Pluto

I just completed a week of programs for kids on the solar system. I had to be fairly brutal when the discussion turned to Pluto.

"Sorry kids," I said, "I think the astronomers did the right thing when they demoted Pluto."

Yes, I know that schoolchildren all over America wrote impassioned, tear-stained letters to the International Astronomical Union asking those bad old scientists to keep Pluto the big number nine. I also know that our politically correct culture would prefer that all planets be equal.

Nevertheless, I forged ahead. "Knowledge marches forward. We know more now than in 1930 when dear Clyde Tombaugh discovered Pluto. He could only have dreamed of today's incredible telescopes. Astronomers have discovered many more Plutos (Kuiper Belt objects) beyond our little Pluto."

The kids still looked bereft, so I had to bring out the best argument in favor of Pluto's tumble to dwarf planet status. "O.K.", I said, "if you want Pluto to remain a planet, then all those scores of other icy snowballs beyond it will have to be named planets, too, and you will have to learn all those names in order!

That did it. Those kids are grateful they only have to memorize, My Very Educated Mother Just Served Us Noodles. The nine pizzas are history.

In case anyone is interested, Pluto may have lost major planet status but has gained its own number in the catalog of minor planets. It is number 134340.

To know your place in the cosmos, check out Neil de Grasse Tyson's 100th Essay, The Cosmic Perspective.