Quantifying the Bioavailable Energy in an Ancient Hydrothermal Vent on Mars and a Modern Earth-Based Analog

Marine Science Can Contribute to the Search for Extra-Terrestrial Life

“…If the connectivity of the most important terms in the search for life on Mars is highlighted, an interesting plot develops in which the term "Earth" is connected to other terms through "microorganism" (Figure S3). Most investigators agree that primary targets for the search for life on Mars are benign paleo-environments (e.g., abundant water, circum-neutral pH), either on the surface or underground, as manifested by the petrology and mineralogy of the geological environment [125][126][127]. The terms "soil", "lake", and "crust" (i.e., meaning planetary crust) primarily suggest such environments (Figure 2).…”

“…Therefore, once the basic questions regarding habitable conditions are established, research efforts should focus on the genetic properties and metabolic pathways of bacterial species that may provide functional flexibility that allows them to interact and survive in extreme environments. Understanding the genetic and metabolic features of extremophiles living in Mars-like environments is crucial in astrobiology [127], as they shed light on the selection mechanisms exerted by the environments on bacteria and archaea groups with functional properties to survive in extreme environments. Microbial life on Earth in such environments is active at high pressures, at temperatures ranging from boiling to freezing, in critical osmotic potentials, in radioactive environments, and in environments with a wide range of pH values and toxic concentrations of metals and other species [113].…”