Yes, it’s true, Pluto has been demoted back to a Kuiper Belt object. The Kuiper Belt describes those objects that are still captured by our Sun’s gravity, but can’t really be called planets. Everything from dust to planetoids orbits at the very outer reaches of our Solar System. Sometimes, not as often recently, objects from the Kuiper Belt will fall in towards the inner planets and the Sun.
Here’s the case against Pluto being a planet. Pluto’s orbit is dramatically tilted from all the other planets. Mercury through Neptune all have very flat orbits. The only other things in our Solar System that have orbits similar to Pluto’s are Kuiper Belt objects. That in itself is enough to keep our planet count at 8. If Pluto is a planet, then there are almost 300 other objects in the Kuiper Belt that would also qualify. How many planets should we have? You think you have to come up with a new rhyme now, just think about memorizing 250 planets!
The next planet contender is nicknamed Xena, with her sidekick moon Gabrielle. These two objects are very similar to Pluto and Charon… Small, icy rocks whose orbits take them far away from the planets.
It may seem like an insignificant, esoteric argument between intellectuals. The discussion about what constitutes a planet frames all the discussions we must have as we move out into the stars, though. We’re at an interesting place in History. The legend for the galactic map is being created right before our eyes.
Perhaps we could fit Pluto in, after all. Think about the way aircraft carriers are named. The new class of carrier, say Nimitz, is named after the first ship to be commissioned. What if we use Pluto in the same way? A planetoid, sentimentally elevated to Planetship to represent all the others. The little black sheep in our Planetary family.