New Planet - Great Debate!
Discovery of a world larger than Pluto at the fringe of our Solar System is renewing debate over exactly what constitutes a planet.
No one, in fact, is quite sure what should be called a planet and what shouldn't. Even the International Astronomical Society doesn't have an ironclad definition, though a committee is being revved up to create one.
In the last half-dozen years, there's even been a movement to strip Pluto of its status as a planet. The reasoning? That Pluto appears to be just another Kuiper Belt object - one of myriad frozen objects inhabiting an area of the Solar System beyond Neptune's orbit.
That description also fits the newly discovered world 2003 UB313, informally known as "Xena". Hence the status of "Xena" as the Solar System's 10th planet remains in doubt.
But "Xena" is out there, bigger than Pluto. And if Pluto deserves planetary status, shouldn't "Xena"? It'd be exciting to have a 10th planet to learn about.