On August 24, 2006
, astronomers had resolved to demote Pluto as a part of the cosmic club. Also on this date, it was officially declared that there are only 8 planets in the solar system
Because, Pluto is considered as a dwarf planet. Under the definition - dwarf planets are not planets.
It is recognized as a new classification of Trans - Neptunian Objects
This resolution (to remove Pluto from the line of planets in the Solar System)
was done by vote. And out of the 10,000 professional astronomers around the globe only 424 astronomers were allowed to vote. (Which is even less than 5% of the world's astronomers.)
A scientist tagged the definition (dwarf planet & categorized as TNO)
as farce and absurd! And said that the astronomers are already spreading around an appeal involved to reverse the IAU (International Astronomical Union) resolution.
Some astronomers attacked the definition as vague
a touch of history*
Venetia Burney Phair - 11 year old British girl who gave the Planet X Pluto its name. On May 1930, the planet was officially called Pluto. Pluto was the Greek god of the underworld.