【科技日报】祝融号发现火星约7.5亿年前仍存在水活动

Core Insights - Recent research indicates that Mars had significant water activity as recently as 750 million years ago, extending the timeline of water presence on the planet and providing new evidence for understanding its climatic evolution, geological processes, and potential habitability for life [1][2]. Group 1: Research Findings - The analysis of high-frequency radar data from the Zhurong rover suggests that the Martian surface was not always cold and dry, contradicting previous beliefs that Mars entered a dry phase around 3 billion years ago [1]. - The Zhurong rover has traveled approximately 1.9 kilometers since its landing in May 2021, utilizing high-frequency quad-polarization radar for shallow subsurface exploration, akin to a detailed CT scan of Mars [1]. - Data reveals a uniform sediment layer approximately 4 meters thick covering the landing area, which is interpreted as evidence of a water deposition environment, similar to shallow seas or large lakes, rather than volcanic or wind-driven processes [1][2]. Group 2: Geological Context - The radar also detected centimeter-scale thin sedimentary layers resembling sedimentary rocks formed in surface water, further supporting the existence of a shallow water environment in the region [2]. - Through crater dating analysis, researchers determined that the sediment layers formed around 750 million years ago, during the late Amazonian epoch, indicating a significant surface reshaping process and ongoing water activity during that period [2].