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Mineralogy and petrology of comet 81P/Wild 2
nucleus samples.
Zolensky M. E., Zega T. J., Yano H., Wirick S., Westphal
A. J., Weisberg M. K., Weber I., Warren J. L., Velbel M. A.,
Tsuchiyama A., Tsou P., Toppani A., Tomioka N., Tomeoka K.,
Teslich N., Taheri M., Susini J., Stroud R., Stephan T.,
Stadermann F. J., Snead C. J., Simon S. B., Simionovici A.,
See T. H., Robert F., Rietmeijer F. J. M., Rao W., Perronnet
M. C., Papanastassiou D. A., Okudaira K., Ohsumi K.,
Oshnishi I., Nakamura-Messenger K., Nakamura T., Mostefaoui
S., Mikouchi T., Meibom A., Matrajt G., Marcus M. A., Leroux
H., Lemelle L., Le L., Lanzirotti A., Langenhorst F., Krot
A. N., Keller L. P., Kearsley A. T., Joswiak D., Jacob D.,
Ishii H., Harvey R., Hagiya K., Grossman L., Grossman J. N.,
Graham G. A., Gounelle M., Gillet P., Genge M. J., Flynn G.,
Ferroir T., Fallon S., Ebel D. S., Dai Z. R., Cordier P.,
Clark B., Chi M., Butterworth A. L., Brownlee D. E., Bridges
J. C., Brennan S., Brearley A., Bradley J. P., Bleuet P.,
Bland P. A., and Bastien R. (2006)
Science 314, 1735-1739.
doi:10.1126/science.1135842
ABSTRACT
The bulk of the comet 81P/Wild 2 (hereafter Wild 2)
samples returned to Earth by the Stardust spacecraft appear
to be weakly constructed mixtures of nanometer-scale grains,
with occasional much larger (over 1 micrometer)
ferromagnesian silicates, Fe-Ni sulfides, Fe-Ni metal, and
accessory phases. The very wide range of olivine and low-Ca
pyroxene compositions in comet Wild 2 requires a wide range
of formation conditions, probably reflecting very different
formation locations in the protoplanetary disk. The
restricted compositional ranges of Fe-Ni sulfides, the wide
range for silicates, and the absence of hydrous phases
indicate that comet Wild 2 experienced little or no aqueous
alteration. Less abundant Wild 2 materials include a
refractory particle, whose presence appears to require
radial transport in the early protoplanetary disk.
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