采样返回是未来国内外火星探测任务的重点。我国计划于2030年左右实施“天问三号”火星采样返回任务,以进一步了解火星宜居性、寻找火星生命迹象。选择合适的着陆点对于确保任务目标的达成具有重要意义。切鲁利(Cerulli)撞击坑位于火星阿拉伯(Arabia)高地西北部,区域内存在多种地貌类型,并可能曾经存在宜居环境。本文利用火星高分辨率遥感影像和地形数据,对Cerulli撞击坑区域的地质特征进行了详细分析,识别了区域内的撞击地貌、水成地貌和冰川地貌等地貌类型,开展了撞击坑统计定年,进而编制了研究区域地质图。研究结果表明,Cerulli撞击坑形成于诺亚纪/西方纪之交(~3.7 Ga),并在西方纪至亚马逊纪存在广泛的水和冰川活动。区域内峡谷网的形成机制可能与撞击事件导致的液态水释放或火星轨道倾角变化导致的冰川活动相关,而多期次的水活动为宜居环境和生命的形成与保存提供了条件,因而该区域可作为“天问三号”等未来火星采样返回任务的备选着陆点。

China plans to carry out the "Tianwen-3" Mars sample-return mission around 2030 to further understand the habitability of Mars and search for the potential signs of Martian life. Selecting a suitable landing site is crucial to ensure the successful achievement of mission objectives. The Cerulli crater is located in the northwestern part of the Arabia highlands of Mars, exhibiting diverse geological features, which may have once hosted habitable environment. In this paper, we conducted a detailed study of the geological characteristics of the Cerulli crater area in the northwestern Arabia Terra of Mars, utilizing high-resolution remote sensing images and topographic data. We identified multiple landform types within the study area, including impact craters, water-related landforms, and glacial landforms. The primary types of impact craters observed within the study area include ancient craters covered by ejecta blankets, fresh craters with central pits, typical ring-mold craters, and craters filled with ice-rich deposits. The main water-related landforms are Type-1 valley networks, which are elongated and sinuous, with narrow widths and well-defined edges. Additionally, Type-2 valley networks, which are wider and often develop at the termini of Type-1 valley networks with linear fissures visible at their bottoms, were observed. The Mamers Vallis, an outflow channel partially buried by the Cerulli crater and its ejecta blanket, was also identified. In addition to ring-mold craters and glacial landforms at the bottoms of valley networks, the glacial landforms in the study area also include viscous flow features, which are concentrated around the central peaks of the craters. Furthermore, this paper conducted crater counting and compiled a geological map of the study area. The research findings indicate that the Cerulli crater formed at the Noachian/Hesperian boundary (~3.7 Ga), suggesting that Mamers Vallis was formed during the Noachian period, prior to 3.7 Ga. At the Noachian/Hesperian transition, the Cerulli crater formed, covering parts of the Mamers Vallis outflow channel and earlier craters with its ejecta blanket. Simultaneously, water activity triggered by the impact event formed various water-related landforms within the ejecta blanket and crater. From the Hesperian to the Amazonian period, after the formation of the Cerulli crater, new craters emerged, modifying the crater floor and ejecta blanket of the Cerulli crater. Meanwhile, the region may have undergone multiple glacial activities, forming various glacial landforms such as viscous flow features and ring-mold craters within the region, and potentially new valley networks carved by glacial meltwater. The formation mechanism of the valley network in the region may be related to the release of liquid water triggered by impact events or glacial activity resulting from changes in the Martian obliquity. The complex water activity characteristics in this region provide clues for a deeper understanding of Mars" climate and water activity history, while also offering conditions conducive to the formation and preservation of habitable environments and even life. Therefore, this region can serve as a potential landing site for future Mars sample-return missions, especially the fan-shaped deposits at the bottoms of the Cerulli crater and the termini of valley networks. Sampling at these locations offers significant advantages for understanding the duration of Martian water activity, sediment composition, climatic environmental characteristics, and searching for signs of life.