UB313 May Be Bigger Than Pluto

German astrophysicists have concluded a space body located in the outer reaches of the solar system is 435 miles larger than Pluto, the smallest planet. Their research puts more pressure on the International Astronomical Union (IAU) to classify the object as the 10th planet in our solar system.

The object, tentatively named 2003 UB313, is an icy body that lies beyond the planet Neptune. The claims of a 10th planet have re-ignited a debate over just how many objects should be called planets -- there is no official definition.

A number of astronomers dispute whether Pluto, discovered in 1930, should really be classified as a planet, because it is so dissimilar from the other eight planets in our solar system. They believe Pluto should be classified only as a Kuiper Belt object, part of an array of icy debris left from the formation of our solar system some 4.5 billion years ago. The IAU, the official arbiter of such disputes, has classified Pluto as a planet and have declined to demote it.

Thousands of Kuiper objects have been discovered, and more are being found all the time. The New Horizons spacecraft, launched on January 19, is on a 10-year journey to explore Pluto, its moons and the Kuiper Belt