{"id":629,"date":"2008-09-18T00:08:50","date_gmt":"2008-09-18T05:08:50","guid":{"rendered":"http:\/\/arxivblog.com\/?p=629"},"modified":"2008-09-18T00:08:50","modified_gmt":"2008-09-18T05:08:50","slug":"flyby-anomalies-explained-by-special-relativity","status":"publish","type":"post","link":"http:\/\/arxivblog.com\/?p=629","title":{"rendered":"Flyby anomalies explained by special relativity"},"content":{"rendered":"<p><a href=\"http:\/\/arxivblog.com\/wp-content\/uploads\/2008\/09\/flyby-anomaly.jpg\" title=\"flyby-anomaly.jpg\"><img decoding=\"async\" src=\"http:\/\/arxivblog.com\/wp-content\/uploads\/2008\/09\/flyby-anomaly.thumbnail.jpg\" alt=\"flyby-anomaly.jpg\" \/><\/a><\/p>\n<p>On 23 January 1998, when NASA\u2019s Near spacecraft swung past Earth on a routine flyby towards more interesting lands, a curious thing happened to its speed. It jumped by 13 mm\/s.<\/p>\n<p><a href=\"http:\/\/arxivblog.com\/?p=207\">This wasn&#8217;t the first time such an effect had been seen.<\/a> Engineers saw similar jumps in speed during the Earth flybys of Galileo (in 1990 and 1992), Cassini (in 1999), Messenger (in 2005) and<br \/>\nRosetta (also in 2005).<\/p>\n<p><a href=\"http:\/\/arxivblog.com\/?p=428\">Various exotic explanations have been put forward<\/a> but today it looks as if the explanation is far more prosaic.\u00a0 Jean Paul Mbelek from CEA-Saclay near Paris, France, says special relativity explains all.<br \/>\nThe speed of the spacecraft is measured by the Doppler shift in radio signals from the craft. That makes the speed\u00a0 easy to calculate.<\/p>\n<p>But Mbelek&#8217;s argument is that the relative motion of the spacecraft and the Earth (which is spinning) have not been properly accounted for. And when they are factored in, using special relativity, the flyby anomalies disappear.<\/p>\n<p>Doh!<\/p>\n<p>Ref: <a href=\"http:\/\/arxiv.org\/abs\/0809.1888\">arxiv.org\/abs\/0809.1888<\/a>: Special Relativity May Account for the Spacecraft Flyby<br \/>\nAnomalies<\/p>\n","protected":false},"excerpt":{"rendered":"<p>On 23 January 1998, when NASA\u2019s Near spacecraft swung past Earth on a routine flyby towards more interesting lands, a curious thing happened to its speed. It jumped by 13 mm\/s. This wasn&#8217;t the first time such an effect had been seen. Engineers saw similar jumps in speed during the Earth flybys of Galileo (in [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[21,6],"tags":[],"class_list":["post-629","post","type-post","status-publish","format-standard","hentry","category-calculatin","category-hellraisin"],"_links":{"self":[{"href":"http:\/\/arxivblog.com\/index.php?rest_route=\/wp\/v2\/posts\/629","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/arxivblog.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/arxivblog.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/arxivblog.com\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/arxivblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=629"}],"version-history":[{"count":0,"href":"http:\/\/arxivblog.com\/index.php?rest_route=\/wp\/v2\/posts\/629\/revisions"}],"wp:attachment":[{"href":"http:\/\/arxivblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=629"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/arxivblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=629"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/arxivblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=629"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}