Picture this, it's 1977, discos everywhere,
and humanity is about to launch something incredible.
Two spacecraft, Voyager 1 and 2.
Destined to become like our farthest reaching emissaries.
It really is a story of audacious dreams
and groundbreaking discoveries.
And the message in a bottle.
Yeah, tossed into the cosmic sea.
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Yes.
OK, so you're probably thinking two spacecraft
launched in the 70s.
Right.
What's the big deal?
Well, the Voyager probes weren't just any mission.
Right.
They were initially conceived as part of this grand plan
called the Planetary Grand Tour.
Imagine a celestial alignment so rare.
It only happens once every 175 years.
Wow.
All the outer planets lining up perfectly.
Allowing a spacecraft to slingshot from one to the next.
Using their gravity.
Exactly.
Was it like a cosmic pinball game?
Kind of, yeah.
That sounds incredibly efficient.
It was a visionary concept.
But ultimately, budget constraints
force NASA to scale back.
Instead of one spacecraft visiting all four gas giants,
they opted for two probes with a more focused mission.
OK.
Voyager 1 and 2.
Right.
But even with the revised plan, the Voyagers
were destined to rewrite our understanding
of the solar system.
And they did, right?
Oh, yeah.
They went above and beyond.
Yeah.
They ended up exceeding those initial expectations
by quite a bit.
For sure.
So where did they even begin?
They started with a bang.
Oh, rather.
A swirling storm.
OK.
Voyager 1 gave us our first close-up look
at Jupiter's Great Red Spot.
We knew it was a giant storm.
Yeah.
But the Voyager images revealed its true scale.
OK.
Imagine a storm so large it could swallow the entire Earth.
That's wow.
OK.
I'm officially starting to grasp the scale of this.
It's massive.
What else did Voyager 1 uncover at Jupiter?
Well.
Didn't it make some pretty groundbreaking discoveries
on one of its moons, too?
It did.
Yeah?
Voyager 1 discovered active volcanoes erupting
on Jupiter's moon, Io.
Great.
Before this, we'd never seen volcanic activity.
Anywhere.
Anywhere beyond Earth.
Wow.
Was a pivotal moment, making us rethink
the possibilities of what could exist on these seemingly
alien worlds.
Volcanoes erupting on a moon of Jupiter.
I know.
That must have sent shockwaves to the scientific community.
Sure.
It sounds like the Voyager probes
are shattering our assumptions from the very beginning.
Absolutely.
And they weren't done yet.
What else?
Voyager 1 also captured stunning close-up images.
Saturn's rings.
Oh, wow.
Revealing their intricate structure
and the tiny moonlets embedded within them.
Cool.
These images weren't just pretty pictures.
They gave us valuable data about the formation and evolution
of planetary rings.
So Voyager 1 was making history at Jupiter and Saturn.
What was Voyager 2 up to during all this?
Voyager 2 was on its own remarkable journey.
OK.
While Voyager 1 was capturing those iconic images
of Jupiter and Saturn, Voyager 2 was continuing outward,
eventually becoming the only spacecraft
to visit Uranus and Neptune.
Hold on.
So Voyager 2 got to see two of the most mysterious planets
in our solar system.
That's right.
That's amazing.
The ice giants.
What did it find at those icy giants?
Well, they're so far away, we barely
know anything about them.
That's precisely what made Voyager 2's mission
so remarkable.
Yeah.
At Uranus, it discovered a bizarre sideways magnetic
field, indicating that the planet had been tilted
on its side by a colossal impact in its distant past.
A planet tilted on its side.
That just sounds chaotic.
It's wild.
Like something out of a sci-fi movie.
Right.
OK, and at Neptune.
At Neptune, Voyager 2 witnessed incredibly fast winds.
How fast?
The fastest in the solar system.
Wow.
Whipping around the planet at speeds.
Faster than.
That would make a hurricane look like a gentle breeze.
Wow.
OK, so these planets are definitely not
the calm blue giants we see in those artist renditions.
Nope.
So both probes visited the gas giants.
But didn't they also have another, perhaps even more
important mission?
They did.
They carried a message for anyone or anything
they might encounter in their interstellar travels.
You're talking about the golden records, right?
Yes.
I remember reading about them.
It's such a fascinating idea.
Yeah, attaching a message to a spacecraft,
hoping it might one day be found by an alien civilization.
Exactly.
It's an incredibly ambitious and hopeful project.
It is.
We essentially put a message in a bottle,
attached it to both Voyager probes,
and flung it out into the cosmos.
That's a great way to put it.
It's almost like a time capsule of humanity
hurtling through interstellar space.
