TEM Analysis on Wild2 cometary dust particles and impact tracks in aerogel: searching for relict structures of hydrous mineral phases

Wild2 彗星尘埃颗粒和气凝胶撞击轨迹的 TEM 分析：寻找含水矿物相的残余结构

• 批准号: 211567154
• 负责人: Professor Dr. Frank Erich Brenker
• 金额: --
• 依托单位: Abteilung Petrologie und Geochemie
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2015-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/211567154?language=en
• 关键词: TEM; Analysis; Wild2; cometary; dust

The Stardust mission is the first mission that brought back samples from a comet and from an interstellar particle stream (ISP). Investigation on several cometary impact tracks using different techniques (Zolensky et al.2006, Brownlee et al., 2006, Flynn et al., 2006) have shown that contrary to all expectations most of the impacted mineral grains are high temperature mineral phases. Hydrous mineral phases are rare until now, only little evidence has been found, although IR data on comet Halley and Tempel 1 demonstrated the existence of hydrous phases. The lack of identified phyllosilicates in the Stardust samples may reflect diversity amongst comets or, if they were present on Wild 2 (Rotundi et al. 2008, Berger et al. 2011), that they may not have survived the capture process (Foster et al., 2008; Wozniakiewicz et al., 2010) or they may still be awaiting discovery in the Stardust collection. In either case it is clear that comets preserve evidence of aqueous processes in the early Solar System. With this proposal we would like to continue the search for aqueous mineral phases and its remnants. Therefore we propose to investigate complete impact tracks using transmission electron microscopy (TEM). For the first time new technical developments (ArIS; Stojic and Brenker, 2010) enable a TEM study of complete impact tracks. By investigating the impact path, we hope to find new information on particle chemistry and structure. Special focus will be on bulbous-shaped impact tracks. These tracks reveal the highest potential for finding hydrous phases (e.g. Maurette & Kurat, 2006). In addition we will extend our work to experimental shots of phyllosilicates into aerogel which will be performed in the framework of a cooperated project.

星尘任务是从彗星和星际粒子流（ISP）带回样品的第一个任务。使用不同技术对几个彗星冲击轨道进行了研究（Zolensky等人2006； Brownlee等，2006； Flynn等，2006）表明，与所有预期的大多数受影响的矿物颗粒相反。到目前为止，液压矿物相很少见，但很少有证据，尽管IR上的HALLEY和TEMPEL 1的数据证明了存在液压相。星尘样品中缺乏鉴定的纤维硅酸盐可能反映了彗星之间的多样性，或者，如果它们存在于Wild 2（Rotundi等，2008年，Berger等人，2011年），它们可能无法在捕获过程中幸存下来（Foster等，2008; Wozniakiewicz等人，2010年，2010年）或他们可能仍在观察到的发现。无论哪种情况，很明显，彗星都保留了早期太阳系中水过程的证据。通过这项建议，我们希望继续寻找水矿物阶段及其残留物。因此，我们建议使用透射电子显微镜（TEM）研究完整的影响轨道。首次新的技术发展（Aris; Stojic and Brenker，2010年）可以对完整的影响轨道进行TEM研究。通过研究影响路径，我们希望找到有关颗粒化学和结构的新信息。特别的重点将放在球茎形的冲击轨道上。这些轨道揭示了寻找含水相的最高潜力（例如Maurette＆Kurat，2006）。此外，我们将把工作扩展到腓骨硅酸盐的实验镜头中，并将其在合作项目的框架中进行。