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



Author: C. Güttler 1, T. Poppe 1, J. T. Wasson 2, J. Blum 1 1 Institut für Geophysik und extraterrestrische Physik, Technische Universi

Source: https://arxiv.org/







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