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彗星67P/Churyumov-Gerasimenko中的聚尘颗粒
Mark S Bentley1, Roland Schmied1, Thurid Mannel1,2
1Space Research Institute, Austrian Academy of Sciences, Schmiedlstrasse 6, 8042 Graz, Austria.
Nature
|September 2, 2016
概括
彗星尘埃颗粒是较小颗粒的等级聚合物,提供了对早期太阳星云状况的见解. 这种结构会影响彗星的粒子聚合和尘埃释放.
科学领域:
- 星球科学
- 宇宙化学
- 天体物理学
背景情况:
- 彗星保留了早期太阳星云中的原始尘埃, 对于理解太阳系形成至关重要.
- 之前的研究表明彗星尘埃由毛的聚合物组成,基于间接的观测和类似于状多孔星际尘埃颗粒的尘埃.
- 在之前的任务中,彗星尘埃中的细粒度聚合物成分在收集过程中发生了改变.
研究的目的:
- 研究来自67P/Churyumov-Gerasimenko彗星的尘埃颗粒的微观特性和聚合结构.
- 确定彗星尘埃是否表现出等级聚合,并比较其与星际尘埃的特性.
- 了解尘埃聚合在彗星形成和尘埃释放机制中的作用.
主要方法:
- 在彗星任务中使用先进仪器对尘埃颗粒进行实地测量.
- 从一微米到几十微米的尘埃颗粒的地形成像.
- 谷物形态,大小和延长的分析.
主要成果:
- 来自67P/Churyumov-Gerasimenko彗星的彗星尘埃颗粒是较小,长长的颗粒的聚合物.
- 在不同的尺寸尺度上观察到等级聚合结构.
- 尘埃颗粒的形态不同,包括紧的单颗粒和类似于体多孔星际尘埃颗粒的多孔聚合物.
- 测量的粒度延长与星际尘埃推断的值保持一致.
结论:
- 彗星尘埃可能代表彗星的构建块,起源于星际尘埃.
- 层次积聚是彗星尘埃集成的重要过程.
- 尘埃堆积的层次结构会影响彗星核的抗拉强度,从而促进尘埃的释放.
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