Newly Proposed Habitable Trinity Concept and the Possibility of Life on Mars, Europa, and Titan

Abstract

Habitable Trinity is a new concept for a habitable environment proposed by Dohm and Maruyama (2015). This concept indicates that the coexistence of an atmosphere, an ocean, and a landmass, accompanied by a continuous circulation of material among these three components driven by the Sun, is one of the minimum requirements for life to emerge and evolve. Because a life body consists of carbon (mainly from the atmosphere), oxygen (mainly from an ocean), hydrogen (mainly from an ocean), nitrogen mainly from the atmosphere), and various nutrients (supplied from a landmass), the presence of water alone is not a sufficient condition. The Habitable Trinity concept can also be applied to other planets such as Mars, Europa, and Titan, and even exoplanets, as a useful index in the quest for life-containing planetary bodies.