BIOAVAILABILITY OF ORGANICS FOR LIFE IN THE SOLAR SYSTEM

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Our understanding of planetary habitability is necessarily limited to our knowledge of life on Earth. A fundamental and as yet underexplored component of habitability is the availability of organic chemical energy for growth. Potentially habitable planetary bodies like Mars and Europa host a plethora of inorganic compounds that could be used as sources of energy (for instance ferric iron, sulfate in minerals and perchlorate at and near the surface), but the availability of organic substrates for growth in anaerobic microbial metabolism is not well understood. This project will combine experimental and molecular microbiology, geochemistry and energetic predictions to assess the ability for microbial life to be fuelled by organic material prevalent in carbonaceous meteorites. These meteorites have rained down on planetary bodies for billions of years, hence organic carbon is not expected to be limiting. Indeed, complex organic matter akin to that found in carbonaceous chondrites was recently detected at Gale Crater on Mars. Most life on Earth uses organic carbon as a substrate for growth, yet the extent to which the myriad organic compounds in meteorites expected to be present on Mars and other potentially habitable planetary bodies is unknown. This represents a critical knowledge gap to our understanding of habitability beyond Earth, and is the focus of this exciting multidisciplinary Astrobiology PhD project.