Cosmos: Possible Worlds (2020) s01e08 Episode Script
The Sacrifice of Cassini
1
MAN (over radio):
Systems this is prop.
I read you 500, do you read me?
TYSON: These people are watching
their life's work come to an end.
MAN (over radio): The
team is on its way to point.
TYSON: On another world.
MAN (over radio):
All right. Roger that.
TYSON: They were all young
when they sent her on her way.
These men and women
have been traveling
vicariously with her for
more than two decades.
And now, her work is
done, so she must die.
But before she
takes the fatal plunge,
they've given her one
final, epic challenge.
(theme music plays)
♪♪
♪♪
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TYSON: Gravity has
a big bag of tricks,
none lovelier than the
ring systems of worlds.
Our own solar system,
alone, has four ringed planets.
This one, with the
romantic name J-1407B,
is the first we've found
circling another sun.
Why haven't we found more
ringed planets in our galaxy?
Is it that the rings
are so unusual,
or are the methods we use
to find exoplanets not very
good at seeing the ring
systems that may surround them?
J-1407B's ring
system is so vast,
that it eclipsed
its star for days.
These rings extend across an
astonishing 112 million miles.
They would more than fill the
distance between Earth and the sun.
But as enormous as they
are, they're shockingly thin.
If the ring system of J-1407B
were the size of a dinner plate,
it would have to be
100 times thinner,
as thin as a human hair.
This surprising contrast
between the immense territory
of a ring system,
and its thinness,
is just as striking in
our own solar system.
The outermost ring of
Neptune is so dainty,
that it was first thought to
be the fragments of a ring.
Not a ring, but a
collection of arcs.
That was, until NASA's
Voyager 2 spacecraft revealed
that the so-called
arcs were clumps,
the thicker parts of a
fainter, complete ring.
It's funny that the weirdest
planet in the solar system has
attracted the least attention.
Voyager 2 is the only
spacecraft that has ever been
sent on a reconnaissance
mission to Uranus,
one of the two ice giant
planets that circle the sun.
During its 20-year-long summers,
the sun never sets on Uranus.
The winters are equally as long,
20 years of unbroken night.
Unlike its fellow gas planets,
Uranus is cold-hearted.
It doesn't generate
any internal heat.
Uranus is one crazy world.
The outer edge of Uranus's
atmosphere is so hot,
it's hotter than 500
degrees Fahrenheit.
But Uranus also has the
coldest clouds in the solar system,
I'm talking nearly 400
degrees below zero.
What kind of ocean is this?
Is it made of ammonia?
Water?
Some scientists think it may
be an ocean of liquid diamonds.
Note to space agencies,
might be worth another visit.
Then there's that thing
about it being sideways.
Uranus revolves around the sun at a roughly
90 degree angle to its own orbital plane.
What could have happened to
Uranus that it got knocked on its ass?
Our best guess is that it
went something like this.
Uranus was in a
terrible accident.
(crashing)
(crashing)
After the second blow, the rotational
axis of Uranus tipped 98 degrees.
There's another world in
our solar system that we don't
think of as having a ring.
The rings of Jupiter were
so dim that no ground-based
telescope ever saw them.
They were discovered when
Voyager I came flying by.
Our Saturn is graced
by the loveliest, largest,
and brightest ring system
of any around our sun.
It's the most distant planet that
can be seen with the naked eye,
and it made quite an
impression on our ancestors.
When I think of the Babylonians
of 3,500 years ago looking up
at the planets and stars,
I wonder how unlikely it would
have seemed that one of their
species would actually
send an emissary to that
distant point of light.
We are in the Deep Space Network
room at NASA's Jet Propulsion Laboratory.
In this place, the most ambitious voyages
of discovery are directed and monitored.
Why are these
people so emotional?
They have committed
their professional lives to
a collaboration with this robot.
And now that partnership
of decades is about to end
in a most violent way.
The pathway from our
Earthbound helplessness to
our presence in Saturn's
skies is about to unfold.
TYSON: What is that shimmering,
unsteady thing we're looking at?
That's what Galileo Galilei
asked himself in 1610 when he
became the first human
to see Saturn as more than
just a point of light.
So, this is the telescope
that made the modern
scientific revolution possible.
You know, you really
started something.
You looked through that
thing and found the cosmos.
That's not to say you didn't
make your share of mistakes.
You guessed wrong at
what you thought you saw,
believing that Saturn sported
two symmetrical moons
on either side of it.
Two years later, when
you took a second look,
you were shocked to find that
your "moons" had vanished.
This was because both
worlds, Earth and Saturn,
were in motion, and the two worlds
had changed in position to each other.
You were now looking
at Saturn's rings, edge-on.
The Saturn ring system
is 175,000 miles across,
but on average only a
few hundred feet thick.
They were too thin for your
fledgling telescope to see.
But two years after
that, you took a third look.
Now, you thought that
the planet had arms.
♪♪
40 years passed, until a
Dutch astronomer named
Christiaan Huygens took
another look at Saturn with
his own greatly
improved telescope.
Huygens was the first
to know that worlds could
be circled by rings, and
Saturn was one of them.
He also discovered
Saturn's largest moon,
which would later
be known as Titan.
When it finally came time
for us to visit that world,
our spacecraft bore
Huygens's name.
In science, there are
the Galileos, the Newtons,
the Darwins, the Einsteins.
And then there's another
kind of great scientist.
Not the kind that paints a
whole new picture of nature,
but, like Christiaan Huygens,
someone who has
much to contribute,
filling in a blank or
two on that vast canvas.
Such a scientist was
Giovanni Domenico Cassini.
He was born early in the 17th
century in the town of Perinaldo,
in what is now Italy.
Cassini didn't start
out as a scientist.
