Wind‐formed features are abundant in Oxia Planum (Mars), the landing site of the 2022 ExoMars mission, which shows geological evidence for a past wet environment. Studies of aeolian bedforms at the landing site were focused on assessing the risk for rover trafficability, however their potential in recording additional climatic fluctuations has not been explored. Here we show that the landing site experienced multiple climatic changes in the Amazonian, which are recorded by an intriguing set of ridges that we interpret as Periodic Bedrock Ridges (PBRs). Clues for a PBR origin result from ridge regularity, defect terminations and the presence of preserved megaripples detaching from the PBRs. PBR orientation differs from superimposed transverse aeolian ridges pointing toward a major change in wind regime. Our results provide constrains on PBR formation mechanisms and offer indications on paleo winds that will be crucial for understanding the landing site geology.

中文翻译：

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2022年ExoMars登陆点的周期性基岩山脊：风向变化的证据

在2022年ExoMars任务的着陆点Oxia Planum（火星）中，风形成的特征非常丰富，它显示了过去潮湿环境的地质证据。着陆点风沙床形态的研究集中在评估流动站可通行性的风险，但是尚未探索其记录其他气候波动的潜力。在这里，我们显示着陆点在亚马逊河地区经历了多种气候变化，这些变化由一组有趣的山脊记录，我们将其解释为周期性基岩山脊（PBR）。PBR起源的线索是由于脊的规则性，缺陷的终止以及保留的巨型波纹从PBR脱离而引起的。PBR的方向不同于叠加的横向风向脊，后者指向风势的主要变化。