Judging the Habitability of Extraterrestrial Planet Based on Structure of the Earth: Is the Plate Tectonic Essential for Existing Life

Abstract

The search for extraterrestrial life is one of the most significant areas of scientific investigation, with a focus on identifying habitable planets beyond Earth. This review critically demonstrates the role of plate tectonics in life formation, based on the theory foundation that humans had discovered on Earth. The Earth's structure and its geodynamic processes are used as a model for assessing the potential habitability of other planetary bodies. Plate tectonics on Earth plays an important role in regulating climate stability, maintaining the magnetic field, and reshaping the surface. They are all supporting the necessary conditions for life. As plate tectonics on Earth are deeply linked with habitability, several exoplanets, such as Mars, Venus, and the icy moons of Jupiter (Europa), have shown that planets without plate tectonics may have the potential of forming life. Mars, for instance, has shown limited evidence of plate tectonics happening, but scientists suggest that its subsurface could still offer conditions for life. Venus has a thick crust and a lack of tectonic activities, but with unique volcanic and tectonic features that suggest the possibility of internal dynamic processes without traditional plate subduction. Europa is covered by a thick icy crust, and it is suggested that the existing subsurface ocean can be maintained by tidal heating rather than tectonics. The article discusses how habitability is not only dependent on plate tectonics but relies on a combination of factors, including liquid water, energy sources, and chemical disequilibrium. As a result, plate tectonics may not be the restrictive feature for a planetary body to have life.