He began his career as a
pseudo-scientist, an astrologer.
Astrology is a collection of
ideas based on the notion that
worlds have certain
human personality traits,
and that the influence
of these distant worlds,
depending on which are
rising and falling at the time
of your birth, will
determine who you are and
what your fate will be.
It's another form of prejudice,
making unfounded
assumptions about who a person
is without bothering
to get to know them.
Astronomy and astrology
used to be the same thing,
until there was a
great awakening to our
actual circumstances
in the cosmos.
In 1543, Nicolaus Copernicus,
a Polish cleric
demonstrated that,
contrary to popular belief,
we were not the
center of the universe
the Earth and the other
planets traveled around the sun.
Demoting the Earth from
the center of the universe
was a severe blow
to human self-esteem.
More than a century later,
some people still
hadn't gotten over it,
and Giovanni Cassini
was one of them.
Cassini accepted
a terrific job offer,
an appointment by Louis the XIV,
the legendary
sun King of France,
Louis believed himself to be an absolute
ruler whose dominion was God's will.
But he was also the first
monarch in Europe to recognize
the great power of science.
He knew it was vital
to national security.
Louis the XIV was
inventing the first modern,
governmental, scientific
research institute,
The Paris Observatory.
Cassini told the absolute
ruler that he would not be
staying long in Paris,
a year or two, at most.
But when the King placed his new
observatory at Cassini's disposal,
he lost all interest in returning
home to Italy ever again.
For the next 125 years,
the Paris Observatory
would be led by a Cassini.
Cassini rewarded his
patron with a map of the Moon
that remained
cutting-edge for a century.
King Louis financed a research
expedition to South America
to obtain more accurate
measurements of longitude,
intel of enormous value to
the captains of his far-flung
fleet and to astronomers.
Cassini took all these data
and became the first person
to calculate the scale of
the Copernican solar system
that he had once rejected.
With his increasingly
powerful telescopes,
he discovered the
length of a day on Jupiter
and the bands and spots
on that planet's surface.
Cassini discovered Jupiter's
Great Red Spot independently
of Robert Hooke in
England, and to this day,
they share the credit.
Cassini went on to determine
the length of the day on Mars.
He was only off
by three minutes.
When he returned to his
observations of Jupiter,
he was stumped by the
contradictions in them.
The eclipses by Jupiter's moons did
not begin when they were supposed to,
they varied from
observation to observation.
Could it be that it was due
to changes in the distance
of the Earth from Jupiter, as the two
worlds moved through the solar system?
If that were true, then
light could not travel at
an infinite speed because it
was taking longer to reach Earth.
Was the speed of light finite?
This idea was just too crazy
for Cassini, too revolutionary.
He rejected it out of hand.
If he had followed the
evidence wherever it led,
he would have given us the
yardstick for the cosmos that
we still use 350 years later.
But Cassini, ever
the conservative,
dismissed the idea as
being just too wacky.
Several years later,
a Danish astronomer,
Ole Romer, became Cassini's
assistant at the Paris Observatory.
Romer made his own
observations of the eclipses
of some of Jupiter's moons and
found the same discrepancies
in the data that
Cassini had dismissed.
But Romer recognized
them for what they were,
Pieces of evidence for
the finite speed of light.
There was a time, however,
when Cassini's faithfulness
to the data was so extreme,
that he was willing to risk the
displeasure of King Louis.
The monarch asked Cassini to
calculate the exact area of his realm.
No one had ever attempted
to make an accurate map,
much less a topographical
one that would feature all
the mountains and rivers
and valleys of France,
or of any other
country for that matter.
Cassini rose to the task,
but discovered results that
could not possibly
please the King.
(sighs)
Cassini told the King,
"I have some rather disappointing
news for you, Your Highness."
We all thought that France was a whole
lot bigger than our studies, revealed.
"I'm afraid, Your Majesty, your kingdom
is much smaller than heretofore thought."
(grunts)
(gasps)
TYSON: The King surprised
everyone with his great good humor,
saying, "Why, Cassini,
you've robbed me of more land
than all the armies of
my enemies combined."
(laughing)
TYSON: And then, there
is his work on Saturn.
He was the first person to know
what the rings of Saturn really were.
He proposed that
they were not solid,
but instead composed of
countless satellites orbiting
the planet, and he
observed that there was
a division between the rings.
Cassini filled in some of the big
blanks in our understanding of Saturn,
but how could we
possibly ever get there?
Accomplishing that mythic
quest was left to one whose
tragic life would have
been completely forgotten,
if not for what you
are about to see.
TYSON: Weighing in at more
than 12,000 pounds at launch,
NASA's Cassini spacecraft
is the size of a bus.
That figure included 70
pounds of plutonium 238 fuel,
enough to last her
for more than 20 years.
But that's not what
powered her mythic odyssey.
She rode gravity's rainbow all
the way to the outer-solar system.
The lineage of the greatest of
human achievements stretches
further back than
we might assume.
Some of their roots are buried
deep inside the tomb of lost hope.
But somehow, dreams rise.
The epic missions of the first
golden age of space exploration,
and likely the next,
were made possible by
a man whose two names,
one real, one fake,
are equally forgotten.
(knocking)
(grunts)
(knocking)
Alexander Shargei's early
years are not well-documented,
but it is believed that his
mother, a political activist,
was taken from him when
he was only five years old.
He took refuge in his father's
physics and mathematics textbooks.
But by the time
Alexander was 13,
the boy had lost
his father, too.
He lived with his grandmother,
and despite great hardship,
he managed to be accepted at
the most prestigious high school,
and afterward
gained admission to the
best engineering
institute in the Ukraine.
But only two months after
he arrived there, in 1914,
he was drafted into
the Czar's army to fight
in the First World War.
