On the Response of Chondrites to Diurnal Temperature Change—Experimental Simulation of Asteroidal Surface Conditions

Author:

Patzek Markus1ORCID,Rüsch Ottaviano1ORCID,Molaro Jamie L.2ORCID

Affiliation:

1. Institut für Planetologie Universität Münster Münster Germany

2. Planetary Science Institute Tucson AZ USA

Abstract

AbstractThermal fatigue is a process that degrades rocks and pebbles exposed to space by diurnal cycling. We simulate the diurnal temperature variation at 1 AU of 5 mm‐sized sample cubes using an evacuated cryostat, allowing conditions that are closer to those expected in space. Sample cubes of ordinary, CV, CM2, and C2 chondrites were investigated using scanning electron microscopy and microcomputed tomography scans. In contrast to previous work, the ordinary and CV chondrite samples did not show any cracking. The CM2 chondrites respond with the formation and extension of cracks. Pre‐existing cracks present in the C2 chondrite Tagish Lake closed in the course of cycling to different degrees, which has not been reported before in the context of thermal fatigue driven rock breakdown. Most changes in crack length occur in the initial ∼20 cycles indicating a rapid buildup of strain followed by a rapid release by the formation and extension of cracks when exposed to diurnal temperature variation. The overall cracking rate is comparable to that of previous work on CM2 chondrites and in 15%–20% of the observed cracking occasions they are associated with fine‐grained rims around chondrules implying that the comminution of CM‐like rocks and pebbles is controlled by the abundance of chondrules (and other coarse‐grained components) and their rims. We propose that thermal fatigue‐driven comminution of rocks and especially pebbles on asteroids under the here studied conditions is controlled by the abundance of hydrated minerals. This, in turn, can result in different abundances and natures of finer‐grained material on asteroid surfaces.

Funder

Alexander von Humboldt-Stiftung

Publisher

American Geophysical Union (AGU)

Subject

Space and Planetary Science,Earth and Planetary Sciences (miscellaneous),Geochemistry and Petrology,Geophysics

Cited by 3 articles. 订阅此论文施引文献 订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3