Habitability Models for Astrobiology

TL;DR

This paper reviews and compares habitability models from ecology and astrobiology, proposing integration to improve the assessment of habitable environments and guide future research and exploration.

Contribution

It introduces a framework for integrating ecological and astrobiological habitability models to establish new standards for evaluating planetary habitability.

Findings

Comparison of ecological and astrobiological models

Proposal for integrated habitability standards

Potential to improve target selection for exploration

Abstract

Habitability has been generally defined as the capability of an environment to support life. Ecologists have been using Habitat Suitability Models (HSMs) for more than four decades to study the habitability of Earth from local to global scales. Astrobiologists have been proposing different habitability models for some time, with little integration and consistency among them, being different in function to those used by ecologists. Habitability models are not only used to determine if environments are habitable or not, but they also are used to characterize what key factors are responsible for the gradual transition from low to high habitability states. Here we review and compare some of the different models used by ecologists and astrobiologists and suggest how they could be integrated into new habitability standards. Such standards will help to improve the comparison and characterization of potentially habitable environments, prioritize target selections, and study correlations between habitability and biosignatures. Habitability models are the foundation of planetary habitability science and the synergy between ecologists and astrobiologists is necessary to expand our understanding of the habitability of Earth, the Solar System, and extrasolar planets.