Ocean worlds in our solar system

Spacecraft-based missions have discovered an increasing number of ocean worlds in our Solar System, with even more candidates awaiting confirmation. The science of ocean worlds shares some commonalities with that of Earth's oceans, making them exciting targets of future exploration. A major known difference, however, is that ice shells up to tens of kilometers thick may present barriers to the introduction of chemical gradients necessary for life's development over the long term. Hence, ocean worlds differ substantially in terms of their energy budget and chemistry, with Europa and Enceladus being currently considered the most promising candidates for life-search missions.