Objectives: this proposal will enhance the scientific basis upon which NASA formulates and implements search-for-life strategies on ocean worlds. Anticipating that the diversity of ocean worlds may…

This is a $6,105,565.00 grant awarded by NASA to the Woods Hole Oceanographic Institution (WHOI) to enhance the scientific basis for NASA's search-for-life strategies on ocean worlds. The objectives are to: 1) construct a theoretical framework to quantify the dependence of biological and biosignature potential on geophysical and (bio)geochemical processes, and 2) identify the most diagnostic observable features for determining these potentials. This interdisciplinary effort will integrate astrobiology, ocean system, and planetary sciences to improve the interpretation of existing and planned observations (e.g., Cassini, Europa Clipper) and help prioritize new measurement capabilities for ocean world exploration. The award is not a set-aside contract. WHOI, a private non-profit research organization, will lead this project, which directly supports NASA's Astrobiology Strategy 2015 objectives related to identifying, exploring, and characterizing habitable environments and biosignatures.

Objectives: this proposal will enhance the scientific basis upon which NASA formulates and implements search-for-life strategies on ocean worlds. Anticipating that the diversity of ocean worlds may vary greatly in the abundance and productivity of life they could support (their biological potential) and the nature and abundance of evidence for life they could manifest (their biosignature potential), we ask: on which ocean worlds, and with what measurements, will we have the greatest potential to successfully detect the presence of life? We will integrate astrobiology, ocean system, and planetary sciences to pursue this question, guided by two basic principles:(i) both biological potential and biosignature potential are governed by a network of geophysical and (BIO) geochemical processes, not just static conditions;(II) to be of greatest utility, efforts to quantify biological potential and biosignature potential must identify which observable features are most diagnostic of that network of processes. With this basis, our principle objectives are to (1) construct and employ a theoretical framework to quantify the dependence of biological and biosignature potential on geophysical and (BIO)geochemical processes; (2) conduct an extensive sensitivity analysis to identify which observable features would be most powerfully diagnostic of processes that determine biological and biosignature potential. The latter analysis will identify high priorities for research and development to support the search for life on ocean worlds, particularly spacecraft measurement capabilities that can best resolve biological and biosignature potential, and understudied ocean system processes and settings, for which earth analogs should be sought. Implementation: we will address these objectives by constructing a comprehensive theoretical framework, informed and groundtruthed by experimental efforts that connects the broad spectrum of physical and chemical processes that could govern the fluxes of material and energy within an ocean system, and thereby determine biological and biosignature potential. The processes active within any ocean are integrated at the system scale, respecting no disciplinary boundaries. Consequently, we have assembled a team with a diversity of expertise in astrobiology together with leaders in the study of processes across the various interfaces of the earth-ocean-life system. Our team members will work across a network of six interconnected investigations. Each investigation is inherently interdisciplinary in itself but, as in earth s oceans, we predict that IT will be at the interfaces between these different sets of investigations that our most exciting and original discoveries will be made. Our goal is thus to move beyond the modeling and experimental efforts planned for each component of the system, to explore the feedbacks and interconnections among those components. We will do so with dedicated synthesis activities that engage both within and beyond our team, to develop a flexible interpretive framework that integrates a diversity of geophysical and geochemical observations to quantify biological and biosignature potential of any ocean world. Significance: our project aims to develop a new culture at the intersection of astrobiology and oceanography, where both disciplines can build on insights and methodology gained from each other. We are directly responsive to major topic 5 of the NASA astrobiology strategy 2015 identifying, exploring and characterizing environments for habitability and biosignatures and our work will both broaden and deepen collaboration within the NAI, particularly through bridging between and adding broader context to can 7 teams: rock powered life and ICY worlds. Our work will improve the confidence with which we can interpret existing and planned observations (e.g., cassini, europa clipper) and help prioritize development of new measurement capabilities for ocean world exploration.