{"id":20120,"date":"2019-07-24T10:07:33","date_gmt":"2019-07-24T08:07:33","guid":{"rendered":"http:\/\/karmaka.de\/?p=20120"},"modified":"2019-07-26T09:41:42","modified_gmt":"2019-07-26T07:41:42","slug":"oxygen-isotopic-composition-of-an-enstatite-ribbon-of-probable-cometary-origin","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=20120","title":{"rendered":"Oxygen isotopic composition of an enstatite ribbon of probable cometary origin<span class=\"badge-status\" style=\"background:#787878\">OPEN ACCESS<\/span>&nbsp;"},"content":{"rendered":"\n<p>Ryan C. Ogliore, Donald E. Brownlee, Kazuhide Nagashima, David J. Joswiak, Josiah B. Lewis, Alexander N. Krot, Kainen L. Utt, Gary R. Huss<\/p>\n\n\n\n<p>Meteoritics &amp; Planetary Science<br>\nFirst Published: 23 July 2019<\/p>\n\n\n\n<p><a href=\"https:\/\/arxiv.org\/pdf\/1907.11177.pdf\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>PDF (OPEN ACCESS)<\/strong><\/a><\/p>\n\n\n\n<p><a href=\"https:\/\/onlinelibrary.wiley.com\/doi\/full\/10.1111\/maps.13364\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>LINK<\/strong><\/a><\/p>\n\n\n\n<p class=\"justify-text\">&#8220;Filamentary enstatite crystals are found in interplanetary dust particles (IDPs) of likely cometary origin but are very rare or absent in meteorites. Crystallographic characteristics of filamentary enstatites indicate that they condensed directly from vapor. We measured the O isotopic composition of an enstatite ribbon from a giant cluster IDP to be \u03b418O = 25 \u00b1 55, \u03b417O = \u221219 \u00b1 129, \u220617O = \u221232 \u00b1 134 (2\u03c3 errors), which is inconsistent at the 2\u03c3 level with the composition of the Sun inferred from the Genesis solar wind measurements. The particle&#8217;s O isotopic composition, consistent with the terrestrial composition, implies that it condensed from a gas of nonsolar O isotopic composition, possibly as a result of vaporization of disk region enriched in 16O\u2010depleted solids. The relative scarcity of filamentary enstatite in asteroids compared to comets implies either that this crystal condensed from dust vaporized in situ in the outer solar system where comets formed or it condensed in the inner solar system and was subsequently transported outward to the comet\u2010forming region.&#8221;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Ryan C. Ogliore, Donald E. Brownlee, Kazuhide Nagashima, David J. Joswiak, Josiah B. Lewis, Alexander N. Krot, Kainen L. Utt, Gary R. Huss Meteoritics &amp; Planetary Science First Published: 23 July 2019 PDF (OPEN ACCESS)&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[77,179,72,65,71],"tags":[551,5109,3623,301],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/20120"}],"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=20120"}],"version-history":[{"count":2,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/20120\/revisions"}],"predecessor-version":[{"id":20125,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/20120\/revisions\/20125"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=20120"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=20120"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=20120"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}