Very weak carbonaceous asteroid simulants I: Mechanical properties and response to hypervelocity impacts
Very weak carbonaceous asteroid simulants I: Mechanical properties and response to hypervelocity impacts
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DOI：
10.1016/j.icarus.2020.113648
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发表时间：
2020-05-01
期刊：
影响因子：
3.2
通讯作者：
Delbo, Marco
中科院分区：
文献类型：
--
作者：
Avdellidou, Chrysa;DiDonna, Alice;Delbo, Marco
两个正在进行的样品返回空间任务，Hayabusa 2和OSIRIS-REx将从碳质近地小行星Ryugu和Bennu返回地球小行星风化层。导致风化层产生的两个主要过程是微陨石撞击和热裂解。在这里，我们报告的生产弱模拟材料，类似碳质陨石与CM样的组合物，Bennu和Ryugu的初步组成结果。这种小行星模拟物的抗压强度和抗弯强度分别为1.8 +/- 0.17和0.7 +/- 0.07 MPa。模拟物在室温下的热导率（在空气中）在0.43和0.47 W m（-1）K-1之间。为了区分由这些过程中的每一个产生的风化层的类型，我们提出并讨论了实验活动的结果，重点是实验室超高速撞击，使用2级轻气枪的大学肯特，模仿微陨石轰击。我们发现，这一过程产生monomineralic和multimineralic碎片，导致难以区分这两个过程，至少在这些弱材料。
The two on-going sample return space missions, Hayabusa2 and OSIRIS-REx are going to return to Earth asteroid regolith from the carbonaceous near-Earth asteroids Ryugu and Bennu. The two main processes that lead to regolith production are the micrometeorite bombardment and the thermal cracking. Here we report the production of a weak simulant material, analogue to carbonaceous meteorites with a CM-like composition, following the preliminary compositional results for Bennu and Ryugu. This asteroid simulant has compressive and flexural strength 1.8 +/- 0.17 and 0.7 +/- 0.07 MPa, respectively. The thermal conductivity (in air) of the simulant at room temperature is between 0.43 and 0.47 W m(-1) K-1. In order to distinguish the type of regolith that is produced by each of these processes, we present and discuss the results of the experimental campaign focused on laboratory hypervelocity impacts, using the 2-stage light-gas gun of the University of Kent, that mimic the micrometeorite bombardment. We find that this process produces both monomineralic and multimineralic fragments, resulting in a difficulty to distinguish the two processes, at least on these weak materials.