[EXPLOSIONS, GUNFIRE]
[EXPLOSIONS, GUNFIRE]
In the hell of war at the front,
Alexander Shargei
conceived a scientific strategy
for exploring the Moon,
not intended as fiction,
but as blueprint.
(engine blast)
(engine blast)
(engine blast)
But Shargei's hell
didn't end with the war.
Now, Shargei was forced
to navigate the treacherous
political mine fields of
revolutionary Russia.
He was much better at figuring
out how to get to the Moon.
Former officers in the
Czar's army and those,
such as Shargei,
who were forced to join
the counter-revolutionary
White Army,
were assumed to be
"enemies of the people."
(shouting in russian)
TYSON: Shargei could find
no peace in the Soviet Union,
so in desperation he
tried to escape to Poland.
Shargei, weakened by
illness, was stopped by guards
and turned back from the border.
TYSON: These were
dangerous times,
and there was no telling what
would get you into serious trouble.
No one knows where Shargei
spent the next three years.
He simply vanished.
When at last he emerged,
Alexander Shargei was no more.
In his desperation
to be left alone,
he took the name of a dead man.
He was now Yuri Kondratyuk.
He finally published the
book he had been dreaming
about since his
time in the trenches.
No publisher was interested,
so he printed it at
his own expense.
It was Kondratyuk's letter to
a future no one else could see.
He wrote it "To Whoever Will
Read This Paper in Order to
Build an Interplanetary Rocket."
In the late 1920s,
Kondratyuk was enlisted
to design a grain elevator.
The Soviet Union was going
through a metal shortage,
so Kondratyuk's challenge
was to build the largest grain
elevator possible without
using more than a single nail.
It ended up being so big,
they named it "the Mastodon."
Such was the nightmare
logic of Stalin's Soviet Union.
You could do the heroic
in service to the state,
successfully execute the
seemingly impossible order
to build a colossus
with but a single nail.
And when it was done,
you could be
imprisoned for sabotage.
Who but an enemy of the state
would do such a reckless thing
as building a colossal grain
elevator with only a single nail.
It made no difference to
Kondratyuk's fate that the
grain elevator functioned
for another 60 years,
until it burned down.
Kondratyuk was sentenced to
three years in a special prison camp,
something new,
called a sharashka,
where scientists and engineers slaved away
on the nation's most ambitious projects.
Kondratyuk threw himself
into a wind power project,
but still he dreamed of
exploring the solar system.
Soon after that, he
met Sergei Korolev,
who also dreamed of leaving
Earth to explore the cosmos.
Korolev would later become the
father of the Soviet rocket program.
Korolev wanted to enlist
Kondratyuk in his fledgling
rocket program, but
Kondratyuk was so terrified
that any change in his status
might result in closer scrutiny by
the secret police, he declined.
If the authorities discovered that
Kondratyuk was really Shargei,
there was no telling
what they would do to him.
When Germany attacked Russia,
Kondratyuk volunteered
for armed service at the front,
where he led a
communications outfit.
His precise fate is unknown,
but he is believed to have
died in battle on a
February night in 1942.
Alexander Shargei, aka
Yuri Kondratyuk, was only 44.
That was the end of his story,
but not his dream.
In the early days of
the Apollo program,
the scientists and engineers
struggled to figure out how
a rocket could leave the Earth
and land directly on the Moon.
They were stymied.
They couldn't figure it out.
You need a big powerful
rocket to reach the Moon.
How could you land
such a thing on the surface
of another world
without crashing it?
Being able to guarantee
that it could take off again and
bring your crew safely home,
was even more of a long shot.
This approach, known
as "Direct Ascent,"
seemed like a dead-end to a NASA engineer
named John Houbolt and his colleagues.
One version of the story goes,
two space scientists had kept
the spark of
Kondratyuk's dream alive.
They delivered his 40
year-old manuscript to Houbolt.
KONDRATYUK: First of all,
to the question of the work,
let it not frighten you
Speaking about the possibility
of flight implementation,
just only remember that there
is nothing improbable on the
theoretical side of the
flight of a rocket into space
MAN (over radio): One, zero.
(engine blast)
(engine blast)
ASTRONAUT (over radio):
37 degrees.
MAN (over radio): It's
still looking very good.
You're go.
ASTRONAUT (over radio):
We got an alarm. Bravo One.
MAN 2 (over radio): Bravo
One. Rocket 1201 alarm.
MAN (over radio): 1201 alarm.
MAN 3 (over radio):
Standby for go, Flight.
MAN (over radio):
Okay, we're go.
MAN 2 (over radio): We're
go. Sync tight. We're go.
MAN 3 (over radio):
Altitude 1600.
MAN 2 (over radio):
Eagle looking great.
ASTRONAUT (over radio):
Tranquility base here.
The eagle has landed.
The surface appears
to be very fine grained
as you get close to it.
It's almost like a powder.
TYSON: NASA picked
up Kondratyuk's vision of a
Lunar Orbiter Rendezvous and
took it all the way to the Moon.
But Kondratyuk's horizon
extended far beyond.
Kondratyuk envisioned
the first reconnaissance of
the solar system by
swinging round the planets,
and using the force of
their gravity to slingshot
the craft farther
out into space.
He dreamt that we would
swing from world to world as
our ancestors had
done from tree to tree,
bending gravity to human
needs on a slightly grander scale.
But what gravity giveth,
it can also taketh away.
TYSON: Why do some worlds
have rings, and others don't?
Why no rings for Earth?
Or Mars?
We wouldn't recognize
Saturn without them.
He looks naked
without his rings,
but how did he get
them in the first place?
This is exactly what the French
astronomer Édouard Roche asked
himself when he looked at Saturn
through his telescope in 1848.
