Bio/organic compound detection using sodium sulfate minerals: Implications in the search for life on Mars and Europa

With the discovery of Na-sulfate minerals (thenardite, mirabilite) on Mars and Europa, recent studies using these minerals have focused on their ability to assist in the detection of biosignatures. On Earth, biotic and biotic processes can assist in the formation and deposition of these minerals. A primary objective of these studies is the detection of bio/organic compounds that may be associated with the mineral. These biosignatures would imply biological involvement during mineral formation. The following research presents a series of natural and synthetic investigations to determine if biological activity is associated with Na-sulfate mineralization, and if these minerals can assist in detecting bio/organic compounds. Biological activity associated with the formation of Na-sulfate deposits in the basaltic subsurface of Craters of the Moon National Monument, Idaho was examined by laser desorption Fourier transform mass spectrometry (LD-FTMS), infrared spectroscopy and sulfur isotopic fractionation. These experiments conclude that bio/organic compounds are associated with the secondary Na-sulfate minerals, giving evidence of biological involvement in the mineralization of these deposits. LD-FTMS results of the synthetic bio/organic-mineral combinations show the potential of Na-sulfate minerals to assist in the detection and identification of bio/organic compounds. These results prove the importance of Na-sulfate minerals for future exploration missions that are likely to use LDMS to search for signs of life in the solar system.