克莱夫·尼尔 demonstrates the process of grinding the tiny samples of ash-like material collected from the surface of the Moon during an Apollo space mission in 1972. 他的研究生, 杰西卡Valenciano, will prepare the minute Moon rocks from the other 19 canisters that arrived on campus in December to measure the exact chemical makeup to the parts per billion.
It’s somehow fitting that cutting-edge geological research of samples from outside this world begins with a tool that humans began using in the Stone Age. 臼和杵做得很好，它们可能是人类历史上变化最小的工具. The rounded bowl 和 club-shaped pestle originated in the Stone Age are nearly identical to those used in kitchens today.
尼尔是电竞赌博平台的教授 土木与环境工程和地球科学, uses a mortar 和 pestle to grind 50 milligrams of lunar regolith — the ashy surface “soil” of the Moon — into a fine dust that will be dissolved in hydrofluoric 和 nitric acids. 这些解决方案将在电竞赌博平台办公室复印机大小的实验室机器上进行分析 环境科学与技术中心 和 中西部同位素和微量元素研究分析中心 测定样品中主要元素和微量元素的丰度.
The samples Neal 和 Valenciano are analyzing were collected in 1972 from the surface of the Moon in vacuum tubes by Apollo 17 astronauts Harrison Schmitt 和 Gene Cernan. 这些试管自被送回后一直未开封，代表着“新”样本.
“These are the first real detailed analyses from this sample — we’re starting to see a new part of the Moon that we basically haven’t seen before,尼尔说。. “样品很珍贵. 为了获得它们，我们投入了大量资金. 所以我们正努力最大化科学成果.”
太阳不断地用太阳风轰击月球, Neal说, 因为月球不像地球那样有大气层来保护它. 太阳风含有丰富的挥发性元素，如氢, 氮, 碳和氦沉淀在尘土飞扬的风化层中.
当风化层被带回地球时, these volatiles are lost to some degree in the process of collection 和 storage or in the shaking that occurs during lift off from the Moon 和 on re-entry to Earth’s atmosphere. What is special about the samples Neal recently received is that they were collected in a vacuum tube at Station 3, 这是一个滑坡区，不同于阿波罗17号着陆的地方.
“These are the first real detailed analyses from this sample — we’re starting to see a new part of the Moon that we basically haven’t seen before.” 克莱夫·尼尔
在地球上，未打开的管子被放置在另一个真空罐中进行保护. 罐内每半厘米深, 全国和世界各地的实验室进行不同的分析. 尼尔收到了20瓶，每瓶含有50毫克的月球岩石，预计还会有20瓶.
尼尔说:“NASA刚刚(在2019年12月)打开了这个罐子，所以这真的是一个新的、令人兴奋的东西。. “我们真的不知道风化层中真正的太阳风含量是多少, 因此我们不知道它可能拥有的资源潜力.”
Neal’s ultimate goal is to discover natural resources that will make a continual presence on the Moon economical 和 possibly power the next step of humans into the further reaches of space. 作为美国宇航局月球探测分析小组的前任主席, 他一直主张重返月球, 无论是作为一个国家还是作为国际空间站这样的联盟的一部分, 可能包括现在兴起的私营公司.
“我看到了第一批12个人在月球上行走，现在我想看看第13个人, 以及看到人类这次回到月球表面停留,尼尔经常说.
Neal believes that America ab和oned the Moon after winning the race against the Soviets to get there first with the Apollo program. He was 8 years old in Britain 和 remembers his father waking him to watch Buzz Aldrin 和 Neil Armstrong take the first walk on the Moon. He hopes his research can further our underst和ing of how lunar resources could support settlement 和 create a new economy for things like building materials, 辐射防护和火箭燃料.
“We can learn from a permanent lunar settlement — how to survive 和 how to keep exploring,他说. “我不认为不去月球我们就能到达火星.”
月岩样本
来自月球的岩石和风化层当然是一种罕见的现象, one that has recently resurfaced with a Chinese mission that brought back the first samples in 44 years. The Chang’e 5 capsule l和ed in December with about 4 pounds of lunar dirt 和 gravel from a different area of the Moon than previous missions.
去年12月前，地球上最后一块月球材料来自苏联的月球24号任务, 它在1976年带回了大约6盎司的风化土. 在此之前，6个美国.S. 1969年至1972年间，阿波罗号地面任务带回了大约842磅的风化层. 在过去的35年里，这是尼尔的金牌.
嫦娥五号的样本有望为了解月球历史提供一个新的窗口, 因为它们来自月球的一个区域，据信是在1月1日左右形成的.50亿年前. 阿波罗带回的火山岩年龄超过30亿年.
“We know they l和ed on a terrain that’s much younger than the Apollo or Soviet missions,尼尔说。. “15亿年对于月球来说还很年轻. Relative age dating has been carried out by looking at the number of craters in a given surface 和 comparing those with Apollo, 我们有样本.
