{"id":41396,"date":"2026-04-21T16:52:24","date_gmt":"2026-04-21T14:52:24","guid":{"rendered":"https:\/\/karmaka.de\/?p=41396"},"modified":"2026-04-21T16:52:25","modified_gmt":"2026-04-21T14:52:25","slug":"physical-analysis-of-bennu-samples-reveals-regolith-production-by-collisional-disruption-on-near-earth-asteroids","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=41396","title":{"rendered":"Physical Analysis of Bennu Samples Reveals Regolith Production by Collisional Disruption on Near-Earth Asteroids<span class=\"badge-status\" style=\"background:#787878\">OPEN ACCESS<\/span>&nbsp;"},"content":{"rendered":"\n<p>R.-L. Ballouz, A. J. Ryan, R. J. Macke, O. S. Barnouin, M. L\u00ea, J. Moreno, S. Eckley, L. Hanton, A. Hildebrand, V. Toy-Edens<\/p>\n\n\n\n<p>The Planetary Science Journal, Volume 7, Number 4, Published: 21 April 2026<\/p>\n\n\n\n<p><a href=\"https:\/\/iopscience.iop.org\/article\/10.3847\/PSJ\/ae4fad\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>LINK (OPEN ACCESS)<\/strong><\/a><br><a href=\"https:\/\/iopscience.iop.org\/article\/10.3847\/PSJ\/ae4fad\/pdf\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>PDF (OPEN ACCESS)<\/strong><\/a><\/p>\n\n\n\n<p class=\"justify-text\">&#8220;Due to the extremely low gravity of small near-Earth asteroids (NEAs), it has been assumed that impact-generated rock fragments escape into space and thus do not contribute to the accumulation of regolith. However, centimeter-sized stones returned from the small NEA Bennu by NASA\u2019s OSIRIS-REx mission exhibit impact craters up to a few millimeters wide, implying that impact fragments and impact-processed rocks are retained despite the microgravity environment. To understand how, we combined detailed physical analysis of Bennu samples, laboratory experiments of impacts into simulant rocks, and 3D numerical simulations of disruptive impacts into boulders. We find that the majority (\u223c85% by mass) of impact fragments eject toward and penetrate the asteroid\u2019s weak, porous surface, leading to their retention. In addition, crater depth-to-diameter ratios (d\/D) suggest that the Bennu samples (median crater d\/D = 0.36 \u00b1 0.1) are structurally representative of the asteroid\u2019s large boulders (median crater d\/D = 0.33 \u00b1 0.08, measured previously). Our analyses indicate that most of Bennu\u2019s surface rocks (those with diameters \u227220 m) could be products of in situ collisional disruption. This impact-driven mechanism of regolith production likely occurs on other small NEAs with highly porous surfaces.&#8221;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>R.-L. Ballouz, A. J. Ryan, R. J. Macke, O. S. Barnouin, M. L\u00ea, J. Moreno, S. Eckley, L. Hanton, A. Hildebrand, V. Toy-Edens The Planetary Science Journal, Volume 7, Number 4, Published: 21 April 2026&#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":[5719,263,2250,4827,359,4899],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/41396"}],"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=41396"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/41396\/revisions"}],"predecessor-version":[{"id":41397,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/41396\/revisions\/41397"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=41396"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=41396"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=41396"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}