Mary Very Easily Makes Jam Saturday Unless No Plums?
Elementrary and high school students may have to come up with a new mnemonic phrase for remembering the planets, depending on the outcome of a debate taking place this month at the International Astronomical Union’s General Assembly meeting in Prague:
At a 12-day conference beginning Monday, scientists will conduct a galactic census of sorts. Among the possibilities at the meeting of the International Astronomical Union in the Czech Republic capital of Prague: Subtract Pluto or christen one more planet, and possibly dozens more.
"It’s time we have a definition," said Alan Stern, who heads the Colorado-based space science division of the Southwest Research Institute of San Antonio. "It’s embarrassing to the public that we as astronomers don’t have one."
The debate intensified last summer when astronomer Michael Brown of the California Institute of Technology announced the discovery of a celestial object larger than Pluto. Like Pluto, it is a member of the Kuiper Belt, a mysterious disc-shaped zone beyond Neptune containing thousands of comets and planetary objects. (Brown nicknamed his find "Xena" after a warrior heroine in a cheesy TV series; pending a formal name, it remains 2003 UB313.)
The Hubble Space Telescope measured the bright, rocky object at about 1,490 miles in diameter, roughly 70 miles longer than Pluto. At 9 billion miles from the sun, it is the farthest known object in the solar system.
The discovery stoked the planet debate that had been simmering since Pluto was spotted in 1930.
Some argue that if Pluto kept its crown, Xena should be the 10th planet by default — it is, after all, bigger. Purists maintain that there are only eight traditional planets, and insist Pluto and Xena are poseurs.
"Life would be simpler if we went back to eight planets," said Brian Marsden, director of the astronomical union’s Minor Planet Center in Cambridge, Mass.
What do you think? How should a planet be defined? Should our solar system have eight, nine or ten planets? And if Xena becomes the 10th, what strange jam will Mary have to make?
