火星上的冰流

On Aug. 18, 2023, the Mars Reconnaissance Orbiter (MRO) captured ridged lines carved onto Mars’ landscape by the gradual movement of ice. While surface ice deposits are mostly limited to Mars’ polar caps, these patterns appear in many non-polar Martian regions.

As ice flows downhill, rock and soil are plucked from the surrounding landscape and ferried along the flowing ice surface and within the icy subsurface. While this process takes perhaps thousands of years or longer, it creates a network of linear patterns that reveal the history of ice flow.

The MRO has been studying Mars since 2006. Its instruments zoom in for extreme close-up photography of the Martian surface, analyze minerals, look for subsurface water, trace how much dust and water are distributed in the atmosphere, and monitor daily global weather. These studies are identifying deposits of minerals that may have formed in water over long periods of time, looking for evidence of shorelines of ancient seas and lakes, and analyzing deposits placed in layers over time by flowing water.

Image Credit: NASA/JPL-Caltech/University of Arizona

2023年8月18日，火星勘测轨道飞行器（MRO）拍摄到了由冰的逐渐移动雕刻在火星地貌上的山脊线。虽然表面冰沉积大多局限于火星的极地冰冠，但这些模式出现在许多非极地的火星地区。

当冰向山下流动时，岩石和土壤从周围的地貌中被带走，沿着流动的冰面运送到冰冷的地下。虽然这一过程可能需要数千年或更长时间，但它创造了一个线性模式网络，揭示了冰流的历史。

自2006年以来，MRO一直在研究火星。它的仪器可以放大火星表面的极端特写照片，分析矿物质，寻找地下水，追踪大气中分布的尘埃和水的数量，并监测每天的全火星天气。这些研究正在识别可能在水中经过长时间形成的矿物质沉积物，寻找古代海洋和湖泊海岸线的证据，并分析随着时间的推移由流动的水形成的沉积物。

影像来源：NASA/JPL-Caltech/University of Arizona