科普知识学英语 水星上曾有一片岩浆海

海量下载 免费学习英语 www.englishvip.com/xinlw.htm （申请网址） By analyzing Mercury's rocky surface, scientists have been able to partially reconstruct the planet's history over billions of years. Now, drawing upon the chemical composition of rock features on the planet's surface, scientists at MIT have proposed that Mercury may have harbored a large, roiling ocean of magma very early in its history, shortly after its formation about 4.5 billion years ago. The scientists analyzed data gathered by MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging), a NASA probe that has orbited the planet since March 2011. Later that year, a group of scientists analyzed X-ray fluorescence data from the probe, and identified two distinct compositions of rocks on the planet's surface. The discovery unearthed a planetary puzzle: What geological processes could have given rise to such distinct surface compositions?   To answer that question, the MIT team used the compositional data to recreate the two rock types in the lab, and subjected each synthetic rock to high temperatures and pressures to simulate various geological processes. From their experiments, the scientists came up with only one phenomenon to explain the two compositions: a vast magma ocean that created two different layers of crystals, solidified, then eventually remelted into magma that then erupted onto Mercury's surface.   "The thing that's really amazing on Mercury is, this didn't happen yesterday," says Timothy Grove, a professor of geology at MIT. "The crust is probably more than 4 billion years old, so this magma ocean is a really ancient feature."   Grove, along with postdoc Bernard Charlier and Maria Zuber, the E.A. Griswold Professor of Geophysics and Planetary Science and now MIT's vice president for research, published the results in the journal Earth and Planetary Science Letters. 通过分析水星表面的岩石，科学家们已经能够部分重建地球的历史上数十亿年。现在，借鉴功能，对地球表面岩石的化学成分，在麻省理工学院的科学家们提出，水星可能窝藏大，滚滚的岩浆海洋，在它的历史非常早，大约4.5亿年前形成后不久。科学家信使（水星表面，空间环境，地球化学和测距），2011年3月以来，围绕行星NASA探测器所收集的数据进行了分析。那年晚些时候，一组科学家从探头X射线荧光光谱数据进行了分析，确定了两种截然不同的岩石组成的行星的表面上。发现出土的行星之谜：什么样的地质变化过程中可能引起这种不同的表面成分？   要回答这个问题，MIT的研究小组使用的成分数据重新两类岩石在实验室，每个合成的岩石受到高温和高压模拟各种地质过程。从他们的实验中，科学家们想出了只有一个现象来解释两个组成：一个巨大的岩浆海洋，创建了两个不同的晶体层，固化，然后最终重熔岩浆喷发到水星表面。   “这件事，真的很神奇水星上，这并没有发生昨天，”蒂莫西·格罗夫说，在麻省理工学院地质学教授。“地壳可能超过4亿岁，所以这个岩浆海洋是一个非常古老的功能。”   树丛，随着博士后伯纳德Charlier和玛丽亚·朱伯EA格里斯沃尔德地球物理和行星科学教授和麻省理工学院的研究副总裁，发表在杂志地球和行星科学快报的结果。 “成千上万人疯狂下载。。。。。。 更多价值连城的绝密英语学习资料， 洛基内部秘密英语，技巧，策略 请在 网上 申请报名” 洛基国际英语 竭诚为您服务