All language subtitles for The universe S07E02 Alien Sounds

Male narrator: In the beginning,
there was darkness,

and then, bang,

giving birth to an endless
expanding existence

of time, space, and matter.

Every day, new discoveries
are unlocking the mysterious,

the mind-blowing,
the deadly secrets

of a place we call
The Universe.

In the deep nothingness
of space,

the cosmic silence is broken.

- Space is actually kind of
a noisy place.

Narrator. Galaxies, stars,
planets, and moons sing out

with strange and alien music.

[electronic warbling]

- They sound a little bit like
an alien fax.

Narrator:
Now the cosmic playlist

in a top ten countdown,

the greatest hits
of the universe...

in a symphony of alien sounds.

As the promo line
for Ridley Scott's

science-fiction film Alien,

it was designed to send chills
down your spine.

It's based on
the unsettling idea

that space is a vacuum,

and sounds, whether screams,
shouts, or songs,

can't travel in a vacuum.

But is that really true?

- Well, it's kind of narrow
to think that, in space,

you can't hear anyone scream,
because, in fact, here on Earth,

there are lots of sounds
we can't hear.

They're either too high a pitch
or too low a pitch.

Moreover, space
isn't completely empty.

And then finally, you know,
what's the definition of space?

If I'm an astronaut
on the surface of Mars

and I have a spacesuit on,
am |I in space, or am I not?

Well, I would think I am.

- Okay, let's try
right over here.

Narrator: Back on Earth,

Bruce Bette
of The Planetary Society

in Pasadena, California,

has given a lot of thought
to Mars

and the subject of sound.

He's programmed his computer

with what he calls
the "Mars in at or”

to demonstrate what his voice
would sound like

in the cold, carbon-dioxide
atmosphere of Mars...

without those space suits.

- The atmosphere of Mars
would actually change your voice

so it sounded deeper.

So let's go ahead and simulate
that using the Mars in at or,

and I will record my voice,

and then we will shift it

to what it would sound like
on Mars.

This is what
I'd sound like on Mars,

although I'd be wishing
I had some oxygen to breathe.

Then I go ahead and process it,
put it through the Mars in at or.

And then we play it back
and see what it sounds like.

[deep voice] This is
how I would sound on Mars,

although I'd be wishing I had
some oxygen to breathe.

Narrator: Of course, if humans
ever do make it to Mars,

we will not hear their voices
through the atmosphere.

Instead, we'll get them
via radio waves...

the way many
of our most important sounds

already reach us.

-Yes.

- We're familiar with thinking
of sound as something

that comes
through the air to us,

just like we hear each other
when we're talking,

but, in fact,
a lot of the sounds that we hear

are transmitted
through electromagnetic signals.

For example, your television
actually transmits

a television signal into sound
that you can hear.

- Who's our first contestant
tonight?

Narrator:
Sound in the cosmos

will never reach us directly
across empty space,

so radio, light,
or other electromagnetic waves

are the inevitable carriers,

bringing us a universe
we can hear...

in all its variety.

[cosmic warbling]

- Space is actually kind of
a noisy place.

It has many, many sources
of noise

that we are able to detect

with special radio telescopes,
for example.

Narrator:
These alien sounds

make up
an incredible collection—

The ultimate playlist.

We've polled our expert panel
of scientists, astronomers,

and physicists
to rank the top ten—

The greatest sounds
from the expanse of space...

ending with a number one
that will surprise us all.

And now the countdown starts.

Coming in at number ten,

ringing out from a distance
of 13 billion light-years,

the birth cry of the universe
in a hit called

"The Audio Afterglow
of the Big Bang."

[whirring]

- It's remarkable
that the young universe

actually made a sound,

and the reason we know that is
that we can actually witness

the glowing gases that were
present at that time.

Narrator: The glow
from these gases

is known as the cosmic microwave
background radiation,

or CMBR.

