PRESQUE ISLE – Kevin McCartney freely admitted Friday: He’s sorry to see Pluto fall from grace.

But McCartney, a professor at the University of Maine at Presque Isle, also sees an opportunity in this week’s decision by astronomers to downgrade Pluto from “planet” status to “dwarf planet.”

He thinks it can serve as a teaching tool at the Northern Maine Museum of Science, which he directs.

Besides, it gives the museum a chance to build on its already expansive Maine solar system model.

In 1998, the museum got high school students from throughout Aroostook County to help build models of the then-nine planets.

Built on a scale of one mile to 93 million miles, each of the planet replicas is built to scale and spaced alongside U.S. Route 1 at the appropriate distances.

The display is the world’s largest complete solar system model.

Most of the model planets are mounted outside on poles – but not Pluto.

The former planet is the smallest of the models, just 1 inch in diameter. Because of its size, Pluto and its moon, Charon, sit in a display case inside the Houlton Information Center – and that is where they will remain, McCartney said Friday.

A planet since it was discovered in 1930, Pluto fell out of favor after the International Astronomical Union decided Pluto did not meet new rules that say a planet not only must orbit the sun and be large enough to assume a nearly round shape, but also must “clear the neighborhood around its orbit.”

“We are going to leave Pluto where it is and make some changes,” he said Friday. “We will erect the new dwarf planets in the model as it exists now, so that these dwarfs will be right out there along with the current eight planets.”

In the solar system model, the sun is portrayed as a large yellow arch three floors high at the museum inside Folsom Hall at UMPI.

Using the scale, the placement of the Pluto model in Houlton reflects the planet’s average distance from the sun – approximately 40 miles – in Maine, but 3.6 billion miles from the sun.

But Pluto’s elliptical orbit is eccentric, according to astronomers. It takes about 247 earth years for Pluto to orbit the sun. A space probe is expected to visit Pluto in 2015.

In the long run, the museum plans to build another model of Pluto. It will be visible from Route 1, and its placement will reflect its projected distance from the sun in 2015. That means the alternate Pluto model will be erected about seven miles north of the Houlton Information Center.

The other dwarf planets – Ceres and Xena – will then be erected to offer Pluto some company. Ceres is slated to be placed about 2.8 miles south of the museum, while Xena would be erected near Topsfield, about 57 miles south of Houlton.

The museum has not yet solidified precise locations or acquired landowner permission.

“I feel it is a better idea to go ahead and add these dwarf planets than it is to take down Pluto and have to explain forever why we did it,” McCartney said. “I think that this is a great teaching tool for us in the science world. You have to reconstruct your understanding as more research comes in – science is about new discoveries.”