Pluto not a Planet?
September 3, 2006 11:23am CST
Recently it was declared that pluto is actually not a planet... It doesnt have the characteristics of a planet. It is just a mass of stone revolving around sun... Do you have more details about this?
3 Sep 06
here is what i have extracted from that link: Pluto is a dwarf planet in the solar system, orbiting 29 - 49 AU from the Sun. About a fifth the mass of the Moon, Pluto is primarily composed of rock and water ice. It has an eccentric orbit that is highly inclined with respect to the planets and takes it closer to the Sun than Neptune during a portion of its orbit. Pluto and its largest satellite Charon have often been considered a binary system because they are more nearly equal in size than any of the planet/moon combinations in the solar system, and because the barycentre of their orbits does not lie within either body. Two smaller moons named Nix and Hydra were discovered in 2005. Pluto is smaller than several of the natural satellites or moons in our solar system (see the list of solar system objects by radius). From its discovery by Clyde Tombaugh in 1930, Pluto was considered the ninth planet from the Sun. In the early 21st century, many similar objects were discovered in the outer solar system, notably 2003 UB313 (nicknamed "Xena") which is slightly larger than Pluto. In 2006 the International Astronomical Union's (IAU) redefined the term "planet", and classified Pluto (along with several other trans-Neptunian objects and the asteroid Ceres) as a dwarf planet. Pluto is also classified as the prototype of a family of trans-Neptunian objects.. Pluto's astronomical symbol is a P-L monogram. This represents both the first two letters of the name Pluto and the initials of Percival Lowell, who had searched extensively for a ninth planet and who had founded Lowell Observatory, the observatory from which Tombaugh discovered Pluto. Besides its astronomical symbol Pluto also has an astrological symbol. Pluto's astrological symbol resembles that of Neptune, but has a circle in place of the middle prong of the trident.