Abstract
This chapter argues that Earth is unique among the planets in the solar system, primarily because of its vast oceans of water. Despite decades of research, the source of much of the Earth’s water is still controversial. Many scientists today believe that life arose in a primordial pudding of clay and water. The chapter explains how shallow clay pools can promote the synthesis of macromolecules and how, at the start of life on Earth, they accumulated the building blocks of life. It explains how life arose in close proximity to hydrothermal vents, which were openings in the seafloor. Heated mineral-rich water flowed out of these vents and created the right environment for life to begin. The chapter points out that it is not an accident that life arose in association with water, whatever its origin, because this substance has several unusual properties that suit it to be the matrix of life. Among these are its thermal properties and unusual solvent characteristics. Water’s properties are directly related to its molecular structure.
