探索月球：重新研究阿波罗登月留下的数据

伤我心太深

月亮里面是什么？重新审视阿波罗时代留下数据所提供的线索。

阿波罗时代月震收集到的数据有望于帮助科学家了解月球地壳下面的情况。到现在科学家们才知道了怎样可以取得有关问题的答案。

阿波罗11号登月舱的驾驶员埃德温·'巴斯'·奥尔德林（Edwin 'Buzz' Aldrin ）在月球表面上放置了一个无源的地震试验装置（Passive Seismic Experiment ，把有关月震、滑坡和陨石撞击的信息用无线电信号送回地球。美国国家航空和航天管理局/文件

作者：皮特·斯波茨，

科学家们由于重新审视了从阿波罗时代就开始已有30年历史的月震数据，才能使他们取得了第一次到月亮中心的替代旅行。

研究人员发现在月球内部深处：有一个跨度约为300英里的固体铁球，包裹在另外56英里厚的铁水里，顶上部分地还有93英里层的熔融材料。

这种努力表示了对月球核心和其各层深度第一次的直接观察，阿拉巴，马州亨茨维尔，马歇尔空间飞行中心的月球科学家蕾妮·韦伯（Renee Weber）说，她负责领导了这个项目科学家的国际研究小组。

月球里有着周围带有融化铁层的铁芯的这个概念并不是新的。但到目前为止，这些证据都是间接的。

新的观察确认了这种情况。它似乎对那些曾经被认为不太适合用来详细研究月球最深部分的数据，赋予了生新的生机。

“我认为利用这些数据还可以做很多的研究。” 韦伯博士说。

在阿波罗计划中，宇航员在月在在月球表面上留下了四个地震仪。于1977年，这些仪器把最后的数据送回到地球，五年后，阿波罗计划就结束了。

目的在于用月震所产生的地震波来探测月球的结构，就像地球上的地质学家用地震来研究地球的内的部结构，和天体物理学家用“恒星震动”的声波来研究恒星的内部相类似。

但月球在它的整个历史中所受到的沉重打击，已经严重地使月球的外壳和其核心之间产生了断裂，也就是说，地震波被削弱了，这些数据变得更加难以解释。

但是，开发用来分析地球上不理想地震数据的新方法，再加上阿波罗时代以后计算机能力的迅速提高，使得韦伯和她的合作者重新审视了阿波罗时代所取得的数据，研究结果于星期四下午发表在网上辅助的科学杂志《科学快讯》上。

这些月震数据支持了月球怎样形成的盛行很广的观点，研究人员说：约在450亿年前，与地球大小相似的物体与地球相撞时，产生了很多碎片，它们之间的引力把它们聚合在一起而形成了月球。

在过去的几年里，月球的研究任务已经表明，它比10年前任何人所设想的，更为复杂和有趣，月球科学家说。

对开发阿波罗数据的能力，连同在未来的月球研究任务中放置更现代化的地震仪，有可能对月球内部做相类似的事情。

“关于月球的内部情况，我们知道得并不多”， 亚利桑那州立大学地震学家埃德·加内罗 （Ed Garnero）和他的研究小组的一个成员在一份声明里声称， “这些信息是破译月亮起源和演化的关键，其中也包括对很早期的地球。”

What's inside the moon? A fresh look at Apollo-era data offers clues  - CSMonitorcomWhat's inside the moon? A fresh look at Apollo-era data offers clues. Moonquake data collected in the Apollo era were supposed to help scientists understand what lay beneath the moon's crust. But only now do scientists have the know-how to unravel the answers. Apollo 11 lunar module pilot Edwin 'Buzz' Aldrin deploys the Passive Seismic Experiment Package, which remained behind on the lunar surface to radio back information concerning  moonquakes, landslides, and meteorite impacts. NASA/File Enlarge By Pete Spotts, Staff writer / January 7, 2011 Scientists have taken their first, vicarious journey to the center of the moon, thanks to a fresh look at 30-year-old moonquake data from the Apollo era. Skip to next paragraph Related Stories Moon's got water, yeah. But it's got other resource goodies, too. The moon may hold 100 times more water than previously thought The moon is shrinking. No, seriously. What the researchers found deep in the lunar interior: a solid iron ball 300 miles across, wrapped in molten iron another 56 miles thick, topped with a 93-mile layer of partially molten material. The effort represents the first direct observation of the moon's core and the depths of its various layers, says Renee Weber, a lunar scientist at the Marshall Spaceflight Center in Huntsville, Ala., who headed a international team of scientists on the project. IN PICTURES: We love the moon The notion that the moon has an iron core with a layer of molten iron surrounding it isn't new. But evidence so far has been indirect. The new look confirms that picture. But also appears to be breathing new life into data once thought to be poorly suited for detailed studies of the deepest portions of the lunar interior. "I think there's a lot more that can be done with these data," Dr. Weber says. During the Apollo program, astronauts left four seismographs on the lunar surface. The instuments returned their last data to Earth in 1977, five years after the Apollo program ended. The goal was to use seismic waves generated by moonquakes to probe the moon's structure, just as geologists on Earth use earthquakes to study Earth's interior structure and astrophysicists use acoustic waves from "star quakes" to study the interiors of stars. But the heavy pummeling the moon has taken throughout its history has severely fractured the region between the crust and core, meaning that seismic waves were degraded, making them too difficult to interpret. But new ways of analyzing less-than-ideal seismic data, developed for use on Earth, plus the rapid increase in computing power since the days of Apollo, prompted Weber and her collaborators to give the Apollo data a fresh look. The results were published Thursday afternoon on Science Express, the online adjunct to the journal Science. The seismic data support the prevailing idea of how the moon formed, the researchers say: Gravity reassembled debris that was generated when an Earth-size object collided with Earth some 4.5 billion years ago. Over the past few years, lunar missions have shown a moon far more complex and interesting than anyone expected a decade a go, lunar scientists say. The ability to mine Apollo's data, along with future missions to plant more-modern seismographs on the moon, hold the potential to do the same for the moon's interior. "There is much we don't know about the lunar interior," said Ed Garnero, a seismologist at Arizona State University and a member of the research team, in a statement. "That information is key to deciphering the origin and evolution of the moon, including the very early Earth."

伤我心太深

月球水不等于地球水

研究表明，月球岩石中的水资源比地球水资源包含更多的重氢元素，意即月球水有可能来源于彗星。克里斯托弗英塔格里塔报道。
虽然阿波罗登月计划在40年前就已经结束，但对于月球科学家来说，它依然在不断揭开月球的神秘面纱。通过研究宇航员从月球上带回来的岩石标本，科学家们发现月球上稀少的水资源与地球水资源的化学成分并不相符。因此他们认为月球水很可能来源于宇宙彗星。该项研究发表在地球科学综合杂志上（詹姆斯格林伍德及多人《月球岩石标本中的氢同位素比例显示月球水来自彗星》）。
研究人员利用离子显微镜对月球岩石标本中正常氢元素（包含1个中子）与重氢元素（包含2个中子）的含量进行了比较。数据显示月球水比地球水包含更多的重氢元素，并与海尔波普彗星、百武彗星及哈雷彗星更为接近。该结果表明在45亿年前古月球刚成型不久，就有彗星造访并留下了水资源。
此研究同时也解释了有关地球水资源的一个谜题——海洋是如何形成的。如果彗星撞击过月球，那它们也很可能撞击过地球：海水确实比地幔中的水含有更多重氢元素。科学家们也表示这可能是因为海水中含有更多的融化掉的彗星冰层。