{"id":38201,"date":"2022-11-11T00:00:00","date_gmt":"2022-11-11T00:00:00","guid":{"rendered":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/?post_type=purple_issue&p=38201"},"modified":"2022-11-25T12:39:00","modified_gmt":"2022-11-25T12:39:00","slug":"how-to-deflect-an-asteroid","status":"publish","type":"post","link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/2022\/11\/11\/how-to-deflect-an-asteroid\/","title":{"rendered":"How to deflect an asteroid"},"content":{"rendered":"\n

An epic trial run of a plan that may one day save Earth took place in September <\/p>\n\n\n\n

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Crash test dummy: DART closes in on small asteroid Dimorphos. ILLUSTRATION <\/figcaption><\/figure>\n\n\n\n

NASA\u2019s Double Asteroid Redirection Test (DART) launched on 24 November 2021, heading towards the Didymos system \u2013 alarge asteroid orbited by a smaller \u2018moon\u2019, Dimorphos. It arrived at the system on 26 September 2022 and at 11:14pm GMT that day crashed into Dimorphos\u2019s surface. The collision wasn\u2019t an accident but the mission\u2019s goal: NASA was attempting to deflect the small asteroid\u2019s orbit in a rehearsal for a future mission that could one day deflect an asteroid on a collision course with Earth, should one ever be found.<\/span><\/p>\n\n\n\n

DART hits the bullseye <\/strong><\/h4>\n\n\n\n
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Crunch time: the final image transmitted of the whole 160m asteroid before DART\u2019s demise<\/figcaption><\/figure><\/div>\n\n\n\n

As DART closed in on Dimorphos at 22,530km\/h, it livestreamed its navigation camera\u2019s view back to Earth. Its last image, taken just six kilometres from the surface, cut out half way through transmitting as the spacecraft was destroyed. <\/p>\n\n\n\n

Three minutes later, the Light Italian CubeSat for Imaging of Asteroids (LICIACube) \u2013 which had separated from DART 15 days earlier \u2013 flew past to photograph the impressive dust cloud raised by the impact. Meanwhile, dozens of amateur and professional telescopes on Earth were watching closely. The asteroid, 9.6 million kilometres away, was just a dot, but they clearly saw a flare in brightness during impact, followed by trails of ejecta spreading away. <\/p>\n\n\n\n

Astronomers then set about remeasuring Dimorphos\u2019s orbit time to see if its speed had changed. The goal was to shorten the orbit by one percent \u2013 about 10 minutes \u2013 though anything over 73 seconds would be a success. Within weeks Dimorphos\u2019s new provisional orbit time was announced: 11 hours and 23 minutes, a reduction of 32 minutes. <\/p>\n\n\n\n

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Both the James Webb and Hubble Space Telescopes captured the flare of the impact<\/figcaption><\/figure>\n<\/div>\n\n\n\n
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Understanding the impact\u2019s impact <\/strong><\/h4>\n\n\n\n
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Plumes of ejected material will be examined for clues about the asteroid and the impact process <\/figcaption><\/figure><\/div>\n\n\n\n

The DART team now want to understand exactly how DART transferred its energy to Dimorphos. One particular area of interest is the dust cloud, as the recoil from its ejection could have amplified the impact. <\/p>\n\n\n\n

First, they need to gauge Dimorphos\u2019s physical properties, such as its mass, composition and physical structure. The wealth of observations of the impact will help, but the best answers will come from the European Space Agency\u2019s Hera spacecraft. Launching in October 2024 and due to arrive in the system in 2026, it will observe both Didymos and Dimorphos for six months, mapping their surfaces and interiors to fully understand the effect of the impact.<\/span><\/p>\n\n\n\n

Should a hazardous asteroid ever be discovered, this understanding will help predict the path of a deflected space rock and keep our planet safe. <\/p>\n\n\n\n

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The thump from DART shortened\nDimorphos\u2019s orbit around the larger\nDidymos by 32 minutes<\/figcaption><\/figure><\/div>\n\n\n\n

PHOTOS: NASA\/JOHNS HOPKINS APL X 4, NASA\/ESA\/CSA\/JIAN-YANG LI (PSI)\/CRISTINA THOMAS (NORTHERN ARIZONA UNIVERSITY) IAN WONG (NASA-GSFC); IMAGE PROCESSING: JOSEPH DEPASQUALE (STSCI) ALYSSA PAGAN (STSCI), ASI\/NASA\/APL,<\/p>\n","protected":false},"excerpt":{"rendered":"

An epic trial run of a plan that may one day save Earth took place in September <\/p>\n","protected":false},"author":24,"featured_media":38195,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"ub_ctt_via":"","purple_page_number":"60","purple_custom_meta_purple_page_number":"60","purple_seq_number":"1","purple_custom_meta_purple_seq_number":"1","purple_source_article":"article_60-1.xml","purple_custom_meta_purple_source_article":"article_60-1.xml","purple_source_issue":"December-2022","purple_custom_meta_purple_source_issue":"December-2022","purple_external_id":"December-2022-60-1","purple_custom_meta_purple_external_id":"December-2022-60-1","purple_issue_code":"|0000086559||","purple_custom_meta_purple_issue_code":"|0000086559||","purple_android_product":"com.im.skyatnight.211","purple_custom_meta_purple_android_product":"com.im.skyatnight.211","purple_ios_product":"com.im.skyatnight.211","purple_custom_meta_purple_ios_product":"com.im.skyatnight.211","purple_web_product":"","purple_custom_meta_purple_web_product":"","purple_publication_id":"075fab74-0a21-4201-866a-899d6c41c40c","purple_migrated":"","kt_blocks_editor_width":""},"categories":[21],"tags":[14],"featured_image_src":"https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/11\/ea40d3b8-67c2-44f0-ba3c-3465e7fc688d.jpg","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\/2022\/11\/ea40d3b8-67c2-44f0-ba3c-3465e7fc688d.jpg",2048,1411,false],"thumbnail":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/11\/ea40d3b8-67c2-44f0-ba3c-3465e7fc688d-150x150.jpg",150,150,true],"medium":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/11\/ea40d3b8-67c2-44f0-ba3c-3465e7fc688d-300x207.jpg",300,207,true],"medium_large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/11\/ea40d3b8-67c2-44f0-ba3c-3465e7fc688d-768x529.jpg",768,529,true],"large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/11\/ea40d3b8-67c2-44f0-ba3c-3465e7fc688d-1024x706.jpg",800,552,true],"1536x1536":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/11\/ea40d3b8-67c2-44f0-ba3c-3465e7fc688d-1536x1058.jpg",1536,1058,true],"2048x2048":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/11\/ea40d3b8-67c2-44f0-ba3c-3465e7fc688d.jpg",2048,1411,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":"An epic trial run of a plan that may one day save Earth took place in September","_links":{"self":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/38201"}],"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=38201"}],"version-history":[{"count":7,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/38201\/revisions"}],"predecessor-version":[{"id":38842,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/38201\/revisions\/38842"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media\/38195"}],"wp:attachment":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media?parent=38201"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/categories?post=38201"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/tags?post=38201"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}