ALLUVIAL FANS AS POTENTIAL SITES FOR PRESERVATION OF BIOSIGNATURES ON MARS

Water is an important central theme in astrobiology. In order for life as we know it to support itself on another planet, a source of water is required. There are several sources of water that have been discovered on Mars. At present, the majority of the sources of water are unavailable, but there were periods in Mars’ geologic history that water was available for life. The next step in discovering life is looking for bio-signatures. Bio-signatures can be anything from isotopes to elements to DNA. A method to preserve the bio-signatures is necessary to study the bio-signatures in present day. Preserved bio-signatures keep information about extinct Mars habitability intact to study further when found. One naturally occurring way to preserve bio-signatures is clay hydrogels. Clay hydrogels are bio-polymers that form when clay minerals come in contact with and interact with water. The clay and water create a confining environment protecting DNA and RNA functions inside the polymer. Potential sites to look for clay hydrogels are alluvial fans, plentiful in the southern hemisphere of Mars. Alluvial fans are characterized as landforms that make a semi conical shape out of sediment deposits forming as water carries the sediment from a steep slope upstream to an unconfined drainage outlet downstream, often in flatter terrain. Due to their mineral composition, water origin, and location through-out Mars, alluvial fans are the perfect site to investigate in the search for preserved bio-signatures.