{"id":42553,"date":"2026-09-16T19:48:00","date_gmt":"2026-09-16T17:48:00","guid":{"rendered":"https:\/\/karmaka.de\/?p=42553"},"modified":"2026-09-16T19:48:01","modified_gmt":"2026-09-16T17:48:01","slug":"low-variable-cohesion-between-bennu-regolith-particles-indicated-by-atomic-force-microscopy-of-returned-samples","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=42553","title":{"rendered":"Low, variable cohesion between Bennu regolith particles indicated by atomic force microscopy of returned samples<span class=\"badge-status\" style=\"background:#787878\">OPEN ACCESS<\/span>&nbsp;"},"content":{"rendered":"\n<p>Keanna Jardine, Christian Hoover, Ronald-Louis Ballouz, Anthony Woolson, Paul S\u00e1nchez, Jens Biele, Andrew Ryan, Robert Macke, Harold Connolly Jr, Dante Lauretta<\/p>\n\n\n\n<p>Nature, this is a preprint; it has not been peer reviewed by a journal, Version 1 posted 13 Sep, 2026<\/p>\n\n\n\n<p><a href=\"https:\/\/www.researchsquare.com\/article\/rs-10911487\/v1\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>PDF (OPEN ACCESS)<\/strong><\/a><\/p>\n\n\n\n<p class=\"justify-text\">&#8220;Observations of near-Earth asteroids (NEAs) suggest that these objects are nearly strengthless rubble piles, held together by microgravity and small interparticle cohesive (van der Waals) forces. These forces could stabilize a rubble pile\u2019s surface and global shape, explaining the existence of fast-spinning asteroids whose centrifugal accelerations would otherwise cause them to rotationally disrupt. Evaluating this theoretical explanation requires experimental measurements of particle-particle cohesion with pristine astromaterials that have not been subjected to alteration by Earth\u2019s atmosphere. Here we show, via nanoscale atomic force microscopy, that micron-scale regolith particles returned by spacecraft from the carbonaceous asteroid (101955) Bennu exert a small average interparticle cohesive force of ~1.25 nN, which corresponds to a tensile strength of 0.001 Pa. These measured cohesive forces are a factor of a few smaller than values obtained for carbonaceous meteorites, and two orders of magnitude smaller than for stony ordinary chondrite and achondrite meteorites. We argue that Bennu\u2019s small interparticle cohesive forces led to the paucity of millimeter-scale particles observed on its surface. This low cohesive strength also implies that carbonaceous NEAs are weakly resistant to rotational disruption, which may explain the observed scarcity of NEAs in proximity to the Sun and suggests that fast-spinning NEAs are not rubble piles.&#8221;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Keanna Jardine, Christian Hoover, Ronald-Louis Ballouz, Anthony Woolson, Paul S\u00e1nchez, Jens Biele, Andrew Ryan, Robert Macke, Harold Connolly Jr, Dante Lauretta Nature, this is a preprint; it has not been peer reviewed by a journal,&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[77,552,1184],"tags":[5719,263,1771,6489,4827,6353],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/42553"}],"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=42553"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/42553\/revisions"}],"predecessor-version":[{"id":42554,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/42553\/revisions\/42554"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=42553"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=42553"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=42553"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}