Pluto: Still a planet

After reading about the possibility that Pluto would lose its status as a planet, I was quite a bit relieved after doing a little more research to find that it status is safe.

Some astronomers had lobbied for reclassifying Pluto because it is so tiny. And at least one major museum has excluded Pluto from its planetary display. But sources tell NPR that under a proposal to be presented at a big meeting of astronomers in Prague next week for a vote, Pluto would become part of a new class of small planets. Several more objects could be granted membership.

[...]

So earlier this year, the International Astronomical Union, which has decided tricky nomenclature issues since it was formed in 1919, appointed a panel to try to define the word "planet."

Seven experts, including a science writer and a variety of astronomers, met in Paris this past June. Under the guidance of Owen Gingerich, a historian and astronomer emeritus at Harvard, they debated for two days.

Gingerich would not discuss the conclusions, but says "I think we have done something that will make the Plutocrats and the children of the United States happy."

NPR interviewed five of the seven panel members. All but one said they thought of Pluto as a planet, or had made statements in the public record to that effect.

Whew! There's still a full vote to worry about, but I'm happy for this development. It may turn into something more, too.

Several panel members have favored dividing planets into categories: terrestrial planets (Mercury, Venus, Earth, Mars), giant planets (Jupiter, Saturn, Uranus, Neptune) and a third class that would include Pluto.

"We'll call them dwarf planets or something," says Iwan Williams, an astronomer at the University of London who favors the idea and also served on the panel.

Sources say the panel's new definition for planets would, in fact, create a third category embracing Pluto.

[...]

Some panel members say they favor counting any object which is large enough that its gravity has made it round. If the object is spinning, a small bulge would be tolerated. "We're talking about no more than four or five new planets," says Iwan Williams.

Small potato-shaped asteroids wouldn't make the cut. But Ceres, a big round asteroid between Mars and Jupiter, might qualify.

Hmm. Better start working on some new mnemonics, in case Mary Vincent Eats Many Jelly Sandwiches Under Ned's Porch or My Very Excellent Mother Just Served Us Nine Pizzas become inoperable. Thanks to SciGuy for the link. Oh, and as long as you're reading about Pluto, here's a nice story about Clyde Tombaugh, the guy who discovered it.

Posted by Charles Kuffner on August 13, 2006 to Technology, science, and math | TrackBack