Introductory Astronomy: 

Pluto and Kuiper Belt

Direct HST image of Pluto and its moon Charon

Surface-feature map of Pluto constructed from multiple eclipses by Charon.

Same as last figure, but with Charon included. Shown are the face of Pluto that always faces Charon, and the face of Charon that always faces away from Pluto.

Red line indicates whether the object passes within Neptune's orbit near perihelion.

Same as previous figure, but larger scale and bigger object list. Red dot in lower panel is Pluto. Objects that inhabit Neptune's 3:2 resonance are dubbed "Plutinos."

Johnston's Up-to-date Version

Sedna has a semi-major axis length of 500 A.U., making it the most distant of known minor planets.