It is a faint trace
of microwaves

that stretches
across every point in the sky.

Discovered by scientists
in the mid-1960s,

the radiation is the afterglow
of the big bang.

The famous blotchy satellite map
of the CMBR

represents the cosmos
in its infancy,

when it was only
380,000 years old.

- When we look at the CMBR map,

we're essentially looking
at a voice print

of the early universe,

because those tiny variations
in color

correspond to variations
in temperature,

and those correspond
to variations

in density and pressure.

Well, pressure waves are just
sound waves.

So we're seeing
little variations in pressure,

little sound waves
in the early universe.

Narrator: To understand
the audio afterglow

of the big bang,

we need to know
how the early universe

varied its pressures
to generate sound waves.

To find out,
astronomer Mark Whittle

and organ builder Manuel Rosales

visit the magnificent pipe organ

at Claremont United Church
of Christ in California.

In a way, the 4,000 pipes
in this organ are comparable

to the voice
of the early universe.

[organ pipes droning]

- Manuel, the amazing thing
about the early universe is that

all its pipes
were sounding together,

and it would be lovely
if we could just try that

with this organ.

So do you think
we could do that now,

play all the notes at once?

- Yes, let's pull out
all the stops and try it.

- Ah, that's where
that phrase comes from.

- Yes.
- Okay, let's go.

[cacophonous droning]

Very powerful, but really
hussy white noise kind of sound,

but an even more remarkable
thing about the primordial sound

is that, in fact,
a few particular tones

were present and were stronger
at any given time.

[cacophonous droning]

[whirring]

Narrator: This is the opening
note of hit number ten,

"The Audio Afterglow
of the Big Bang."

A computer sound analyzer
reveals its strong tones

as distinct columns
on a color-coded graph.

As hussy as the early
cosmic sound is,

it differs
from pure white noise...

which has no organized features
at all on the analyzer.

[hissing]

The sound of the audio
afterglow, on the other hand,

comes through with a vaguely
musical quality.

[whirring]

[hissing]

[whirring]

[cacophonous droning]

The pipes of this, or any organ,
are made of wood and metal,

but the pipes
of the early universe

were pits of dark matter,

the mysterious substance
whose existence is known

only from its gravity.

- What drives the sound waves
is gravity.

So, for example,
if there's a region

of slightly higher density
of dark matter,

there's a gravitational force
pulling in.

Gas that's surrounding
this region feels that pull,

and it falls in.

But it's gas, so it also—
as it falls in, it compresses.

That compression acts
like a spring,

and so it pushes the gas
back out.

But then it overshoots
until it falls back in again.

This is how the motion of
the gas falls in, bounces out,

falls in, bounces out.

So we have an oscillating
pressure wave, a sound wave.

Narrator: The cosmic
background radiation,

as important as it is,
is just a still picture.

Its imprint of sound
has the effect

of no more than one noisy,
barely musical note.

And even hearing that
is a struggle.

The pipe organ
helps show us why.

♩ ♩

- The sounds of the universe
are way too low for us to hear.

In fact, what's the lowest note
that this organ plays?

- It is a pipe 32 feet long,

and it can only be played
with one's foot.

[deep note plays]

- Yeah, that's pretty deep.

32 feet were nothing compared
to the cosmic organ pipes.

They were between 20,000
and 400,000 light-years across.

- Sorry, we don't have
any pipes quite that long.

- No.

Narrator: The deep sound
of the early universe is so low,

we can hear it only after
a massive shift upward.

[tone zooming higher]

The background radiation
of the universe

dates from 380,000 years
after its creation.

But what happened before that?

Is it possible to uncover
the whole song of the universe

from the very instant
of the big bang?

The cosmos is filled with
a symphony of alien sounds,

and we're counting down
the top ten

of the universe's greatest hits.

Number ten on the playlist
sings out

with the earliest tones
of the universe

from "The Audio Afterglow
of the Big Bang."

