I think TheOnion put it well: http://www.theonion.com/content/node/56641 NASA Launches Probe To Inform Pluto Of Demotion In August, the International Astronomical Union downgraded Pluto to a dwarf planet. The panel of experts met to officially redefine the characteristics of a planet. To deliver the news to the distant orb about its newly lowered status, scientists at NASA's Kennedy Space Center launched a special messenger probe in September.

A giant Comet

It is considered a "minor planet", a new category it shares with Ceres and other.

It is considered a Dwarf Planet because it does not meet the specifications to be considered a planet.

Ceres, Pluto, Charon and 2003 UB313 are barely visible. Now Charon will continue to be considered Pluto's satellite, and the three other worlds will be dubbed "dwarf planets" rather than full-fledged planets. The planets are drawn to scale, but without correct relative distances.

Pluto is now considered a dwarf planet. In order for a body to be considered a planet, it must 1. be in an independent orbit around the sun, 2. have enough mass to pull itself in to a round shape, and 3. be able to clear its orbit of debris. Pluto fails on the third criterion. There is still a lot of debris in the neighborhood of its orbit. Thus is has been demoted to a dwarf planet. ************** "yohoho05: can't we just give it a little more time and see if it does clear this debris?" There was a very good article on this a few months ago in Scientific American. Unfortunately, I don't remember the exact issue other than that it was the last part of last year. Anyway, the upshot of the article is that Pluto and the other dwarf planets are incapable of clearing out their orbits because they simply lack the gravity to do so. All eight of the planets have arranged the debris in their neighborhoods so as to make collisions with this debris impossible. (This does not apply to debris that is on planetary orbit crossing paths. Just that which is in similar orbits.) They did this by either sweeping the debris up into the planets, ejecting the debris from their neighborhoods, or (in the case of Jupiter) forced them into Lagrangian points of stability (Trojan asteroids; http://en.wikipedia.org/wiki/Trojan_asteroid). Once again, the dwarf planets do not have the necessary gravity to do this. So, their orbits are still littered with other bodies in similar orbits.

Pluto is now considered a Plutoid, and any other similar celestial objects we find shall be called the same. http://www.iau.org/public_press/news/release/iau0804/

A has been.... Only collecting royalties from all those times it is referred to as a planet in syndication. :D

Well, one might, if one were so inclined, refer to it as a Heavenly Body. But I prefer these examples of that, so tough call.