Thank you for accurately pointing out that the debate over Pluto's planet status is far from settled. Umost objects in the Kuiper Belt, it has attained hydrostatic equilibrium, meaning it has enough self-gravity to have pulled itself into a round shape. When an object is large enough for this to happen, it can become differentiated with core, mantle, and crust, just like Earth and the larger planets, and can develop the same geological processes as the larger planets, processes that inert asteroids and most KBOs do not have. Ceres meets this criterion and should have its planet status restored as well.
Not distinguishing between shapeless asteroids and objects whose composition clearly makes them planets is a disservice and is sloppy science. As of now, there are three other KBOs that meet this criterion and therefore should be classified as planets—Haumea, Makemake, and Eris. Only one KBO has been found to be larger than Pluto, and that is Eris.
Not distinguishing between shapeless asteroids and objects whose composition clearly makes them planets is a disservice and is sloppy science. As of now, there are three other KBOs that meet this criterion and therefore should be classified as planets—Haumea, Makemake, and Eris. Only one KBO has been found to be larger than Pluto, and that is Eris.