MARS Theory: A Mineral–Organic–Aqueous Reactor–Filter Architecture for Partially Decoupled Astrobiological Windows on Mars

MARS (mineral–organic–aqueous reactor systems) theory is presented as a formal theory for planetary astrobiology, with Martian environments represented as coupled reactor–filter systems. Its central proposition holds that prebiotic synthesis, metabolic plausibility, and biosignature preservation are physically coupled, although their maxima may occur in different places, times, or mineral assemblages. Partial overlap is both allowed and expected; complete co-location is regarded as a restrictive scenario. Admissible states satisfy elemental and charge conservation, non-ideal activity relations, mineral-saturation constraints, reaction-affinity conditions, and cross-domain transport compatibility. Brines, reactive minerals, redox gradients, irradiation, burial, diagenetic overprint, impacts, volcanism, and hydrothermal alteration can therefore enhance one function while suppressing another. Time-dependent atmospheric and redox boundary conditions, cryo-thermal cycling, exogenous catalytic minerals, shock mineralogy, and post-impact hydrothermal circulation are incorporated as sign-variable controls. An illustrative reduced-state ensemble shows the internal logic of window displacement; it does not constitute a calibrated uncertainty analysis or a planet-wide simulation. The theory yields operational thresholds, observable tests, and falsifying outcomes for rover and returned-sample investigations without constituting evidence that life existed on Mars.