Halophiles: A Terrestrial Analog for Life in Brines on Mars

Abstract

Dr. Rocco L. Mancinelli is a Senior Research Scientist with the SETI Institute. His research interests are broad, encompassing ecology, physiology, and biogeochemistry. Specifically he studies microbe-environment interactions with emphasis on the environmental limits in which organisms can live. He currently uses four systems in these studies: 1) Halophiles in evaporitic salt crusts that form along the marine intertidal; 2) Microbial mats inhabiting diverse environments (e.g., the intertidal area of the Baja coast, the alkaline and acid hot springs of Yellowstone National Park, hypersaline lakes and the perennially ice-covered lakes in the dry valleys of Antarctica); 3) Areas where rock (desert) varnish occurs; and 4) The space environment in Earth orbit. The results of such experiments are used to model microbe-microbe and microbe-environment interactions. The models are used in formulating hypotheses regarding mechanisms of survival of organisms in the space environment as well as the evolution of the nitrogen cycle and the role exogenous sources of fixed nitrogen play in the physiology of nitrogen metabolism, biogeochemistry and microbe community structure. Further, these models are extrapolated to what is known about the environment (geochemistry and climatology) of early Mars in an attempt to determine the potential for life to evolve on that planet.