Pluto, Soon to Orbit in a Less Important Circle?
Thursday, August 17, 2006
For some generations, it's "My Very Eager Mother Just Served Us Nine Pickles." For others, it might be "Mother Very Easily Made Jane Stop Using Nail Polish," or "My Very Enormous Monster Just Sucked Up Nine Planets."
We discovered such mnemonic devices in grade school to learn the planetary order of things. And since 1930, these silly little sentences have ended in P for Pluto, that planet on the edge, the bad boy fronting the darkness beyond telescopes.
But these memory aids -- as well as all the solar-system posters in classrooms -- might have to go.
A committee of astronomers sat around a table in Prague last week and reflected on whether Pluto should be called a planet. Yesterday, the seven-member Planet Definition Committee released a proposal that will be hotly debated leading up to a vote next Thursday. This star chamber suggests that Pluto shift from its status as the underdog ninth planet to become leader of a new category of subplanets called plutons.
And once-mighty Pluto, named for that Roman god of the underworld, wouldn't even be the only "pluton." Under the new definition -- spherical bodies of a certain mass -- Pluto would have to hang around with a bunch of losers -- Ceres (which orbits between Mars and Jupiter), UB313 (just one subway stop farther out of town) and its own moon, Charon.
"It really won't change much," said Elizabeth Warner, director of the University of Maryland's observatory, who leads a class of amateur astronomers. "Now that we have 12 'planets,' we have to think of a longer rhyme."
You can think up your own (perhaps even "My Very Early Map Can't Justify Such Unusual New Planets Coming Up"). But it probably won't have the same ring -- especially when you consider UB313, commonly referred to as Xena (in 2003, its discoverer named it after a certain TV warrior princess).
"Xena in particular would really throw it off," reflected Jim Zimbelman, chairman of the Smithsonian's Center for Earth and Planetary Studies. "It won't make it easier for the teachers."
Personally, he hopes the Prague panel will elevate the three contenders to pluton status, but professionally, he's worried about the extra work.
Zimbelman wondered about adding the three plutons to an existing solar-system model on the Mall. Visitors can walk from a beach-ball-size sun to a speck representing Pluto that's at the Smithsonian Castle. "What are we gonna have?" he mused, referencing the relative distance of UB313. "It's twice as far from Pluto as from the modeled sun! We'll be sending Boy Scouts out into the Potomac!"
At the Hayden Planetarium in New York, curators thought back in 2000 about how to avoid a Pluto controversy: They never included the planet in their exhibit -- prompting a flood of letters from disappointed schoolchildren.
Some people are fiercely loyal to Pluto, but Venetia Phair of Surrey, England, isn't necessarily one of them. In 1930, at age 11, she won a contest to name the planet, but now, "I've been largely indifferent to [the debate]; though I suppose I would prefer it to remain a planet," she told the BBC in January.
So too, probably, would Walt Disney, who in 1930 named the rambunctious cartoon dog for the planet. And it's bad news for the crazy futuristic title character in "Pluto Nash" played by Eddie Murphy, who might now have to answer to a dull sidekick named Charon.
Then there's the Bay Area restaurant chain Pluto's, which offers "celestial sandwich of the week" and "orbital onion rings." Co-founder Gerry Bugas, a former Springfield resident, was dismayed to hear of the planet's slipping status, but said he wouldn't give up his vision. "We're going to march forth with Pluto being a planet," he said. "In our minds, it always will be."
If Pluto's status does change, the observatory's Warner noted: "I would say those elementary-school posters would become a little bit more valuable in some weird way. Even now, we find astro textbooks from 80 years ago, before Pluto was discovered, with no mention of Pluto. It feels very weird to have no Pluto in there."
Brianna Stratton of Seattle, who runs the educational Web site Homeschool Science, pondered how to revise her lesson plan "Interplanetary Hike," which helps kids walk distances to the scale of a solar model.
To get to the plutons, she said, "You might have to go to the next town over."
Stratton learned her own planets the simple way: "My Very Earnest Mother Just Sent Us Nine Pickles."
"But now there won't be any pickles," she said. "That was weird, anyway. To have someone send you pickles."