Scientists confirms new planet is bigger than Pluto

Scientists say they have confirmed that a so-called 10th planet discovered last year is bigger than Pluto, but that likely will not quell the debate over what makes a planet. The astronomers who spotted the icy, rocky body, informally called UB313, had reported only a rough estimate of its size based on its brightness.

But another group of researchers has come up with what is believed to be the first calculation of UB313's diameter. By measuring how much heat it radiates, German scientists led by Frank Bertoldi of the University of Bonn estimated that UB313 was about 3,000 kilometers (1,860 miles) across. That makes it larger than Pluto, which has a diameter of about 2,300 kilometers (1,430 miles).

"It is now increasingly hard to justify calling Pluto a planet if UB313 is not also given this status," Bertoldi said in a statement. Details were published in Thursday's issue of the journal Nature. Some astronomers have debated over what is a planet and whether Pluto should keep its status. The difficulty is there is no official definition and some argue that setting standards such as size limits opens the door too wide, reports the AP. I.L.