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Transmission electron microscopy of cometary residues from micron‐sized craters in the Stardust Al foils
Author(s) -
Leroux Hugues,
STroud Rhonda M.,
Dai Zu Rong,
Graham Giles A.,
Troadec David,
Bradley John P.,
Teslich Nick,
Borg Janet,
Kearsley Anton T.,
Hörz Friedrich
Publication year - 2008
Publication title -
meteoritics and planetary science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.09
H-Index - 100
eISSN - 1945-5100
pISSN - 1086-9379
DOI - 10.1111/j.1945-5100.2008.tb00615.x
Subject(s) - hypervelocity , impact crater , transmission electron microscopy , amorphous solid , shock metamorphism , materials science , meteorite , olivine , mineralogy , scanning electron microscope , electron microscope , astrobiology , geology , crystallography , composite material , chemistry , optics , nanotechnology , physics , thermodynamics
Abstract— We report transmission electron microscopy (TEM) investigations of micro‐craters that originated from hypervelocity impacts of comet 81P/Wild 2 dust particles on the aluminium foil of the Stardust collector. The craters were selected by scanning electron microscopy (SEM) and then prepared by focused ion beam (FIB) milling techniques in order to provide electron transparent cross‐sections for TEM studies. The crater residues contain both amorphous and crystalline materials in varying proportions and compositions. The amorphous component is interpreted as resulting from shock melting during the impact and the crystalline phases as relict minerals. The latter show evidence for shock metamorphism. Based on the residue morphology and the compositional variation, the impacting particles are inferred to have been dominated by mixtures of submicron olivine, pyroxene and Fe sulfide grains, in agreement with prior results of relatively coarse‐grained mineral assemblages in the aerogel collector.