China’s Zhurong Mars rover has been analysing deposits on the surface of Mars in a low-lying plain in the planet’s Northern hemisphere, since its landing in May 2021. Previous research has suggested that materials in this region may have originated from flooding and marine sediments, with a fine grain size more consistent with this environment than material from volcanic activity.
Bo Wu and colleagues analysed data retrieved from the orbiter and by the Zhurong rover to provide estimates of the surface ages and mineral compositions of material found in southern Utopia Planitia. They identified distinct geomorphological features such as troughs and sediment channels consistent with a nearshore zone, suggesting a possible formation event involving flooding approximately 3.68 billion years ago. In this scenario, a short-lived frozen ocean formed a coastline, with the ocean surface likely freezing and disappearing approximately 3.42 billion years ago.
