Anhuai Lu

Abstract The marine iron cycle is now recognized as fast and dynamic, partly fueled by vast particulate iron inputs. Yet the mechanisms that activate this reservoir to sustain productivity remain unresolved. Here we show that mineral photocatalysis, an overlooked abiotic process, provides a key activation pathway for Fe(II) production.

Abstract The duration and dynamic evolution of surface water on Mars are key to understanding its past habitability. Utopia Planitia, Mars’ largest northern basin, preserves mineralogical signatures of ancient aqueous activity that remains chronologically unconstrained. Here, we present the quantitative reconstruction of the Hesperian Ocean’s lifecycle using spectral analysis of manganese (Mn) (hydr)oxides as paleohydrological markers.

Abstract Atmospheric chemistry in Venus remains elusive, especially the photochemical role of sulfur species and the unexplained presence of ammonia (NH3). Here we show, through combined experiments and quantum chemical calculations, that elemental sulfur (S0) can photoreduce nitrate (NO3−) to NH3 under Venus-like acidic and UV-irradiated conditions.