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New advances in lunar soil research offer scientific evidence to unravel mystery of moon’s 'two faces'_我的网站

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    Lunar soil Photo: IC
Chinese scientists have made new progress in the study of lunar soil samples returned by the Chang'e-6 mission, providing fresh evidence to the striking differences between the moon's near and far sides, which have long puzzled scientists.
Because the moon is tidally locked to Earth, its rotation period matches its orbital period, meaning the same side always faces Earth. The moon's near side features vast dark basaltic plains known as lunar maria, while its far side is dominated by bright highlands with far fewer maria, creating a striking contrast between the two sides. Why does the moon have such "two faces"?
Scientists studying the moon's early formation and evolution have long used the lunar magma ocean model as a basic framework. Under the model, the chemical and isotopic characteristics of different types of lunar magma can be explained by the mixing of different components in varying proportions after the magma ocean cooled, Guangming Daily reported on Saturday. 
However, previous lunar samples were collected only from the moon's near side, while significant differences exist between the near and far sides in their topography, composition and internal structure.
Against this backdrop, the research team from Institute of Geology from Chinese Academy of Geologist Sciences studied feldspathic impact-melt rocks in lunar soil samples returned by the Chang'e-6 mission. Using China's first independently developed ion probe system, researchers conducted a comprehensive analysis to test the lunar magma ocean model and examine how large impacts reshaped reservoirs in the lunar crust and mantle.
Through high-precision analyses, the team identified key clues to the moon's evolutionary history, suggesting that the stark differences between its near and far sides may be linked to the ancient giant impact that formed the South Pole-Aitken Basin.
The study found that the massive impact continued to profoundly reshape the lunar crust and upper mantle after the lunar magma ocean had solidified, fundamentally altering the material composition of parts of the moon's far side.
The findings add to the traditional lunar magma ocean model, suggesting that the formation and preservation of the moon's crustal and mantle reservoirs may have varied significantly from region to region and cannot be fully explained by a single, uniform model of primordial magma-ocean differentiation.
The research provides new scientific evidence for understanding the differences between the moon's near and far sides, while offering fresh insights into the moon's complex evolutionary history, according to Guangming Daily. 
Global Times
。    据中国气象局官微消息，4月19日8时至21日8时，贵州南部、江南南部、华南北部和中东部等地的部分地区出现暴雨到大暴雨、局地特大暴雨。中国气象局于4月18日8时30分启动暴雨三级应急响应。4月21日10时，中央气象台继续发布暴雨橙色预警、强对流天气黄色预警。　　多地累计降水量突破4月历史纪录，珠江流域北江发生2024年第2号洪水　　19日8时至21日8时，广西北部、广东中北部、湖南东南部、江西南部累计降水量达100毫米至200毫米，其中广西东北部、广东西北部达250毫米至350毫米，局地超过400毫米。最大小时降水量达40毫米至80毫米，广西南宁、广东茂名局地超过100毫米。20日8时30分至9时15分，广西壮族自治区梧州市藤县发生中等强度龙卷风（相当于最大瞬时风力达15级）。　　受强降水影响，珠江流域北江发生2024年第2号洪水。21日早晨，北江下游控制站石角水文站流量为14900立方米/秒，已经超过2024年第1号洪水，并在广西、广东造成多条中小河流水位超警戒水位，多地发生地质灾害。　　气象部门密切关注此次强降水过程，中国气象局与水利部联合发布山洪灾害气象风险提醒，并联合自然资源部提前启动2024年度全国地质灾害气象风险联合预警业务。广西、广东省（自治区）气象局与当地水利厅、自然资源厅联合发布山洪灾害与地质灾害气象风险预警。　　多重因素导致近期南方降雨偏多偏强，未来强降水过程多仍需加强防范　　中央气象台首席预报员马学款介绍，4月以来，副热带高压比常年同期偏强，有利于南海和孟加拉湾水汽向南方地区输送，同时高原槽和南支系统活跃，导致南方地区强降水过程频繁、降水持续时间偏长。另外，江南、华南等地气温比常年同期明显偏高，大气含水量丰富、不稳定能量高，导致对流发展旺盛、降雨强度高，多地累计降水量突破4月历史纪录。　　中央气象台预计，4月21日至22日，江南南部和东部、华南中东部和南部等地仍有强降水，局地有大暴雨并伴有雷暴大风或冰雹等强对流天气。

B | 23日，华南地区的降雨将明显减弱，但华南南部沿海部分地区仍有大到暴雨。

C | 另外，在25日前后，贵州、江南、华南等地还将有一次较强降水过程。　　马学款提示，未来几天，我国南方地区强降水过程多、局地雨强大，并可能伴有风雹天气，公众需及时关注当地气象部门发布的预报预警信息，在强降水时段减少外出，避免在山涧、河道等低洼地带逗留，注意防雨防雷电，防范山洪、滑坡、泥石流等次生灾害风险。相关部门要注意城市低洼地带及时排水，加固户外设施，防范强风对临时搭建物、高空作业装置和人员、航运等的安全威胁。　　（中国小康网综合中国气象局官微）。

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Published on:06:26:48