[whirring]

But our download
of the universe's birth song

has some problems.

With the cosmic organ playing
all its pipes at once,

what reaches our ears
sounds like

only one complex, noisy note.

[whirring]

It's only one note because it
comes from the pressure waves

we read from the map of
the cosmic background radiation,

which is just a still picture of
the sound in the early universe

taken 380,000 years
after its birth.

How then do we run
the clock backwards

and hear the rest of the song?

- Modern cosmology
is sufficiently advanced

that it's possible to create
a computer replication,

a simulation
of the young universe.

It's possible to re-create
within a computer

what's going on
and how the sound developed

right from the very,
very beginning

through those
first 400,000 years.

Narrator: They are the same kind
of supercomputer simulations

that have given us pictures

showing how the early universe
evolved.

The dark-matter pipes
of the early universe

acted like those
in the church organ.

As bigger pipes were played,
deeper notes were sounded.

As the universe expanded,

there was more space
and more time.

More space meant bigger pipes.

So the notes in the song
got lower and lower

as the song played out.

[deep whirring, creaking]

Put it all together,

and the first 400,000 years
of the universe

can be condensed down
to just ten seconds—

A haunting primal scream.

[whirring]

- The gas that's falling in
and out

of these dark-matter regions

is ultimately going to become
the first stars,

the first galaxies,
and ultimately,

it'll be corralled
into the thousands of galaxies

that we see around us today.

So while it's been amusing,
really, and playful

to reproduce these sounds
for us to listen to,

in the big picture, they play
an enormously important role

in crafting the structure
of the universe

that's going to unfold
and the universe

that we find ourselves in today.

[whirring]

Narrator: From the big-band
sound of the big bang,

our countdown
takes a step down in size

to the modest
15-million light-year span

of a galaxy cluster.

Coming in at number nine
on our list

of the universe's
top ten hits

is the "Deep Tone of Perseus."

[deep warbling]

This is low sound
to the extreme,

emanating
from the Perseus cluster,

a grouping
of roughly 1,000 galaxies

250 million light-years
from Earth.

- The central galaxy
in this cluster of galaxies

has a huge super-massive
black hole at its center.

Narrator: The cluster's central
galaxy is called Perseus A,

and its super-massive black hole
gives it what's called

an active galactic nucleus,

which shoots out energy
in the form of gigantic jets,

tearing
into the surrounding space.

- For reasons which we don't
fully understand,

it seems to be coming out.

The energy is being produced
episodically

about every 10 million years or so.

Narrator. Those energy pulses
are actually waves of pressure.

And that's exactly
what sound waves are:

pressure waves.

The wave, as demonstrated
by sports fans,

has an up-and-down motion
that's very familiar to us.

But these UC Berkeley students
will switch gears

and show us how a sound wave
is different.

- Okay, everyone,
lose the pom-poms!

Since sound waves
are pressure waves,

we're gonna build a pressure
wave out of all these students.

Okay, everybody, let's line up.

You go over here
and then shoulder-to-shoulder

just like this.

Stretch out over there
a little bit, no gaps.

You're gonna be students
colliding with each other

like molecules colliding
in a sound wave.

That's looking a lot better.

Do you feel like a bunch
of molecules?

All: Yeah!

- Okay, okay,
this is looking good.

We have a bass drum
at each end of the line.

You'll see why in a minute.

We'll get things going
with this drummer over here.

He's gonna hit the drum,
and watch what happens.

Bang!

In this case, the pressure is
a good healthy shove,

and it moves
from student to student

all the way down the line.

At the end, the last student
applies his pressure

to the second drum
by banging on it.

Bang!

This second drum is like
our eardrum.

When pressure from a sound wave
in the air hits our eardrums,

we hear the sound.

This is just how sound travels
through the air,

except instead of having
students shoving each other,

there are air molecules
shoving each other.

A sound needs a medium
to travel through.

It can't travel
through a vacuum.

