Xena

Not the Warrior Princess. The new planet. That's right, the new planet. After going back and forth on the size of Xena (UB313), astronomers appear to have settled on the conclusion that she is indeed larger than Pluto -- considerably larger in relative terms.

Bertoldi and his colleagues, from the University of Bonn and the Max Planck Institute for Radio Astronomy, determined the diameter of UB313 to be 3,000 km—about 700 km larger than Pluto. The astronomers measured the wavelength of radiation from the object to be 1.2 mm. At this wavelength, only the surface temperature of the object and its size—not the reflection of the sunlight— contribute to its brightness. Since surface temperature can be estimated as a function of distance from the sun, radiation at this frequency provides a reasonable estimate of size.

I'm firmly in the camp that would characterize Xena as the 10th Planet of the Solar System. I do wonder, though, whether the name will stick. Given its widespread usage and the ongoing debate over proper taxonomy, I suspect it just might. If you ask me, that's cool. And Xena has a single moon. Surely, it must be Gabrielle. Astronomers continue the search for theoretical companion-moon, Joxer.

P.S. Seed is a terrific online science magazine/portal. Check it out.