Biosignature Preservation and Detection in Mars Analog Environments

Abstract

This review of material relevant to the Conference on Biosignature Preservation and Detection in Mars Analog Environments summarizes the meeting materials and discussions and is further expanded upon by detailed references to the published literature. From this diverse source material, there is a detailed discussion on the habitability and biosignature preservation potential of five primary analog environments: hydrothermal spring systems, subaqueous environments, subaerial environments, subsurface environments, and iron-rich systems. Within the context of exploring past habitable environments on Mars, challenges common to all of these key environments are laid out, followed by a focused discussion for each environment regarding challenges to orbital and ground-based observations and sample selection. This leads into a short section on how these challenges could influence our strategies and priorities for the astrobiological exploration of Mars. Finally, a listing of urgent needs and future research highlights key elements such as development of instrumentation as well as continued exploration into how Mars may have evolved differently from Earth and what that might mean for biosignature preservation and detection. Key Words: Biosignature preservation—Biosignature detection—Mars analog environments—Conference report—Astrobiological exploration. Astrobiology 17, 363–400.

Table of Contents

Abstract

1. Executive Summary

2. Introduction

2.1. Habitable environments, biosignatures, preservation

3. Mars Analog Environments on Earth

3.1. Hydrothermal spring systems

3.1.1. Definition of hydrothermal spring systems

3.1.2. Habitability of hydrothermal spring systems

3.1.2.1. Habitability pros

3.1.2.2. Habitability cons

3.1.3. Biosignature preservation in hydrothermal spring systems

3.1.3.1. Biosignature preservation pros

3.1.3.2. Biosignature preservation cons

3.2. Subaqueous environments

3.2.1. Definition of subaqueous environments

3.2.2. Habitability of subaqueous environments

3.2.2.1. Habitability pros

3.2.2.2. Habitability cons

3.2.3. Biosignature preservation in subaqueous environments

3.2.3.1. Biosignature preservation pros

3.2.3.2. Biosignature preservation cons

3.3. Subaerial environments

3.3.1. Definition of subaerial environments

3.3.2. Habitability of subaerial environments

3.3.2.1. Habitability pros

3.3.2.2. Habitability cons

3.3.3. Biosignature preservation in subaerial environments

3.3.3.1. Biosignature preservation pros

3.3.3.2. Biosignature preservation cons

3.4. Subsurface environments

3.4.1. Definition of subsurface environments

3.4.2. Habitability of subsurface environments

3.4.2.1. Habitability pros

3.4.2.2. Habitability cons

3.4.3. Biosignature preservation in subsurface environments

3.4.3.1. Biosignature preservation pros

3.4.3.2. Biosignature preservation cons

3.5. Iron-rich environments

3.5.1. Definition of iron-rich environments

3.5.2. Habitability of iron-rich environments

3.5.2.1. Habitability pros

3.5.2.2. Habitability cons

3.5.3. Biosignature preservation in iron-rich environments

3.5.3.1. Biosignature preservation pros

3.5.3.2. Biosignature preservation cons

4. Exploring Past Habitable Environments on Mars

4.1. Common challenges

4.1.1. Identification of sites

4.1.1.1. Orbital observations for site selection

4.1.1.2. Surface observations

4.1.1.3. Sample collection

4.1.1.4. Mars 2020 rover instrument suite

4.1.2. Preservation

4.2. Orbital observations

4.2.1. Hydrothermal spring systems

4.2.2. Subaqueous environments

4.2.3. Subaerial environments

4.2.4. Subsurface environments

4.2.5. Iron-rich environments

4.3. Observations and sample selection on the ground

4.3.1. Hydrothermal spring systems

4.3.1.1. Observations

4.3.1.2. Sample selection

4.3.2. Subaqueous systems

4.3.2.1. Observations

4.3.2.2. Sample selection

4.3.3. Subaerial environments

4.3.3.1. Observations

4.3.3.2. Sample selection

4.3.4. Subsurface environments

4.3.4.1. Observations

4.3.4.2. Sample selection

4.3.5. Iron-rich environments

4.3.5.1. Observations

4.3.5.2. Sample selection

4.4. Strategies and priorities

5. Urgent Needs and Future Research

Acknowledgments

Author Disclosure Statement

References

Abbreviations Used