I like that.
So what's on these golden records?
What kind of message did we decide to send to the stars?
We wanted to show off the best of humanity.
OK.
Imagine this.
An alien civilization stumbles upon this spacecraft
billions of years from now.
The golden record plays greetings.
In how many languages?
In 55 different languages.
They hear the sounds of our planet.
Whales.
Singing thunder.
A mother's kiss.
A mother's kiss to her child.
OK.
They see images of Earth's diverse landscapes,
the incredible life that thrives here.
OK.
And then they hear music.
Like what kind of music?
From Baco to Chuck Berry.
Wow, what a range.
A testament to our creativity and artistic expression.
It's a beautiful and almost poetic thought, isn't it?
It is.
A snapshot of humanity frozen in time.
Yeah.
Traveling through the galaxy for eons.
I love it.
Did anyone object to the idea of including human sounds
and images on the record?
Actually, there was a bit of debate at the time.
Really?
Some scientists argued that revealing our location
might be risky.
What if we attract the attention of a hostile alien civilization?
Exactly.
That's a good point.
Do they suggest any alternatives?
Some suggested sending a purely mathematical message,
something that could convey information
about our scientific understanding,
but wouldn't reveal anything about our culture or location.
Interesting.
So what happened?
How did they ultimately decide what
to put on the golden record?
Well, in the end, the desire to share our story
outweighed the potential risks.
Yeah.
It was a bold decision, a testament to our optimism
and our belief that there might be other intelligent life out
there, curious enough to find and understand our message.
It's a fascinating ethical dilemma.
It is.
One that we might face more often as we continue
to explore space.
Right.
But for now, we know those golden records are out there.
Yeah.
Hurdling through the void, carrying
a piece of humanity with them.
It's amazing.
So what happened after the Voyager probes finished
their planetary encounters?
That's where things get even more interesting.
OK.
Buckle up, because we're about to delve
into the realm of interstellar space.
All right, let's go.
After their grand tour of the gas giants,
the Voyager probes weren't content to just hang around.
Right.
They embarked on a new phase of their journey,
one that would take them farther than any human-made object
had gone before.
You just zipped through it.
Interstellar space, it sounds so vast and mysterious.
It is.
What exactly is it?
Right.
What makes it different from, say,
the space between planets?
Well, you're right.
It is incredibly vast and mysterious.
Imagine this.
You have our solar system with the sun at the center.
OK.
All the planets orbiting around it,
that's interplanetary space, where the sun's influence
reigns supreme.
Right.
But beyond the planets extending far, far outwards
is a region where the sun's magnetic field and solar wind
weaken, and the environment becomes
dominated by particles and radiation from other stars.
OK.
That's interstellar space.
So it's like leaving the sun's protective bubble.
Exactly.
And venturing out into the wild, unknown territory
between solar system.
It is.
And it's a journey that takes a long, long time.
In fact, it took Voyager 1 over 35 years after its launch
to officially cross that boundary
and enter interstellar space.
35 years.
That's longer than I've been alive.
I know.
It's incredible.
To think that this little spacecraft launched back
when disco was still cool is out there right now exploring
the space between stars.
Yeah.
It's mind blowing.
What was it like when Voyager 1 finally
reached interstellar space?
It was a historic moment, a testament
to human ingenuity and our enduring spirit of exploration.
Yeah.
Scientists eagerly awaited data from Voyager 1's instruments,
hoping to get a glimpse into this uncharted territory.
What did they find?
Well, one of the first things they noticed
was a change in the density of plasma.
OK.
That soup of charged particles that permeate space.
Right.
The plasma in interstellar space is much denser
than the plasma found within our solar system.
OK.
It's like moving from a thin, dry atmosphere
to a thicker, more humid one.
Interesting.
So even the very fabric of space is different out there.
It is.
What else did they learn?
Voyager 1's instruments also detected a dramatic drop
in the number of charged particles coming from the sun.
OK.
This was further confirmation that the probe had indeed
left the heliosphere.
That protective bubble.
Yeah, that protective bubble surrounding our solar system.
Created by the sun's solar wind.
Right.
So it's really like Voyager 1 has left home.
It has.
And is now venturing out into the wider galactic
neighborhood.
Precisely.
And its journey is far from over.
Where's it going?
Voyager 1 is still speeding away from us
at about 38,000 miles per hour.
Wow.
It's on a trajectory that will take it within 1.6 light years
of a star called Gliese 445 in about 40,000 years.
40,000 years?
That's an incredibly long time.
I can't even imagine what Earth will be like then,
let alone what kind of technology we might have by then.
