Latest science has astronomers quarreling over dwarf planet's status.
National Geographic News
Published August 24, 2011Since the 2006 ruling, astronomers have also made a number of scientific advances that further cloud the issue, from discoveries of planets that don't orbit stars to new models of how our own solar system may have rearranged itself since birth.The discovery prompted the IAU to convene a committee to decide on an official definition of a planet.Exoplanets Complicate MattersSince 2006 there's been an explosion in the number of these extrasolar planets, or exoplanets, known to exist, with the current count at more than 400 and rising. Many are bigger than the gas giant Jupiter, but astronomers have found an increasing number of worlds close to Earth's mass, some of which may be habitable.And "it's okay with me if we have another definition for exoplanets. I imagine that's something that will be revised with time."Spahr also notes that recent models of the solar system suggest the planets didn't form where they currently reside.