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DART was bang on target<\/h2>\n\n
The asteroid-deflecting DART mission worked with incredible accuracy <\/p>\n\n Although no known <\/em>asteroid poses a threat to Earth for at least the next century, the database we\u2019ve built up of near-Earth asteroids is not yet complete for smaller bodies that could still cause devastation on a regional scale. <\/p>\n\n Several methods have been proposed to protect Earth from asteroids on a collision course, including blowing them up with a nuclear weapon and using a \u2018gravity tractor\u2019, a large spacecraft whose gravity pulls the asteroid so it misses our planet. The strategy identified as the highest priority to develop and test, however, is kinetic impact. In simple terms: fly a spacecraft at high speed into the asteroid so that it is nudged onto a different trajectory. <\/p>\n\n NASA\u2019s DART (Double Asteroid Redirection Test) mission was developed to demonstrate just this approach. Launched in November 2021, DART successfully impacted Dimorphos, the 160m moon of 800m asteroid Didymos, at just over 22,000km\/h at 23:14 UTC on 26 September 2022. <\/p>\n\n A number of research papers have described what this milestone space mission taught us. Here I\u2019m focusing on a report led by Terik Daly, Carolyn Ernst and Olivier Barnouin, all at Johns Hopkins University Applied Physics Laboratory, which pieces together the details of the impact itself with astonishing precision. <\/p>\n\n DART continuously beamed back images from its onboard camera during the approach. The final full image, taken just under two seconds before impact, shows a boulder-strewn landscape, with a pixel resolution of just 5cm. DART impacted in the direction opposite the asteroid\u2019s motion, almost straight down into the asteroid\u2019s surface, at an angle of around 73\u00b0. By analysing the images, the team determined the precise point that DART hit to an accuracy of better than 70cm. The impact site was within 25m of the equator of Dimorphos: like striking a snooker ball with the cue, the perfect spot to hit to impart the maximum momentum (without \u2018wasting\u2019 any of the impact energy in causing the target body to spin). The final image even allowed the team to model the precise nature of the impact. Two large boulders can be seen in the centre of the photo, and the team describe how the leading edge of the spacecraft\u2019s left-hand solar panel must have struck one of the boulders; almost immediately afterwards, the right-hand solar panel grazed the other boulder, and 0.3 milliseconds later the main body of the spacecraft slammed into the surface between the two. For the final four hours before impact,<\/span><\/p>\n\n \u201cThe impact site was within 25m of the equator: like striking a snooker ball with the cue, the perfect spot to hit\u201d <\/p><\/blockquote>\n\n DART\u2019s autonomous manoeuvring system controlled the spacecraft\u2019s trajectory to target it directly into the middle of Dimorphos, and this technology proved itself admirably. The success demonstrates that a spacecraft like DART would be able to deflect an asteroid on a collision course with Earth, without needing a precursor reconnaissance mission. The impactor could be launched directly to the target itself. We can breathe a little easier for knowing that should a deadly asteroid be discovered, we\u2019ve demonstrated that a kinetic impactor could protect Earth from the threat. <\/p>\n\n Prof Lewis Dartnell is an astrobiologist at the University of Westminster.<\/p>\n\n Lewis Dartnell was reading Successful Kinetic Impact into an Asteroid for Planetary Defense <\/em>by R Terik Daly et al<\/em><\/em><\/em><\/em><\/em><\/em><\/em><\/em><\/p>\n\n Read it online at: arxiv.org\/abs\/2303.02248<\/a><\/strong><\/a><\/strong><\/em><\/em><\/em><\/em><\/em><\/em><\/p>\n\n <\/p>\n\n The asteroid-deflecting DART mission worked with incredible accuracy <\/p>\n","protected":false},"author":24,"featured_media":44280,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"ub_ctt_via":"","purple_page_number":"16","purple_custom_meta_purple_page_number":"16","purple_seq_number":"1","purple_custom_meta_purple_seq_number":"1","purple_source_article":"article_16-1.xml","purple_custom_meta_purple_source_article":"article_16-1.xml","purple_source_issue":"May-2023","purple_custom_meta_purple_source_issue":"May-2023","purple_external_id":"May-2023-16-1","purple_custom_meta_purple_external_id":"May-2023-16-1","purple_issue_code":"|0000086564||","purple_custom_meta_purple_issue_code":"|0000086564||","purple_android_product":"com.im.skyatnight.216","purple_custom_meta_purple_android_product":"com.im.skyatnight.216","purple_ios_product":"com.im.skyatnight.216","purple_custom_meta_purple_ios_product":"com.im.skyatnight.216","purple_web_product":"","purple_custom_meta_purple_web_product":"","purple_publication_id":"075fab74-0a21-4201-866a-899d6c41c40c","purple_migrated":"","kt_blocks_editor_width":""},"categories":[20],"tags":[14],"featured_image_src":"https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2023\/04\/DART-ejecta.png","author_info":{"display_name":"importmanagerhub@sprylab.com","author_link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/author\/importmanagerhubsprylab-com\/"},"acf":{"readingTimeMinutes":"3","apple_news_title":""},"uagb_featured_image_src":{"full":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2023\/04\/DART-ejecta.png",556,456,false],"thumbnail":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2023\/04\/DART-ejecta-150x150.png",150,150,true],"medium":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2023\/04\/DART-ejecta-300x246.png",300,246,true],"medium_large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2023\/04\/DART-ejecta.png",556,456,false],"large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2023\/04\/DART-ejecta.png",556,456,false],"1536x1536":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2023\/04\/DART-ejecta.png",556,456,false],"2048x2048":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2023\/04\/DART-ejecta.png",556,456,false]},"uagb_author_info":{"display_name":"importmanagerhub@sprylab.com","author_link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/author\/importmanagerhubsprylab-com\/"},"uagb_comment_info":0,"uagb_excerpt":"The asteroid-deflecting DART mission worked with incredible accuracy","_links":{"self":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/43651"}],"collection":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/users\/24"}],"replies":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/comments?post=43651"}],"version-history":[{"count":5,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/43651\/revisions"}],"predecessor-version":[{"id":44390,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/43651\/revisions\/44390"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media\/44280"}],"wp:attachment":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media?parent=43651"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/categories?post=43651"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/tags?post=43651"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"\"](\"https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2023\/04\/f862e611-ca61-4e76-8bfa-6537515bcfd6.jpg\")
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