Roche speculated that Saturn's
rings were the debris of a moon,
or moons, that had
ventured too close,
and were pulled apart
by the massive planet.
♪♪
Roche was able to devise an
equation that applies to all worlds.
It tells you how closely a
body can come to a planet
before it's pulled apart by the
planet's tidal forces of gravity,
and is turned into a ring.
That's the Roche limit.
But until NASA's Cassini
spacecraft executed a series
of daredevil maneuvers
in the Saturn system,
there was a vigorous
scientific debate about
when his rings formed.
Some astronomers
suggested they were nearly
as old as the planet itself.
More than 4 billion years ago,
when the planet coalesced out
of the disc of gas and dust that
surrounded the newborn sun,
a moon, or moons, likely
violated Saturn's Roche limit
Others thought the
rings to be fairly recent.
Perhaps, only 100
million years old or so.
And the Cassini spacecraft
proved them right.
What is Earth's own Roche limit?
If the Moon were ever to
come closer than 12,000 miles,
which, by the way, it's
absolutely in no danger of doing.
And it's a good thing, too,
because I like our
Moon right where it is.
There's only one other moon
in the solar system that moves
me like ours does.
Maybe it's because it's
the only one with a thick
atmosphere like Earth's, and
the kind of surface features,
lakes and mountains,
that remind me of home.
All of this was hidden
from view by a dense layer
of orange smog, until the
European Space Agency
collaborated with NASA
to send a spacecraft to land
on his mysterious surface.
Yes, that would be the
one named after you,
Christiaan Huygens, first to see
that world through your telescope.
After an interplanetary
voyage of seven years,
the Cassini-Huygens spacecraft
arrived in the Saturn system,
the fourth of our
ships to venture there.
But the first to send a probe to explore
the surface of Saturn's moon, Titan
and to reveal a moon of far
greater complexity and splendor
than our own rather
dull and lifeless Moon.
As Carl Sagan had predicted
more than two decades before,
there were seas of
methane, and ethane,
and there was water-ice.
When Cassini first
arrived in 2004 at Saturn's
northern hemisphere, it
was in the depths of winter.
And the Sun didn't come
out until five years later,
when Saturn's
northern spring began.
Is it just me, or is this
whirling hexagon at Saturn's
North Pole every bit as exotic
as the fantasies our ancient
ancestors had of these worlds?
The geometrically regular
hexagonal shape of this
feature brings to mind the
handiwork of intelligence,
terraforming, re-working the
surface for some unknown purpose.
But it's actually the result
of the sudden change in wind
speeds as vast upwellings of
ammonia rise near the poles.
It's the mother
of all hurricanes,
a frenzy of thunder
and lightning,
containing countless
hurricanes within it.
Spring can be a violent,
stormy season, on Earth, too.
But it was during Saturn's
seven year-long summer that
Cassini was commanded
to take her own life.
♪♪
TYSON: There's a human
conceit that at the moment of death,
we re-live our
greatest memories.
You are riffling through the
memory bank of a doomed robot,
about to carry out
the cruelest command.
♪♪
♪♪
♪♪
♪♪
♪♪
The mission planners at
NASA's Jet Propulsion Laboratory
call this the "ball of yarn,"
13 years of exploration
through the Saturn system.
From the time of her launch in
1997 and throughout her epic voyage,
she has used the gravity assist conceived
100 years before by Yuri Kondratyuk.
But it was her supply
of rocket fuel that made it
possible for her Earthbound
controllers to steer her into
new trajectories of exploration.
In April of 2017, Cassini
was running low on that fuel.
It was time for her most
daring maneuvers of all,
before she was to be
sent into a final death dive.
These are the mission
scientists of Cassini,
some of whom have been
working on the project since
the 1990s, when it was
no more than a dream.
They know that Cassini must die.
It's too dangerous to
let her wander aimlessly.
She might crash into one of
the moons in the Saturn system
where life might be hiding.
This would violate
NASA's planetary protection
conventions on quarantine
in the book of space laws.
If left to chance,
Cassini could alter the
possible biological destiny
of Titan or Enceladus.
A terrible command
must now be given.
Cassini is so far away,
it will take the message,
traveling at the speed of light,
more than an hour to reach her.
Every microchip in her has
been programmed to resist
the commands
she's now receiving.
The inner-turmoil of the
loyal robot commanded to defy
her own instincts
must be fierce.
The same engineers who
ordered her to protect herself
in every situation now force
her to plunge to her death.
They must be obeyed.
MAN (over radio):
System lead ace.
We have telemetry
AOS at zero one.
One, niner. One two.
TYSON: She fights off the
immense forces by struggling
to right herself one last time.
She fires her thrusters at 100%,
all the while faithfully
sending back more data than
her designers ever
hoped she would.
WOMAN (over radio): Project
Manager. Flight Director.
MAN (over radio): Go ahead.
WOMAN (over radio): Okay.
We'd call loss of signal at 11:55:4.
TYSON: She fights the brutal
atmospheric resistance until
her fuel tanks are empty,
and there's no
more fight left in her.
MAN (over radio): Project manager
on, maybe a trickle of telemetry left, but,
just heard the signal
from the spacecraft is gone
and within the next 45
seconds so will be the spacecraft.
♪♪
TYSON: Official time of
death: 11:55 universal time.
There are all kinds of stories in the
struggle to understand the cosmos.
Sometimes your
dreams die with you,
but sometimes the scientists
of another age pick them up,
and take them to the
Moon, and far beyond.
The name of Yuri
Kondratyuk was forgotten,
but there was one
who remembered.
When Neil Armstrong returned
from his trip to the Moon,
he made a pilgrimage to the
childhood home of the man
who made his mythic
voyage possible.