It's mind boggling, isn't it?
Yeah.
But here's something even more fascinating.
Voyager 1 won't actually reach the true edge
of our solar system for another 30,000 years.
After that.
After that close encounter with Gliese 445.
Hold on.
So there's even more to our solar system
than we typically think about.
There is.
We learned about all the planets in grade school.
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.
Right.
And of course, Pluto, even though it's
been demoted to a dwarf planet.
What else is out there?
You're about to enter a region called the Oort Cloud.
The Oort Cloud.
Picture this, a vast spherical cloud
of icy bodies trillions of miles outward from the sun.
Wow.
It's like a giant cosmic shell enveloping
our entire solar system.
So Voyager 1 is going to spend tens of thousands of years
just traveling through this Oort Cloud.
It is.
What will it encounter there?
The Oort Cloud is thought to be the source of long period
comets.
OK.
Those icy wanderers that take hundreds or even thousands
of years to orbit the sun.
Right.
While it's unlikely that Voyager 1
will have a close encounter with any of these comets,
it will be measuring the density and distribution
of particles in this mysterious region,
giving us valuable data about the outer reaches
of our solar system.
That's incredible.
So even after all these years, Voyager 1
is still sending back valuable information,
helping us understand the universe around us.
It truly is.
And it's not alone out there.
Right.
Voyager 2.
Remember Voyager 2?
Of course, it's the one that visited Uranus and Neptune,
right?
Is it also headed out of the solar system?
It is.
Voyager 2 is on a slightly different trajectory
than Voyager 1.
It's headed towards a star called Ross 248,
which it will pass within 1.7 light years in about 40,000
years.
Wow.
After that, it's expected to cruise by Sirius, the brightest
star in our night sky, in roughly 296,000 years.
Wow.
So both Voyager probes are on these incredibly long journeys.
They are.
Destined to wander the galaxy for eons,
it makes you wonder, what are the chances
that either of them will ever actually be
found by an alien civilization?
That's the million dollar question, isn't it?
The galaxy is vast.
Yeah.
And the chances of an alien civilization
stumbling upon a tiny, silent spacecraft
are, well, astronomically small.
But it's not impossible, right?
Exactly.
And that's what makes the Voyager mission so compelling.
It's a testament to human ingenuity.
And our insatiable curiosity about the universe,
we've sent these emissaries out into the cosmos,
carrying a message of who we are,
even if they are never found it today.
It's still a profound statement about our place
in the universe.
It's like throwing a message in a bottle into the ocean.
You never know where it might end up.
Right.
But there's always a chance, however slim,
that it might reach someone somewhere.
A beautiful analogy.
But the Voyager probes weren't the only spacecraft
to set off on a journey beyond our solar system.
Right.
Remember New Horizons?
Of course, New Horizons was the mission
that gave us those incredible close-up images of Pluto
in 2015.
That's right.
And after its Pluto encounter, New Horizons
continued on a path that will eventually take it out
of our solar system as well.
So we actually have three spacecraft,
Voyager 1, Voyager 2, and New Horizons, all heading out
into interstellar space.
We do.
That's amazing what a legacy we're leaving out there.
It really speaks to our drive to explore, doesn't it?
Yeah.
But what's even more interesting is
that New Horizons carries its own unique message
from humanity.
Well, this sounds intriguing.
What kind of message do we send with New Horizons?
Well, it's not a golden record like on the Voyagers.
OK.
Instead, New Horizons carries a small container
of the ashes of Clyde Tombo.
Of Clyde Tombo?
The astronomer who discovered Pluto back in 1930.
Wow.
Talk about a cosmic send-off.
A part of the man who discovered Pluto
is now on a journey to the stars.
It's a poetic gesture, isn't it?
It speaks to that deep connection
we feel to the cosmos we explore, we discover,
and in a way, we become part of the universe we're studying.
So these three emissaries, each carrying a piece of humanity,
are out there in the vastness of space.
It's incredible to think about.
It's like planting seeds on the cosmic wind
with the potential to take root in ways we can't even imagine.
It's a beautiful way to think about it.
And while the Voyagers are nearing
the end of their operational lives,
New Horizons still has a lot of exploring left to do.
It's currently studying the Kuiper Belt, a region
beyond Neptune filled with icy objects left over
from the formation of our solar system.
So while the Voyagers are saying goodbye,
New Horizons is just getting started
on a new chapter of exploration.
It is.
It's like a relay race.
Yeah.
Isn't it a quest to understand our place in the cosmos passed
down through generations?
And speaking of generations, there's
another fascinating aspect to the Voyager mission
that's worth exploring.
