Thursday, August 24, 2006
From hero to zero?
Pluto was demoted to "dwarf" status when astronomers meeting in the Czech capital voted on a formal definition for the term "planet".
Experts have been divided over whether Pluto - further away and considerably smaller than the eight other planets in our Solar System - deserves the title.
Since the early 1990s, astronomers have found several other objects of comparable size to Pluto in an outer region of the Solar System called the Kuiper Belt.
Some astronomers believe Pluto belongs with this population of small, icy "Trans-Neptunians", not with the objects we call planets.
Allowances were once made for Pluto on account of its size. At just 2,360km (1,467 miles) across, Pluto is significantly smaller than the other planets. But until recently, it was still the biggest known object in the Kuiper Belt.
The big question now is which Dwarf will he be - Sneezy, Sleepy, Happy, Grumpy, Dopey, Doc, or Bashful.