Computer Science
Scientific paper
Feb 2008
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008m%26ps...43..273t&link_type=abstract
Meteoritics & Planetary Science, vol. 43, Issue 1, p.273-284
Computer Science
21
Silicates, Tem, Cometary Dust, Comets
Scientific paper
A transmission electron microscope (TEM) study of seven comet Wild 2 samples shows that three samples consist mainly of olivine and pyroxene and four samples consist of Mg-Fe-bearing Si-O glass with minor amounts of Fe-Ni sulfide and metal. The olivine in the silicate-rich samples differs in fayalite content between the samples and shows a wide range of fayalite content within individual samples, indicating that the degree of thermal metamorphism on the comet, if any, was extremely low. One olivine grain has a high density of dislocations with Burgers vector b = [001], suggesting that the Wild 2 particles experienced hypervelocity impacts before capture. The structural type and composition of pyroxene differ between the samples and within individual samples. Both low-Ca and high-Ca pyroxenes are present. Enstatite occurs as ortho- and clinoenstatite, suggesting that the Wild 2 particles contain materials that went through distinct high-temperature and cooling histories. One silicate-rich sample exhibits a zone texture consisting of a core of low-Ca pyroxene surrounded by an inner rim of Mg-Fe-bearing Si-O-rich glass and an outer rim of melted aerogel. The texture suggests that the inner rim was formed by the mixing of melted cometary low-Ca pyroxene and melted aerogel during capture heating. The four Mg-Fe-bearing, Si-O glass rich samples show close similarities in mineralogy and texture to the inner rim of the zoned silicate-rich sample. The four samples are probably secondary products formed by interaction between melted cometary silicates and melted aerogel during the capture process.
Ohnishi Ichiro
Tomeoka Kazushige
Tomioka Naotaka
No associations
LandOfFree
Silicate minerals and Si-O glass in comet Wild 2 samples: Transmission electron microscopy does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Silicate minerals and Si-O glass in comet Wild 2 samples: Transmission electron microscopy, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Silicate minerals and Si-O glass in comet Wild 2 samples: Transmission electron microscopy will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1324351