LITTLETON – It has been nearly two years since the International Astronomical Union decided Pluto was no longer a planet but rather a “dwarf planet.”

The status change came after the IAU decided Pluto did not meet new definitions stating that 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.”

When that decision was made, Pluto was downgraded to “dwarf planet” status, which altered not only its status in the solar system, but also its place in the Northern Maine Museum of Science’s Maine Solar System Model.

Now, the museum is ready to put Pluto back in the spotlight.

A new model of the dwarf planet Pluto will be added to the model Friday. It will be located at the Southern Aroostook Agricultural Museum in Littleton and will be the last of three dwarf planets to be installed. The dwarf planet’s installation will complete the expansion of the 80-mile-long model.

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

Built on a scale of one mile equal to 93 million miles (the distance from the Earth to the sun, also known as an astronomical unit), each of the planet replicas is built to scale and spaced alongside U.S. Route 1 at appropriate distances.

Most of the model planets are mounted outdoors on poles.

The display, the world’s largest complete solar system model, stretches from Presque Isle to Topsfield. It now includes the sun, nine planets, seven moons and three dwarf planets.

In the solar system model, the sun is portrayed as a large yellow arch three floors high at the museum in Folsom Hall at the University of Maine at Presque Isle. Locations for the planets along Route 1 were determined as close as possible to the average distance of each planet from the model of the sun.

The location for the model of the planet Pluto was placed at the Houlton Information Center because its distance of 40 miles from the UMPI campus matched its average distance from the sun.

That model will remain intact, but a new model of the now dwarf planet Pluto will be erected next to the sign at the Littleton museum. The new model will reflect the fact that dwarf planets typically have orbits that are more elliptical than those of traditional planets, according to Dr. Kevin McCartney, director of the Northern Maine Museum of Science. That means Pluto will be located at a different distance from the sun several years from now.

He noted that the dwarf planet’s distance from the sun varies from 29 to 49 astronomical units, which prompted the museum to choose the Littleton location.

The new model is going to be “smaller than a golf ball,” he said Wednesday, acknowledging that he likely will “spend the rest of my life answering the question: ‘Why do you have two Plutos?’

“But this is a wonderfully elegant solution to the Pluto situation,” he said. “This not only expands the model, it also adds a whole new educational element to this. When people ask that question, we can educate them on planets and dwarf planets and the IAU’s decision.”

Museum education coordinator Jeanie McGowan and McCartney both said the new location is “ideal” for the model of dwarf planet Pluto. They noted that the SAAM is both a tourist attraction and an educational tool.

“They have wonderful work going on there and they have new exhibits and artifacts coming in all the time,” McCartney added.

Karen Donato, the secretary at the Littleton museum, said museum officials are similarly excited about the new model.

“We are happy to have Pluto here and hope it will bring more people in to see our museum,” she said.

A ceremony to unveil the new Pluto is scheduled to begin at 9 a.m. Friday, at the museum.

jlbdn@ainop.com

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