Lunar soil preserves numerous fragments of meteorites impacting on the Moon,providing a unique opportunity to investigate the distribution of the types of projectiles over billions of years.Here we report the first di...Lunar soil preserves numerous fragments of meteorites impacting on the Moon,providing a unique opportunity to investigate the distribution of the types of projectiles over billions of years.Here we report the first discovery of an iron meteorite fragment from the Chang’e-5 lunar soil,which consists mainly of martensite(quenched from taenite),kamacite,and schreibersite,with a trace of pentlandite.The meteorite fragment is Ni-and P-rich,S-poor,and based on its mineral chemistry and bulk composition,can be classified into the IID-group,a rare and carbonaceous group of iron meteorite originating in the outer Solar System.This meteorite fragment experienced only limited partial melting followed by fast cooling,suggestive of efficient preservation of intact remnants of iron meteorites impacting on the porous lunar regolith.Alternatively,it is a relic of a low-velocity impact of submillimeter-sized metal grains originated from an IID-like iron meteorite.Our observations demonstrate that it is feasible to achieve the type distribution of meteorites impacting on the Moon via systematically analyzing a large number of metal grains separated from lunar soils,thus shedding light on the dynamic evolution of the Solar System.展开更多
月球火山活动历史是月球科学基本问题之一,是理解月球内部物质组成和热演化历史的关键(Head and Wilson,2017).2020年12月17日,我国嫦娥五号任务从月球风暴洋克里普地体北部的吕姆克山附近(51.92°W,43.06°N)(Wang et al.,2021...月球火山活动历史是月球科学基本问题之一,是理解月球内部物质组成和热演化历史的关键(Head and Wilson,2017).2020年12月17日,我国嫦娥五号任务从月球风暴洋克里普地体北部的吕姆克山附近(51.92°W,43.06°N)(Wang et al.,2021)采集了1731 g月壤样品,并成功返回地球,实现了我国首次地外天体采样(Yang and Lin,2021).对嫦娥五号月壤样品中玄武岩岩屑的系统定年结果显示,着陆区的火山活动至少可以持续至20亿年前(Che et al.,2021;Li et al.,2021),该结果将阿波罗样品和月球陨石限定的月球火山活动结束时间推迟了8亿年(Merle et al.,2020).然而,这一定年结果也给月球科学研究提出了新的问题.月球的质量仅为地球的1.2%,由于比表面积大,理论上应该快速冷却.热演化模拟计算也表明,月球火山活动应当结束于25亿年前(Spohn et al.,2001),且撞击坑定年显示月球背面的火山活动确实结束于25亿年前(Haruyama et al.,2009).但是,嫦娥五号玄武岩定年结果确证了月球风暴洋克里普地体的火山活动可以持续到20亿年前,那么,为何月球火山活动能够持续如此之久呢?更进一步,月球火山活动的最终结束时间是多晚?展开更多
基金supported by the National Natural Science Foundation of China(42230206,42241152,and 42103035)the Key Research Program of Frontier Sciences,Chinese Academy of Sciences(QYZDJ-SSW-DQC001).
文摘Lunar soil preserves numerous fragments of meteorites impacting on the Moon,providing a unique opportunity to investigate the distribution of the types of projectiles over billions of years.Here we report the first discovery of an iron meteorite fragment from the Chang’e-5 lunar soil,which consists mainly of martensite(quenched from taenite),kamacite,and schreibersite,with a trace of pentlandite.The meteorite fragment is Ni-and P-rich,S-poor,and based on its mineral chemistry and bulk composition,can be classified into the IID-group,a rare and carbonaceous group of iron meteorite originating in the outer Solar System.This meteorite fragment experienced only limited partial melting followed by fast cooling,suggestive of efficient preservation of intact remnants of iron meteorites impacting on the porous lunar regolith.Alternatively,it is a relic of a low-velocity impact of submillimeter-sized metal grains originated from an IID-like iron meteorite.Our observations demonstrate that it is feasible to achieve the type distribution of meteorites impacting on the Moon via systematically analyzing a large number of metal grains separated from lunar soils,thus shedding light on the dynamic evolution of the Solar System.
文摘月球火山活动历史是月球科学基本问题之一,是理解月球内部物质组成和热演化历史的关键(Head and Wilson,2017).2020年12月17日,我国嫦娥五号任务从月球风暴洋克里普地体北部的吕姆克山附近(51.92°W,43.06°N)(Wang et al.,2021)采集了1731 g月壤样品,并成功返回地球,实现了我国首次地外天体采样(Yang and Lin,2021).对嫦娥五号月壤样品中玄武岩岩屑的系统定年结果显示,着陆区的火山活动至少可以持续至20亿年前(Che et al.,2021;Li et al.,2021),该结果将阿波罗样品和月球陨石限定的月球火山活动结束时间推迟了8亿年(Merle et al.,2020).然而,这一定年结果也给月球科学研究提出了新的问题.月球的质量仅为地球的1.2%,由于比表面积大,理论上应该快速冷却.热演化模拟计算也表明,月球火山活动应当结束于25亿年前(Spohn et al.,2001),且撞击坑定年显示月球背面的火山活动确实结束于25亿年前(Haruyama et al.,2009).但是,嫦娥五号玄武岩定年结果确证了月球风暴洋克里普地体的火山活动可以持续到20亿年前,那么,为何月球火山活动能够持续如此之久呢?更进一步,月球火山活动的最终结束时间是多晚?
