I did a ton of reading after this Pluto craze, and there's some interesting history to the discovery (and following classification) of planets/objects in our system.
Ceres was initially called the fifth planet. After that, we began discovering larger members of the asteroid belt to the point that Jupiter was once considered the 20th (!) planet orbiting our snazzy star.
It's funny that everyone makes a stink about Pluto, but Ceres gets no love.
Ceres is (sort of) to the asteroid belt as Pluto is to the Kuiper Belt*
* The Kuiper Belt is also far more massive than the asteroid belt, so let's say "to scale". Fun fact, many scientists and space geeks have theorized there may be 20, 30, or even a ridiculous number of dwarf planets further out but still under the influence of our son. I believe Pluto is around 40-45AU (astronomical unit = earths distance from the sun); speculation has placed planets at 1000-1500AU.. Really far out, man.
Check out Sedna and others from this image if you're bored.
