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China's first Mars rover, Zhurong, successfully landed in southern Utopia Planitia on the Martian surface (Figure 1) on 15 May 2021. Zhurong was onboard the Tianwen-1 probe, which was successfully launched on 23 July 2020; the probe entered the Martian orbit on 10 February 2021 and released the Zhurong rover for landing about 3 hr before its touchdown (Li et al., 2021;Wan et al., 2020;Wu et al., 2021). The Zhurong rover landing represents the tenth in situ investigation of the Martian surface and the first in the lowland area of southern Utopia Planitia. Using the scientific payloads onboard the Zhurong rover (Li et al., 2021), including the Navigation and Terrain Camera (NaTeCam), Multispectral Camera (MSCam), Mars Surface Composition Detector (MarSCoDe), Mars Rover Penetrating Radar (RoPeR), Mars Rover Magnetometer, and Mars Climate Station, the Zhurong rover will investigate the topography, soil structure and geology of the roving area and the physical characteristics of the atmosphere. The rover will also analyze elements, minerals and rock types and search for signatures of water or ice in the roving area (Li et al., 2021;Zou et al., 2021).The landing site selection process for Zhurong included several stages. In the first stage, a global search process was conducted on the Martian surface to identify suitable regions that met the engineering constraints, including adequate solar illumination for generating power and warmth, lower elevation for a thicker atmosphere and longer deceleration time, and a flat terrain surface for safer landing (Dong et al., 2019;Wu et al., 2021). Three

This paper presents our efforts to characterize the candidate landing region (109°–133°E, 23°–30°N) for Tianwen‐1, China's first mission to Mars, in terms of engineering safety and scientific significance. Topographic analysis reveals that the region has a low elevation around −4,230 m, and 98% of the region have slopes smaller than 8°. The geomorphological mapping and analysis show that the region has an average crater density of about 28 craters (≥200 m in diameter) per 100 square kilometers, with several clusters of high crater densities distributed around the center of the region. There are also pitted cones distributed mainly in the southern part of the region, with a density of approximately 6.6 cones per 100 square kilometers in specific local areas. The region has rock abundances ranging from 1% to 23%, with local clusters of low and high rock abundances. The region comprises four main geological units, including a lowland unit formed in the Late Hesperian and a volcanic unit formed in the Amazonian and Hesperian period. Their specific surface ages are estimated through the analysis of crater size‐frequency distribution. Combining the engineering constraints on surface slopes, crater density, cone density, and rock abundance, a hazard map of the candidate landing region is generated for landing site evaluation and safety assessment. Based on the results, we further discuss the potential scientific outcomes from the exploration in this region. The findings will be helpful for the mission planning and maximization of the scientific return from Tianwen‐1, and complement existing Martian scientific research.

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The Chinese lunar probe Chang'E-4 successfully landed in the Von Kármán crater on the far side of the Moon. This paper presents the topographic and geomorphological mapping and their joint analysis for selecting the Chang'E-4 landing site in the Von Kármán crater. A digital topographic model (<small>DTM</small>) of the Von Kármán crater, with a spatial resolution of 30 m, was generated through the integrated processing of Chang'E-2 images (7 m/pixel) and Lunar Reconnaissance Orbiter (<small>LRO</small>) Laser Altimeter (<small>LOLA</small>) data. Slope maps were derived from the <small>DTM</small>. Terrain occlusions to both the Sun and the relay satellite were studied. Craters with diameters ≥ 70 m were detected to generate a crater density map. Rocks with diameters ≥ 2 m were also extracted to generate a rock abundance map using an <small>LRO</small> narrow angle camera (<small>NAC</small>) image mosaic. The joint topographic and geomorphological analysis identified three subregions for landing. One of them, recommended as the highest-priority landing site, was the one in which Chang'E-4 eventually landed. After the successful landing of Chang'E-4, we immediately determined the precise location of the lander by the integrated processing of orbiter, descent and ground images. We also conducted a detailed analysis around the landing location. The results revealed that the Chang'E-4 lander has excellent visibility to the Sun and relay satellite; the lander is on a slope of about 4.5° towards the southwest, and the rock abundance around the landing location is almost 0. The developed methods and results can benefit future soft-landing missions to the Moon and other celestial bodies.