Habitability: a Process Versus a State Variable Framework With Observational Tests and Theoretical Implications (International Journal of Astrobiology, 2021)

• Adrian Lenardic

Full Citation:
Lenardic, A., & Seales, J. (2021). Habitability: a process versus a state variable framework with observational tests and theoretical implications. International Journal of Astrobiology, 1–8. https://doi.org/10.1017/s1473550420000415

Abstract:
The term habitable is used to describe planets that can harbour life. Debate exists as to specific conditions that allow for habitability but the use of the term as a planetary variable has become ubiquitous. This paper poses a meta-level question: What type of variable is habitability? Is it akin to temperature, in that it is something that characterizes a planet, or is something that flows through a planet, akin to heat? That is, is habitability a state or a process variable? Forth coming observations can be used to discriminate between these end-member hypotheses. Each has different implications for the factors that lead to differences between planets (e.g. the differences between Earth and Venus). Observational tests can proceed independent of any new modelling of planetary habitability. However, the viability of habitability as a process can influence future modelling. We discuss a specific modelling framework based on anticipating observations that can discriminate between different views of habitability.

URL:
https://doi.org/10.1017/s1473550420000415

VPL Research Tasks:
Task C: The Habitable Planet
Task E: The Observer