You never know when you’ll be called upon to speak authoritatively on something you know little about. Fortunately, since I began blogging two years ago, I have experience.

I heard a news story on the radio this morning about the demotion of Pluto from its status as a full planet. It is now classified a dwarf planet.

Immediately I thought about my fourth-graders, who study the solar system in science. The solar system is a hard topic for a hands-on approach. Naturally, we can do gravity demonstrations, and we can learn about atmospheric properties, but the size and scale of the solar system is a bit of a stretch.

The kids get enthusiastic gathering information about the planets themselves. Many have never thought about Earth as a planet, or the Sun as a star.

Most kids seem to like Pluto more than the other planets. I suppose it’s because of its remoteness. They like googol for the same reason. They’re attracted to the aura of power that comes from big things, or in this case, things that are very far out.

With its popularity, I figured the kids would have something to say on the subject. I wondered what the textbook publishers would do about it, with all that print to rewrite! Wikipedia had no such trouble. Score 1 for the Wikipedia. The Wikpedians were all over it, and the planets talk pages are fun to read through.

I also wondered how my favorite kid-information source for planet info on the web would handle this. The nineplanets.org might have to change their domain name. But they were ahead of me, and they say that they’ll stay right where they are and call Pluto a “planet emeritus.”

As the morning rolled along, I forgot about this big deal, but then one of the other teachers showed a reporter into my classroom so he could ask me some questions about how this would affect schools. I hadn’t really considered that it would make any difference! My group was getting ready for recess, and I couldn’t talk to him. I’m glad, because it was my lunch period, and I hate to lose that. I decided to talk over the heads of the kids as they were pulling on their jackets and finding basketballs.

I told him my approach to teaching this subject would be no different. “Really!” he said. And I thought, “God, what is he going to make of anything I tell him?” So I added, “It’s funny how a single definition can change the shape of the universe (I should have said ’solar system’ but universe sounds better.) He smiled, and started writing. Then I said, “The kids always like Pluto best, and this will probably make it even more popular - the Outcast Planet” He smiled bigger and said, “Thank you very much.” Who knows what the paper will say in the morning!

This evening I was thinking about all of this and speculating on why it mattered, the reclassification of the ex-planet. The only new thing I can think of is that with Pluto out of the way, scale models of the solar system will be a lot easier to enter in the science fair. It seems fitting that Pluto, named for the god of the underworld, would be cast out of the heavens, so to speak. But of course, it’s still out there, just more precisely defined.

I don’t know about the science involved, but at least one source attempts to explain the issues and claims that this means more to the general public than it does to scientists. It seems to me that the re-definition, like any definition, must be a way of controlling membership in the category since many similar objects have recently been discovered and threaten to crowd what has until now been a very limited field.

But I’m not an expert. The reporter should have talked to one of my students. They talk all day on subjects they know very little about, and they’re full of interesting observations. That’s the real story.

I guess that one is up to me. The question of what should happen to Pluto will be a great writing prompt.

If anyone wants to explain why this might matter to us, I’m listening.