John A. Baross (born August 27, 1940) is an American marine microbiologist and professor of oceanography and astrobiology at the University of Washington who has made significant discoveries in the field of the microbial ecology of hydrothermal vents and the physiology of thermophilic bacteria and archaea.
[2] Baross was one of the first to show that thermophilic microbes grow in deep-sea hydrothermal vents, work that involved incubating samples on the research vessel's engine block.
[3][4][5] His research group has studied microorganisms at Axial Seamount,[6] North Gorda Ridge,[7] and the CoAxial Segment in the Northeast Pacific Ocean,[8] and Lost City Hydrothermal Field.
He is therefore a major proponent for the exploration of icy moons like Enceladus which was discovered to be geochemically active and may favor the production of essential biomolecules.
[18] His recent contributions stress the importance of an environmentally diverse planetary surface with active hydrological and geological cycles as an ideal setting for prebiotic reaction networks.