LINK<\/strong><\/a><\/p>\n\n\n\n“Aluminum foils from the Stardust cometary dust collector contain impact craters formed during the spacecraft’s encounter with comet 81P\/Wild 2 and retain residues that are among the few unambiguously cometary samples available for laboratory study. Our study investigates four micron\u2010scale (1.8\u20135.2 \u03bcm) and six submicron (220\u2013380 nm) diameter craters to better characterize the fine (<1 \u03bcm) component of comet Wild 2. We perform initial crater identification with scanning electron microscopy, prepare the samples for further analysis with a focused ion beam, and analyze the cross sections of the impact craters with transmission electron microscopy (TEM). All of the craters are dominated by combinations of silicate and iron sulfide residues. Two micron\u2010scale craters had subregions that are consistent with spinel and taenite impactors, indicating that the micron\u2010scale craters have a refractory component. Four submicron craters contained amorphous residue layers composed of silicate and sulfide impactors. The lack of refractory materials in the submicron craters suggests that refractory material abundances may differentiate Wild 2 dust on the scale of several hundred nanometers from larger particles on the scale of a micron. The submicron craters are enriched in moderately volatile elements (S, Zn) when normalized to Si and CI chondrite abundances, suggesting that, if these craters are representative of the Wild 2 fine component, the Wild 2 fines were not formed by high\u2010temperature condensation. This distinguishes the comet’s fine component from the large terminal particles in Stardust aerogel tracks which mostly formed in high\u2010temperature events.”<\/p>\n","protected":false},"excerpt":{"rendered":"
Brendan A. Haas, Christine Floss, Rhonda M. Stroud, Ryan C. Ogliore Meteoritics & Planetary Science First Published: 27 January 2020 LINK “Aluminum foils from the Stardust cometary dust collector contain impact craters formed during the…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[179,181],"tags":[1329,1870,1083],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/21315"}],"collection":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=21315"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/21315\/revisions"}],"predecessor-version":[{"id":21316,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/21315\/revisions\/21316"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=21315"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=21315"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=21315"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}