So, in fact, to get
from point A to point B,

you need air molecules
hitting each other.

That's how it works.

Narrator: So how do
those pressure waves

from number nine's
"Deep Tones of Perseus"

travel through
what's essentially

the vacuum
of intergalactic space?

Astrophysicist Richard Pogge
of Ohio State University

gives us a sense
of the emptiness in deep space

at his school's
football stadium.

- While it's true
that sound waves can't travel

through the vacuum of space,
space is not a complete vacuum.

I'm here at Ohio Stadium,
home of the Buckeyes.

It's very empty today.
I'm the only one here.

And I can't think
of a better place

to illustrate
the vacuum of space.

Narrator: The empty stadium
can be a stand-in

for the vacuum of space

if we compare it with what
it looks like on game day.

[crowd cheering]

With more than 102,000 people
in its seats,

Ohio Stadium would be like
the atmosphere on Earth

jam-packed with air molecules.

- So how much do we have to
clear out this stadium

to equal the vacuum of space?

Believe it or not,
you have to clear out everybody,

including me,
and then even I'm too much.

Narrator: No more than
a single cell from Pogge's body

could remain in Ohio Stadium

to come close to the vacuum
of deep space.

With what seems like almost
nothing in the expanse

between galaxies
of the Perseus cluster,

the existence of sound waves
seems all the more incredible.

- How do you propagate
a sound wave through empty space

when it's mostly empty?

Let's use the example of me
running down the field.

I have to run a long ways
before I encounter somebody,

but I still encounter somebody,

and I can pass energy
along to them.

The same is true of atoms
in interstellar space.

It has to travel a long ways,
maybe 300 light-years,

before it encounters
another particle,

but when it encounters it,
it passes the energy,

and the wave moves along.

Narrator: The colliding
particles in the Perseus cluster

also emit faint X-rays
whose traces,

imaged by the Chandra
space telescope,

tell us the waves are there.

But these waves are huge,

and the notes they produce
are lower

than anything any human
has ever experienced.

- The pitch is about 57 octaves
below our hearing,

below the middle
of a piano range,

and that actually qualifies this
for the Guinness Book of Records

as the deepest pitch
known to man.

[deep pulsing]

Narrator: The extreme deep note
emanating from Perseus

is so far below
our hearing range

that it can only be
approximated.

It's been said
the galaxy cluster is playing

an awesomely low B-flat,

and scientists calculate
it'll be playing constantly

for 2 1/2 billion years.

Number nine's
"Deep Tone of Perseus"

drones on,
as the countdown advances.

A secret number one waits
at the end of the line,

but first...

[high-pitched squeal]

A strange, high-pitched squeal

hints at what comes in
at number eight...

sounds from space and their link
to signals from...

extraterrestrials.

Starting with the big bang,

we've been tracking the top ten

of the universe's
greatest hits—

The best of the alien sounds
from space.

Jumping to number eight
on the countdown,

we find a sudden wide variety
of different sounds—

Clicks, whines, and screeches—

All coming from strange stars

singing out from everywhere
we look in the galaxy.

They're cosmic squeals
with a rhythm section

in the "Beat of the Pulsars."

Every pulsar has
a different sound,

but they are all related,

because they're repeating blips,

beating out regular rhythms.

The different sounds come
from beats

sounding out
at different speeds.

[buzzing]

The first pulsars to be detected
emitted radio waves so regular

that astronomers first thought
they were signals from aliens.

But the truth about them was
quickly discovered.

- A pulsar is a rapidly rotating
neutron star.

That's a very dense star.

And it's got two beams of
radiation coming out the poles.

As those beams rotate
and intersect our line of sight,

we see a series of pulses.

[clicking]

We can think of pulsars being
associated with sound,

because they were
first discovered

with radio telescopes.

There was a series of beeps
that radio telescopes detected.

For a slowly rotating pulsar,

you might have a series of beats
like a metronome—

Beep, beep, beep, beep.

