Free Republic

LOS ANGELES - Scientists say they have confirmed that a so-called 10th planet discovered last year is bigger than Pluto, but that likely won't 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...

Scientists are over the moon at the W.M. Keck Observatory and the California Institute of Technology over a new discovery of a satellite orbiting the Solar System's 10th planet (2003 UB313). The newly discovered moon orbits the farthest object ever seen in the Solar System. The existence of the moon will help astronomers resolve the question of whether 2003 UB313, temporarily nicknamed "Xena," is more massive than Pluto and hence the 10th planet. A paper describing the discovery was submitted to the Astrophysical Journal Letters on October 3, 2005. "We were surprised because this is a completely different type of...