The Inventory of Stardust Grains in the Solar Nebula - Implications from Isotopic and Petrologic Studies of Primitive Solar System Materials

太阳星云中星尘颗粒的清单——原始太阳系材料的同位素和岩石学研究的启示

• 批准号: 145226721
• 负责人: Privatdozent Dr. Peter Hoppe
• 金额: --
• 依托单位: Max-Planck-Institut für Chemie (Otto-Hahn-Institut)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2013-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/145226721?language=en
• 关键词: Inventory; Stardust; Grains; Solar; Nebula

Primitive meteorites, interplanetary dust particles, and samples from comet 81P/Wild 2 contain small quantities of refractory dust grains that are older than our Solar System and which formed in the winds of evolved stars or in the ejecta of stellar explosions. These presolar (stardust) grains can be identified on the basis of large isotopic anomalies with respect to average Solar System matter. Their abundances vary among different primitive Solar System materials, apparently reflecting processes of secondary alteration (e.g., aqueous alteration or thermal heating) and possibly also heterogeneities in the solar nebula. Here, we will continue to investigate the presolar grain inventories of CR clan chondrites, which are amongst the most primitive meteorites known, by NanoSIMS ion imaging. The matrix petrology in these meteorites will be studied in detail by optical microscopy and electron microprobe and compared with the presolar grain inventory to investigate the effects of thermal and aqueous alteration, genetic relationships and formation scenarios for CR clan chondrites, and to infer constraints on the presolar grain abundance in the solar nebula. We will also continue to study matter from comet Wild 2, returned by NASA’s STARDUST mission, in order to explore the currently not well determined presolar grain abundance in matter from this pristine Solar System body. These studies will be complemented by a search for and possible chemical and isotopic studies of residues in impact craters in Al foils from STARDUST’s interstellar dust collector.

原始陨石、行星际尘埃粒子和来自81P/Wild 2彗星的样本含有少量难熔尘埃颗粒，这些尘埃颗粒比我们的太阳系更古老，形成于演化恒星的风或恒星爆炸的喷射物中。这些前太阳系（星尘）颗粒可以根据相对于平均太阳系物质的大同位素异常来识别。它们的丰度在不同的原始太阳系物质中有所不同，显然反映了次生蚀变过程（例如，水蚀变或热加热），也可能反映了太阳星云中的非均质性。在这里，我们将继续研究CR族球粒陨石的太阳前颗粒清单，这是已知最原始的陨石之一，通过纳米sims离子成像。利用光学显微镜和电子探针对这些陨石的基质岩石学进行了详细的研究，并与太阳星云前的颗粒清单进行了比较，以探讨热蚀变和水蚀变对CR族球粒陨石的影响、成因关系和形成情景，并推断太阳星云中太阳星云前颗粒丰度的约束条件。我们还将继续研究由美国宇航局“星尘”任务返回的怀尔德2号彗星的物质，以探索这个原始太阳系天体中目前尚未确定的太阳系前物质的颗粒丰度。这些研究将由“星尘号”星际尘埃收集器对铝箔撞击坑中残留物的寻找和可能的化学和同位素研究来补充。