LINK<\/strong><\/a><\/p>\n\n\n\n“Highlights<\/p>\n\n\n\n
\u2022 We simulate impacts to investigate the dwell time of Martian meteorites.
\n\u2022 Dwell time is the period of time that these meteorites spent at high pressure.
\n\u2022 Dwell time can be used to infer the scale of the impact needed to eject a meteorite.
\n\u2022 Previous estimates of how dwell time depends on impactor size are inaccurate.
\n\u2022 We show how dwell time depends on provenance, impactor size, and impact velocity.”<\/p>\n\n\n\n
“Martian meteorites are currently the only rock samples from Mars available for direct study in terrestrial laboratories. Linking individual specimens back to their source terrains is a major scientific priority, and constraining the size of the impact craters from which each sample was ejected is a critical step in achieving this goal. During ejection from the surface of Mars by hypervelocity impacts, these meteorites were briefly compressed to high temperatures and pressures. The period of time that these meteorites spent at high pressure during ejection, or the \u2018dwell time\u2019, has been used to infer the size of the crater from which they were ejected. This inference requires assumptions that relate shock duration to impactor size, and the relation used by many authors is neither physically motivated nor accurate. Using the iSALE2D shock physics code we simulate vertical impacts at high resolution to investigate the dwell time that basaltic rocks from Mars (shergottites) spend at high pressure and temperature during ejection. Future simulation of oblique impacts will lead to more accurate dwell time estimates. Ultimately, we find that dwell time is insensitive to changes in impact velocity but for a given impact, dwell times are longer for material originating from greater depth and material that experiences higher shock pressures. Using our results, we provide scaling laws for estimating impactor size. During the formation of craters 1.9, 14, and 104\u202fkm in diameter, material capable of escaping Mars will have mean dwell times of 1, 10, and 100\u202fms, respectively.”<\/p>\n","protected":false},"excerpt":{"rendered":"
T.J. Bowling, B.C. Johnson, S.E. Wiggins, E.L. Walton, H.J.Melosh, T.G. Sharp Icarus In Press, Journal Pre-proof, Available online 13 February 2020 LINK “Highlights \u2022 We simulate impacts to investigate the dwell time of Martian meteorites….<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[90,122,42,43],"tags":[5452,1423,1858,1828,1829,5453],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/21461"}],"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=21461"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/21461\/revisions"}],"predecessor-version":[{"id":21462,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/21461\/revisions\/21462"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=21461"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=21461"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=21461"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}