研究人员认为，大型河流可输送更多营养物质，有助于维持多样的生态系统。水流经距离越远，水与岩 石的相互作用就越多，发生化学反应的机会就更高，这些反应可能转化为生命迹象。 研究人员表示，虽然这些大型流域只占火星地表面积的5%左右，却贡献了火星河流侵蚀沉积物的约 42%。由于沉积物携带营养物质，这些地点被认为是寻找过去生命证据的主要目标，但需要进一步研究 以精确确定这些沉积物最终的沉积位置。 研究结果已发表在美国《国家科学院学报》上。（完） 新华社华盛顿12月31日电 火星一直是科学家寻找地外生命的热门目标。一项新研究首次确定了火星上 规模最大的16个古河流域，被视为最有希望寻找生命的区域。 由大型河流系统塑造的区域是地球上最富饶的生态系统，地球上有91个超过10万平方公里的流域，仅亚 马孙河流域就孕育了数万已知物种。科学家们认为，古代火星也有类似环境，曾经存在有液态水的时 期，可能为生命提供了有利条件。 美国得克萨斯大学奥斯汀校区的研究人员通过收集并分析之前发表的关于火星山谷、湖泊和河流特征的 数据发现，火星上有19个主要的山谷、溪流、湖泊、峡谷和沉积物群，其中有16个形成了面积至少达10 万平方公里、相互连接的 ...

Core Insights - NASA's Perseverance rover has made significant discoveries that suggest the possibility of ancient microbial life on Mars, particularly in the Jezero Crater [1][2] - The findings include unique rock samples that may contain evidence of biological activity dating back 3.5 billion years [1][3] Group 1: Discovery Details - The Perseverance rover identified a rock layer called "Bright Angel" in the Nerretwa Canyon, which may have formed in a water-rich environment [2][3] - The rover found green spots, referred to as "poppy seeds," containing a phosphorus-rich mineral called blue iron ore [2][3] - The "Chiawa Falls" rock sample contains small circular structures known as "leopard spots," which are composed of iron minerals that could indicate past microbial activity [2][3] Group 2: Scientific Interpretation - Researchers are cautious in labeling these findings as definitive signs of life, preferring the term "potential biosignatures" [3][4] - The study emphasizes the need for multiple lines of evidence to confirm any signs of life, as non-biological processes could produce similar mineral formations [4][5] - The current evidence is considered indirect, and further analysis is required to establish a direct link to ancient life [3][5] Group 3: Future Exploration - Returning Martian samples to Earth is deemed crucial for validating the findings and conducting more advanced analyses [5][6] - Various countries, including China, are advancing their Mars exploration missions, with plans for sample return missions to further investigate potential life signs [6][7] - The European Space Agency's Rosalind Franklin rover is also set to join the Mars exploration efforts, highlighting the global interest in uncovering the mysteries of Martian life [7]

Core Points - NASA's Perseverance rover has discovered what is considered the "most obvious signs of life" on Mars, marking a significant milestone in Mars research over the past 30 years [1][2] - The discovery involves organic carbon and iron compounds found in the Jezero crater, which are similar to chemical structures on Earth that indicate the presence of life [2][4] Group 1: Discovery Details - The samples collected by the Perseverance rover show unusual spots and seed-like shapes in ancient Martian rocks, suggesting the possibility of past microbial life [2][4] - The features, referred to as "leopard spots," were found in the mudstone of the Jezero crater, an area that was once home to a river billions of years ago [2][4] - Chemical substances such as iron and phosphorus detected in the rocks are indicative of the decomposition of organic matter, a hallmark of early life on Earth [4][5] Group 2: Scientific Implications - Scientists believe that the samples' texture, chemical, and mineral characteristics warrant consideration of the possibility of life [6] - The discovery has prompted discussions among scientists about the need for more advanced laboratory facilities on Earth to analyze the samples thoroughly [6][7] Group 3: Future Plans and Challenges - NASA's Mars sample return mission has been delayed due to budget overruns and complexity, with a target to bring samples back to Earth between 2035 and 2039 [8][10] - NASA is exploring cost-effective commercial partnerships and plans to finalize the mission's structure by mid-2026 [8] - The agency's future missions include the Artemis program, which aims to establish a sustainable human presence on the Moon [11]

Core Viewpoint - NASA's Perseverance rover has discovered unique mudstones on Mars, which may provide the clearest signs of potential ancient life on the planet, characterized by distinctive markings referred to as "leopard spots" and "poppy seeds" [1][3][4] Group 1: Discovery Details - The mudstones, approximately 3.5 billion years old, were found in the Bright Angel Formation, an area previously shaped by river activity [7] - The features observed in the rocks could be explained by biological processes if they were found on Earth, suggesting a possible link to ancient Martian microorganisms [3][4][7] - NASA has classified these findings as "potential biosignatures," warranting further investigation to determine their biological origin [1][3] Group 2: Scientific Implications - The analysis indicates that a series of chemical reactions occurred in the sediment, potentially involving interactions between mud and organic materials, leading to the formation of new minerals [7][8] - While natural geological processes could also explain the mineral formation, the absence of high temperatures in the rocks suggests a biological influence [7][8] - The only definitive way to confirm the microbial origin of these minerals would be to return the samples to Earth for analysis, a plan currently facing budget cuts [3][8] Group 3: Future Missions - NASA's plans for a Mars sample return mission are uncertain due to budget constraints outlined in the proposed 2026 fiscal budget [3][8] - In contrast, China's Tianwen-3 mission aims to launch in 2028 and return samples by 2031, potentially achieving a historic milestone in Mars exploration [10]