{"id":34581,"date":"2023-11-27T21:14:49","date_gmt":"2023-11-27T20:14:49","guid":{"rendered":"https:\/\/karmaka.de\/?p=34581"},"modified":"2023-11-27T21:16:18","modified_gmt":"2023-11-27T20:16:18","slug":"the-magnesium-isotope-composition-of-samples-returned-from-asteroid-ryugu","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=34581","title":{"rendered":"The Magnesium Isotope Composition of Samples Returned from Asteroid Ryugu<span class=\"badge-status\" style=\"background:#787878\">OPEN ACCESS<\/span>&nbsp;"},"content":{"rendered":"\n<p>Martin Bizzarro, Martin Schiller, Tetsuya Yokoyama, Yoshinari Abe, J\u00e9r\u00f4me Al\u00e9on, Conel M. O&#8217;D. Alexander, Sachiko Amari, Yuri Amelin, Ken-ichi Bajo, Audrey Bouvier et al<\/p>\n\n\n\n<p>The Astrophysical Journal Letters, Volume 958, Number 2<br>Published: 2023 November 24<\/p>\n\n\n\n<p><a href=\"https:\/\/iopscience.iop.org\/article\/10.3847\/2041-8213\/ad09d9\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>LINK (OPEN ACCESS)<\/strong><\/a><br><a href=\"https:\/\/iopscience.iop.org\/article\/10.3847\/2041-8213\/ad09d9\/pdf\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>PDF (OPEN ACCESS)<\/strong><\/a><\/p>\n\n\n\n<p class=\"justify-text\">&#8220;The nucleosynthetic isotope composition of planetary materials provides a record of the heterogeneous distribution of stardust within the early solar system. In 2020 December, the Japan Aerospace Exploration Agency Hayabusa2 spacecraft returned to Earth the first samples of a primitive asteroid, namely, the Cb-type asteroid Ryugu. This provides a unique opportunity to explore the kinship between primitive asteroids and carbonaceous chondrites. We report high-precision \u03bc26Mg* and \u03bc25Mg values of Ryugu samples together with those of CI, CM, CV, and ungrouped carbonaceous chondrites. The stable Mg isotope composition of Ryugu aliquots defines \u03bc25Mg values ranging from \u2013160 \u00b1 20 ppm to \u2013272 \u00b1 30 ppm, which extends to lighter compositions relative to Ivuna-type (CI) and other carbonaceous chondrite groups. We interpret the \u03bc25Mg variability as reflecting heterogeneous sampling of a carbonate phase hosting isotopically light Mg (\u03bc25Mg \u223c \u20131400 ppm) formed by low temperature equilibrium processes. After correcting for this effect, Ryugu samples return homogeneous \u03bc26Mg* values corresponding to a weighted mean of 7.1 \u00b1 0.8 ppm. Thus, Ryugu defines a \u03bc26Mg* excess relative to the CI and CR chondrite reservoirs corresponding to 3.8 \u00b1 1.1 and 11.9 \u00b1 0.8 ppm, respectively. These variations cannot be accounted for by in situ decay of 26Al given their respective 27Al\/24Mg ratios. Instead, it requires that Ryugu and the CI and CR parent bodies formed from material with a different initial 26Al\/27Al ratio or that they are sourced from material with distinct Mg isotope compositions. Thus, our new Mg isotope data challenge the notion that Ryugu and CI chondrites share a common nucleosynthetic heritage.&#8221;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Martin Bizzarro, Martin Schiller, Tetsuya Yokoyama, Yoshinari Abe, J\u00e9r\u00f4me Al\u00e9on, Conel M. O&#8217;D. Alexander, Sachiko Amari, Yuri Amelin, Ken-ichi Bajo, Audrey Bouvier et al The Astrophysical Journal Letters, Volume 958, Number 2Published: 2023 November 24&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[77,9,4909,10,2243,1184],"tags":[3872,448,2229,1854,3273,1809,2244,2227],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/34581"}],"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=34581"}],"version-history":[{"count":2,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/34581\/revisions"}],"predecessor-version":[{"id":34583,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/34581\/revisions\/34583"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=34581"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=34581"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=34581"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}