The demotion of Pluto is a result of a recent astronomy conference held in Prague, which decided to call Pluto and other small objects “dwarf planets.” Presently two other objects, Ceres in the asteroid belt and UB-313 in the more distant reaches of the solar system, have also been placed in this category.

“The decision to remove Pluto from the ranks of planethood was difficult and will surely be controversial,” said Kevin McCartney, UMPI professor who coordinated the construction of the Maine Solar System Model. “However, the number of Pluto-like bodies discovered in recent years meant that either there would be eight planets or dozens, depending on how ‘planet’ was defined.”

“Pluto was always an odd bird,” said McCartney. “The other planets are much larger and have more circular orbits that lie more or less in the same plane. Pluto’s orbit is much more elliptical. While its average distance from the sun is 40 astronomical units – an “AU” is the 93,000,000 mile distance from the earth to sun – Pluto presently is just outside the orbit of Neptune.”

McCartney said the elliptical orbit of Pluto has created something of a problem for the Northern Maine Museum of Science. The museum, located on the University of Maine at Presque Isle campus, is an educational participant in the New Horizons program, which has launched a space probe that will visit Pluto in 2015. That visit will happen at 33 AU from the sun, which for the model is seven miles north of where the Pluto model is currently located. The solution is to have a second Pluto model, and to position the other dwarf planets at their present rather than average distances from the sun.

McCartney has already contacted some of the original “planet builders” to start design and construction of new posts and bases for the dwarf planets. “We are planning to build the parts for six new objects,” he said. “Three of these will be for the second Pluto model, Ceres and UB-313. These will be located along Route 1, 55 feet from the center line of the road, the same as the existing parts of the model.”

Ceres will be located about 2.8 miles south of the museum, within the boundaries of Presque Isle. UB-313, which has been nicknamed “Xena,” will be located near Topsfield, about 57 miles south of Houlton. McCartney has not yet determined the precise location along Route 1 nor talked with landowners to get permission.

Ultimately, McCartney feels other dwarf planets will be included in the model as their status is determined by scientists. Two potential dwarf planets, nicknamed Sedna and Quaoar, among others, are currently being studied. The Maine Solar System Model will only include along route 1 objects that in scale are larger than a marble, although smaller objects may be displayed indoors at schools, planetaria or information centers such as at Houlton.

The plan is for dwarf planets to be positioned at odometer distances from the sun, at the scale of 1 mile to the astronomical unit, along Route 1 as far as Calais. Any object that would be further than Calais would be positions at straight line distances from the sun, since Route 1 swings to the west along the coast, and the road no longer is in an essentially straight line.

Eventually, portions of the model may occur over the entire length of the state. McCartney said there is a school in Massachusetts that has been regularly making a field trip to Aroostook County to see the solar system model. “It would be nice,” he said, “if we could have a dwarf planet located at their school.”