Pluto, you know, it's the little guy in the solar system.
Right.
The one that got demoted from planet status.
Yeah.
But there's so much more to it than most people realize.
And that's what we're gonna do today.
We're gonna do a deep dive into this
fascinating world of Pluto.
It's a really interesting story.
It is.
From its discovery to its surprising features,
what those features might tell us about life beyond Earth.
Welcome to Cosmos in a Pod, Space and Astronomy series.
It's a story that actually starts with a hunch, you know.
An astronomer named Percival Lowell,
back in the early 1900s,
had this idea that there was another planet out there.
This hidden planet X, he called it.
And he thought it was tugging at the orbits
of Uranus and Neptune.
Oh wow, so he was way ahead of his time.
So did he find it?
He looked and looked,
but he never actually found planet X.
Oh man, that's gotta be disappointing.
So did anyone ever pick up where he left off?
Well yeah, fast forward a few decades to 1930,
and we meet Clyde Tombaugh at the Lowell Observatory.
And get this, he was using like old school methods.
No fancy computers, no high tech telescopes,
just photographic plates and a ton of patients.
Can you imagine hours and hours comparing these images,
trying to find any little dot that moved?
Wow, that sounds incredibly tedious.
I can't even imagine.
Oh, it was.
But after almost a year of this meticulous work,
he found it, just this tiny speck of light
that shifted against the background stars.
Pluto had been found.
Wow, that must have been a huge moment for astronomy.
Did they realize back then how small Pluto actually was?
Not at all, they thought it might even be bigger
than our moon, which is part of the reason
why it got that planet label in the first place.
But as our technology improved,
astronomers started realizing that Pluto
was actually much, much smaller.
So how small are we talking exactly?
Like, give us a sense of scale.
Think about it this way.
Pluto's diameter is smaller than the width
of the United States.
Whoa, that's crazy small.
I guess I can see why that would raise some questions
about its planet status.
But was that the only reason it got demoted?
That and the discovery of the Kuiper Belt in the 1990s,
it really changed the game.
Okay, hold on, what's the Kuiper Belt?
Well, it's like this huge zone out past Neptune,
just chock full of icy objects,
like a cosmic deep freeze out there.
And surprise, Pluto turned out to be just one
of many objects hanging out in this icy neighborhood.
And some of them were pretty close to Pluto's size.
So basically, Pluto wasn't so unique after all.
It had a lot of company out there.
So what happened then?
Well, that brings us to that infamous year, 2006.
The year Pluto got reclassified.
The International Astronomical Union, the IAU,
decided it was time to have a serious conversation
about what a planet actually is.
Right, because clearly there was some confusion.
So what criteria did they come up with?
Okay, so they laid down three main rules.
Got it.
First, a planet has to orbit the sun.
Okay, makes sense.
Second, it needs enough gravity
to pull itself into like a round shape.
Right, gotta be spherical.
What's the third rule?
This is the one where Pluto got tripped up.
The third rule is that a planet has to clear
its neighborhood of other objects,
meaning it has to be the dominant gravitational force
in its orbit.
Ah, so Pluto couldn't keep its orbital space tidy enough.
That's what did it in.
Pretty much.
It shares its space with all those other
Kuiper belt objects.
So the IAU created a new category.
They called it dwarf planet,
and that's where Pluto ended up.
But honestly, being reclassified
didn't make it any less interesting.
Oh, absolutely.
In fact, I think it made it even more intriguing.
So what makes Pluto so fascinating?
Well, first of all, imagine this.
A surface made of nitrogen ice,
like vast stretches of it.
And then mixed in, you have these patches of methane
and carbon monoxide ice.
Wow, that sounds so alien.
So different from anything here on Earth.
Totally.
And that's not all.
Pluto even has this like super thin atmosphere
that actually expands and contracts as it orbits the sun,
almost like it's breathing.
No way.
That is seriously cool.
So what else makes Pluto stand out?
Remember those incredible images we got
from the New Horizons mission back in 2015?
Of course.
Who could forget those?
They were stunning.
One of the most iconic ones was that huge,
heart-shaped region they found.
Officially, it's called Tombow Regio,
named after its discoverer.
