{"id":28366,"date":"2021-07-09T06:56:38","date_gmt":"2021-07-09T04:56:38","guid":{"rendered":"https:\/\/karmaka.de\/?p=28366"},"modified":"2021-07-15T17:45:11","modified_gmt":"2021-07-15T15:45:11","slug":"dark-primitive-asteroids-account-for-a-large-share-of-k-pg-scale-impacts-on-the-earth","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=28366","title":{"rendered":"Dark Primitive Asteroids Account for a Large Share of K\/Pg-Scale Impacts on the Earth<span class=\"badge-status\" style=\"background:#787878\">OPEN ACCESS<\/span>&nbsp;"},"content":{"rendered":"\n<p>David Nesvorny, William F. Bottke, Simone Marchi<\/p>\n\n\n\n<p>Icarus<\/p>\n\n\n\n<p><a href=\"https:\/\/arxiv.org\/pdf\/2107.03458\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>PDF (OPEN ACCESS)<\/strong><\/a><\/p>\n\n\n\n<p><a rel=\"noreferrer noopener\" href=\"https:\/\/www.sciencedirect.com\/science\/article\/abs\/pii\/S0019103521002840\" target=\"_blank\"><strong>LINK<\/strong><\/a> (Update: 15 July 2021)<\/p>\n\n\n\n<p>&#8220;Highlights<\/p>\n\n\n\n<p>\u2022 We develop a dynamical model for large near-Earth asteroids to understand the occurrence rate and nature of Cretaceous-Paleogene (K\/Pg) scale impacts on the Earth.<br>\u2022 About a half of impactors are found to be dark primitive asteroids.<br>\u2022 This explains why the Chicxulub crater, the third largest impact structure found on the Earth, was produced by impact of a carbonaceous chondrite.<br>\u2022 The impactor that triggered the K\/Pg mass extinction 66 Myr ago was a main belt asteroid that quite likely (60% probability) originated beyond 2.5 au.&#8221;<\/p>\n\n\n\n<p class=\"justify-text\">&#8220;A dynamical model for large near-Earth asteroids (NEAs) is developed here to understand the occurrence rate and nature of Cretaceous-Paleogene (K\/Pg) scale impacts on the Earth. We find that 16&#8211;32 (2&#8211;4) impacts of diameter D&gt;5 km (D&gt;10 km) NEAs are expected on the Earth in 1 Gyr, with about a half of impactors being dark primitive asteroids (most of which start with semimajor axis a&gt;2.5 au). These results explain why the Chicxulub crater, the third largest impact structure found on the Earth (diameter \u2243180 km), was produced by impact of a carbonaceous chondrite. They suggest, when combined with previously published results for small (D\u22721 km) NEAs, a size-dependent sampling of the main belt. We conclude that the impactor that triggered the K\/Pg mass extinction \u224366 Myr ago was a main belt asteroid that quite likely (\u224360\\% probability) originated beyond 2.5 au. &#8220;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>David Nesvorny, William F. Bottke, Simone Marchi Icarus PDF (OPEN ACCESS) LINK (Update: 15 July 2021) &#8220;Highlights \u2022 We develop a dynamical model for large near-Earth asteroids to understand the occurrence rate and nature of&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[77,9,90],"tags":[1854,3274,3273,821,2055,2053,2881,2888,3873,4827,382],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/28366"}],"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=28366"}],"version-history":[{"count":2,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/28366\/revisions"}],"predecessor-version":[{"id":28396,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/28366\/revisions\/28396"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=28366"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=28366"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=28366"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}