section_path: Overview/Solar System planetary bodies
section_name: Solar System planetary bodies
paragraph_text: Solar System planetary bodies
  
  Ocean worlds are of interest to astrobiologists for their potential to develop life and sustain biological activity. Major moons and dwarf planets in the Solar System thought to harbor subsurface oceans are of interest because they can be reached and studied by space probes, in contrast to exoplanets, which are light-years away, beyond the reach of current technology. The best-established water worlds in the Solar System, other than the Earth, are Callisto, Enceladus, Europa, Ganymede, and Titan. Europa and Enceladus are considered compelling targets for exploration due to their thin outer crusts and cryovolcanic features.
  
  Other bodies in the Solar System are considered candidates to host subsurface oceans based upon a single type of observation or by theoretical modeling, including Ariel, Titania, Umbriel, Ceres, Dione, Mimas, Miranda, Oberon, Pluto, Triton, Eris, and Makemake.