The Possible Others

In this chapter, we continue our exploration of the potential ocean worlds, this time focusing our attention on the planetary objects that might host a subsurface ocean, but for which we have limited observational data to confirm this hypothesis at present. For each object, we go into detail on their discovery, any missions that have ventured to explore them, if applicable, and endeavor to describe the hypothetical characteristics of their potential subsurface oceans. The objects we review here are the moon of Saturn, Rhea, and the moons of Uranus, Titania and Oberon. We also review Kuiper Belt Objects such as Charon, Makemake, Quaoar, Salacia, Orcus, and 2002 MS4, as well as Scattered Disk Objects such as Eris, Gonggong, and Sedna. In doing so, we also consider their habitability and potential to host extraterrestrial life.