Cometary dust: the diversity of primitive refractory grains
Cometary dust: the diversity of primitive refractory grains
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彗星尘埃：原始耐火颗粒的多样性
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
M. Zolensky
中科院分区：
文献类型：
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作者：
D. Wooden;H. Ishii;M. Zolensky
彗星尘埃是原始的，表现出显著的多样性。通过对宇宙尘埃样本（无水行星际尘埃颗粒（IDPs）、球粒状多孔（CP） IDPs和超碳质南极微陨石、星尘和罗塞塔）以及遥感（斯皮策红外光谱）的微观研究，我们对原始彗星颗粒性质的了解得到了显著扩展。彗星尘埃是在亚微米尺度上不平衡的物质的聚集粒子。我们讨论了彗星中原始物质的性质和经历的过程。原始粒子表现出不同的结构和类型；成分分布；碳质和难熔有机质的浓度和形态；硅酸盐矿物的镁、铁含量；硫化物;II型球粒碎片的存在/丰度；高温钙铝包体和阿拟石-橄榄石聚集体；以及很少出现的碳酸镁和磁铁矿，它们的解释需要母体的水蚀变。耐火材料的性质意味着存在圆盘过程，导致不同的彗星具有特定的原始材料选择。原始粒子的多样性暗示了在彗星形成的时间和区域存在的原行星盘中物质的多样性。这篇文章是“罗塞塔号之后的彗星科学”主题的一部分。
Comet dust is primitive and shows significant diversity. Our knowledge of the properties of primitive cometary particles has expanded significantly through microscale investigations of cosmic dust samples (anhydrous interplanetary dust particles (IDPs), chondritic porous (CP) IDPs and UltraCarbonaceous Antarctic micrometeorites, Stardust and Rosetta), as well as through remote sensing (Spitzer IR spectroscopy). Comet dust are aggregate particles of materials unequilibrated at submicrometre scales. We discuss the properties and processes experienced by primitive matter in comets. Primitive particles exhibit a diverse range of: structure and typology; distribution of constituents; concentration and form of carbonaceous and refractory organic matter; Mg- and Fe-contents of the silicate minerals; sulfides; existence/abundance of type II chondrule fragments; high-temperature calcium–aluminium inclusions and ameboid-olivine aggregates; and rarely occurring Mg-carbonates and magnetite, whose explanation requires aqueous alteration on parent bodies. The properties of refractory materials imply there were disc processes that resulted in different comets having particular selections of primitive materials. The diversity of primitive particles has implications for the diversity of materials in the protoplanetary disc present at the time and in the region where the comets formed. This article is part of the themed issue ‘Cometary science after Rosetta’.