Hydrothermal systems associated with martian impact craters

With widespread evidence of both heat sources and water (either liquid or solid), hydrothermal systems are likely to have existed on Mars. We model hydrothermal systems in two sizes of fresh impact craters, one simple and one complex, and find that a hydrothermal system forms on the crater floor. In the larger complex craters with a substantial melt sheet, a lake can form, even under current martian atmospheric conditions. By comparing these hydrothermal systems to those that exist and have been studied extensively on the Earth, we make predictions as to the types of minerals that could be precipitated and the potential habitability of such systems by primitive organisms. (C) 2002 Elsevier Science (USA).