Thresholds of Detection and Identification of Halite Nodule Habitats in the Atacama Desert Using Remote Imaging

The guiding theme of Mars exploration is shifting from global and regional habitability assessment to biosignature detection. To locate features likely to contain biosignatures, it is useful to focus on the reliable identification of specific habitats with high biosignature preservation potential. Proposed chloride deposits on Mars may represent evaporitic environments conducive to the preservation of biosignatures. Analogous chloride- bearing, salt-encrusted playas (salars) are a habitat for life in the driest parts of the Atacama Desert, and are also environments with a taphonomic window. The specific geologic features that harbor and preserve microorganisms in Atacama salars are sub- meter to meter scale salt protuberances, or halite nodules. This study focuses on the ability to recognize and map halite nodules using images acquired from an unmanned aerial vehicle (UAV) at spatial resolutions ranging from mm/pixel to that of the highest resolution orbital images available for Mars.