Pluto is no longer a planet...

Today, I read that scientists have removed Pluto's status as a planet, because the International Astronomical Union (IAU) has voted on August 16, 2006 on a new definition as to what a planet is. The definition is as follows: "a celestial body that is in orbit around the sun, has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a ... nearly round shape, and has cleared the neighbourhood around its orbit."

And since Pluto's orbit overlaps with Neptune, it is no longer a planet by this definition. It is however, a "dwarf planet", which is a category for minor planets.

I do not understand why scientists felt it was necesary to redefine the definition of a planet. The study of planets, is not a social science, and new terms are not being constantly constructed. Is this study becoming so boring that they need to redefine new terms so that there is meaning to their work?

What I find troublesome and flawed with this new definition is that Pluto is no longer a planet, because its orbit overlaps with Neptune, but an asteroid (mostly Ceres, discovered in 2003) can be considered, since it is a celestial body that is in orbit around the sun, has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a ... nearly round shape, and has cleared the neighbourhood around its orbit.

And thank goodness that the series Sailor Moon has stopped production. Because if they haven't, they would have needed to change the name of Sailor Pluto, since she can no longer be a Sailor Scout, as Pluto is no longer a planet. They would have to kill off the guardian of time, or rename her Sailor Ceres or Sailor UB313.

What's next? Scientists redefining definitions in biology, because they believe the cell should be required to be seen under the naked eye in a student-model microscope? Anything that is smaller needs to be classified as a dwarf-cell?