Abstract

Detailed information of Martian subsurface structure and properties is crucial for studying the geological evolution and environmental changes of Mars, and constitutes one of the essential components of Mars exploration. By analyzing the low-frequency radar data collected by the Zhurong rover of China’s Tianwen-1 mission, a detailed Martian subsurface image has been constructed along the ~1,171 m traverse of the rover in southern Utopia Planitia. The image shows an approximately 70-m-thick, multi-layered structure below a less than 10-m-thick regolith, reflecting the occurrence of episodic water-involved resurfacing on Mars during the Late Hesperian to Amazonian. Though no direct evidence for the existence of liquid water was found, based on the new radar data, the presence of saline ice cannot be ruled out in the subsurface of the landing area.