Confirmed and Proposed Missions to the Ocean Worlds
The last two decades of space exploration have been remarkable. No less than five ocean worlds have been identified in our Solar System, and, as we have seen throughout the last chapters, there is potential for more. Not only is the volume of liquid water currently orbiting our Sun (in moons and potentially dwarf planets) vastly greater than what we have on Earth, the fact that a good proportion of it is in direct contact with rocks and organic compounds is astounding. This represents a shift from how we previously understood our Solar System. If you recall from Chapter 6, it was only in 1971 when astronomer John S. Lewis first proposed that liquid water might exist under the icy crust of small planetary objects such as moons. Even though few supported this idea at the time, these days scientists recognize that instead of being the exception, such water habitats might be the norm within our Solar System.