（来源：江苏科技）原标题：科普知识 | 1吨月壤中约含170克水！嫦娥五号矿物表层带来新发现
点击上方"蓝字"关注江苏科技近日，中科院地化所科研团队针对嫦娥五号月壤样品开展研究，发现嫦娥五号矿物表层中存在大量的太阳风成因水，估算出太阳风质子注入为嫦娥五号月壤贡献的水含量至少为170ppm（ppm为百万分比浓度）。 Russian Agriculture Minister Dmitry Patrushev said Friday that the country might be forced to take some 50 million tonnes of grain off the market after this year’s crops fell short of the 130 million tonne target.,"I don't expect major problems in Europe in both categories of grain, for cattle breeding and for human consumption, since this year's crops were excellent despite the drought at the end of the season. The problems, if they arise, will be in the Middle East and Africa, and maybe in some countries of Southeast Asia," Gisele Fichefet said.,The only problem facing Europe, Fichefet said further, is a low nitrogen content of the wheat crop in many places, which means it will not be used in the baking industry but only for livestock feed.,Russia was the world's top exporter of nitrogen fertilizers in 2021, the most valued variety, according to the UN Food and Agriculture Organization (FAO). Many European and Central Asian countries rely on Russia for over 50% of their fertilizer supply, and shortages are expected to extend to next year.,Russia is also the world's largest exporter of wheat, with Ukraine in fifth place. Together, the two countries account for more than one-third of global cereal exports and a half of the world's sunflower oil export market.,FAO predicted in March that supply disruptions in Russia and Ukraine could affect some 50 countries that depend on the two for 30% or more of their wheat supply. Many of them are low-income countries in northern Africa, Asia and the Near East.,AfricaAnti-Russia Sanctions Left Africa Without Access to Grain and Fertilisers, African Union Chief Says3 June, 11:13 GMT,Fichefet said it was "not so much a price problem, as a delivery issue" because price fluctuations had not been more than 20% up or down since the start of the Ukrainian conflict. A UN-brokered deal among Russia, Ukraine and Turkey has at least temporarily stabilized the prices. That may change if Russia slashes grain exports, she predicted.,The West has repeatedly accused Russia of undermining global food security. Moscow argues that Western sanctions on financial transactions and maritime transportation have disrupted global food supply chains, curbing the access of Russian food products and fertilizers to markets. The deal, agreed in Istanbul in July, seeks to facilitate the transport of grain and foodstuffs from Ukrainian ports, while simultaneously addressing limits on Russian exports.。月球上的水从何而来？以什么形态存在？新华日报·交汇点记者采访到了江苏省地质学会专家、南京大学教授张爱铖，试图探寻到更多月球之水的“秘密”。
张宣/摄“本次在月壤样品中发现的水为太阳风成因水，简单来说，就是太阳风吹来的水。”张爱铖告诉记者，太阳风主要由氢和氦组成，它不断地吹向月球表面。
B | 月球没有大气，没有办法阻止太阳风粒子的轰击，所以太阳风的氢和氦就会被注入到月球表面的月壤矿物中，但是注入深度很有限，主要是在矿物的表面。“如果月壤因为微陨石撞击发生局部熔融形成玻璃，这些矿物表面的水就会被转移到玻璃中或者部分丢失。”月球上除了太阳风成因水，还有月球自身的水、小行星或彗星带来的水。“虽然月球在形成的时候有部分水可能残留下来，在月球漫长的演化历史中慢慢富集。”张爱铖介绍说，“比如月球玄武岩（月幔熔融形成的熔体喷发到月表的岩石）中一种叫磷灰石的矿物就可以含有达到几千ppm的氢氧根形式存在的结构水。
C | ”而富含水冰的小行星或者彗星当撞击月球表面时，虽然大量水在撞击时蒸发了，但仍有一些水深入月壤中存留下来。一吨月壤含水约170克，相比之下，地球上一吨沙漠中沙子的含水量可达十几公斤。月球上的水为何消失那么快？月壤中的水绝大多数是太阳风贡献的，而月岩中的水大多数是岩浆凝固前就有的。“陨石的撞击、太阳辐射都会导致月壤中水的丢失。”张爱铖认为，一方面，陨石撞击会带来短时间的高温，从而导致撞击坑及附近的一些月壤失去水。另一方面，虽然月球表面白天的温度不是特别高，但因为月表接近真空，太阳辐射的温度有可能会导致月壤矿物表面的水释放和迁移。“避免太阳的辐射，可以帮助月球上的水不丢失。”月表矿物是重要的储水“仓库”，那月幔中会有水吗？“嫦娥五号玄武岩月幔源区，每克岩石的水含量不超过5微克。
D | ”嫦娥五号月球样品中的月海玄武岩，是月球最“年轻”玄武岩之一，年龄为20亿年，其晚期岩浆活动的源区并不富集放射性元素。“嫦娥五号着陆区异常活跃的火山活动既不能归因于源区富集放射性生热元素，也不是由于源区富含水，这对未来的科学研究和月球探测提出了新的目标。”在科幻电影《火星救援》中，宇航员在火星种起了土豆。月球上发现的水能否用来种菜？“种菜需要液态水，但是目前尚无确凿证据表明月球表面存在液态水。”张爱铖介绍道，目前月球上存在的实际上是矿物中的结构水，主要是以氢离子或者氢氧根形式存在，不易被植物吸收。“当然，从科学角度讲，月球矿物中发现的水是可以通过技术手段释放出来的，但是成本比较高。前人曾经依据遥感探测手段，提出月球两极阴影区会有水冰存在。如果能采集到这些水冰，用于种菜是有可能的。”来源：交汇点新闻编辑：李艳茹校对：韩博初审：薛腾霄终审：刘波相科普知识 | 航天员出舱作业为什么不会“飘走”？南航专家解析中国空间站航天员第五次出舱作业 关科普知识 | 黑洞真会发声吗？ 链科普知识 | 生活中的辐射对人体有害吗？ 接科普知识 | 一图读懂暗物质粒子探测卫星 大力建设科技强省勇当科技创新开路先锋微信公众号：JiangSu_ST点分享点收藏点点赞点在看返回搜狐，查看更多责任编辑：
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