title: Fourier transform infrared spectral detection of life in polar subsurface environments and its application to Mars exploration.
abstract: Cryptoendolithic lichen communities of the Dry Valleys, Antarctica, survive in an extremely inhospitable environment, finding refuge in microscopic niches where conditions suitable for life exist. Such "within-rock" communities may have evolved on Mars when conditions for life on the surface deteriorated to such an extent that they could no longer survive. Fourier transform infrared spectroscopy of unprepared whole-rock Antarctic Beacon sandstones was used to vertically profile molecular vibrations of fatty acids, proteins, and carboxylic acids created by endolithic communities. Spectral biosignatures were found localized to lichen-rich areas and were absent in crustal regions and the bulk rock substrate. These cryptoendolithic profiles will aid similar spectroscopic investigations of organic biosignatures during future Martian subsurface studies and will help in the identification of similar communities in other localities across the Earth.
authors.affiliation: The Open University, Department of Physical Sciences, Milton Keynes MK7 6AA, UK.
authors.forename: Louisa J
authors.initials: LJ
authors.lastname: Preston
authors.forename: Diane
authors.initials: D
authors.lastname: Johnson
authors.forename: Charles S
authors.initials: CS
authors.lastname: Cockell
authors.forename: Monica M
authors.initials: MM
authors.lastname: Grady
mesh_terms: D000864:Antarctic Regions; D002264:Carboxylic Acids / Q000032:analysis / Q000737:chemistry; D003080:Cold Temperature; D005227:Fatty Acids / Q000032:analysis / Q000737:chemistry; D018535:Mars; D011506:Proteins / Q000032:analysis / Q000737:chemistry; D013026:Space Flight / Q000379:methods*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*
chemical_list: D002264:Carboxylic Acids; D005227:Fatty Acids; D011506:Proteins