Introduction: Oceans on Earth and Elsewhere

Abstract

Samuel Taylor Coleridge’s ancient mariner lamented, “Water, water, everywhere, nor any drop to drink.” Today, it seems that planetary scientists are faced with the same situation. Drinking aside, the prospect of oceanic planets and moons scattered across the cosmos is brighter than ever. During its first 3 years of operation, NASA’s planet-hunting Kepler spacecraft tracked down somewhere in the neighborhood of 100 planet candidates that appear to be in the “habitable zone” around their parent stars. In other words, these planets, or moons circling planets in the case of giant planets, have the capacity to support liquid water on their surfaces.