{"id":42272,"date":"2026-08-04T00:38:14","date_gmt":"2026-08-03T22:38:14","guid":{"rendered":"https:\/\/karmaka.de\/?p=42272"},"modified":"2026-08-04T00:38:15","modified_gmt":"2026-08-03T22:38:15","slug":"reflectance-spectroscopy-250-2500-nm-of-an-aggregate-sample-from-asteroid-101955-bennu","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=42272","title":{"rendered":"Reflectance spectroscopy (250\u20132500\u202fnm) of an aggregate sample from asteroid (101955) Bennu"},"content":{"rendered":"\n<p>E.A. Cloutis, D.M. Applin, A.A. Simon, B.E. Clark, X.-D. Zou, V.E. Hamilton, R.E. Milliken, T. Hiroi, M.E. Zolensky, K.M. Peters, L.P. Keller, D.N. DellaGiustina, H.C. Connolly Jr, D.S. Lauretta<\/p>\n\n\n\n<p>Icarus<br>Available online 3 August 2026, 117289<\/p>\n\n\n\n<p><a href=\"https:\/\/www.sciencedirect.com\/science\/article\/abs\/pii\/S0019103526003556\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>LINK<\/strong><\/a><\/p>\n\n\n\n<p>&#8220;Highlights<\/p>\n\n\n\n<ul>\n<li>An aggregate (unsorted particulate) sample of Bennu was studied using reflectance spectroscopy (250\u20132500\u202fnm).<\/li>\n\n\n\n<li>The spectra show features that can be assigned to a number of phases in the sample whose presence has been determined independently.<\/li>\n\n\n\n<li>The sample&#8217;s low albedo (&lt;~3%), weak to non-existent absorption bands (&lt;~2% deep), and red spectral slo.pe over the 300\u20132500\u202fnm range are most consistent with CI1 chondrites<\/li>\n\n\n\n<li>Spectral slope becomes bluer with increasing particle size, consistent with Bennu&#8217;s boulder-covered, blue-sloped surface.&#8221;<\/li>\n<\/ul>\n\n\n\n<p class=\"justify-text\">&#8220;We measured reflectance spectra (250\u20132500\u202fnm) of a 200\u202fmg aliquot (sample id OREX-800029-0) of aggregate (unsorted) regolith particles returned from asteroid Bennu by the OSIRIS-REx mission). Our measurements include spots centered on small (&lt;0.5\u202fmm), medium (0.5\u20131\u202fmm), and large particles (1\u20132\u202fmm), as well as spots dominated by larger individual particles, including angular, hummocky, and mottled examples. The ultraviolet (UV) spectra (250\u2013450\u202fnm) are characterized by low reflectance (&lt;3%), slightly red spectral slopes, absorption features near 270 and 320\u202fnm attributable to Fe2+-O charge transfers, and Fe3+-associated absorption features, respectively. The 450\u20132500\u202fnm region spectra are of low reflectance (&lt;3% at 550\u202fnm), red-sloped, and exhibit variable but weak absorption features, the most ubiquitous being a broad region of absorption in the 1000\u202fnm region (&lt;~2%), attributable to magnetite and Fe2+-bearing phyllosilicates. The low albedo, weak absorption features, and red-sloped spectra can be attributed to the presence of carbonaceous components. Overall, we confirm the spectral similarities between Bennu aggregate material and powders of the rare CI1 chondrite meteorites. The spectra we measured are generally red-sloped, in contrast to the blue-sloped global-average spectra measured by ground-based telescopes and the OSIRIS-REx spacecraft. This difference is consistent with Bennu&#8217;s boulder-dominated surface and limited fine-grained dust, in combination with compositional contributions from optically efficient minor phases.&#8221;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>E.A. Cloutis, D.M. Applin, A.A. Simon, B.E. Clark, X.-D. Zou, V.E. Hamilton, R.E. Milliken, T. Hiroi, M.E. Zolensky, K.M. Peters, L.P. Keller, D.N. DellaGiustina, H.C. Connolly Jr, D.S. Lauretta IcarusAvailable online 3 August 2026, 117289&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[77,9,10,552,130,1184],"tags":[5719,1854,1771,2777,1479,1480,4899],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/42272"}],"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=42272"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/42272\/revisions"}],"predecessor-version":[{"id":42273,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/42272\/revisions\/42273"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=42272"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=42272"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=42272"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}