TENTH PLANET

Xena, or UB313, on the left is just smaller than our Moon (Image: Nature)
Xena bigger than Pluto

Xena, the possible 10th planet in our solar system, is even larger then Pluto, research shows.
Astronomers led by Professor Frank Bertoldi of Germany's University of Bonn say Xena, or 2003 UB313 to give it its official name, has a diameter of about 3000 kilometers, about 700 kilometres larger than Pluto's.
This would make UB313 the largest solar system object to be spotted since the discovery of Neptune in 1846.
Astronomers have been debating the status of UB313 ever since the announcement last year that it had been discovered 15 billion kilometres from Earth.
Pluto's defenders blasted it, saying it was not a planet ... but a vulgar rock.
The polite term for such abuse is a KBO, Kuiper Belt Object, for the estimated 100,000 pieces of icy, primeval debris that slowly encircle the Sun on the outskirts of the solar system, far beyond the orbit of Neptune.

[Since UB313 is decidedly larger than Pluto, it is now increasingly hard to justify calling Pluto a planet if UB313 is not also given this status]