass ejections.
514
00:56:55,480 --> 00:56:57,720
When we originally did the proposal,
515
00:56:57,720 --> 00:57:00,320
we were thinking that we would see
five
516
00:57:00,320 --> 00:57:05,040
in the entire seven year
mission, if we were lucky.
517
00:57:05,040 --> 00:57:09,360
We ended up seeing around four
to five in the first year,
518
00:57:09,360 --> 00:57:12,600
so there has been just a total
switch
519
00:57:12,600 --> 00:57:16,040
in terms of how active the
Sun is
520
00:57:16,040 --> 00:57:18,560
or what we classify as
coronal mass ejections.
521
00:57:18,560 --> 00:57:20,480
Maybe a little bit of both.
522
00:57:25,960 --> 00:57:29,440
It is a joy to see all the data
coming back.
523
00:57:29,440 --> 00:57:31,800
It's a joy to share it with others
524
00:57:31,800 --> 00:57:35,880
and to see them be as curious
as I have been for the last decade.
525
00:57:39,560 --> 00:57:42,040
So Parker's just begun its mission,
really,
526
00:57:42,040 --> 00:57:44,920
and it's already really started to
truly transform our understanding
527
00:57:44,920 --> 00:57:46,640
for how the Sun works.
528
00:57:53,920 --> 00:57:56,000
Next time...
529
00:57:56,000 --> 00:57:58,680
..we had deeper
into the galaxy...
530
00:58:02,040 --> 00:58:06,760
..on the hunt for alien worlds...
531
00:58:06,760 --> 00:58:11,080
..and perhaps the first signs of
life.
532
00:58:18,080 --> 00:58:20,520
Journey through the universe
with the Open University
533
00:58:20,520 --> 00:58:25,320
and learn more about stars, planets
and galaxies with this free poster.
534
00:58:27,120 --> 00:58:31,680
Order your poster by calling...
535
00:58:31,680 --> 00:58:35,120
Or go to...
536
00:58:35,120 --> 00:58:38,120
and follow the links to the
Open University.
537
00:58:40,040 --> 00:58:43,120
MUSIC: Who Knows Where The Time
Goes? by Fairport Convention
538
01:00:17,200 --> 01:00:21,240
Explore this and more with our
academic experts.
539
01:00:21,240 --> 01:00:24,360
Go to bbc.co.uk/theuniverse
540
01:00:24,360 --> 01:00:28,000
and follow the links to the Open
University.