♪♪
MAN (over radio):
Systems this is prop.
I read you 500, do you read me?
TYSON: These people are watching
their life's work come to an end.
MAN (over radio): The
team is on its way to point.
TYSON: On another world.
MAN (over radio):
All right. Roger that.
TYSON: They were all young
when they sent her on her way.
These men and women
have been traveling
vicariously with her for
more than two decades.
And now, her work is
done, so she must die.
But before she
takes the fatal plunge,
they've given her one
final, epic challenge.
(theme music plays)
♪♪
♪♪
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!!! Hope you enjoy the TV-Series !!!
TYSON: Gravity has
a big bag of tricks,
none lovelier than the
ring systems of worlds.
Our own solar system,
alone, has four ringed planets.
This one, with the
romantic name J-1407B,
is the first we've found
circling another sun.
Why haven't we found more
ringed planets in our galaxy?
Is it that the rings
are so unusual,
or are the methods we use
to find exoplanets not very
good at seeing the ring
systems that may surround them?
J-1407B's ring
system is so vast,
that it eclipsed
its star for days.
These rings extend across an
astonishing 112 million miles.
They would more than fill the
distance between Earth and the sun.
But as enormous as they
are, they're shockingly thin.
If the ring system of J-1407B
were the size of a dinner plate,
it would have to be
100 times thinner,
as thin as a human hair.
This surprising contrast
between the immense territory
of a ring system,
and its thinness,
is just as striking in
our own solar system.
The outermost ring of
Neptune is so dainty,
that it was first thought to
be the fragments of a ring.
Not a ring, but a
collection of arcs.
That was, until NASA's
Voyager 2 spacecraft revealed
that the so-called
arcs were clumps,
the thicker parts of a
fainter, complete ring.
It's funny that the weirdest
planet in the solar system has
attracted the least attention.
Voyager 2 is the only
spacecraft that has ever been
sent on a reconnaissance
mission to Uranus,
one of the two ice giant
planets that circle the sun.
During its 20-year-long summers,
the sun never sets on Uranus.
The winters are equally as long,
20 years of unbroken night.
Unlike its fellow gas planets,
Uranus is cold-hearted.
It doesn't generate
any internal heat.
Uranus is one crazy world.
The outer edge of Uranus's
atmosphere is so hot,
it's hotter than 500
degrees Fahrenheit.
But Uranus also has the
coldest clouds in the solar system,
I'm talking nearly 400
degrees below zero.
What kind of ocean is this?
Is it made of ammonia?
Water?
Some scientists think it may
be an ocean of liquid diamonds.
Note to space agencies,
might be worth another visit.
Then there's that thing
about it being sideways.
Uranus revolves around the sun at a roughly
90 degree angle to its own orbital plane.
What could have happened to
Uranus that it got knocked on its ass?
Our best guess is that it
went something like this.
Uranus was in a
terrible accident.
(crashing)
(crashing)
After the second blow, the rotational
axis of Uranus tipped 98 degrees.
There's another world in
our solar system that we don't
think of as having a ring.
The rings of Jupiter were
so dim that no ground-based
telescope ever saw them.
They were discovered when
Voyager I came flying by.
Our Saturn is graced
by the loveliest, largest,
and brightest ring system
of any around our sun.
It's the most distant planet that
can be seen with the naked eye,
and it made quite an
impression on our ancestors.
When I think of the Babylonians
of 3,500 years ago looking up
at the planets and stars,
I wonder how unlikely it would
have seemed that one of their
species would actually
send an emissary to that
distant point of light.
We are in the Deep Space Network
room at NASA's Jet Propulsion Laboratory.
In this place, the most ambitious voyages
of discovery are directed and monitored.
Why are these
people so emotional?
They have committed
their professional lives to
a collaboration with this robot.
And now that partnership
of decades is about to end
in a most violent way.
The pathway from our
Earthbound helplessness to
our presence in Saturn's
skies is about to unfold.
TYSON: What is that shimmering,
unsteady thing we're looking at?
That's what Galileo Galilei
asked himself in 1610 when he
became the first human
to see Saturn as more than
just a point of light.
So, this is the telescope
that made the modern
scientific revolution possible.
You know, you really
started something.
You looked through that
thing and found the cosmos.
That's not to say you didn't
make your share of mistakes.
You guessed wrong at
what you thought you saw,
believing that Saturn sported
two symmetrical moons
on either side of it.
Two years later, when
you took a second look,
you were shocked to find that
your "moons" had vanished.
This was because both
worlds, Earth and Saturn,
were in motion, and the two worlds
had changed in position to each other.
You were now looking
at Saturn's rings, edge-on.
The Saturn ring system
is 175,000 miles across,
but on average only a
few hundred feet thick.
They were too thin for your
fledgling telescope to see.
But two years after
that, you took a third look.
Now, you thought that
the planet had arms.
♪♪
40 years passed, until a
Dutch astronomer named
Christiaan Huygens took
another look at Saturn with
his own greatly
improved telescope.
Huygens was the first
to know that worlds could
be circled by rings, and
Saturn was one of them.
He also discovered
Saturn's largest moon,
which would later
be known as Titan.
When it finally came time
for us to visit that world,
our spacecraft bore
Huygens's name.
In science, there are
the Galileos, the Newtons,
the Darwins, the Einsteins.
And then there's another
kind of great scientist.
Not the kind that paints a
whole new picture of nature,
but, like Christiaan Huygens,
someone who has
much to contribute,
filling in a blank or
two on that vast canvas.
Such a scientist was
Giovanni Domenico Cassini.
He was born early in the 17th
century in the town of Perinaldo,
in what is now Italy.
Cassini didn't start
out as a scientist.
