The Venus Life Equation

TL;DR

The paper introduces the Venus Life Equation, a model to estimate the likelihood of extant life on Venus based on origination, robustness, and continuity, suggesting life could plausibly exist there today.

Contribution

It presents a new theoretical framework, the Venus Life Equation, to assess the probability of current life on Venus using environmental and astrobiological factors.

Findings

Probability of life origination on Venus similar to Earth

Other factors like robustness and continuity are likely nonzero

Identifies key unknowns for future Venus exploration

Abstract

Ancient Venus and Earth may have been similar in crucial ways for the development of life, such as liquid water oceans, land-ocean interfaces, favorable chemical ingredients and energy pathways. If life ever developed on, or was transported to, early Venus from elsewhere, it might have thrived, expanded and then survived the changes that have led to an inhospitable surface on Venus today. The Venus cloud layer may provide a refugium for extant life that persisted from an earlier more habitable surface environment. We introduce the Venus Life Equation - a theory and evidence-based approach to calculate the probability of extant life on Venus, L, using three primary factors of life: Origination, Robustness, and Continuity, or L = O x R x C. We evaluate each of these factors using our current understanding of Earth and Venus environmental conditions from the Archaean to the present. We find that the probability of origination of life on Venus would be similar to that of the Earth and argue that the other factors should be nonzero, comparable to other promising astrobiological targets in the solar system. The Venus Life Equation also identifies poorly understood aspects of Venus that can be addressed by direct observations with future exploration missions.