The Paleo-Environment Reconstruction on Mars: Focus Points for the next Astrobiology Missions

Abstract

The reconstruction of past environmental conditions is important for estimation of the astrobiology potential and to support the targeting of future missions for Mars. Reviewing those observable features (e.g., paleo-environment indicators) that help such reconstruction is important, as they provide focus for current and future research, both in remote and in situ activities, as are Earth based laboratory analysis and simulation. In this work, these indicators are collected and characterized, focusing on the available data, uncertainties, missing information and targets of future research work. These indicators can be classified into groups of: surface morphological (kilometre spatial scale, water and ice related surface structures like fluvial channels, alluvial fans, banks, etc.); in situ m-µm spatial scale features (observable especially in vertical outcrops); and mineralogical (mineral types, OH content). Based on the collected indicators, good general (although not complete) knowledge is available on surface morphological features. Whereas information can be extrapolated from these data regarding the liquid water or frozen ice volume, and temperature, during the formation of certain features, information on pH and salt content, as well as temporal issues, can be only poorly estimated. Mineral paragenesis and different types of indicators should be used together to further support the interpretation. The missing data regarding certain environmental conditions represent the directions for future research.