Why is Pluto not classified as a planet?

Answer 1

It is two planets together as it shares its center of gravity with Charon in the space between them.

Pluto is not classified as a planet because of several reasons. one reason is that its moon is about half the size of the planet, and no planets moon is even close to being half the planets size (it goes into gravitational laws and gets pretty complicated so lets leave it at that). another reason is that plutos planet is not elliptical. All the planets orbits are elliptical, for the most part. Elliptical is not spherical, but not necessarily oval either. its like a slightly stretched sphere, but not stretched enough to be oval. Plutos orbit crosses over neptunes. one last reason is that there have been objects found past Pluto that are very similar to Pluto, in size and appearance, and these objects are not planets there are more like comets or asteroids, so it is possible that Pluto is one of these objects in close range to the sun.

A lot of debate still rages over this decision. The most common argument is that Neptune can't be a planet either because it hasn't cleared its neighborhood of Pluto. The idea of dwarf planets isn't a bad one, but we need a far more static criteria to sort out what is an asteroid, a dwarf planet, and a planet.

Neptune is most definitely a planet.

Answer 2

Its debatable, some people don't like it being classified as a dwarf planet and would rather it remain as one of the main planets. It was known as the ninth planet for a long time, from its discovery in 1930 to its reclassification in 2006.

With newer objects being discovered of a similar size (or even larger in the case or Eris) we either had to add to the list of planets, call a stop and just leave the nine planets as they were or reclassify what a planet actually is.

Pluto was re-classified as a dwarf planet on August 24th 2006 by the International Astronomical Union (IAU). A new definition for a planet was established, Pluto did not fit the new criteria, so was deemed a dwarf planet - known to be spherical in shape and orbit the sun directly, but not dominating its orbit like all 8 remaining planets.

Answer 3

Pluto is not classified as a planet because in 2006, the International Astronomical Union redefined what a planet is and Pluto failed to meet one of the new criteria, which required a planet to clear its orbit of other debris. Pluto shares its orbit with other objects in the Kuiper Belt, so it was reclassified as a dwarf planet.

Answer 4

No, it is a dwarf planet.