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Bulbous tracks arising from hypervelocity capture in aerogel
Author(s) -
TrigoRodríguez Josep M.,
Domínguez Gerardo,
Burchell Mark J.,
Hörz Friedrich,
Llorca Jordi
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.tb00610.x
Subject(s) - hypervelocity , aerogel , fragmentation (computing) , particle (ecology) , astrobiology , jupiter (rocket family) , physics , materials science , geology , astronomy , composite material , oceanography , space shuttle , computer science , operating system
— The capture of 81P/Wild 2 cometary particles in aerogel with a well‐defined impact velocity (6.1 km s −1 ) has provided a wealth of data concerning the composition of Jupiter‐family comets. To interpret this data we must understand the capture processes in the aerogel. A major category of tracks are those with bulbous cavities lined with particle fragments. We present a new model to account for the production of these “turnip”‐shaped impact cavities. The model uses a thermodynamic approach in order to account for the likely expansion of vapors from particles rich in volatile species. Volume measurements of some of the largest Stardust tracks analysed so far, together with theoretical considerations, indicate that for the majority of Stardust cometary aggregate particle impacts, fragmentation of relatively weak impactors (combined with radial expansion of the resulting subgrains) is the leading cause of bulbous track production, while volatile release of vapors played a secondary role.