LINK<\/strong><\/a><\/p>\n\n\n\n“We present an integrated analysis of the bulk elemental and isotopic compositions of H, C, and N in samples of diverse types returned from near-Earth asteroid (101995) Bennu collected by the OSIRIS-REx spacecraft (including homogenized aggregate mixtures and splits from individual angular, hummocky, and mottled particles). We also conducted elemental, isotopic and Raman spectroscopic analyses of extracted insoluble organic matter (IOM). In addition, we quantified the fraction of total C residing in carbonate minerals and measured their C and O isotopic compositions within the aggregate samples. Aggregate samples and extracted IOM from the carbonaceous chondrites Murchison and Tarda, as well as homogenized samples from the Tagish Lake (11L) meteorite, underwent parallel analyses for comparison with the Bennu materials.
In the Bennu samples, the bulk H, C and N concentrations are 0.76\u20131.02\u202fwt%, 3.54\u20134.70\u202fwt% and 0.145\u20130.250\u202fwt%, respectively. The bulk \u03b413C and \u03b415N of the samples ranges from \u22125.5\u202f\u2030 to 7.2\u202f\u2030 and from 43.6\u202f\u2030 to 109.5\u202f\u2030, respectively. The \u03b4D values for the homogenized aggregate, and the angular and hummocky particles ranged from 244\u202f\u2030 to 351\u202f\u2030. The observed \u03b4D variability among the subsamples of a mottled particle (350\u202f\u2030 to 641\u202f\u2030) may be attributed to evaporative processes. The C in carbonate minerals accounts for\u202f\u223c\u202f0.6\u202fwt% of the aggregate sample with \u03b413C of 72\u202f\u2030 and \u03b418O of 30\u202f\u2030. Five IOM residues extracted from Bennu aggregate material exhibit an average H content of 4.0\u202f\u00b1\u202f0.2\u202fwt%, C content of 68.0\u202f\u00b1\u202f2.5\u202fwt% and N content of 2.9\u202f\u00b1\u202f0.1\u202fwt%. The corresponding average isotopic compositions are \u03b4D\u202f=\u202f1111\u202f\u00b1\u202f30\u202f\u2030, \u03b413C\u202f=\u202f\u221215.7\u202f\u00b1\u202f1.0\u202f\u2030 and \u03b415N\u202f=\u202f47.2\u202f\u00b1\u202f0.8\u202f\u2030. The elemental and isotopic compositions of H, C and N in the bulk Bennu and IOM samples generally support a genetic relationship between Bennu, Ryugu and other primitive carbonaceous chondrites, including the CIs, CMs, and the C2-ung Tagish Lake and Tarda. Based on the measured N\/C and H\/C atomic ratios, Bennu\u2019s IOM may have undergone a low degree of thermal alteration similar to that experienced by CIs, CMs, Tagish Lake 5b and Tarda. This alteration could have occurred in an aqueous environment, enabling the evolution of N\/C and H\/C atomic ratios to approximate those found in type-2 carbonaceous chondrites. Similar conclusions are supported for the evolution of the IOM \u03b4D assuming H exchange between IOM and H2O under hydrothermal conditions. Furthermore, Raman vibrational spectra suggest that the Bennu IOM, akin to Murchison and Tarda IOM, is characterized by a higher degree of disorder than in heated CMs. Laboratory analyses of H, C and N in the returned Bennu samples confirm the major compositional inferences made from spacecraft-based spectra and reconcile Bennu\u2019s spectral heterogeneity with true lithologic variability, demonstrating that the asteroid\u2019s surface diversity reflects genuine compositional\/mineralogical heterogeneity rather than observational artifacts.”<\/p>\n","protected":false},"excerpt":{"rendered":"
Dionysis I. Foustoukos, Conel M. O\u2019D. Alexander, George D. Cody, Jennifer C. Stern, Steven M. Bates, Yoshihiro Furukawa, Toshiki Koga, Daniel P. Glavin, Jason P. Dworkin, Jessica J. Barnes, Ann N. Nguyen, Harold C. Connolly…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[77,9,10,18,2243,552,181,1184,3172,5746,335,47],"tags":[5719,3872,1771,4958,250,3273,4844,700,743,2489,107,2346,4899,463,5747,4693],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/41711"}],"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=41711"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/41711\/revisions"}],"predecessor-version":[{"id":41712,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/41711\/revisions\/41712"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=41711"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=41711"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=41711"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}