The Subsurface Structure of the Martian Utopia Basin Revealed by the Radar Data of the Zhurong Rover

The Zhurong rover, a key component of China's inaugural Mars exploration mission, successfully landed on the southern Utopia Planitia on 15 May 2021. Equipped with a dual-channel ground-penetrating radar (GPR), the rover conducted comprehensive investigations of the martian subsurface. This study focuses on the processing of GPR data collected between 25 May and 31 October 2021, utilizing both high and low-frequency channels. By integrating GPR data with images from the High-Resolution Imaging Camera and the Navigation and Terrain Cameras, this research offers valuable insights into the subsurface structure of the landing site. The low-frequency data indicate a multi-layered underground structure extending to a depth of 80 m. The strata display a progressive increase in roughness from top to bottom, likely resulting from a combination of sedimentary processes, including flood deposition, long-term weathering, and repeated meteorite impacts. These processes imply a history of intermittent flooding events, gradual sediment accumulation, and the effects of prolonged weathering and impacts, likely driven by climatic and environmental fluctuations. Meanwhile, the high-frequency data have revealed the reshaping of martian surface sediments caused by meteorite impacts and weathering in the regolith up to a depth of 5 m underground. These findings are crucial for understanding the geological evolution of Utopia Planitia.