Constraints on water activity at the Zhurong landing site in Utopia Planitia, Mars

Mineralogical evidence of water–rock interactions is a strong indicator of the presence of liquid water on ancient Mars. Previous observations have found widely distributed hydrated minerals in the southern highlands, whereas such discoveries have been rare in the younger northern lowlands. China’s first Mars exploration mission successfully landed a rover (Zhurong) in southern Utopia Planitia, providing an opportunity to analyze the exposed rocks in the northern lowlands. Using data from the short-wave infrared (SWIR) spectrometer and the laser-induced breakdown spectrometer (LIBS) onboard the Zhurong rover, we found evidence for the widespread presence of hydrated minerals (probably sulfates or silica) around the landing site. The basaltic-like elemental compositions of the targeted samples further indicated that hydrated minerals are likely minor components. The results from Zhurong suggest that active aqueous activities occurred during the overall cold and dry Amazonian era on Mars. However, further evaluations are needed on the duration and scale of these activities.