Variation of crater morphological parameters in the landing area of Tianwen-1: relationships with the geological environment and climate change

Abstract

The Zhurong rover of the Tianwen-1 mission successfully landed in the southern part of the Utopian Planitia and the northern region of the dichotomy boundary. Craters within a ~ 134 km2 region surrounding the Zhurong rover were identified and divided into seven degradation classes based on their preservation states and morphological details. Assessing how craters have degraded over time provides insight into local surface processes and then speculates on the climate evolution of the study area. The small depth/diameter (d/D) of craters in the study area may be caused by the rapid filling of sediments or by impact processes occurring in poorly cohesive weathering layers, and may also be associated with the volatile material alteration. As time went by, the process of crater degradation is nonlinear, and the degradation rate of the fresh crater in the study area at the initial stage of degradation may be as high as 0.2 m/Myr. The calculated surface erosion rate for the study area is ~ 10–2–10–3 m/Myr, indicating that the erosion of the Martian surface since the Middle Amazonian occurred in the dry environment dominated by wind-sand erosion.Graphical