Pluto wins reprieve but number of planets may rise...
Debate has raged within the scientific community over the status of
Pluto for decades.
It intensified in 2003 when astronomers at the Cal Tech discovered
UB 313. Nicknamed Xena after the character in the television show,
UB 313 is one of more than a dozen celestial bodies in our solar
system found to be larger than Pluto.
Under the definition put forward on Wednesday, and subject to
ratification by a vote of IAU members on August 24, an object must
be in orbit around a star, while not being itself a star.
Secondly, the object must be large enough in mass for its own
gravity to pull it into a nearly spherical shape.
Therefore, Pluto would remain a planet, but fall in a newly created
category called Plutons, which are distinguished from classical
planets in that they reside in orbits around the sun that take
longer than 200 years to complete.
Pluto would be joined in this category by two other celestial
bodies, Xena and Charon, while another, Ceres, would be known as a
dwarf planet.
In all, 12 planets would be listed in our solar system, at least
for the time being.
