Omaha (Nebraska), Oct. 21 (AP): Pluto may be no more than a distant, icy rock in the minds of international scientists who stripped it of planethood. But the dwarf planet’s downgrade is creating a teachable moment in US classrooms.

So some museums have to adjust exhibits and publishers update texts while other scientists protest to keep the puny rock a planet.

That’s just science, many teachers said yesterday at a regional meeting of the National Science Teachers Association.

“Pluto’s still the same Pluto,” said Gerry Wheeler, executive director of the NSTA. “It’s still up there doing exactly the same thing.”

Pluto’s regrouping with the newly-named Eris and the asteroid Ceres will help teachers define what is — and isn’t — a planet.

“I’ve been saying Pluto’s not a planet for years,” said Donna Governor, a middle-school science teacher from Cumming, Georgia.

Governor teaches the solar system by having students measure and label orbits of each planet on a long roll of toilet paper. On one end is the sun; 250 sheets away is Pluto’s outer orbit.

By modelling and comparing Pluto’s orbit to orbits of other bodies, students can grasp the timing of its discovery in 1930 and why scientists reclassified it years later, Governor said.

“The science community wants change,” she said. “All of these new revisions mean we know more than we did before.”

Other Pluto-inclusive materials for teachers include flash cards, pictures, textbooks and online lessons. “Pluto is the smallest planet in our solar system. It is made of ice and some rock,” Pluto’s card says.

Educational materials won’t change overnight, but Nasa will re-evaluate them once appeals to keep Pluto in the club die down, Nasa spokesman Robert Mirelson said.