[metronomic clicking]

Or you might hear
a beep-beep, beep-beep,

beep-beep, beep-beep.

[rapid clicking]

[buzzing]

Now, for a rapidly
rotating pulsar,

the beeps blur together,
so you got...

[trilling tongue]
Like that.

[buzzing]

[high-pitched buzzing]

And for a very rapidly
rotating pulsar,

it's just a continuous sound

that registers like a note
in your ears.

[high-pitched buzzing]

Narrator: Pulsars form
from the collapse

of very massive stars

after they explode
as supernovas.

But how long
does it actually take

for a massive star to collapse?

That's what Sherman D.
of Tampa, Florida, wanted to...

when he texted
his question to us.

- Sherman, the visible effects
of a supernova can last

for months or years
or even centuries

if you're looking
at the supernova remnant—

The expanding gases.

But although
it may seem incredible,

the collapse of the core
of a massive star

can take just a second or two,

and that's what initiates
the supernova explosion.

Narrator: Our own Sun isn't
massive enough to go supernova,

but it is a giant ball
of hydrogen

330,000 times more massive
than the Earth

and burning by nuclear fusion.

So our home star
can hardly keep quiet,

as our next hit proves.

This hot combo chimes in at
number seven on the countdown.

Here it is,
the "Song of the Sun."

- The Sun makes sounds,

but they're not really
sunny sounds.

They're not happy sounds.

They're kind of low, ominous
roars that gurgle along.

[low humming]

The Sun makes sounds because
there are a bunch of gases

going up and down through
a process called convection.

So they're sending
pressure waves

through the ball of gas
that is the Sun,

and it kind of rings
like a bell.

[low humming]

Narrator: Unlike a bell,
the Sun rings

with 10 million different tones
at once.

We detect them
from the tiny bulges

from the pressure waves
on the Sun's surface.

Solar satellites measure
the height of the bulges

with exquisite accuracy.

Apart from sound,
they also produce science.

- So using these sounds from
the Sun that we can observe,

we can actually tell
very detailed things

about the interior structure
of our star.

For example, one of the amazing
things that we can tell

is when there's a sun spot group
on the other side of the star,

even before it comes
around the limb

and we're able to see it
with our optical telescopes.

Narrator: The Sun may be
the biggest source for sound

in the solar system.

But next in line is Jupiter.

So coming in at number six
in the top ten is a medley

of strange electronic
"Jazz from Jupiter."

[whistling static]

"Jazz from Jupiter" comes to us

courtesy of the two legendary
Voyager spacecraft,

now on their epic journey
to the edge of the solar system.

- The two Voyager spacecraft

are headed
for interstellar space.

They're on the very outer edges

of the bubble the Sun creates
around itself.

Today Voyager 1 is 118 times
as far from the Sun

as the Earth is,

almost four times as far
from the Sun as Neptune is.

Narrator: Project scientist
Ed Stone has been heading

the Voyager mission
since its two spacecraft

made their grand tour
of the outer planets

beginning in 1979.

On their approach to Jupiter,

the first thing
each one encountered

was the giant planet's
bow shock,

producing a wind-like sound
from the electronic data.

[wind rushing]

- There's a wind blowing
outward from the Sun

at about a million miles
per hour.

It is supersonic.

As that wind approaches contact
with a magnetic field

around, say, Jupiter,
it has to go subsonic.

There is a sonic shock
which forms

in front of the magnetic field
of Jupiter.

That's called the bow shock.

It's very much like
a sonic shock

in front
of a supersonic aircraft.

[wind rushing]

Narrator: More intriguing
than the bow shock

is the Jovian chorus,

sounding something like
the chorus of birds

chirping at dawn.

[high-pitched chirping]

Both it and the bow shock
come from radio waves

generated by
fast-moving charged particles

within the bubble
of Jupiter's magnetic field.

