Building robust conceptual models in the search for life beyond Earth ? terrestrial and extraterrestial hydrothermal systems

CAMPBELL, K.; GUIDO, D.; VAN KRANENDONK, M.; RUFF, S.; FARMER, J.; WESTALL, F.; DJOKIC, T.

Conferencia; 2018 TAM Conference; 2018

?Follow thewater? ? hot or cold ? has been a key component in exploration of the martiansurface for habitable environments and potential signs of ET life for more than20 years, as liquid water is essential for life as we know it. This ?mantra? guidescurrent and planned orbiter and robotic missions to Mars, including samplereturn proposals. It also has been applied to the outer Solar System, whereEnceladus and Europa send jets of water ice into space, potentially driven byhydrothermal circulation arising from the floors of liquid-water oceans beneaththe moons? fractured ice shells. Some suggest life may be lurking in oceanic hydrothermalvents on these Icy Worlds. In the case of Mars, where water once flowed acrossthe surface ~3 billion years ago, several types of ancient, water-laidsedimentary settings have been identified as favourable targets in the searchfor (fossil) life beyond Earth. Clement conditions for life to haveoriginated/survived on Mars? surface were fleeting, and the obvious?biosignatures? that are replete on Earth are lacking there. Research on bothterrestrial and martian hydrothermal systems over the past 20 years has led todevelopment and refinement of robust conceptual models, underpinned by nestedscales of observation in the field and laboratory, which have advanced ourunderstanding of where and how life may most likely have been preserved. Thus,such studies substantially help narrow search windows in the quest to find asecond outpost of life in the Solar System.