10th Planet in Question

<July 29th, 2003, saw the official announcement of the discovery of a celestial body which many hope will be named and granted status as the 10th planet in our solar system. Temporarily named “Xena”, the body cataloged as 2003 UB313 was discovered with the Samuel Oschin Telescope at the Palomar Observatory.

Michael E. Brown of Caltech, Chad Trujillo of Gemini Observatory and David Rabinowitz of Yale University are credited with the find. The International Astronomical Union will have to determine the final name of the body, if it concludes that UB313 is in fact a planet.
Some controversy exists as to what should be considered a planet. Besides the numerous rocks that float about our solar system, there are two areas of space in which rocks and debris converge into belts (Main Belt & Kuiper Belt) that orbit the sun. Some of these rocks, inhabiting these belts are very large, approaching the size of Pluto, the smallest planet.

The controversy surrounds the question of what should be the minimum size for an object before it is considered a planet. When UB313 was discovered to be larger than Pluto, some in the astronomical world called for Pluto to be removed from the list of planets, stating that it was just another Kuiper Belt Object; simply a very large asteroid.

The controversy will be decided by the IAU which as no concrete definition of what a planet is.