Ceres

• Ceres is a (dwarf) planet (just like Pluto and its moon Charon).
  
• Ceres is the largest asteroid in the asteroid belt in the gap between Mars and Jupiter where
  one would maybe expect a planet if it weren't for the large gravitational disturbances of Jupiter.
• Ceres is one on the bodies in our solar system where a subsurface water ocean and cryovolcanism is suspected.

Why is Ceres interesting in regards to advanced APM:

• The challenge of exploring and eventually exploiting cryovolcanic channels robotically.
• Gravitative material differentiation may have led to a different chemical composition near the surfaces. Maybe more volatile ices close to the on the surface under a dust cover? This may be of interest for colonization given that volatiles are otherewise still scarce at these "close" distances from the Sun (TODO: do more fact checking here).