As a kid at school I memorised the nine planets. Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune — and Pluto.
The list got etched into my little brain. I’d sing it with bubbly spirits and if I got it right, which I always did, my teacher would nod in approval. And I’d be elated.
Then one day, out of the blue, I was told that there were no longer nine planets, just eight. I was disappointed. I had spent time learning something that suddenly became incorrect — officially. Just like that.
Apparently, astronomers had come together in one of their little meetings and decided that Pluto was too small to be a planet.
I guess the ladies are right: size does matter.
It wasn’t easy to accept it at first. It just felt so unnatural to say eight instead of nine planets. To recite all the way to the end of that list and then just stop at Neptune. It would feel like something was missing.
But reflecting on the Pluto episode now, almost two decades later, I’ve realised that there is an important lesson to learn from it. (There’s always plenty of those going around, to be sure, but I feel that this one’s genuinely important.)
I guess one thing it teaches is that knowledge changes. It changes. Things we know today can suddenly reverse based on new information.
As rational people, we have to be willing to accept that.
Otherwise, we would just be like those other goofs who continued to mention nine planets instead of eight, relying on outdated information.
Here’s to you, Pluto — the planet that once was.
