When Pluto was downgraded last year from a planet to a so-called dwarf planet, my son was thunderstruck and quickly joined the counter-revolution seeking to restore Pluto to its traditional place. "I don't understand," he anguished. "How can they just not make it a planet anymore?"
I explained the rationale: that Pluto was smaller than Earth's moon. That its orbit was not in the same plane as the other planets. That it has the temerity, on occasion, to cross paths with Neptune.
But it was no use. Anton had a vested interest in Pluto's planetary nature. He had just completed a report in his science class. Each student had to pick a planet. His was Pluto. Did the revision of its status mean he could not keep his B+ for a job well done? Perhaps his grade would be demoted to a dwarf grade. He was suddenly feeling like a man without a country, or, in this case, a planet.
I understood his travail. When I was a kid, I had a favorite planet. It seemed that all my friends did. Mine, for a reason I can no longer put my finger on, was Venus. I still recall a schoolyard fray in which I faced off against a kid who was ballyhooing the case for Jupiter as the "best" planet. The volume of recriminations rose to the point where a crowd gathered and one of the teachers had to separate us. Who knew that astronomy could stoke such passions?
I don't know why Pluto has captivated my son so. It is the planet we know the least about. It's never visible to the naked eye or even to any but the most powerful telescopes. While Venus blazes white-hot as the evening or morning star, and Mars glows unmistakably red, and Jupiter and Saturn make their own showy transits across the heavens, Pluto remains little more than a concept.
When it was discovered in 1930, it was visible only as a tiny, nondescript smudge of light among all the other tiny, nondescript smudges of light on a grainy photographic plate. It almost seemed not to matter at all. One wonders if anything in our own planet's history would have changed for better or worse if that dim body had been allowed to wander on its way unmolested.
The thing is, like that long-ago schoolyard standoff pitting Venus against Jupiter, the astronomy conference in the Czech Republic, where Pluto was stripped of its epaulets, also saw its share of fireworks. (USA Today described the proceedings over Pluto's fate as "stormy.") Apparently Pluto had its vociferous defenders, such as Dr. Alan Stern, principal investigator of the New Horizons space probe mission, scheduled to arrive at Pluto in 2015.
His website defiantly continues to call Pluto "the last planet." I transmitted this note of optimism to my son.
Ah, yes, science is indeed fickle. Tomatoes were vegetables before they became fruits. The one, all-encompassing universe is, on second thought, believed to be one of many universes (or perhaps not). Dinosaurs, once regarded as cool and uncaring toward their young, are now being touted as models of parental care. The critical observer soon gets the sense that, if he only waits, science will eventually see things the way he does.
It was with this faith that I went out the other night with my son to sit on the picnic table in our backyard under a particularly starry sky. Orion was ascendant, presaging the winter to come. The Milky Way cut a path through the firmament. An unusually bright star blazed in the south. "That's either Saturn or Jupiter," I remarked.
"Why can't we see Pluto?" Anton asked with a note of wistfulness.
"Because it's so terribly far away."
"But the stars are farther away."
"Yes, but they're huge and on fire." And then I reminded him about the New Horizons space probe. "In eight years we'll get our first real look at Pluto," I said. "Then who knows? Maybe they'll decide it's a planet again."
Anton looked at me, his eyes full of hope. "Do you really think so?"
"Anton," I began, "there's a microscopic creature called a euglena. When I was about your age, we were taught it was an animal. By the time I was in high school, they had decided it was a plant. Now it's something else altogether. Things change." And then, after a moment's thought, I added, "Maybe you could pick another planet as your favorite until that space probe gets to Pluto. Venus is a good one."
My son wrinkled his nose. "Jupiter is better," he said with authority.
This time I held my tongue.