[wind rushing]

[high-pitched chirping]

Now, the scramble toward
the mysterious number one

in the top ten
swings to the moons of Jupiter

and the rings of Saturn,

where the noises
from electric loops,

glowing gases,
and streams of wind

vie for distinction
as the spookiest sounds

in the solar system.

[eerie buzzing]

The top ten countdown

in the alien sounds
of the universe

has reached Jupiter,

sending out its own brand
of space music.

But the next hit is no solo.

Jupiter has a backup group.

They're the Jovian moons
circling the giant planet.

And now they have
their own album.

It places at number five
in the top ten,

and the tune is called
"Moons Over Jupiter."

[electronic warbling]

The lead singer
is the moon Ganymede,

recorded by
the Galileo spacecraft,

arriving at Jupiter
in late 1995.

- The sounds that Galileo
sent back

from Jupiter's moon Ganymede—

By the way, the largest moon
in the solar system—

Are very intriguing.

They sound a little bit like
an alien fax.

[electronic warbling]

In fact, when I played
that sound clip

in my office yesterday,

people came around the corners
to see what was going on,

if I was receiving
some alien transmission.

[electronic warbling]

Narrator:
As with Voyager,

Galileo's sounds came
from ionized gas, or plasma.

Atoms in a plasma are split
apart into negative electrons

and positive atomic nuclei,

in other words,
charged particles.

Two slender antennas

on the spacecraft's
plasma wave instrument

picked up the radio waves

that the charged particles
produced

as they were set in motion
by a magnetic field.

[electronic warbling]

- These sounds that we hear
from Ganymede are the evidence

that Ganymede actually has
a magnetic field,

and you cannot find
that information

without using
the plasma-wave instrument,

as we did on Galileo.

[electronic warbling]

Narrator: A very sudden burst
of alien sound

came from another
of Jupiter's moons.

It happened when Galileo flew
over lo's north pole.

[static thundering]

- My favorite moon
in the solar system

is Jupiter's moon lo.

It looks a lot like a pizza.

This is the most
volcanically active moon

in the entire solar system,

10 or 100 times
more volcanically active

than the Earth.

It literally spews tons
of material

into space every second—

Sulfur and oxygen atoms.

These get ionized
in Jupiter's magnetic field

and actually connect back
to Jupiter,

to the north and south poles,
making a doughnut.

Narrator: The doughnut is called
the lo flux tube,

and the charged particles carry
a monster electric current

between Jupiter
and its volcanic moon.

As Galileo flew through it...

[static thundering]

The sound ended as abruptly
as it started.

[static continues]

[static stops]

With Jupiter and its moons
finishing their acts,

our countdown swings to Saturn,

smaller than Jupiter but right
up there in the top ten.

The ringed planet comes in
at number four on the list.

Listen up for
the "Surreal Sounds of Saturn."

[ghostly buzzing]

They come to us
from the Cassini spacecraft,

which has been delivering
mind-blowing pictures and data

since its arrival
at the ringed planet in 2004.

As on Voyager and Galileo,

Cassini's plasma wave
instrument is our proxy

for human ears in space.

[ghostly buzzing]

- The eerie and bizarre sounds

we hear from Cassini's radio
and plasma-wave instrument

make me think of Halloween.

[ghostly buzzing]

They're due to the aurora
on Saturn,

very similar to Earth's aurora.

[ghostly buzzing]

Your ears could never pick up
these frequencies,

but we move them into a range,
and when we do,

we were surprised to see
how eerie and scary

they actually were.

[ghostly buzzing]

Narrator:
The "Surreal Sounds of Saturn"

isn't the ringed planet's
only song on the countdown.

Turn it over, and we find
number three on the playlist:

"Saturn's Flip Side."

[wind blowing eerily]

Scientists call this hit
a crossover.

This crossover has nothing to do
with mixing musical styles

but describes radio waves

from Saturn's northern
and southern hemispheres,

as they actually crisscross
in frequency

over a period of time.

