Crystal Habits as Potential Biosignatures.

Our understanding of crystalline structures within terrestrial planetary analog environments can shed light on how these features can be interpreted on rocky planets and icy moons in our solar system. The ability to distinguish biogenic and abiotic components within the mineral, crystal, and structural features allows us to inform future life detection missions, science payloads, and instrument measurement resolutions. Moreover, having these terrestrial reference measurements in a review format allows the measurement rationale to be understood in the context of mission concepts and geomicrobiological assessment of life in extreme environments.

Laminae as Potential Biosignatures.

Laminae are millimeter-scale features in rocks created by physiochemical processes that can be influenced by the presence and activities of communities of organisms that occur as biofilms and microbial mats. The structure and composition of laminae reflect the processes involved in their formation and can be preserved in the rock record over geologic time; however, diagenetic and metamorphic alteration can lead to the loss of primary information and confusion over the interpretation of their origins. As potential records of ancient life, laminae can preserve evidence of microbial activity over billions of years of Earth's history.