It's a testament to the human spirit of collaboration
and long-term thinking.
OK, tell me more.
Well, think about it.
The Voyager probes were launched in 1977.
Yeah, way back when.
The scientists and engineers who designed and built them
knew they would never live to see the probes reach
interstellar space.
Right, so they were creating something
that would outlive them.
They were.
A legacy project for future generations
to inherit and learn from.
Exactly.
They were planting a tree whose shade they would never enjoy.
It was an incredible act of faith in the future.
A belief that the quest for knowledge
is worth pursuing, even if the rewards
lie beyond our own lifetimes.
It's humbling to think about the dedication and foresight
of those who came before us who paved the way for discoveries
they would never witness themselves.
It makes you wonder, what are we doing today
that will inspire and benefit generations to come?
What seeds of knowledge are we planting?
That's a question worth pondering.
But before we get too philosophical,
let's shift our focus back to the here and now.
There's one more fascinating story to tell
about the Voyager mission.
OK, lead the way.
What other stories are hiding in the vast data set collected
by these incredible probes?
OK, I'm ready for that last Voyager story you mentioned.
What is it?
Remember how we talked about the heliosphere,
that protective bubble created by the sun's solar wind?
Yeah, it's like our solar system's personal force field,
shielding us from harmful radiation
from interstellar space, right?
Exactly.
And as the Voyager probes journeyed outward,
they were actually able to study the heliosphere in ways
we could never do from Earth.
So they became probes not just of the planets,
but of the very fabric of our solar system's protective
bubble.
That's incredible.
What do they find out there at the edge of the sun's influence?
Well, one of the most surprising discoveries
was that the heliosphere isn't a perfect sphere,
as we once thought.
It's more like a teardrop shape, constantly being pushed
and sculpted by the pressure of interstellar gas
and magnetic fields.
So it's dynamic, always changing,
as it interacts with the interstellar environment.
Yeah.
That makes sense.
It's not like there's a hard line where the sun's influence
just stops.
You got it.
And the Voyagers were able to measure those changes,
providing us with crucial data about how our solar system
interacts with the galaxy.
It's like they were taking the pulse of our solar system's
protective shield.
What an amazing thought.
Those tiny probes giving us insight
into processes happening on scales
we can barely comprehend.
And here's where it gets really interesting.
The data from the Voyagers has helped scientists create
better models of the heliosphere, which in turn
has improved our understanding of space weather here on Earth.
So these distant probes, billions of miles away,
are actually helping us understand things
that affect our own planet.
You bet space weather refers to the conditions in space
that can impact Earth.
Things like solar flares, those bursts of intense energy
from the sun, and coronal mass ejections,
which are like giant bubbles of charged particles
that the sun blasts into space.
I remember reading about how these solar storms can disrupt
satellites, power grids, and even radio communications.
They can cause all sorts of havoc.
Absolutely.
And by studying the heliosphere and how
it interacts with the interstellar medium,
we can better predict and prepare for these events.
The data from the Voyagers, along with data
from other spacecraft, is helping
us paint a more complete picture of how space weather works,
allowing us to protect our technology and infrastructure
here on Earth.
So in a way, the Voyagers are still protecting us,
even from billions of miles away.
It's like they're giving back to the planet that launched them
on this epic journey.
That's a beautiful way to put it.
And it really highlights this interconnectedness
of everything in the universe, doesn't it?
What happens out there in interstellar space
can have real impacts right here on Earth.
It makes you realize that we're not just
inhabitants of this planet.
We're citizens of the cosmos.
What happens out there affects us,
just as what we do here can affect the universe around us.
A profound thought and a fitting reminder
as we conclude our deep dive into the Voyager mission.
I feel like we've been on an incredible journey
from the planets to the heliosphere and beyond.
The Voyagers have shown us the incredible beauty
and vastness of the universe, haven't they?
They certainly have.
And they've left us with a legacy of exploration
and discovery that will continue to inspire generations to come.
It's inspiring, to say the least.
If you're ever feeling small or insignificant,
just remember those two little probes out there,
hurtling through the vastness of space,
carrying a message from humanity to the stars.
What a legacy.
And remember, if you want to learn more
about the Voyager mission, there's a wealth of information
available online.
You can find images, videos, even the sounds
from the golden record on NASA's website.
It's definitely worth checking out.
It is.
And before we wrap up, don't forget to follow and subscribe
to Cosmos in a Pod and our YouTube channel
for more explorations of the cosmos.
We'll be back soon with another deep dive
into the mysteries of the universe.
Until then, keep looking up, keep exploring,
and keep wondering.