[meteorite-list] Chondrule Formation

[Pete Pete]

For the full PDF file:





http://eprintweb.org/S/article/astro-ph/0712.0561


http://eprintweb.org/S/article/astro-ph/0712.0561















arXiv:0712.0561 (December 2007)


Exposing metal and silicate charges to electrical discharges: Did chondrules form by nebular lightning?


C. Güttler, T. Poppe, J. T. Wasson and J. Blum


Institut für Geophysik und extraterrestrische Physik, Technische Universität Braunschweig
Institute of Geophysics and Planetary Physics, University of California, Los Angeles



Received. 04 December 2007  Last updated. 04 December 2007


Abstract. In order to investigate the hypothesis that dust aggregates were transformed to meteoritic chondrules by nebular lightning, we exposed silicatic and metallic dust samples to electric discharges with energies of 120 to 500 J in air at pressures between 10 and 10^5 Pa. The target charges consisted of powders of micrometer-sized particles and had dimensions of mm. The dust samples generally fragmented leaving the major fraction thermally unprocessed. A minor part formed sintered aggregates of 50 to 500 micrometer. In a few experiments melt spherules having sizes smaller than 180 micrometer in diameter (and, generally, interior voids) were formed; the highest spherule fraction was obtained with metallic Ni. Our experiments indicate that chondrule formation by electric current or by particle bombardment inside a discharge channel is unlikely.


Categories. astro-ph


Comment. Accepted by Icarus


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