It's this gigantic plane of nitrogen ice.
It really captured everyone's imagination.
Yeah, that picture was everywhere.
It's amazing how we went from like a blurry dot
to those detailed pictures.
What else did New Horizons teach us about Pluto?
It was a game changer for sure.
For one, it showed us that Pluto
is not just a dead, frozen world.
There's evidence of cryovolcanism.
Hold on, cryovolcanism?
What in the world is that?
Imagine volcanoes, but instead of spewing out molten rock,
they erupt with icy materials like water, ammonia,
or methane.
So there's actually geological activity happening
beneath Pluto's surface.
Does that mean there could be?
A subsurface ocean.
Scientists think it's possible, and that's a big deal.
Because liquid water, even as it's deep underground,
could mean that there's a chance for life,
even on a dwarf planet billions of miles away.
Exactly.
It's one of the most exciting things about Pluto.
Wow, you've totally blown my mind here.
An ocean on Pluto.
It changes everything.
So what else makes this place so unique?
Well, Pluto's not alone out there.
It's got a whole entourage, a system of five moons.
Five moons.
Wow, Pluto might be small, but it sounds like it's
got a lot going on.
Oh, it definitely does.
And its relationship with its largest moon, Charon,
is particularly interesting.
What's so special about Charon?
Most moons, they orbit their planets pretty predictably.
Charon is so large, almost half the size of Pluto itself,
that they actually orbit a common center of gravity.
And get this, that center of gravity is outside of Pluto.
Wait, seriously?
So they're more like a pair of dancers
than a planet and its moon?
Exactly.
It's called a binary system.
And it's a pretty unique dance these two icy worlds
do together.
This is incredible.
Pluto just keeps getting more and more fascinating.
From a heart-shaped nitrogen glacier to a possible ocean,
a constantly changing atmosphere,
and this unique dance with Charon.
And to think, it was all just a blurry dot
before New Horizons.
It really shows you the power of space exploration, right?
Absolutely.
It completely transforms how we see these distant worlds
and how we understand them.
For sure.
Before we move on, I have to ask about the whole demotion
thing.
It seemed like the whole world was upset about it.
Like, Pluto was everyone's favorite underdog.
It definitely captured the public's imagination,
didn't it?
There were people who felt like Pluto
had been unfairly demoted.
They started campaigns like, Pluto is a planet.
Bring back our ninth planet, and things like that.
It was almost like people felt personally offended
on Pluto's behalf.
Meh.
Like, how dare you demote our little buddy?
Well, I think there's a sentimental attachment there,
right?
It was this tiny world on the edge of our solar system.
People grew up with it being a planet.
So it was hard to let go.
I get it.
But what's the scientific take on all this?
Was the demotion justified?
From a purely scientific point of view,
the reclassification was needed.
It was all about consistency and reflecting what
we know about the solar system.
It helped us to see that there's a whole spectrum of objects
out there, from giant planets to these dwarf planets,
asteroids, comets.
And they each have their own story to tell.
So it was less about Pluto losing its status
and more about gaining a new understanding of the solar
system as a whole.
Exactly.
It's about recognizing the incredible variety
that's out there.
I like that.
It's not about demotion.
It's about evolution, about refining our understanding
as we learn more.
Absolutely.
And even though Pluto is not considered a planet anymore,
it's still an amazing and complex world.
Right.
And in a way, losing its planet status
gave it something maybe even more valuable,
a whole new level of mystery and intrigue.
Definitely.
So what are some of the biggest mysteries
that scientists are still trying to solve about Pluto?
Well, one of the big ones is that ocean we talked about.
We still don't know for sure if it's there.
And if it is, what's it like?
Could there be some form of life down there?
Those are big questions.
And what about its atmosphere?
You mentioned how it expands and contracts.
What happens to it over Pluto's 248-year orbit around the sun?
Yeah, that's another area where we need more data.
Pluto's atmosphere is constantly changing.
It's a dynamic system.
And we're still trying to understand the nuances
of how it all works.
So many questions still to be answered.
It really seems like Pluto's demotion didn't diminish
its importance at all.
If anything, it highlighted how important it is as a window
into this icy frontier of our solar system.
