My Very Educated Mother Just Served Us Nine.... dwarf planets?

That's right. Children are going to have to use a different mnemonic device to help them memorize the order of the eight planets of our solar system. Pluto has been demoted. We always knew that pluto is weird. It is way smaller than the other planets, less spherical, and the biggest conundry is that it has its own orbital plane. I've wondered several times in the past why it is even considered a planet, when it is so different from everything else that we call "planet". Apparantly the scientific community thought I was onto something, because just this week there was a vote by the International Astronomical Union on a more complete definition of the word "planet." This new definition excludes objects such as pluto as well as other recently discovered objects (which are very similar to pluto) This is what they decided:

RESOLUTIONS
Resolution 5A is the principal definition for the IAU usage of "planet" and related terms.Resolution 6A creates for IAU usage a new class of objects, for which Pluto is the prototype. The IAU will set up a process to name these objects.IAU Resolution: Definition of a Planet in the Solar SystemContemporary observations are changing our understanding of planetary systems, and it is important that our nomenclature for objects reflect our current understanding. This applies, in particular, to the designation 'planets'. The word 'planet' originally described 'wanderers' that were known only as moving lights in the sky. Recent discoveries lead us to create a new definition, which we can make using currently available scientific information.RESOLUTION 5AThe IAU therefore resolves that "planets" and other bodies in our Solar System be defined into three distinct categories in the following way:(1) A "planet"1 is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit.(2) A "dwarf planet" is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape2 , (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite.(3) All other objects3 except satellites orbiting the Sun shall be referred to collectively as "Small Solar-System Bodies".
1The eight planets are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.2An IAU process will be established to assign borderline objects into either dwarf planet and other categories.3These currently include most of the Solar System asteroids, most Trans-Neptunian Objects (TNOs), comets, and other small bodies.
IAU Resolution: PlutoRESOLUTION 6AThe IAU further resolves:Pluto is a "dwarf planet" by the above definition and is recognized as the prototype of a new category of trans-Neptunian objects.1

A probe is currently on its way to pluto to collect more information about these objects laying in the outskirts of our solar system. By the way, I like the word "trans-neptunian"; they made up a word in order to make the definition of an existing word less vague.. great. Except sometimes Pluto orbits closer to the sun than Neptune, so maybe they'll have to revise this one too!*sigh* life was so much simpler before the geeks started to rule the world!