An asteroid that NASA used for target practice a few years ago was nudged into a slightly different route around the sun, findings that could help divert a future incoming killer space rock, scientists reported Friday.<\/p>\n
It\u2019s the first time that a celestial body\u2019s orbit around the sun was deliberately changed. The asteroid that NASA’s Dart spacecraft slammed into was never a threat to Earth.<\/p>\n
\u201cThis study marks a notable step forward in our ability to prevent future asteroid impacts on Earth,\u201d the international research team wrote in Science Advances.<\/p>\n
The changes were slight \u2014 reductions of just one-tenth of a second and one-half of 720 metres to a solar lap spanning two years and hundreds of millions of kilometres, according to the scientists.<\/p>\n
\u201cEven though this seems small, a tiny deflection … can add up over decades and make the difference between a potentially hazardous asteroid hitting or missing the Earth in the future,\u201d lead author Rahil Makadia, of the University of Illinois Urbana-Champaign, said in an email.<\/p>\n
For any save-the-planet tests, \u201cthe key isn\u2019t delivering a huge shove at the last minute. The key is delivering a tiny shove many years in advance”, he added.<\/p>\n
Launched in 2021 on the world\u2019s first planetary defence exercise, the Dart spacecraft deliberately ploughed into Dimorphos, which orbits a bigger asteroid, Didymos, as they circle the sun together. The space agency quickly determined that the 2022 strike trimmed the smaller asteroid’s orbit around its bigger companion.<\/p>\n
But it took until now for scientists to confirm, based on observations from around the world, that the impact cut the duo\u2019s travel time around the sun by 0.15 seconds. With each solar orbit lasting 769 days, that\u2019s a real-time slowdown of just over 10 micrometres per second, shrinking the asteroids\u2019 480-million-kilometre orbit by 720 meters.<\/p>\n
The researchers said all the boulders and other debris flung off Dimorphos in the crash provided as much push to Dimorphos as the spacecraft itself \u2014 a doubling of momentum. Last summer, a US-Italian team estimated that 35 million pounds (16 million kilograms) of rock and dust were ejected.<\/p>\n
The good news is that even with the change in the asteroids\u2019 course, Earth remains safely out of their way for the foreseeable future. That\u2019s why this rubble-packed system was picked for the mission, said Steven Chesley of NASA’s Jet Propulsion Laboratory, who took part in the study.<\/p>\n
\u201cWhile it is just a single experiment, it is nonetheless an important data point that will be relevant to any future asteroid deflection missions,\u201d Chesley said in an email.<\/p>\n
Scientists expect to learn even more about the impact\u2019s aftermath when the European Space Agency\u2019s Hera spacecraft reaches the asteroids in November. Dimorphos is 160 metres in diameter. Fast-spinning Didymos is 780 metres across, with, according to the latest study, 200 times more mass than its sidekick.<\/p>\n
Unlike Dart, Hera will not strike but will tag along for months of surveying. A pair of small experimental probes will peel away and attempt to land.<\/p>\n","protected":false},"excerpt":{"rendered":"An asteroid that NASA used for target practice a few years ago was nudged into a slightly different…\n","protected":false},"author":2,"featured_media":316807,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23],"tags":[111,139,69,147,392],"class_list":["post-316806","post","type-post","status-publish","format-standard","has-post-thumbnail","category-space","tag-new-zealand","tag-newzealand","tag-nz","tag-science","tag-space"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/316806","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/comments?post=316806"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/316806\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media\/316807"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media?parent=316806"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/categories?post=316806"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/tags?post=316806"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}