He began his career as a
pseudo-scientist, an astrologer.
Astrology is a collection of
ideas based on the notion that
worlds have certain
human personality traits,
and that the influence
of these distant worlds,
depending on which are
rising and falling at the time
of your birth, will
determine who you are and
what your fate will be.
It's another form of prejudice,
making unfounded
assumptions about who a person
is without bothering
to get to know them.
Astronomy and astrology
used to be the same thing,
until there was a
great awakening to our
actual circumstances
in the cosmos.
In 1543, Nicolaus Copernicus,
a Polish cleric
demonstrated that,
contrary to popular belief,
we were not the
center of the universe
the Earth and the other
planets traveled around the sun.
Demoting the Earth from
the center of the universe
was a severe blow
to human self-esteem.
More than a century later,
some people still
hadn't gotten over it,
and Giovanni Cassini
was one of them.
Cassini accepted
a terrific job offer,
an appointment by Louis the XIV,
the legendary
sun King of France,
Louis believed himself to be an absolute
ruler whose dominion was God's will.
But he was also the first
monarch in Europe to recognize
the great power of science.
He knew it was vital
to national security.
Louis the XIV was
inventing the first modern,
governmental, scientific
research institute,
The Paris Observatory.
Cassini told the absolute
ruler that he would not be
staying long in Paris,
a year or two, at most.
But when the King placed his new
observatory at Cassini's disposal,
he lost all interest in returning
home to Italy ever again.
For the next 125 years,
the Paris Observatory
would be led by a Cassini.
Cassini rewarded his
patron with a map of the Moon
that remained
cutting-edge for a century.
King Louis financed a research
expedition to South America
to obtain more accurate
measurements of longitude,
intel of enormous value to
the captains of his far-flung
fleet and to astronomers.
Cassini took all these data
and became the first person
to calculate the scale of
the Copernican solar system
that he had once rejected.
With his increasingly
powerful telescopes,
he discovered the
length of a day on Jupiter
and the bands and spots
on that planet's surface.
Cassini discovered Jupiter's
Great Red Spot independently
of Robert Hooke in
England, and to this day,
they share the credit.
Cassini went on to determine
the length of the day on Mars.
He was only off
by three minutes.
When he returned to his
observations of Jupiter,
he was stumped by the
contradictions in them.
The eclipses by Jupiter's moons did
not begin when they were supposed to,
they varied from
observation to observation.
Could it be that it was due
to changes in the distance
of the Earth from Jupiter, as the two
worlds moved through the solar system?
If that were true, then
light could not travel at
an infinite speed because it
was taking longer to reach Earth.
Was the speed of light finite?
This idea was just too crazy
for Cassini, too revolutionary.
He rejected it out of hand.
If he had followed the
evidence wherever it led,
he would have given us the
yardstick for the cosmos that
we still use 350 years later.
But Cassini, ever
the conservative,
dismissed the idea as
being just too wacky.
Several years later,
a Danish astronomer,
Ole Romer, became Cassini's
assistant at the Paris Observatory.
Romer made his own
observations of the eclipses
of some of Jupiter's moons and
found the same discrepancies
in the data that
Cassini had dismissed.
But Romer recognized
them for what they were,
Pieces of evidence for
the finite speed of light.
There was a time, however,
when Cassini's faithfulness
to the data was so extreme,
that he was willing to risk the
displeasure of King Louis.
The monarch asked Cassini to
calculate the exact area of his realm.
No one had ever attempted
to make an accurate map,
much less a topographical
one that would feature all
the mountains and rivers
and valleys of France,
or of any other
country for that matter.
Cassini rose to the task,
but discovered results that
could not possibly
please the King.
(sighs)
Cassini told the King,
"I have some rather disappointing
news for you, Your Highness."
We all thought that France was a whole
lot bigger than our studies, revealed.
"I'm afraid, Your Majesty, your kingdom
is much smaller than heretofore thought."
(grunts)
(gasps)
TYSON: The King surprised
everyone with his great good humor,
saying, "Why, Cassini,
you've robbed me of more land
than all the armies of
my enemies combined."
(laughing)
TYSON: And then, there
is his work on Saturn.
He was the first person to know
what the rings of Saturn really were.
He proposed that
they were not solid,
but instead composed of
countless satellites orbiting
the planet, and he
observed that there was
a division between the rings.
Cassini filled in some of the big
blanks in our understanding of Saturn,
but how could we
possibly ever get there?
Accomplishing that mythic
quest was left to one whose
tragic life would have
been completely forgotten,
if not for what you
are about to see.
TYSON: Weighing in at more
than 12,000 pounds at launch,
NASA's Cassini spacecraft
is the size of a bus.
That figure included 70
pounds of plutonium 238 fuel,
enough to last her
for more than 20 years.
But that's not what
powered her mythic odyssey.
She rode gravity's rainbow all
the way to the outer-solar system.
The lineage of the greatest of
human achievements stretches
further back than
we might assume.
Some of their roots are buried
deep inside the tomb of lost hope.
But somehow, dreams rise.
The epic missions of the first
golden age of space exploration,
and likely the next,
were made possible by
a man whose two names,
one real, one fake,
are equally forgotten.
(knocking)
(grunts)
(knocking)
Alexander Shargei's early
years are not well-documented,
but it is believed that his
mother, a political activist,
was taken from him when
he was only five years old.
He took refuge in his father's
physics and mathematics textbooks.
But by the time
Alexander was 13,
the boy had lost
his father, too.
He lived with his grandmother,
and despite great hardship,
he managed to be accepted at
the most prestigious high school,
and afterward
gained admission to the
best engineering
institute in the Ukraine.
But only two months after
he arrived there, in 1914,
he was drafted into
the Czar's army to fight
in the First World War.
