Microstructural Indications for Protoenstatite Precursor of Cometary MgSiO3 Pyroxene: A Further High-Temperature Component of Comet Wild 2-猫眼课题宝

彗星 MgSiO3 辉石原火辉石前体的微观结构迹象：Wild 2 号彗星的进一步高温成分

DOI：

10.1086/590411

发表时间：

2008

期刊：

The Astrophysical Journal Letters

影响因子：

通讯作者：

中科院分区：

文献类型：

作者：

S. Schmitz;F. Brenker

利用透射电子显微镜（TEM）技术对NASA星尘任务中Wild 2号采集的彗星顽辉石（Mg/Si 0.858; Fe/Si 0.027; Ca/Si 0.01; Al/Si 0.009; Cr/Si 0.01）显微结构进行了研究。该顽辉石具有高度无序平行堆积（100）的特点，包括斜顽辉石（CLEN）和正顽辉石（OREN）交替片层和（100）孪晶。此外，还发现了4.5 Å宽平行半平面（100）的普遍现象，这导致了该结构的13.5和22.5 Å多型。这些微观结构特征表明，这是由原辉橄榄石（PEN）前体直接转变而来的，这需要超过1275 K的温度和快速冷却（bbb10 K hr−1）。我们的发现表明，在怀尔德2号彗星形成的冰冷地区，还存在另一种高温成分。

Microstructural studies by transmission electron microscope (TEM) techniques of a microtomed cometary enstatite (Mg/Si 0.858; Fe/Si 0.027; Ca/Si 0.01; Al/Si 0.009; Cr/Si 0.01) from Wild 2 sampled during NASA's Stardust mission were conducted. The enstatite is characterized by high stacking disorder parallel (100) which includes alternating clinoenstatite (CLEN) and orthoenstatite (OREN) lamellae and (100) twins. In addition a widespread occurrence of 4.5 Å wide half-planes parallel (100) are detected, which leads to 13.5 and 22.5 Å polytypes of the structure. These microstructural features are indicative of the direct transformation from a protoenstatite (PEN) precursor, which requires temperatures of more than 1275 K and rapid cooling (>10 K hr−1). Our finding represents a further high-temperature component originally present in the cold icy region where comet Wild 2 was formed.

Elemental Compositions of Comet 81P/Wild 2 Samples Collected by Stardust

DOI： 10.1126/science.1136141

发表时间： 2006-12

期刊：

Science

影响因子： 56.9

作者：

G. Flynn;P. Bleuet;J. Borg;J. Bradley;F. Brenker;S. Brennan;J. Bridges;D. Brownlee;E. Bullock;M. Burghammer;B. Clark;Z. Dai;C. Daghlian;Z. Djouadi;S. Fakra;T. Ferroir;C. Floss;I. Franchi;Z. Gainsforth;J. Gallien;P. Gillet;P. Grant;G. Graham;S. Green;F. Grossemy;P. Heck;G. Herzog;P. Hoppe;F. Hörz;J. Huth;K. Ignatyev;H. Ishii;K. Janssens;D. Joswiak;A. Kearsley;H. Khodja;A. Lanzirotti;J. Leitner;L. Lemelle;H. Leroux;K. Luening;G. MacPherson;K. Marhas;M. Marcus;G. Matrajt;Tomoki Nakamura;K. Nakamura-messenger;T. Nakano;M. Newville;D. Papanastassiou;P. Pianetta;W. Rao;C. Riekel;F. Rietmeijer;D. Rost;C. Schwandt;T. See;J. Sheffield-Parker;A. Simionovici;I. Sitnitsky;C. Snead;F. Stadermann;T. Stephan;R. Stroud;J. Susini;Yoshio Suzuki;S. Sutton;S. Taylor;N. Teslich;D. Troadec;P. Tsou;A. Tsuchiyama;K. Uesugi;B. Vekemans;E. Vicenzi;L. Vincze;A. Westphal;P. Wozniakiewicz;E. Zinner;M. Zolensky

通讯作者：

Microstructural Indications for Protoenstatite Precursor of Cometary MgSiO3 Pyroxene: A Further High-Temperature Component of Comet Wild 2

彗星 MgSiO3 辉石原火辉石前体的微观结构迹象：Wild 2 号彗星的进一步高温成分

文献摘要

参考文献

被引文献

相似文献