{"id":31244,"date":"2022-09-13T06:51:08","date_gmt":"2022-09-13T04:51:08","guid":{"rendered":"https:\/\/karmaka.de\/?p=31244"},"modified":"2023-06-08T19:21:14","modified_gmt":"2023-06-08T17:21:14","slug":"exoatmospheric-detection-of-a-meter-sized-earth-impactor","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=31244","title":{"rendered":"Preatmospheric Detection of a Meter-sized Earth Impactor<span class=\"badge-status\" style=\"background:#787878\">OPEN ACCESS<\/span>&nbsp;"},"content":{"rendered":"\n<p>David L. Clark, Paul A. Wiegert, Peter G. Brown, Denis Vida, Aren Heinze, Larry Denneau<\/p>\n\n\n\n<p>This article has been submitted for publication in The Planetary Science Journal<\/p>\n\n\n\n<p><a href=\"https:\/\/arxiv.org\/pdf\/2209.04583\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>PDF (OPEN ACCESS)<\/strong><\/a><\/p>\n\n\n\n<p>Update: (8 June 2023):<\/p>\n\n\n\n<p>The Planetary Science Journal, Volume 4, Number 6<\/p>\n\n\n\n<p><a href=\"https:\/\/iopscience.iop.org\/article\/10.3847\/PSJ\/acc9b1\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>LINK (OPEN ACCESS)<\/strong><\/a><br><a href=\"https:\/\/iopscience.iop.org\/article\/10.3847\/PSJ\/acc9b1\/pdf\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>PDF (OPEN ACCESS)<\/strong><\/a><\/p>\n\n\n\n<p class=\"justify-text\">&#8220;On 2020 September 18 U.S. Government (USG) sensors detected a bolide with peak bolometric magnitude of \u221219 over the Western Pacific. The impact was also detected by the Geostationary Lightning Mapper instrument on the GOES-17 satellite and infrasound sensors in Hawaii. The USG measurements reported a steep entry angle of 67\u00b0 from horizontal from a radiant 13\u00b0 east of north and an impact speed of 11.7 km s\u22121. Interpretation of all energy yields produces a preferred energy estimate of 0.4 kt TNT, corresponding to a 23,000 kg, 3 m diameter meteoroid. A postimpact search of telescopic images found that the Asteroid Terrestrial-impact Last Alert System survey captured the object just 10 minutes prior to impact at an Earth-centered distance of nearly 11,900 km with apparent magnitude m = 12.5. The object appears as a 0.44\u00b0 streak originating on the eastern edge of the image, extending one-third of the USG state-vector-based prediction of 1.26\u00b0 over the 30 s exposure. The streak shows brightness variability consistent with small asteroid rotation. The position of Earth&#8217;s shadow, the object&#8217;s size, and its consistency with the reported USG state vector confirm the object is likely natural. This is the eighth preatmospheric detection of a near-Earth asteroid (NEA) impactor and the closest initial telescopic detection prior to impact. The high altitude of peak fireball brightness suggests it was a weak object comparable in many respects with 2008 TC3 (the Almahata Sitta meteorite), with an absolute magnitude H = 32.5 and likely low albedo. Therefore, we suggest the NEA was a C-complex asteroid.&#8221;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>David L. Clark, Paul A. Wiegert, Peter G. Brown, Denis Vida, Aren Heinze, Larry Denneau This article has been submitted for publication in The Planetary Science Journal PDF (OPEN ACCESS) Update: (8 June 2023): The&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[96,97],"tags":[118,1162,5205,4612,2888,98,4173,141],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/31244"}],"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=31244"}],"version-history":[{"count":2,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/31244\/revisions"}],"predecessor-version":[{"id":33859,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/31244\/revisions\/33859"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=31244"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=31244"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=31244"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}