title: A sulfur-based survival strategy for putative phototrophic life in the venusian atmosphere.
abstract: Several observations indicate that the cloud deck of the venusian atmosphere may provide a plausible refuge for microbial life. Having originated in a hot proto-ocean or been brought in by meteorites from Earth (or Mars), early life on Venus could have adapted to a dry, acidic atmospheric niche as the warming planet lost its oceans. The greatest obstacle for the survival of any organism in this niche may be high doses of ultraviolet (UV) radiation. Here we make the argument that such an organism may utilize sulfur allotropes present in the venusian atmosphere, particularly S(8), as a UV sunscreen, as an energy-converting pigment, or as a means for converting UV light to lower frequencies that can be used for photosynthesis. Thus, life could exist today in the clouds of Venus.
authors.affiliation: Department of Geological Sciences, Program of Environmental Science and Engineering, University of Texas at El Paso, El Paso, Texas 79968-0555, USA. dirksm@geo.utep.edu
authors.forename: Dirk
authors.initials: D
authors.lastname: Schulze-Makuch
authors.forename: David H
authors.initials: DH
authors.lastname: Grinspoon
authors.forename: Ousama
authors.initials: O
authors.lastname: Abbas
authors.forename: Louis N
authors.initials: LN
authors.lastname: Irwin
authors.forename: Mark A
authors.initials: MA
authors.lastname: Bullock
mesh_terms: D001272:Atmosphere; D013455:Sulfur; D014466:Ultraviolet Rays; D018536:Venus
chemical_list: D013455:Sulfur