Many star gazers and amateur astronomers breathed a sigh of relief today as Pluto escaped being reclassified as a non-planet. Instead of downgrading Pluto, the Solar System has been split into two tiers of classification.
The eight classical planets still remain unchanged, however Pluto lends its name to a sub-catergory, called Plutons. The new catergory includes Charon, which was previously thought to be Pluto’s moon, but is now thought of as a sister planet.
Other newcomers are Ceres, the biggest asteroid in nthe Solar system and 2003 UB303 (Xena). This now makes the total number of planets in the solar system 12. Under the guidelines other small planets could soon join the solar system such as some of the Plutinos and Sedna
The plan has been drawn up by the International Astronomical Union (IAU) with the aim of settling the question of what does and does not count as a planet.