Water/ice-related features in the Zhurong landing region: implications for the aqueous history of southern Utopia Planitia, Mars

Aqueous activities on Mars have gradually declined since the Noachian (>3.7 Ga). During the Hesperian and Amazonian periods, records of aqueous activity are relatively fragmentary. In 2021, the Zhurong rover, part of China’s Tianwen-1 mission, successfully landed in the southern Utopia Planitia which belongs to the northern lowlands of Mars. High-quality orbital and in-situ data of the landing region have been acquired by the Tianwen-1 orbiter and the Zhurong rover, which provides unprecedent opportunities for studying the post-Noachian aqueous activities as well as testing the hypothesis of an ancient northern ocean on Mars. A series of possible water/ice-related features have been identified, such as polygons, cones, and sedimentary rocks. We analyzed their morphological characteristics, stratigraphic relationships, and possible origins. Based on these studies, we proposed the aqueous history of the southern Utopia Planitia, and provided possible evidence for the existence of an ancient ocean on Mars.