Why is pluto not a planet anymore?

well, because based on their propsed definition of a planet, pluto doesn't qualify for the criteria with regards to its mass. It satisfies only 1 criteria and according to them, 2 criteria must be satisfied in order to be called a planet.

It has not been decied yet if Pluto is a planet or not. The I.A.U. (international astrological union) a body of scientists which have been fromed to help regulate astrological matters, are working on a definition for planets. The current form would make Pluto and Charon both planets along with two other objects, also under this definition shortly the number of planets in out solar system would be moved up to 34, then to 54, and possibly beyond. The I.A.U. is has not yet accepted this definition and is still working. What looks wo be the most promising prospect for classifing planets is a sytem similar to how we classify stars. Having types like "dwarf planets" "Super massive gas giants" "Classic solid (rock) planets" and "Historical planets", where this will cause a lot of nameclature to be used it will allow for a great accurcy in the description of planetary bodies. In all it is pretty complicated trying to do something like this an so a definate answer will pobably not be coming soon.

To be considered a planet, a celestial body must:

1) orbit a star and not be a star itself

2) have enough mass to have formed a spherical or nearly spherical shape

By that definition, there are now twelve planets in our solar system:

1) Mercury

2) Venus

3) Earth

4) Mars

5) Ceres (formerly the largest asteroid)

6) Jupiter

7) Saturn

8) Uranus

9) Neptune

10) Pluto

11) Charon (formerly considered Pluto's moon)

12) "Xena" or 2003UB313 (newly discovered, and the reason for the hubbub)

As for astrology, I don't think Uranus, Neptune or Pluto were ever included in astrological signs and charts. If they were, then I don't see why the new planets couldn't be included as well!

Pluto is more like a comet than a planet, see below.

As for astrology --- astrology is not a science, it is non-science, it is nonsense.

copied from the link below

An increasing number of astronomers believe that Pluto, rather than being a planet, is really an unusually large comet whose true family lies within the Kuiper belt. In 1999, however, the International Astronomical Union (IAU) reaffirmed that Pluto was a planet because of its size and its satellite, something no comet was known to have, but recent discoveries have brought Pluto's status into question once again. One Kuiper belt object, designated 1988 W31, has a satellite, and another, 2002 LM60 (Quaoar), is more than half as large as Pluto.

I thought it is still not decided if Pluto is a planet? But anyway, in both way (planet or not) it will greatly affect astrology because of the three others (not decided if planets).

Pluto's status as a planet is the same as Austrailia's being a continent and Greenland not being...

"Planet" is just a term used by astronomers, it yet has no absolute definition. I am aware of 3 large "planetoids" further than pluto being known, the most recient being larger than pluto. However there is no 1 definition that makes Pluto a planet and this larger one remaining a planetoid.

pluto remains a planet according to the members of international asronomical union pluto remains a planet and we will have a new set of planets in our solar system 12 planets will now comprise our solar system ceres charon and xena ( 2003 ub313 ) plus the other 9 pluto included

Previous to today's decision, the biggest problem was that there were TNOs (Trans-Neptunian Objects) that were larger than Pluto. That means there were things like Pluto, only bigger, that were not considered planets.

What makes you think it is not a planet anymore ?

first they said it probobly was a star

then they said it was out of the soloar system but still was a planet then they made the solor system bigger becuz of that now they say it turned to pieces of rocks and gasses. thats all crazy isnt it