So, THAT’s Pluto!
And it’s not the cratered, ancient, barren rock of blandness I thought it was going to
be...
Hi there!
I’m Ian O’Neill, space producer for Discovery News, and today I’m at Youtube Spaces in
Los Angeles to talk a little about NASA’s New Horizons mission to Pluto and some Kuiper
belt awesomeness.
As you may have heard, New Horizons punched through the Plutonian system on July 14, carrying
out the mother of all flyby photo ops.
During its brief encounter, after flying through the solar system for nearly a decade to get
there, the probe carried out thousands of observations of the dwarf planet and its wonderfully
diverse moons.
The probe is now hurtling through the Kuiper belt, nearly 17 million miles from Pluto (at
time of filming!)
Although the flyby was over in a matter of minutes, huge quantities of data is now stored
inside the spacecraft’s computer memory and it’s going to take over a year for the
mission to beam all that information back to Earth.
But already we are seeing some rather dreamy high-resolution views of a surprisingly dynamic
and -- frankly -- amazing little world.
Now before we get into WHAT Pluto really is, let’s look back at what we thought it would
look like before we got this very privileged closeup view.
Pluto lives in the Kuiper belt, a frozen hinterland in the outer solar system.
In recent years, dozens and dozens of other small objects have been discovered out there,
but only a small number have, so far, been categorized as dwarf planets.
In 2005, Kuiper belt astronomer Mike Brown discovered the small world Eris.
That discovery spurred on the debate of what a planet actually IS, resulting in the controversial
decision by the IAU to reclassify Pluto as a dwarf planet in 2006.
As it turns out, with the help of New Horizons, Pluto’s size has been precisely measured,
and, although it may not be technically a planet, it is the KING of dwarf planets, beating
Eris’ width by 20 or so miles.
The question of whether or not Pluto is a planet now seems rather academic as New Horizons
has revealed a world that is UNLIKE anything else in our solar system.
It doesn’t even resemble Neptune’s moon Triton, which came as a surprise to astronomers.
The biggest surprise for me -- and many planetary scientists -- is how young Pluto’s surface
is.
Living in the Kuiper belt, one would expect Pluto to have a craggy, cratered and ancient
surface, not so dissimilar to its inner solar system dwarf planet cousin, Ceres.
The Kuiper belt is supposed to be a historic record frozen in time when the solar system
was violently forming and smashing asteroids and planets together.
Mike Brown refers to the Kuiper belt as the “blood spatter” of the solar system, where
the forensic evidence of the solar system’s violent formation billions of years ago can
be found frozen in time.
But Pluto’s surface appears fresh, only a few tens of millions of years old, so this
evidence has been mostly eroded away by surprisingly dynamic processes.
Amazingly, through high-res images of Pluto, we can see active ICE FLOWS AROUND MOUNTAINS,
much like the glaciers on Earth.
Where the energy comes from to support these flows is, for the moment, anyone’s guess.
Then there’s Pluto’s heart.
I mean really, a HEART emoji.
Pluto is just messing with us now.
The heart, named “Tombaugh Regio” after Pluto’s 1930 discoverer Clyde Tombaugh,
is a wonderfully exotic region containing ice sheets, mountain ranges and active geological
features.
The entire surface is covered with a rich assortment of minerals and chemicals that
will take scientists years to understand where they came from and how they fit with the early
formation of our solar system.
And then there’s Pluto’s atmosphere!
Although we’ve known for years that the dwarf planet possesses a thin atmosphere,
New Horizons was able to look back THROUGH these atmospheric gases after flyby, seeing
a beautiful solar eclipse and took critical measurements of the atmospheric chemicals.
New Horizons has found that Pluto’s atmosphere is a complex hydrocarbon factory, where methane
gets broken down by UV light from the sun and more complex hydrocarbon compounds create
an ice particle haze at lower altitudes.
THOSE compounds then undergo chemical alterations freezing onto Pluto’s surface as tholins.
And tholins are exciting as they are prebiotic chemicals that all life as we know it is based
on.
Even though we are in early stages of understanding the New Horizons observations, we’re already
seeing an incredibly complex Pluto that seems to have surpassed everyone’s wildest fantasies
as to how exotic this place really is.
And I haven’t even discussed Pluto’s moons, including Charon, which could be considered
to be Pluto’s binary partner -- that will have to wait for a future video.
So does it really matter whether or not Pluto is classified as a planet?
In my view, no.
I actually think Pluto is showing us just how diverse and complex planetary bodies can
be and, perhaps, our notion as to what constitutes a planet is woefully outdated.