编译 | 李言
Nature,做作周论 10 August 2023, Volume 620 Issue 7973
《做作》2023年8月10日,第620卷,出书7973期
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地舆学Astronomy
Sustained wet–dry cycling on early Mars
火星早期不断的干湿循环
▲ 作者:W. Rapin, G. Dromart, B. C. Clark et al.
▲ 链接 :
https://www.nature.com/articles/s41586-023-06220-3
▲ 摘要 :
在此,咱们陈说好奇号火星车在盖尔陨石坑的做作周论审核服从,表明在早期火星概况情景中爆发了高频率的出书干湿循环 。咱们审核到在Y形衔接处衔接开掘出的文导具备硫酸盐富集的厘米级多边形山脊,记实了由于纪律强度的做作周论一再干湿循环而在别致泥浆中组成的裂痕 。
咱们的出书发现不是由撞击或者火山引起的无意偶尔水文行动 ,而是文导指向了火星早期不断的 、周期性的做作周论,致使可能是出书季节性的天气 。此外,文导由于干湿循环可能增长宿世物聚合,做作周论盖尔蒸发盆地可能特意有利于这些历程。出书
咱们审核到的文导多角形模子在物理以及光阴上与蒙脱石粘土向含硫酸盐地层的转变无关,这是一个全天下扩散的矿物过渡。这表明Noachian–Hesperian过渡时期(38 - 36亿年前)可能具备了相似地球的天气制度以及有利于宿世物进化的地情绪景。
▲ Abstract:
Here we report observations by the Curiosity rover at Gale Crater indicating that high-frequency wet–dry cycling occurred in early Martian surface environments. We observe exhumed centimetric polygonal ridges with sulfate enrichments, joined at Y-junctions, that record cracks formed in fresh mud owing to repeated wet–dry cycles of regular intensity. Instead of sporadic hydrological activity induced by impacts or volcanoes, our findings point to a sustained, cyclic, possibly seasonal, climate on early Mars. Furthermore, as wet–dry cycling can promote prebiotic polymerization, the Gale evaporitic basin may have been particularly conducive to these processes. The observed polygonal patterns are physically and temporally associated with the transition from smectite clays to sulfate-bearing strata, a globally distributed mineral transition. This indicates that the Noachian–Hesperian transition (3.8-3.6 billion years ago) may have sustained an Earth-like climate regime and surface environments favourable to prebiotic evolution.
Martian dunes indicative of wind regime shift in line with end of ice age
火星沙丘表明,风向随着冰河时期的停止爆发修正
▲ 作者 :Jianjun Liu, Xiaoguang Qin et al.
▲ 链接 :
https://www.nature.com/articles/s41586-023-06206-1
▲ 摘要:
在这里 ,咱们揭示了祝融号探测器在穿梭火星乌托邦平原南部LDM地域时取患上的一组丈量服从。咱们发现了一个地层序列的证据 ,搜罗最后的barchan沙丘组成 ,表明东冬风及沙丘聚积物胶结,之后受到西北风的侵蚀,侵蚀barchan沙丘并发生配合的纵向沙丘 ,风向转变与冰河时期的停止相不同。
这些服从与火星极地地层记实相不同,将有助于后退咱们对于火星今世天气历史的清晰。
▲ Abstract :
Here we present a suite of measurements obtained by the Zhurong rover during its traverse across the southern LDM region in Utopia Planitia, Mars. We find evidence for a stratigraphic sequence involving initial barchan dune formation, indicative of north-easterly winds, cementation of dune sediments, followed by their erosion by north-westerly winds, eroding the barchan dunes and producing distinctive longitudinal dunes, with the transition in wind regime consistent with the end of the ice age. The results are compatible with the Martian polar stratigraphic record and will help improve our understanding of the ancient climate history of Mars.
物理学Physics
Solid-body trajectoids shaped to roll along desired pathways
固体轨迹体被塑组成沿着期望道路转动的形态
▲ 作者:Yaroslav I. Sobolev, Ruoyu Don et al.
▲ 链接:
https://www.nature.com/articles/s41586-023-06306-y
▲ 摘要 :
在此 ,咱们开拓了一种算法来妄想“轨迹体” ,而后经由3D打印合计出的形态并跟踪它们的转动道路来验证这些妄想 ,搜罗那些挨近自己的物体,这样物体的品质中间就会间歇性地向上挪移 。
咱们的钻研次若是出于好奇心 ,可是大少数道路的轨迹线的存在对于量子以及典型光学具分心想不到的影响,由于量子比特、自旋以及光偏振的能源学可能精确地映射到轨迹线及其道路