Orbital and in situ observation of transverse aeolian ridges at Zhurong landing site

A large amount of transverse aeolian ridges (TARs) bedforms exist in the Zhurong rover landing region. The acquisition of high-resolution data from orbiter and the rover from Tianwen-1 mission provides an excellent opportunity to study the geological characteristics of TARs. The length, width, and density of a total of 8,274 TAR samples at the landing site are analyzed. The orientation of TARs at the landing region is dominated in an E-W direction. Analysis of Mars Climate Station (MCS) data shows that the present-day wind direction is inconsistent with the wind forces that promoted the formation of TARs, suggesting that the formation of TARs is dependent on the ancient wind direction.With the help of the Zhurong MarSCoDe shortwave infrared (SWIR) spectrometer data, we investigate the composition materials including TARs, soil, and rocks, and the results show that their spectra display similar distinct absorptions consistent with the presence of hydated minerals such as hydrated sulfates. The cemented and dusty crust covering the TARs indicate that the TARs have not migrated for a period of time in landing site area. Some of the TARs have been eroded into small sand ridges or ripples due to the change of the prevailing wind directions which may indicate the climate change on Mars.

祝融号（Zhurong）巡视器着陆区内存在大量横向风成脊（transverse aeolian ridges, TARs）这类风成床形构造。天问一号（Tianwen-1）任务环绕器与巡视器获取的高分辨率数据，为研究TARs的地质特征提供了绝佳契机。本研究对着陆区内共计8274个TAR样本的长度、宽度与密度开展了分析。着陆区内TARs的走向以东西向为主。火星气候站（Mars Climate Station, MCS）数据分析结果显示，现今风向与塑造TARs形成的风力并不匹配，这表明TARs的形成依赖于古风向。借助祝融号搭载的MarSCoDe短波红外（shortwave infrared, SWIR）光谱仪数据，我们对TARs、土壤与岩石等组成物质开展了成分分析，结果显示三者的光谱均呈现出相似的特征吸收峰，与含水硫酸盐等含水矿物的存在特征相符。覆盖在TARs表面的胶结风尘壳表明，着陆区内的TARs已有一段时间未发生位移。部分TARs因盛行风向变化被侵蚀为小型沙脊或沙波纹，这一现象或可反映火星的气候变化。