Once upon a time, in a place far, far, far away in our galaxy, there was a small planet called Pluto. He lived in harmony with the other eight planets… until 2006. That fatal year… when the astronomers attacked. Verbally, that is. Pluto was made an ex-planet. They stripped his title from him, reduced him to a dwarf (so apparently size does matter) and no one could do a thing. Soon, everything changed— Wikipedia, textbooks, everywhere it was proclaimed that the number of planets in our Solar System had dropped from nine to eight. A new generation of kids would be taught in school to list the eight planets and they’d go “Mercury, Venus, the Earth, Mars, Jupiter, Saturn, Uranus and Neptune”. And it would be totally normal for them. In turn, several older generations would shake their heads and remind those little runts that “when I was your age, Pluto was still a planet”. Some of them would simply refuse to accept that new truth. “Pluto still is a planet.”
So… what about poor little Pluto? How did he feel? Maybe he was angry, maybe even disappointed… Though, apparently, there was no reaction from him… No, Pluto, named after the Roman God of the Underworld, waited patiently —just as Death waits for the opportune moment to strike— he waited and said: “Oh, they’ll come to realise their mistake. They don’t know what they’ve done.” Maybe.
Apparently we didn’t unleash the wrath of the Underworld. (Or perhaps we actually did and we just didn’t notice.) And maybe, just maybe, it’s time for Pluto’s big comeback. It’s not like there haven’t been enough new discoveries to give him back his rightful title…
Just a small headcount: Eris, a dwarf planet that’s even farther away than Pluto and thought to be bigger, apparently isn’t. It is not certain, but thanks to research conducted by Emmanuel Lellouch at the Paris Observatory, Pluto appears to have won this round. Admittedly, there’s always been a lot of doubt when it comes to Pluto’s size. When it was first discovered, it was believed to be larger than Mercury and possibly even larger than Earth! Fact number two: Pluto has an atmosphere! That same research has found methane in Pluto’s air. There is also speculation about a possible underground ocean on Pluto, or maybe cryovolcanoes or geysers.
And fact number three: it’s known that Pluto has at least five moons—the last one, Styx, was found in 2012. Charon, its biggest moon, is about half the size of Pluto, and they’re sometimes viewed as a binary system, because they orbit a common centre of mass somewhere between them.
And now we might be a little closer to our goal, about to explore New Horizons. Yes, that’s also the name of the spacecraft NASA sent to Pluto in 2006 and now, on July 14th, it will finally fly by. It will be studying Pluto, taking pictures and gathering data: Pluto’s exact diameter will be measured, and who knows, maybe we’ll even find more—more moons, the God of the Underworld himself sitting on his throne, I mean…
Jokes aside, following the New Horizons mission is strongly recommended! NASA has all kinds of information about it on their website and it is already broadcasting live from NASA’s control centre (you can watch it on our Mission Pluto microsite), and of course NatGeo will be following up close, too. Watch out for Mission Pluto, premiering in July on the National Geographic Channel.