Valuing life detection missions

TL;DR

This paper discusses the importance and value of conducting life detection missions on other planets and moons, proposing a framework to evaluate their scientific worth, emphasizing hypothesis testing even in case of nondetections.

Contribution

It introduces a quantitative framework for assessing the scientific value of life detection missions, advocating for hypothesis testing to maximize scientific return.

Findings

Life detection missions are valuable for testing hypotheses about extraterrestrial life.

A framework is proposed: (Reach x grasp x certainty x payoff) / cost.

Hypothesis testing enhances scientific value, even with nondetections.

Abstract

Recent discoveries imply that Early Mars was habitable for life-as-we-know-it; that Enceladus might be habitable; and that many stars have Earth-sized exoplanets whose insolation favors surface liquid water. These exciting discoveries make it more likely that spacecraft now under construction - Mars 2020, ExoMars rover, JWST, Europa Clipper - will find habitable, or formerly habitable, environments. Did these environments see life? Given finite resources (\$10bn/decade for the US ), how could we best test the hypothesis of a second origin of life? Here, we first state the case for and against flying life detection missions soon. Next, we assume that life detection missions will happen soon, and propose a framework for comparing the value of different life detection missions: Scientific value = (Reach x grasp x certainty x payoff) / \$ After discussing each term in this framework, we conclude that scientific value is maximized if life detection missions are flown as hypothesis tests. With hypothesis testing, even a nondetection is scientifically valuable.