The Kamil Crater in Egypt
The Kamil Crater in Egypt
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埃及卡米尔陨石坑
作者：
L. Folco;M. Di Martino;A. El Barkooky;M. D’Orazio;A. Lethy;S. Urbini;I. Nicolosi;M. Hafez;C. Cordier;M. van Ginneken;A. Zeoli;A. Radwan;S. El Khrepy;Mohamed Nabil ElGabry;M. Gomaa;A. A. Barakat;R. Serra;M. El Sharkawi
一个保存异常完好的直径45米的陨石坑为小规模陨石撞击地球提供了地面真相。我们报告在埃及南部发现了一个直径45米、具有原始射线结构的撞击坑。这种原始结构通常在太阳系中没有大气层的岩石或冰行星上观察到。这一特征以及与铁陨石撞击物和冲击变质作用的联系提供了一幅独特的关于地壳小规模超高速撞击的画面。与目前的地球物理模型相反，地面数据表明，质量在几十吨左右的铁陨石可以穿透大气层，而不会产生大量碎片。
An unusually well-preserved 45-meter-diameter crater provides ground truth for small-scale meteorite impacts on Earth. We report on the detection in southern Egypt of an impact crater 45 meters in diameter with a pristine rayed structure. Such pristine structures are typically observed on atmosphereless rocky or icy planetary bodies in the solar system. This feature and the association with an iron meteorite impactor and shock metamorphism provides a unique picture of small-scale hypervelocity impacts on Earth’s crust. Contrary to current geophysical models, ground data indicate that iron meteorites with masses of the order of tens of tons can penetrate the atmosphere without substantial fragmentation.