Of all the Earth-Moon-like systems in all the solar system, Pluto might not come to
mind.
But maybe it should.
Hey guys, Amy on DNews today taking you all the way to Pluto!
Well, not literally…
We’re all pretty familiar with Pluto.
If you're around my age, Pluto was very much a planet in your grade school science books.
But then in 2006 it was reclassified as a dwarf planet and a lot of people mourned the
loss.
But Pluto’s still out there, and the New Horizons mission is a little over a month
from its closest encounter with the distant body.
But we’re not just going to Pluto for the sake of understanding the little planet-turned-dwarf-planet,
though of course that’s a scientifically important goal.
An up close study of Pluto might help us understand our own planet a little more.
So first off, Pluto isn’t just a little ball of ice somewhere between 680 and 720
miles in diameter orbiting an average of 3.7 billion miles from the Sun.
It’s a planet with an atmosphere.
Astronomers first found it in 1988 when Pluto passed in front of a star.
The starlight flickered before being completely obscured by the planet, offering solid evidence
of a gaseous medium surrounding the body.
Further observations revealed that this atmosphere is composed predominantly of nitrogen.
That’s pretty uncommon.
There are only three other bodies in the solar system that we know have nitrogen-rich atmospheres:
Saturn’s moon Titan, Neptune’s moon Triton, and our very own Earth.
In Pluto’s case, the atmosphere constantly regenerates as surface ice sublimates, and
that tenuous atmosphere is just pouring off the little planet much like scientists think
the primitive atmosphere escaped from the early Earth.
Measuring and understanding how and why Pluto’s atmosphere behaves the way it does might help
explain how the Earth’s atmosphere developed, which could have some interesting implications
on why and how it is that our planet alone seems suitable for life.
But there’s something else Pluto could teach us about Earth, and that’s about its relationship
with its largest moon Charon.
Or “Karon.”
Both pronunciations are correct.
For the time being, we know Pluto has five moons: Charon, Hydra, Nix, Styx, and Kerberos.
Charon is massive compared to Pluto; it’s about half the size of its host planet.
It’s so big that it doesn’t simply orbit Pluto, the dwarf planet and its largest moon
actually both orbit a point in space between them, making them a binary system.
The only other planet with a surprisingly large moon is, you guessed it, Earth!
The Moon is a little more than a quarter the size of the Earth, large enough that both
bodies orbit a point just slightly off the Earth’s centre.
Pluto and Charon are also tidally locked to one another, always showing the same face
to each other.
It’s a rare arrangement and, you guessed it, the only other such system is our Earth-Moon
system.
Notice how you only see one face of the Moon?
It’s tidally locked to the Earth so we’ll never see the far side from home!
So with Pluto we have a celestial body with a nitrogen-rich atmosphere escaping at an
alarming rate and a relatively massive moon showing the safe face to that planet…
Scientists want to understand all these features because they’re fascinating, but if we learn
something about our own planet in the process all the better, because it might help in our
future search for life on other planets.
In the meantime here on Earth and on the not-so-distant horizon, Toyota is fueling the future with
the new Toyota Mirai.
Using the most abundant element in the universe, Hydrogen, the new Mirai is looking to the
future with sustainability in mind.
So, how excited are you guys to get to Pluto?
Really excited, or totally beside yourself giddy excited!