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Over the past several decades it has become increasingly clear that there may be multiple worlds in our solar system besides Earth that either once had or may still have environments capable of supporting microbial life as we know it. Our current NASA supported research is focused on four aspects of the search for life in our solar system: 1. Since its discovery on Mars in 2008, the widespread occurrence of perchlorate (ClO4-) has been confirmed by its detection in Mars meteorites and by the Curiosity and Perseverance rovers. Photochemically, it can be produced by UV irradiation of Cl-bearing minerals where silica and metal-oxides act as photocatalysts to generate O2-, which then reacts with chlorine to form oxychlorines (ClOx) as well as radicals (‧OCl, ‧Cl, and ‧OH). We are investigating ClOx reaction pathways to help answer fundamental questions about the martian surface chemistry and help guide future missions as to what types of biomarkers/fragments we might expect, their effects on potential indigenous microbial life, and their possible health effects on human explorers and habitats on Mars. More > 2. In the search for past or present life on Mars, our goal is to understand how biologically-produced molecules (biomarkers) are altered when exposed to solar UV irradiation in the presence of oxychlorines (ClOx) and their intermediate products, and if the resulting “fragmentation” patterns can be used, in conjunction with the Molecular Assembly index, to identify the original biomarker and thus provide evidence for life on Mars. More > 3. We are developing microfluidic electroanalytical instrumentation, based on the Phoenix Mars lander Wet Chemistry Lab, to determine (a) the habitability of the subsurface oceans of Saturn's moon Enceladus by analyzing the ejected ice particles collected by transits through the plumes, and (b) to sample and study the chemistry of the martian surface materials. More > 4. The effects of the: oxidizing soil chemistry; intense UV irradiation; and hyperaridity; on bacterial survival and growth in the Atacama Desert, Antarctic Dry Vallys, and other extreme environments on Earth and Mars. More> |