Although biologists do not agree on what “life” is, given a few provisions, we understand the smallest unit is a cell bounded by a membrane across which is an electrochemical potential far from thermodynamic equilibrium. In the early part of the 20th century, Vladimir Vernadsky recognized that all cells exchange gases with the environment. These universal properties of life on Earth gave rise to a global scale electrical circuit, powered almost exclusively by light. The atmosphere and oceans are, in effect, planetary “wires” that connect the circuit from the power supply (light) to the biological transistors (“life”). The global scale electrical circuit has altered the gas composition of the planet to such an extent that the planet itself is essentially analogous to a cell in a vast sea of extrasolar planets, most of which appear not to harbor life. In this talk, I will focus on how abiotic reactions potentially led to autocatlytic processes. I will further explore how the evolution of the microscopic nanomachines that are the core of “life’s engines” became an emergent property that forms an unmistakable signature of life on a planetary scale.