Astronomers Discover the Most Distant Dwarf Planet in the Solar System

— -- Move over Pluto, there's a new dwarf planet in the solar system. Actually, there's room enough for both, because this object is three times farther away from the sun than Pluto.

Astronomers have discovered the most distant dwarf planet ever in the solar system, astronomer Scott Sheppard told ABC News today. The object, designated V774104, measures between 500 and 1,000 kilometers in diameter, which is about one third of the size of Pluto, Sheppard said.

Sheppard, an astronomer at the Carnegie Institution for Science in Washington, D.C., said he discovered the object a few weeks ago while observing the solar system from Hawaii and announced his discovery Tuesday at a meeting of the American Astronomical Society.

"We don't know much about its orbit," Sheppard said. "If the object becomes interesting or not depends on its orbit."

It will take a year of observation to determine its orbit and how to classify this object, Sheppard said, adding that if it moves closer to the sun "it won't be so interesting," but if it stays out as far as it is now, at 103 astronomical units -- which is 103 times the distance of Earth from the sun -- astronomers can learn a lot about the outer solar system.

"We don't know of any other objects that are this far away from the sun," Sheppard said. "This can help us understand how the outer solar system was formed."

The former record holder for the most distant object was dwarf planet Eris, which is 96 astronomical units from the sun.