For a not-so-recent birthday, I got given a lovely T-shirt with very cutesy renditions of all the planets on it; with each one sporting a friendly face and a colourful label. It’s the perfect blend of astronomer & dad nerd. But one thing about it that I almost totally missed when I first saw it, was the sneaky inclusion of Pluto, hanging out with the rest of the gang; partying like it’s 1999.

The shirt is a recent design —newer than 18 years, at the very least— and I would argue Pluto’s planetary declassification is probably one of more better-known bits of astronomy trivia in the mainstream. So really, whoever had included it had to be aware of Pluto’s non-planetary status and did it deliberately. The question is, why?

It turns out that quite a lot of people are remarkably loyal to this ball of ice and rock 1/6th the mass of the moon, hanging out on average about 40 times further from the sun than we are. How loyal, you say? Well, aside from a (admittedly not completely serious) pledge by the state of California that Pluto will always be treated as a planet, there seems to be a general, grassroots sentiment that Pluto was short-changed by a stuffy scientific establishment, out-of-touch with the people. “Make your mind up, scientists!” & “I was taught there was a planet there, so that’s what I’m going to keep believing.” And so on.

For what it’s worth, I don’t think the fanaticism is about the rock. This phenomenon seems to have a whole lot more to do with distrust of science, anti-authority, conspiracy theory and generational solidarity.