Interpretation of Wild 2 dust fine structure: Comparison of Stardust aluminum foil craters to the three-dimensional shape of experimental impacts by artificial aggregate particles and meteorite powders

Kearsley, A.T. and Burchell, Mark J. and Price, M.C. and Graham, G.A. and Wozniakiewicz, Penelope J. and Cole, Mike J. and Foster, N.J. and Teslich, N. (2009) Interpretation of Wild 2 dust fine structure: Comparison of Stardust aluminum foil craters to the three-dimensional shape of experimental impacts by artificial aggregate particles and meteorite powders. Meteoritics and Planetary Science, 44 (10). pp. 1489-1509. ISSN 1086-9379. E-ISSN 1945-5100. (doi:https://doi.org/10.1111/j.1945-5100.2009.tb01188.x) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided)

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Official URL
http://dx.doi.org/10.1111/j.1945-5100.2009.tb01188...

Abstract

New experimental results show that Stardust crater morphology is consistent with interpretation of many larger Wild 2 dust grains being aggregates, albeit most of low porosity and therefore relatively high density. The majority of large Stardust grains (i.e. those carrying most of the cometary dust mass) probably had density of 2.4 g cm-3 (similar to soda-lime glass used in earlier calibration experiments) or greater, and porosity of 25% or less, akin to consolidated carbonaceous chondrite meteorites, and much lower than the 80% suggested for fractal dust aggregates. Although better size calibration is required for interpretation of the very smallest impacting grains, we suggest that aggregates could have dense components dominated by μ-scale and smaller sub-grains. If porosity of the Wild 2 nucleus is high, with similar bulk density to other comets, much of the pore space may be at a scale of tens of micrometers, between coarser, denser grains. Successful demonstration of aggregate projectile impacts in the laboratory now opens the possibility of experiments to further constrain the conditions for creation of bulbous (Type C) tracks in aerogel, which we have observed in recent shots. We are also using mixed mineral aggregates to document differential survival of pristine composition and crystalline structure in diverse finegrained components of aggregate cometary dust analogues, impacted onto both foil and aerogel under Stardust encounter conditions. © The Meteoritical Society, 2009.

Item Type: Article
Additional information: Unmapped bibliographic data: LA - English [Field not mapped to EPrints] J2 - Meteorit. Planet. Sci. [Field not mapped to EPrints] AD - IARC, Department of Mineralogy, The Natural History Museum, London S W7 5BD, United Kingdom [Field not mapped to EPrints] AD - Centre for Astrophysics and Planetary Sciences, School of Physical Science, University of Kent, Canterbury CT2 7NH, United Kingdom [Field not mapped to EPrints] AD - Lawrence Livermore National Laboratory, Institute of Geophysics and Planetary Physics, 7000 East Avenue, Livermore, CA 94550, United States [Field not mapped to EPrints] DB - Scopus [Field not mapped to EPrints] M3 - Article [Field not mapped to EPrints]
Subjects: Q Science > QB Astronomy > QB651 Planets, Minor
Divisions: Faculties > Sciences > School of Physical Sciences > Centre for Astrophysics and Planetary Sciences
Depositing User: Giles Tarver
Date Deposited: 29 Jan 2016 10:31 UTC
Last Modified: 02 Feb 2016 17:00 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/53883 (The current URI for this page, for reference purposes)
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