“These Chang’e samples are completely different from what we have 和 are an exciting new chapter in our underst和ing of the Moon.”
而尼尔很想研究他们的样本, 他说，中国政府最近公布了如何申请访问的要求. 尽管中国科学家不能申请阿波罗号的样本, 尼尔希望通过一个科学家联盟来研究嫦娥五号的样本, 他认为这种模型对于研究和资助现代太空探索是必要的.
“There’s an international group that I’m part of that is hoping to get involved with the Chinese samples, 没有任何NASA的资金,他说.
科学的精度
月球物质的稀有性解释了为什么分析它们的过程如此细致. It starts in a Cushing Hall lab near Neal’s office by opening each numbered vial 和 weighing it exactly. 洁净实验室要求脱鞋，穿白大褂，戴安全眼镜.
真空密封的塑料袋里装着小袋的贴有标签的金属小瓶. The dusty regolith weighs slightly less than 50 milligrams because some sticks on the surface of the vial 和 lid. 把它倒进一个小钵里, 它的盖子上有一个洞，这样杵就可以把它磨碎，而不会把灰尘散到空气中去.
尼尔向瓦伦西亚诺展示了研磨的方法，并让她接手. 这项研究的成果将成为她的博士论文.
“我们想让它达到滑石粉的稠度，”他解释说. “这是至关重要的，因为我们不能在它进入酸后重新研磨——我们需要完全溶解.”
阿波罗号的风化层在研磨后又稍微轻了一点, 因为有少量黏在臼里. 它被放入一个小塑料瓶中，等待在氢氟酸和硝酸中溶解. The mortar 和 pestle get wiped down with dilute nitric acid 和 ultrapure water to avoid cross-contamination with the next sample to grind. 当五瓶样品准备好后，瓦伦西亚诺在每个样品中加入酸.
The dissolved samples are now ready for the analyses that will determine the major 和 trace elements down the sample tubes, 尼尔称之为“化学地层学”.”
“我们有两台独立的机器，都是基于电感耦合等离子体(ICP)，”他说. “基本上, you use a radio frequency to induce a plasma that atomizes 和 ionizes the liquid at high temperature. 然后用ICP发射光谱仪观察等离子体, 光谱中波段的强度可以得到完整的定量主元素分析. ICP质谱仪对离子进行计数，并对痕量元素进行全面定量分析。
在电竞赌博平台工作了30多年分析月球和小行星的物质, 尼尔促进了人类对月球地质和历史的了解. 他的团队首次对所有微量元素进行了全面研究, identified minerals from different source regions 和 made some of the first full analysis of volcanic basalt rocks.
他的过程是破坏性的, 意思是样本用完了, 但真空核心管中每半厘米的其他部分将保留下来. 其他实验室，如新墨西哥大学和圣华盛顿大学. 路易斯，正在对相同的样本进行不同的分析.
“It takes an international consortium to do this because no one lab has all the instrumentation you need,尼尔说。. “这就是为什么你要把拥有不同专业知识的不同人聚集在一起.”
奔向月球
而珍贵的风化层可能看起来像壁炉里的灰烬, 它确实来自另一个天体，因此具有非常不同的性质. 太阳风在月球尘埃中植入的挥发物之一是氢.
“我在约翰逊航天中心看过这个实验，你拿月球风化层, 把它放在真空里, 把它加热，水就会从底部滴出来,尼尔说。. “现在, 里面没有水, but it is exciting those hydrogen atoms to then combine with oxygen in iron oxides to create metallic iron 和 water.”
This kind of scientific wonder shows why Neal believes a permanent settlement on the Moon is more than science fiction. But why would humans want to spend exorbitant 和 limited capital to go to a place we’ve already been? 什么理由会促使我们花费必要的金钱和精力呢?
尼尔认为，太空探索带来了巨大的回报，而不仅仅是满足了我们的好奇心. Many of the inventions necessary for survival in space have advanced the science 和 engineering of products that benefit us at home, 比如手机.
如果人类要在太空中走得更远, he believes the necessary science 和 technology will be invented through humans surviving 和 thriving on the Moon. 他最后的论点显示了这一承诺最终将如何实现.
氦-3是地球上极为罕见的同位素. But scientists like Neal have shown it is relatively abundant on the Moon as another volatile that solar wind embeds in lunar regolith. 如果氦-3能在月球上开采, 然后科学家们推测，它可以用作持续核聚变的材料, 这是中国和其他国家正在发展的一项技术.
“这是核聚变的天堂，”尼尔说. “没有有毒的副产品. 从理论上讲, 一个装载氦-3的航天飞机货舱, 也就是开采大约2到3个足球场的地下一米或一米半, 就像我们从阿波罗中了解到的那样，你为整个美国提供了一年的燃料.”
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