[EXPLOSIONS, GUNFIRE]
[EXPLOSIONS, GUNFIRE]
In the hell of war at the front,
Alexander Shargei
conceived a scientific strategy
for exploring the Moon,
not intended as fiction,
but as blueprint.
(engine blast)
(engine blast)
(engine blast)
But Shargei's hell
didn't end with the war.
Now, Shargei was forced
to navigate the treacherous
political mine fields of
revolutionary Russia.
He was much better at figuring
out how to get to the Moon.
Former officers in the
Czar's army and those,
such as Shargei,
who were forced to join
the counter-revolutionary
White Army,
were assumed to be
"enemies of the people."
(shouting in russian)
TYSON: Shargei could find
no peace in the Soviet Union,
so in desperation he
tried to escape to Poland.
Shargei, weakened by
illness, was stopped by guards
and turned back from the border.
TYSON: These were
dangerous times,
and there was no telling what
would get you into serious trouble.
No one knows where Shargei
spent the next three years.
He simply vanished.
When at last he emerged,
Alexander Shargei was no more.
In his desperation
to be left alone,
he took the name of a dead man.
He was now Yuri Kondratyuk.
He finally published the
book he had been dreaming
about since his
time in the trenches.
No publisher was interested,
so he printed it at
his own expense.
It was Kondratyuk's letter to
a future no one else could see.
He wrote it "To Whoever Will
Read This Paper in Order to
Build an Interplanetary Rocket."
In the late 1920s,
Kondratyuk was enlisted
to design a grain elevator.
The Soviet Union was going
through a metal shortage,
so Kondratyuk's challenge
was to build the largest grain
elevator possible without
using more than a single nail.
It ended up being so big,
they named it "the Mastodon."
Such was the nightmare
logic of Stalin's Soviet Union.
You could do the heroic
in service to the state,
successfully execute the
seemingly impossible order
to build a colossus
with but a single nail.
And when it was done,
you could be
imprisoned for sabotage.
Who but an enemy of the state
would do such a reckless thing
as building a colossal grain
elevator with only a single nail.
It made no difference to
Kondratyuk's fate that the
grain elevator functioned
for another 60 years,
until it burned down.
Kondratyuk was sentenced to
three years in a special prison camp,
something new,
called a sharashka,
where scientists and engineers slaved away
on the nation's most ambitious projects.
Kondratyuk threw himself
into a wind power project,
but still he dreamed of
exploring the solar system.
Soon after that, he
met Sergei Korolev,
who also dreamed of leaving
Earth to explore the cosmos.
Korolev would later become the
father of the Soviet rocket program.
Korolev wanted to enlist
Kondratyuk in his fledgling
rocket program, but
Kondratyuk was so terrified
that any change in his status
might result in closer scrutiny by
the secret police, he declined.
If the authorities discovered that
Kondratyuk was really Shargei,
there was no telling
what they would do to him.
When Germany attacked Russia,
Kondratyuk volunteered
for armed service at the front,
where he led a
communications outfit.
His precise fate is unknown,
but he is believed to have
died in battle on a
February night in 1942.
Alexander Shargei, aka
Yuri Kondratyuk, was only 44.
That was the end of his story,
but not his dream.
In the early days of
the Apollo program,
the scientists and engineers
struggled to figure out how
a rocket could leave the Earth
and land directly on the Moon.
They were stymied.
They couldn't figure it out.
You need a big powerful
rocket to reach the Moon.
How could you land
such a thing on the surface
of another world
without crashing it?
Being able to guarantee
that it could take off again and
bring your crew safely home,
was even more of a long shot.
This approach, known
as "Direct Ascent,"
seemed like a dead-end to a NASA engineer
named John Houbolt and his colleagues.
One version of the story goes,
two space scientists had kept
the spark of
Kondratyuk's dream alive.
They delivered his 40
year-old manuscript to Houbolt.
KONDRATYUK: First of all,
to the question of the work,
let it not frighten you
Speaking about the possibility
of flight implementation,
just only remember that there
is nothing improbable on the
theoretical side of the
flight of a rocket into space
MAN (over radio): One, zero.
(engine blast)
(engine blast)
ASTRONAUT (over radio):
37 degrees.
MAN (over radio): It's
still looking very good.
You're go.
ASTRONAUT (over radio):
We got an alarm. Bravo One.
MAN 2 (over radio): Bravo
One. Rocket 1201 alarm.
MAN (over radio): 1201 alarm.
MAN 3 (over radio):
Standby for go, Flight.
MAN (over radio):
Okay, we're go.
MAN 2 (over radio): We're
go. Sync tight. We're go.
MAN 3 (over radio):
Altitude 1600.
MAN 2 (over radio):
Eagle looking great.
ASTRONAUT (over radio):
Tranquility base here.
The eagle has landed.
The surface appears
to be very fine grained
as you get close to it.
It's almost like a powder.
TYSON: NASA picked
up Kondratyuk's vision of a
Lunar Orbiter Rendezvous and
took it all the way to the Moon.
But Kondratyuk's horizon
extended far beyond.
Kondratyuk envisioned
the first reconnaissance of
the solar system by
swinging round the planets,
and using the force of
their gravity to slingshot
the craft farther
out into space.
He dreamt that we would
swing from world to world as
our ancestors had
done from tree to tree,
bending gravity to human
needs on a slightly grander scale.
But what gravity giveth,
it can also taketh away.
TYSON: Why do some worlds
have rings, and others don't?
Why no rings for Earth?
Or Mars?
We wouldn't recognize
Saturn without them.
He looks naked
without his rings,
but how did he get
them in the first place?
This is exactly what the French
astronomer Édouard Roche asked
himself when he looked at Saturn
through his telescope in 1848.
