Life Will Find a Way: Investigating Entombed Microorganisms in Gypsum at Great Salt Lake as a Model for Studies of Gypsum on Mars

Space Dynamics Laboratory, Auditorium Rooms D & E

Great Salt Lake (GSL) is the second saltiest lake in the world, whose hypersaline geochemistry, high UV irradiation and volatile climate coalesce into a fascinating and extreme environment. The genetic diversity of the microbial community of GSL is primarily comprised of “salt-loving” halophiles ranging from archaea, bacteria and fungi. These organisms have the ability to live in high osmolarity brines, survive the high UV radiation and high salinity. Halophiles have “superpowers” including lifestyle flexibility that allows a state of dormancy when trapped within tiny inclusions such as small pockets of fluid or clay, in gypsum or halite minerals. The entombment of dormant but still living halophiles has been demonstrated in modern and ancient minerals millions of years old —halite being a prime example —but few of these techniques have applied to gypsum. We have succeeded in cultivating several strains of the Halorubrum genus from gypsum inclusions. Is this genus especially tolerant of entombment? In order to examine the entire microbial community, and to ensure that we are preventing contamination from the crystal surface, we developed a robust sterilization protocol. These evaporite minerals have also been well mapped on mars by recent missions, suggesting the evaporation of large lake systems. Imaging by orbiters led to the discovery of abundant gypsum, which has a unique infrared signature on Mars. In addition, rovers on the surface of Mars, using spectral, visual and chemo-analytic techniques, which have provided evidence of mineral composites consistent with ancient salt lake systems akin to those observed on Earth, such as at GSL. The recent discovery of gypsum on Mars, and our understanding of the capacity to which these minerals can entomb living organisms for millions of years, begs the question: Could living organisms or evidence of previously living organisms be found entrapped in the gypsum on Mars?