Stardust Interstellar Preliminary Examination IX: High-speed interstellar dust analog capture in Stardust flight-spare aerogel

Postberg, F. and Hillier, Jon K. and Armes, S. P. and Bugiel, S. and Butterworth, A. and Dupin, D. and Fielding, L. A. and Fujii, S. and Gainsforth, Z. and Grün, E. and Li, Y. W. and Srama, R. and Sterken, V. and Stodolna, J. and Trieloff, M. and Westphal, A. and Achilles, C. and Allen, C. and Ansari, A. and Bajt, S. and Bassim, N. and Bastien, R. K. and Bechtel, H. A. and Borg, J. and Brenker, F. and Bridges, J. and Brownlee, D. E. and Burchell, Mark J. and Burghammer, M. and Changela, H. and Cloetens, P. and Davis, A. and Doll, R. and Floss, C. and Flynn, G. and Frank, D. and Heck, P. R. and Hoppe, P. and Huss, G. and Huth, J. and Kearsley, A. and King, A. J. and Lai, B. and Leitner, J. and Lemelle, L. and Leonard, A. and Leroux, H. and Lettieri, R. and Marchant, W. and Nittler, L. R. and Ogliore, R. and Ong, W. J. and Price, M. C. and Sandford, S. A. and Tressaras, J.-A. Sans and Schmitz, S. and Schoonjans, T. and Schreiber, K. and Silversmit, G. and Simionovici, A. and Solé, V. A. and Stadermann, F. and Stephan, T. and Stroud, R. M. and Sutton, S. and Tsou, P. and Tsuchiyama, A. and Tyliczszak, T. and Vekemans, B. and Vincze, L. and Zevin, D. and Zolensky, M. E. (2014) Stardust Interstellar Preliminary Examination IX: High-speed interstellar dust analog capture in Stardust flight-spare aerogel. Meteoritics and Planetary Science, 49 (9). pp. 1666-1679. ISSN 1086-9379. (doi:https://doi.org/10.1111/maps.12173) (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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http://doi.org/10.1111/maps.12173

Abstract

The NASA Stardust mission used silica aerogel slabs to slowly decelerate and capture impinging cosmic dust particles for return to Earth. During this process, impact tracks are generated along the trajectory of the particle into the aerogel. It is believed that the morphology and dimensions of these tracks, together with the state of captured grains at track termini, may be linked to the size, velocity, and density of the impacting cosmic dust grain. Here, we present the results of laboratory hypervelocity impact experiments, during which cosmic dust analog particles (diameters of between 0.2 and 0.4 μm), composed of olivine, orthopyroxene, or an organic polymer, were accelerated onto Stardust flight-spare low-density (approximately 0.01 g cm−3) silica aerogel. The impact velocities (3–21 km s−1) were chosen to simulate the range of velocities expected during Stardust's interstellar dust (ISD) collection phases. Track lengths and widths, together with the success of particle capture, are analyzed as functions of impact velocity and particle composition, density, and size. Captured terminal particles from low-density organic projectiles become undetectable at lower velocities than those from similarly sized, denser mineral particles, which are still detectable (although substantially altered by the impact process) at 15 km s−1. The survival of these terminal particles, together with the track dimensions obtained during low impact speed capture of small grains in the laboratory, indicates that two of the three best Stardust candidate extraterrestrial grains were actually captured at speeds much lower than predicted. Track length and diameters are, in general, more sensitive to impact velocities than previously expected, which makes tracks of particles with diameters of 0.4 μm and below hard to identify at low capture speeds (<10 km s−1). Therefore, although captured intact, the majority of the interstellar dust grains returned to Earth by Stardust remain to be found.

Item Type: Article
Divisions: Faculties > Sciences > School of Physical Sciences
Depositing User: Mark Burchell
Date Deposited: 20 Jan 2017 16:19 UTC
Last Modified: 30 May 2018 09:51 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/59982 (The current URI for this page, for reference purposes)
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