- We saw something really
strange in our radio data,

in our plasma-wave data—

A couple of crossing frequencies
that apparently suggested

that the northern
and southern hemispheres

were rotating
at different rates.

That's very unfamiliar to us
on a solid Earth,

where the Earth rotates
at one rate.

It actually turns out
we don't think Saturn's rotating

at different rates.

We think that high-altitude
zonal winds are tricking us

and making us think that
there's different rotation

in the northern
and southern hemisphere,

but it's probably not the case.

[electronic whirring]

Narrator: Similar waves,

following the lines of Saturn's
magnetic field,

revealed a surprise
about the ringed planet.

- One of the most bizarre things
that Cassini found

was apparently the Saturn day
was about six minutes longer

than it was back
in the days of Voyager,

mere decades earlier.

The determination of the length
of Saturn's day

is actually not possible
by watching the clouds rotate

around the planet.

We have to use
these radio emissions,

the sounds of space,

to see what the deep interior
is doing.

And that's where we found
this mystery.

Narrator: It's virtually
impossible to slow down a planet

the size of Saturn that much
in such a short time.

So scientists now realize
the radio emissions

probably don't give
an accurate picture.

And by sophisticated mapping
of Saturn's winds,

they now have a better take
on Saturn's day,

which happens to be 10 hours,
34 minutes, and 13 seconds long.

[electronic whirring]

Now we're closing in
on the surface of Titan,

Saturn's biggest moon,

as it swings
into the Alien Sounds Countdown.

Hit number two rings out
as "Totally Titan."

And it opens with
an otherworldly hiss

from an actual microphone
on the Huygens lander,

separated from Cassini

and parachuting through
Titan's methane atmosphere,

nearly a billion miles away
from Earth.

- If you're parachuting,
you're going to hear...

[imitates wind rushing]

That's exactly what we hear
in these Huygens sounds.

[wind rushing]

Narrator: The sound was
transmitted as the lander headed

toward Titan's surface in 2005.

- The acoustic sensor on Huygens
was essentially a microphone,

but it only sampled
every couple seconds.

It would take a little sound—
tiny, tiny sound bite

and then nothing and then
a tiny, tiny sound bite.

It wasn't planned
to turn that into sounds

that the public could hear.

[wind rushing]

Narrator: But unlike
the other sounds from Saturn,

these were not converted
from radio waves.

They began as true sound waves
in Titan's methane atmosphere,

and The Planetary Society
stepped in

to convert the staccato sampling
of the microphone

into something audible
to human ears.

- In the end, what you hear
is mostly wind noise

as the parachute's descending
through the atmosphere.

And then things get much,
much quieter on the surface.

It goes from...

[imitates wind rushing]

To suddenly being...

[imitates air hissing]

[wind rushing]

But what's really profound is,
we're hearing sounds

taken by
an actual acoustic sensor

from a billion miles away.

First time we've ever heard
sounds from another planet

or moon around another planet.

Narrator: But the rushing wind
wasn't the only sound

coming from Huygens.

As data streamed in
from the lander

on the way to Titan's surface,

white-knuckled engineers
in Mission Control

held their breath,

hoping the intrepid spacecraft
would make its landing safely.

The final chapter in the story

is told in
an incredible music video

guaranteed to keep you
on the edge of your seat.

We've been counting down

the top ten alien sounds
of the universe,

and we've almost reached
number one.

But first we're shifting
into high gear...

as number two runs
with an astronomical riff

from the Huygens space probe

visiting
Saturn's largest moon...

Titan.

It's the only alien sound that
comes with its own music video.

Look and listen.

Cut two on number two—
it's "Totally Titan."

- Here we have what's called
the bells and whistles movie

from Cassini-Huygens,

and it's showing the descent,

and it's a great example
of using sound

to convey all sorts
of different kinds of data.