Roche speculated that Saturn's
rings were the debris of a moon,
or moons, that had
ventured too close,
and were pulled apart
by the massive planet.
♪♪
Roche was able to devise an
equation that applies to all worlds.
It tells you how closely a
body can come to a planet
before it's pulled apart by the
planet's tidal forces of gravity,
and is turned into a ring.
That's the Roche limit.
But until NASA's Cassini
spacecraft executed a series
of daredevil maneuvers
in the Saturn system,
there was a vigorous
scientific debate about
when his rings formed.
Some astronomers
suggested they were nearly
as old as the planet itself.
More than 4 billion years ago,
when the planet coalesced out
of the disc of gas and dust that
surrounded the newborn sun,
a moon, or moons, likely
violated Saturn's Roche limit
Others thought the
rings to be fairly recent.
Perhaps, only 100
million years old or so.
And the Cassini spacecraft
proved them right.
What is Earth's own Roche limit?
If the Moon were ever to
come closer than 12,000 miles,
which, by the way, it's
absolutely in no danger of doing.
And it's a good thing, too,
because I like our
Moon right where it is.
There's only one other moon
in the solar system that moves
me like ours does.
Maybe it's because it's
the only one with a thick
atmosphere like Earth's, and
the kind of surface features,
lakes and mountains,
that remind me of home.
All of this was hidden
from view by a dense layer
of orange smog, until the
European Space Agency
collaborated with NASA
to send a spacecraft to land
on his mysterious surface.
Yes, that would be the
one named after you,
Christiaan Huygens, first to see
that world through your telescope.
After an interplanetary
voyage of seven years,
the Cassini-Huygens spacecraft
arrived in the Saturn system,
the fourth of our
ships to venture there.
But the first to send a probe to explore
the surface of Saturn's moon, Titan
and to reveal a moon of far
greater complexity and splendor
than our own rather
dull and lifeless Moon.
As Carl Sagan had predicted
more than two decades before,
there were seas of
methane, and ethane,
and there was water-ice.
When Cassini first
arrived in 2004 at Saturn's
northern hemisphere, it
was in the depths of winter.
And the Sun didn't come
out until five years later,
when Saturn's
northern spring began.
Is it just me, or is this
whirling hexagon at Saturn's
North Pole every bit as exotic
as the fantasies our ancient
ancestors had of these worlds?
The geometrically regular
hexagonal shape of this
feature brings to mind the
handiwork of intelligence,
terraforming, re-working the
surface for some unknown purpose.
But it's actually the result
of the sudden change in wind
speeds as vast upwellings of
ammonia rise near the poles.
It's the mother
of all hurricanes,
a frenzy of thunder
and lightning,
containing countless
hurricanes within it.
Spring can be a violent,
stormy season, on Earth, too.
But it was during Saturn's
seven year-long summer that
Cassini was commanded
to take her own life.
♪♪
TYSON: There's a human
conceit that at the moment of death,
we re-live our
greatest memories.
You are riffling through the
memory bank of a doomed robot,
about to carry out
the cruelest command.
♪♪
♪♪
♪♪
♪♪
♪♪
The mission planners at
NASA's Jet Propulsion Laboratory
call this the "ball of yarn,"
13 years of exploration
through the Saturn system.
From the time of her launch in
1997 and throughout her epic voyage,
she has used the gravity assist conceived
100 years before by Yuri Kondratyuk.
But it was her supply
of rocket fuel that made it
possible for her Earthbound
controllers to steer her into
new trajectories of exploration.
In April of 2017, Cassini
was running low on that fuel.
It was time for her most
daring maneuvers of all,
before she was to be
sent into a final death dive.
These are the mission
scientists of Cassini,
some of whom have been
working on the project since
the 1990s, when it was
no more than a dream.
They know that Cassini must die.
It's too dangerous to
let her wander aimlessly.
She might crash into one of
the moons in the Saturn system
where life might be hiding.
This would violate
NASA's planetary protection
conventions on quarantine
in the book of space laws.
If left to chance,
Cassini could alter the
possible biological destiny
of Titan or Enceladus.
A terrible command
must now be given.
Cassini is so far away,
it will take the message,
traveling at the speed of light,
more than an hour to reach her.
Every microchip in her has
been programmed to resist
the commands
she's now receiving.
The inner-turmoil of the
loyal robot commanded to defy
her own instincts
must be fierce.
The same engineers who
ordered her to protect herself
in every situation now force
her to plunge to her death.
They must be obeyed.
MAN (over radio):
System lead ace.
We have telemetry
AOS at zero one.
One, niner. One two.
TYSON: She fights off the
immense forces by struggling
to right herself one last time.
She fires her thrusters at 100%,
all the while faithfully
sending back more data than
her designers ever
hoped she would.
WOMAN (over radio): Project
Manager. Flight Director.
MAN (over radio): Go ahead.
WOMAN (over radio): Okay.
We'd call loss of signal at 11:55:4.
TYSON: She fights the brutal
atmospheric resistance until
her fuel tanks are empty,
and there's no
more fight left in her.
MAN (over radio): Project manager
on, maybe a trickle of telemetry left, but,
just heard the signal
from the spacecraft is gone
and within the next 45
seconds so will be the spacecraft.
♪♪
TYSON: Official time of
death: 11:55 universal time.
There are all kinds of stories in the
struggle to understand the cosmos.
Sometimes your
dreams die with you,
but sometimes the scientists
of another age pick them up,
and take them to the
Moon, and far beyond.
The name of Yuri
Kondratyuk was forgotten,
but there was one
who remembered.
When Neil Armstrong returned
from his trip to the Moon,
he made a pilgrimage to the
childhood home of the man
who made his mythic
voyage possible.
♪♪