Comet 81P/Wild 2: The size distribution of finer (sub-10 ?m) dust collected by the Stardust spacecraft

Price, Mark C. and Kearsley, Anton T. and Bloemink, Marieke J. and Horz, Friedrich and Borg, Janet and Bridges, John C. and Cole, Mike J. and Floss, Christine and Graham, Giles A. and Green, Simon F. and Hoppe, Peter and Leroux, Hugues and Marhas, Kuljeet and Park, N and Stroud, Rhonda and Stadermann, Frank J. and Telisch, N and Wozniakiewicz, Penelope J. (2010) Comet 81P/Wild 2: The size distribution of finer (sub-10 ?m) dust collected by the Stardust spacecraft. Meteoritics & Planetary Science, 45 (9). pp. 1409-1428. ISSN 1086-9379. (doi:https://doi.org/10.1111/j.1945-5100.2010.01104.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.1945-5100.2010.01104.x

Abstract

he fluence of dust particles <10 ?m in diameter was recorded by impacts on aluminum foil of the NASA Stardust spacecraft during a close flyby of comet 81P/Wild 2 in 2004. Initial interpretation of craters for impactor particle dimensions and mass was based upon laboratory experimental simulations using projectiles less than >10 ?m in diameter and the resulting linear relationship of projectile to crater diameter was extrapolated to smaller sizes. We now describe a new experimental calibration program firing very small monodisperse silica projectiles (470 nm–10 ?m) at approximately 6 km s?1. The results show an unexpected departure from linear relationship between 1 and 10 ?m. We collated crater measurement data and, where applicable, impactor residue data for 596 craters gathered during the postmission preliminary examination phase. Using the new calibration, we recalculate the size of the particle responsible for each crater and hence reinterpret the cometary dust size distribution. We find a greater flux of small particles than previously reported. From crater morphology and residue composition of a subset of craters, the internal structure and dimensions of the fine dust particles are inferred and a “maximum-size” distribution for the subgrains composing aggregate particles is obtained. The size distribution of the small particles derived directly from the measured craters peaks at approximately 175 nm, but if this is corrected to allow for aggregate grains, the peak in subgrain sizes is at <100 nm.

Item Type: Article
Subjects: Q Science > QB Astronomy
Divisions: Faculties > Sciences > School of Physical Sciences
Faculties > Sciences > School of Physical Sciences > Centre for Astrophysics and Planetary Sciences
Depositing User: Mark Burchell
Date Deposited: 05 Dec 2013 13:07 UTC
Last Modified: 28 Jan 2016 16:36 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/37220 (The current URI for this page, for reference purposes)
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