For 76 years it was a planet, and for 76 years we were taught this. Now suddenly it's too small to hang with the rest of the planets? It never changed from when first being called a planet, so why the demotion? That's why people are upset.
It wasn't merely the size of Pluto that resulted in it being reclassified, it really does not fit the parameters for what constitutes a planet. For one its orbit was wrong. Really the reclassification was intended to make it easier on astronomers. It was either create a new class of astrological bodies,of which Pluto is now a part, or have our solar system be filled with hundreds if not thousands of "planets" (imagine the nightmare of trying to memorize of those in school XD.) It would be as if we one day decided that ever asteroid in the asteroid belt was now a planet.
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