{"id":42628,"date":"2026-10-16T15:10:29","date_gmt":"2026-10-16T13:10:29","guid":{"rendered":"https:\/\/karmaka.de\/?p=42628"},"modified":"2026-10-16T15:10:31","modified_gmt":"2026-10-16T13:10:31","slug":"water-and-hydroxyl-on-asteroid-bennu-reconciling-remote-observations-with-osiris-rex-sample-analysis","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=42628","title":{"rendered":"Water and hydroxyl on asteroid Bennu: Reconciling remote observations with OSIRIS-REx sample analysis<span class=\"badge-status\" style=\"background:#787878\">OPEN ACCESS<\/span>&nbsp;"},"content":{"rendered":"\n<p>Hannah H. Kaplan, Amy A. Simon, Victoria E. Hamilton, Joshua P. Emery, Dennis Reuter, Andy J. L\u00f3pez-Oquendo<\/p>\n\n\n\n<p>MAPS, Version of Record online: 14 October 2026<\/p>\n\n\n\n<p><a href=\"https:\/\/onlinelibrary.wiley.com\/doi\/10.1111\/maps.70239\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>LINK (OPEN ACCESS)<\/strong><\/a><br><a href=\"https:\/\/onlinelibrary.wiley.com\/doi\/epdf\/10.1111\/maps.70239\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>PDF (OPEN ACCESS)<\/strong><\/a><\/p>\n\n\n\n<p class=\"justify-text\">&#8220;This study investigates the spatial distribution and spectral characteristics of the broad hydration feature near 3\u2009\u03bcm across the surface of asteroid (101955) Bennu using OVIRS (OSIRIS-REx Visible and InfraRed Spectrometer) data. We analyzed multiple global OVIRS data sets obtained at different times throughout the Bennu day, revealing variations in band depth with wavelength, as well as wavelength-dependent correlations with temperature and other surface properties. Our analysis distinguishes between the behavior of the 2.74-\u03bcm and 3.0-\u03bcm features, which contribute to a broad 3-\u03bcm region absorption, suggesting they may have different origins or respond differently to surface conditions. The 2.74-\u03bcm band depth shows strong negative correlation with temperature and positive correlation with albedo and hydroxyl, whereas the 3.0-\u03bcm band depth exhibits primarily weak relationships with other spectral and surface parameters, such as temperature, albedo, and UV\/visible spectral slope, indicating that these features probe different aspects of the surface materials. These findings demonstrate that space weathering likely plays a strong role within the hydration band. Specifically, temperature and time-of-day dependencies observed at 2.74-\u03bcm point to an active hydroxyl cycle on Bennu&#8217;s surface driven by solar wind hydrogen implantation, hydroxylation, and subsequent thermal desorption. Conversely, the distinct behavior of the 3.0-\u03bcm band suggests it may serve as an indicator of surface composition, including the phosphate minerals recently found in the returned sample; however, the lack of correlation with other expected diagnostic spectral features, such as a bluer UV\/visible slope, currently leaves this relationship inconclusive.&#8221;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Hannah H. Kaplan, Amy A. Simon, Victoria E. Hamilton, Joshua P. Emery, Dennis Reuter, Andy J. L\u00f3pez-Oquendo MAPS, Version of Record online: 14 October 2026 LINK (OPEN ACCESS)PDF (OPEN ACCESS) &#8220;This study investigates the spatial&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[77,181,1184],"tags":[5719,5443,1400,5517,1854,1771,3984,1886,5125,4899,602,1915,1855],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/42628"}],"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=42628"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/42628\/revisions"}],"predecessor-version":[{"id":42629,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/42628\/revisions\/42629"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=42628"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=42628"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=42628"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}