I couldn't agree more.
Pluto's story is a reminder that our solar system
is full of surprises.
And we still have so much more to learn.
It is.
Yeah.
And I have a feeling you've got even more fascinating things
to tell us about Pluto.
Oh, absolutely.
So let's take a quick break.
And then we'll be right back to delve even deeper
into this captivating dwarf planet.
It's incredible when you think about it.
Pluto's story is a real testament to human curiosity
and this desire we have to explore the unknown.
It all started with this basic question, right?
Is there another planet out there hiding in the darkness?
And that question led to this amazing discovery,
this whole new region of our solar system
that we call the Kuiper Belt.
It's a huge shift in perspective, isn't it?
We went from seeing Pluto as this lone oddball, way out
there on its own, to realizing it's
part of this huge family of icy objects.
Yeah.
So does that mean, like, are there
other Pluto-like worlds in the Kuiper Belt
just waiting for us to find them?
Oh, absolutely.
The Kuiper Belt is vast.
It's like this giant cosmic treasure chest.
And we've barely scratched the surface.
Who knows what other icy worlds are hiding out there,
each one with its own unique story waiting to be told.
Maybe we'll even find some that, like,
make us rethink our definition of a planet altogether.
Wow.
The possibilities are endless.
It's mind blowing.
So thinking about Pluto and its neighbors in the Kuiper Belt,
what can they teach us about the early solar system?
I mean, we're talking about objects that were formed
billions of years ago.
That's one of the most exciting things
about studying the Kuiper Belt.
These objects are like time capsules.
They hold clues about the conditions
that existed when our solar system was just a baby.
By studying their composition, what they're made of,
their orbits, how they interact with each other,
we can actually piece together the events that led
to the solar system we see today.
So in a way, Pluto's demotion actually
led to something even bigger.
It's not just about planets anymore.
It's about this much grander story,
the evolution of our entire solar system,
and understanding the diversity of objects within it.
Exactly.
Pluto's story is a perfect example of how science works.
Sometimes what seems like a step back
can actually open up a whole new world of understanding.
And who knows, maybe someday with new discoveries
and new ways of thinking, Pluto might even
earn its way back into the planet club.
Maybe.
But even if it doesn't, Pluto will always hold
a special place in our hearts.
It's this little world that challenged our assumptions
and pushed us to look beyond what we thought we knew.
I agree.
It's a great story.
And it reminds us that the universe is full of surprises.
We just have to keep exploring.
Speaking of surprises, I'm curious,
when you look at Pluto and everything
we've learned about it, it makes you
realize just how much our understanding of space
has changed in such a short amount of time.
It really is amazing, isn't it?
It's been an incredible journey.
Just a few decades ago, Pluto was
nothing but a blurry dot, a symbol of the unknown.
And now, thanks to missions like New Horizons,
we see it as this complex, dynamic world,
a place with its own unique beauty
and incredible scientific value.
And that's what makes astronomy so fascinating,
this drive to explore, to push the boundaries
of our knowledge to uncover the secrets of the universe.
It's not just about finding answers.
It's about asking the right questions,
the questions that lead us to even greater discoveries.
Couldn't have said it better myself.
It's a never-ending quest.
And I think Pluto's story is the perfect embodiment
of that spirit.
It's a reminder that there's always more to learn,
more to explore.
The universe is full of surprises,
just waiting to be uncovered.
Well said.
I think we've given Pluto the attention it deserves,
wouldn't you say?
We've covered its discovery, its demotion, its unique features,
those fascinating moons, the groundbreaking New Horizons
mission.
We've even touched on some of the bigger questions
that Pluto raises about the nature of our solar system
and the constantly evolving field of astronomy.
It's been a fantastic deep dive.
I think we've covered just about everything.
And Pluto, even with its dwarf planet status,
has really solidified its place as a cosmic celebrity,
a world that continues to inspire us and remind us
that there's always more to learn, always more to explore.
And if you're as captivated by Pluto
and the mysteries of the universe as we are, be sure to.
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OK, folks, thanks for joining us on this incredible journey
to Pluto, to Pluto and beyond.
Until next time.
Keep looking up.
And keep exploring the cosmos.