[warbling and squealing]

Narrator:
Just as a Geiger counter

announces radioactivity
using audible clicks,

the instruments
on the Huygens lander

were given their own sounds

to register the measurements
they were taking.

[warbling and chiming]

- Those chimes you hear—
each one of those means

that an instrument
was taking a picture

or some other kind of data.

Different instruments are
a different chime.

We also are hearing a kind of
a hum in the background.

That's the signal strength
to the Cassini spacecraft.

We've got a ticking that occurs

that has to do with the spinning
and rotation of the spacecraft.

Every time it rotates once,
they have the tick.

Narrator:
Though it's just an assembly

of pure scientific information,

the video seems to preserve
what must have been

those last moments
of high tension...

when the scientists
in Mission Control wondered,

"Will the tiny spacecraft
land safely,

or will it crash?"

[warbling and squealing]

- So here we go,
and almost down...

and then...

and we're landed.

Narrator:
Mission accomplished...

with sound a billion miles away.

"Totally Titan"
has been a thrill

at number two on the countdown,

but now we spin the platter
on the mysterious number one...

[cosmic whistling]

A song that comes from a place
totally unlike anything else

in the universe
we've ever encountered.

While some remind us
of the strange signals

from Jupiter and Saturn,

there are also sounds
in this song

that are completely different
from anything we've measured

or detected anywhere else
in the cosmos...

because number one
on the countdown

has sounds alien
to the entire universe,

except for the place
where they originate.

Number one in the universe's
greatest hits

resounds with echoes
of a singular place.

"The Echoes of Earth."

- Here on Earth, we're used to
thinking of the alien sounds

as being everything that comes
from beyond our planet,

and that might be examples
of plasma waves

and pressure moving through
astrophysical media or objects.

But, really, if you think about
observing our Earth from afar,

the aliens are us.

And our sounds are unique,

because they come
from living organisms,

whether it be human language...

[indistinct chatter]

Or bird songs.

[bird trilling]

Narrator: An alien probe
exploring Earth space

would certainly pick up the
Jupiter- or Saturn-like sounds

of charged particles propelled
by Earth's magnetic field.

But our planet,
unlike the others,

also emits radio waves,

broadcast into the cosmos
by human beings.

[warbling and beeping]

[static whirring]

- Good evening, this is
Professor Reginald A. Fessenden,

speaking to you
from Brant Rock, Massachusetts.

Narrator: In 1906,
at Brant Rock, Massachusetts,

Reginald Fessenden made
the first radio broadcast

of speech and music.

Fessenden was the inventor
of AM radio,

transmitting his first signals
on Christmas Eve.

It was picked up by sailors
hundreds of miles out at sea

and has been traveling
through space ever since.

- Ever since the beginning
of radio,

we've really been broadcasting
out into space.

And we've been sending out
these signals,

in the hopes that somebody
will intercept them.

Of course,
space is a very large place,

and, therefore,
it's hard to know

who would have gotten them
and when,

but there they are on their way
out to who knows where.

- Hello from the children
of Planet Earth.

[woman speaking Japanese]

Narrator. Earthly sounds are
also traveling through space,

not by radio, but aboard the two
Voyager space probes...

on a slow but steady course
to the stars.

- Bonjour, tout le monde.

- One of the examples
of how important sound is

to us here on Earth is that
when we launched Voyager,

we actually included
a golden record

of sounds from our Earth.

And this was to represent
not only human sound

but also sounds
of the many creatures

that live here on Earth with us.

So it's really
a sound fingerprint

of life on our planet.

[dog barking]

Narrator:
As we take our own place

among the top ten hits
in our playlist,

we realize they only scratch
the surface

of the cosmic voices
calling out in the void.

From creation
to the present day,

space has produced
a broad catalog of sounds

to accompany
its brilliant sights.

As strange as
these many sounds seem,

we've learned that they carry
important messages,

helping to solve mysteries
of nature

and our ultimate understanding
of the universe.