Pluto slight no big deal - it's all relative

September 06, 2006|By Kurt Ullrich

MAQUOKETA, Iowa -- Shed no tears for erstwhile planet Pluto.

As everyone knows by now, the International Astronomical Union recently concluded its triennial General Assembly in Prague. The assembled scientists talked of many things, such as "Precession Theory and Definition of the Ecliptic" and "Redefinition of Barycentric Dynamical Time TBD." The conference attendees likely also discussed weightier matters, such as "the Best Place in Prague for Wurst and Beer," but we'll never read about that one.

We know they discussed "Definition of Planet." The IAU agreed on a three-part definition: 1) It orbits the sun; 2) it is, essentially, round; and 3) it has cleared the neighborhood in its orbit. It's a simple definition and, somewhat surprisingly, fits a couple of thugs I knew in the old days. Pluto, however, can't get past point No. 3 and so is now considered a dwarf planet, not a planet.

Humans have known about planets for many hundreds of years. A very long time ago, we began to notice that some of the points of light in the sky were moving. Stars could be counted on to be at certain fixed places, so we figured the moving lights must be something else, and we began calling them planets.

The icy sphere we call Pluto has been riding high in the night sky for millions of years, but we weren't aware of it until 1930, when a young man named Clyde Tombaugh discovered it while working at the Lowell Observatory in Arizona. Born on a farm in Illinois, Mr. Tombaugh was fascinated by time and space from the time he was a child until his death in 1997. No doubt the expansive sky that sits seductively over the central Illinois plains played a large role in his lifelong interest.

Mr. Tombaugh's task was not any easy one. Not only is Pluto smaller than Earth's moon, it is also so far out in the universe that if one could stand on its surface and look up, the sun would appear to be a star in the night sky. If you could place Pluto on top of the United States, it would only cover about half the country.

1930 was not a hugely significant year, but a few items of historical importance took place. Interestingly, a number of future space travelers were born in 1930, including Americans Buzz Aldrin, James Irwin, Charles "Pete" Conrad, Edward White, Michael Collins and Neil Armstrong, along with a couple of future Russian cosmonauts. On a less-celestial note, a few miles west of my place here in Iowa, Grant Wood was sitting at his easel in Stone City, painting American Gothic.

Hanging in my kitchen is a photograph from 1930. Looking like the subject of a Grant Wood painting, it's a photo of a small child dressed in a white gown, wearing sturdy shoes and standing among orbiting chickens. It's likely someone put feed in the child's hand to dole out to the small flock. The child is my mother.

For years, my mother might have fit an early definition of a planet, a wandering, unfixed point of light. However, that all changed when she found my father, a man 10 years her senior. He offered her a place in his universe, his orbit, and she accepted. That sounds extremely sexist, but in those days the world was a different place. And perhaps, like Pluto, one's existence may be important only as it relates to others.

Our place here on Earth and Pluto's spot in the cosmos are fully the geometry and arithmetic of perspective, and perspective is only possible at a carefully measured distance. Is it important that Pluto is no longer considered a planet? No. A few romantic writers will complain a little, and a handful of textbook publishers will scramble for a bit, but that's about the extent of it.

And is it important that a small child who once walked among chickens in the same year Pluto was discovered no longer walks among us?

Again, no. I believe she too, like Pluto, is still out there somewhere, out beyond all sight, beyond perspective. It's not something I know empirically. It's something I sense on late summer nights when I cross the pasture in front of my house, when the air has softened and settled on the damp grass, and someone throws a celestial switch and twinkling lights appear overhead.

Kurt Ullrich writes essays from his home in Iowa. His e-mail is

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