"This whole business of trying to somehow devalue Pluto as an interesting object...I’m not sure what purpose that serves," said Jeff Moore, a NASA Ames research scientist who studies the satellites of the outer planets, as well as Pluto.

Moore likened the demoting of Pluto by the Hayden Planetarium as "subterfuge, if not sabotage."

"First of all, it’s rather amazing that Tyson, an astrophysicist, would even venture into such waters. I feel, as a planetary geologist, equally qualified to demote the Magellanic Clouds to glorified star clusters as opposed to small galaxies. So in that spirit, I think he’s full of baloney," Moore said.

Traditionally and culturally, Pluto has been treated as the ninth planet, Moore said. "People will want to stick with their cultural traditions," he said.

Kevin Zahnle, also a space scientist at NASA Ames, said Pluto is a true-blue American planet, discovered by an American for America. As far as debating the issue, "any person, who knows the names of the planets are in a position to have an opinion on this matter," he said.

Planets of the solar system.

Zahnle said that no other object yet discovered in the Kuiper Belt is as large as Pluto. "But as soon as they discover another one that’s the same size, at that point the planet Pluto is going to loose its support," he said.

Cruikshank said giving Pluto dual citizenship, adoring it as both planet and Kuiper Belt object is a compromise, in a sense.

"I think it correctly recognizes the changing face of the solar system," Cruikshank said.

Kuiper Belt objects are more numerous than the Asteroid Belt, with first detection of a Kuiper Belt object made less than 10 years ago.

For Cruikshank, Pluto is a place calling out for further exploration.

"Whether Pluto is the last outpost of the planets or the first outpost to a whole new system of objects, it is a meritous place to go."