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.

星尘使命是第一个从彗星和星际粒子流（ISP）带回样本的使命。使用不同技术对几个彗星撞击轨迹的研究（Zolensky等人，2006年，Brownlee等人，2006年，Flynn等人，2006）已经表明，与所有预期相反，大多数受冲击的矿物颗粒是高温矿物相。虽然哈雷彗星和坦普尔1号彗星的红外光谱数据证明了含水矿物相的存在，但迄今为止，含水矿物相的存在还很少见，证据很少。星尘样本中缺乏已识别的页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野生2号上（Rotundi等人，2008年，Berger等人，2011年），它们可能没有在捕获过程中幸存下来（Foster等人，2011年）。2008; Wozniakiewicz等人，2010年），或者它们可能仍然在星尘收集中等待发现。无论哪种情况，彗星都保存了早期太阳系中水循环过程的证据。有了这个建议，我们想继续寻找含水矿物相及其残留物。因此，我们建议使用透射电子显微镜（TEM）研究完整的影响轨迹。新的技术发展（阿里斯; Stojic和Brenker，2010年）首次使完整的撞击轨迹的TEM研究成为可能。通过研究撞击路径，我们希望找到有关粒子化学和结构的新信息。特别关注的是球根形的撞击轨迹。这些轨迹揭示了发现含水相的最高潜力（例如Maurette和Kurat，2006年）。此外，我们将把我们的工作扩展到层状硅酸盐到气凝胶的实验镜头，这将在一个合作项目的框架内进行。