BETHEL – Just two weeks before school starts, Gould Academy astronomy professor Nancy Eaton got the answer Thursday to last year’s scientific debates among her pupils: Pluto isn’t a planet.

“This will not fundamentally change the way I teach, but, fundamentally, as a scientist, the stuff I taught last year has to be reconsidered,” Eaton said early Thursday evening at home in West Bethel. She is in her third year teaching astronomy and her eighth year teaching physics.

“This is going to change a final exam question,” added the former NASA orbiting space-telescope operator.

At its 26th General Assembly in Prague, Czech Republic, the International Astronomical Union stripped Pluto of its planetary status by redefining planets and other celestial objects.

However, neither Eaton nor amateur astronomer Jack Nordahl of Bethel were surprised by the news.

“Astronomically, the issue was settled in the last 10 years, that Pluto no longer qualifies as a planet,” Nordahl said Thursday afternoon at his East Bethel Road home.

“This is just really an after-the-fact thing,” he said of the IAU resolution.

“Fifteen years ago, when they found that Pluto was so small, I and others decided then that it didn’t really qualify as a major planet. But, the IAU needed to decide on it, so that we didn’t have people finding the 51st planet,” he said, laughing.

Pluto, according to the union’s resolve, is a dwarf planet, which, Nordahl said, better befits the chunk of ice.

The Associated Press reported Thursday that the IAU’s new rules for a planet require that the celestial body must:

• orbit around the sun,

• have sufficient mass for its self gravity to overcome rigid body forces so that it assumes a nearly round shape, and

• have cleared the neighborhood around its orbit.

The same resolution, the article states, defines a dwarf planet as both A and B, with the exceptions that it has not cleared the neighborhood around its orbit, and isn’t a satellite.

Nordahl said Pluto was discovered in 1930 by Clyde Tombaugh, who died at the age of 90 on Jan. 17, 1997.

“It was a very hard object for amateurs to find, because it was very dim. Originally, astronomers thought, because it is so far away, that it must be of large size,” he said.

In the past 10 to 15 years, however, astronomers began zeroing in on Pluto, learning that it’s actually two bodies orbiting tightly together, not one large body, Nordahl said.

“The bigger issue was there was no formal definition for a planet, because we thought we knew what a planet was. Pluto forced the issue of deciding what’s a planet and what’s not. So, textbooks are wrong, but that’s not pretty unusual,” Eaton said.

Additionally, as technology has improved, she said scientists are discovering new things with telescopes that allow them to see farther into space.

“They’re finding a whole bunch of things that are Pluto-like. It’s funny. We may start finding new things that meet the new definition of a planet, which will force us to rethink it if we find a new object that meets the new definition,” Eaton said.

“Science aside,” said Gene Clough, who teaches lunar and planetary science at Bates College in Lewiston, “this gives one an odd feeling. Poor Pluto! Just think how many good friends it has its own size beyond it, so it doesn’t have to feel that it’s the dregs of the classical planets. It can be a leader of the dwarf planets!”


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