Selecting the right spot to smash a spacecraft into the surface of a hazardous asteroid to deflect it must be done with great care, according to new research presented at the EPSC-DPS2025 Joint Meeting this week in Helsinki. Slamming into its surface indiscriminately runs the risk of knocking the asteroid through a ‘gravitational keyhole’ that sends it back around to hit Earth at a later date.<\/p>\n
“Even if we intentionally push an asteroid away from Earth with a space mission, we must make sure it doesn’t drift into one of these keyholes afterwards. Otherwise, we’d be facing the same impact threat again down the line,” said Rahil Makadia, a NASA Space Technology Graduate Research Opportunity Fellow at the University of Illinois at Urbana-Champaign, who is presenting the findings at the EPSC-DPS2025 meeting.<\/p>\n
NASA’s DART, the Double Asteroid Redirection Test mission, struck the small asteroid Dimorphos, which is in orbit around the larger asteroid Didymos, in September 2022. DART was a ‘kinetic impactor’ – effectively a projectile that slammed into the asteroid with enough energy to nudge it into a new orbit, thereby proving that it is possible to deflect an asteroid that could be on a collision course with Earth.<\/p>\n
A European Space Agency mission called Hera will follow-up on the DART impact when it reaches Didymos and Dimorphos in December 2026.<\/p>\n
Where DART struck on Dimorphos was of relatively little concern, since the Didymos system is too massive to be deflected onto a collision course with Earth. However, for another hazardous asteroid orbiting the Sun, even a small variation in its orbit could send it through a gravitational keyhole.<\/p>\n
The keyhole effect revolves around a small region of space where a planet’s gravity can modify a passing asteroid’s orbit such that it returns on a collision course with that planet at a later date. In this way, a gravitational keyhole unlocks more dangerous orbits.<\/p>\n
Should a kinetic impactor mission similar to DART nudge a hazardous asteroid so that it passes through a gravitational keyhole, then it only postpones the danger.<\/p>\n
“If an asteroid passed through one of these keyholes, its motion through the Solar System would steer it onto a path that causes it to hit Earth in the future,” said Makadia.<\/p>\n
The trick, therefore, is to find the best spot on the surface of an asteroid to impact with a spacecraft so that the chances of pushing it through the keyhole are minimized.<\/p>\n
Each point on the surface of an asteroid has a different probability of sending the asteroid through a gravitational keyhole after deflection by a kinetic impactor. Makadia’s team has therefore developed a technique for computing probability maps of an asteroid’s surface. Their method uses the results from DART as a guide, although each asteroid, with its own characteristics, will be subtly different.<\/p>\n
The asteroid’s shape, surface topology (hills, craters etc), rotation and mass all must be determined first. Ideally this would be done with a space mission to rendezvous with the asteroid, producing high-resolution images and data. However, this might not be possible for all threatening asteroids, particularly if the time between discovery and impact on Earth is short.<\/p>\n
“Fortunately, this entire analysis, at least at a preliminary level, is possible using ground-based observations alone, although a rendezvous mission is preferred,” said Makadia.<\/p>\n
By computing the subsequent trajectory of the asteroid following a kinetic impact, and seeing which trajectories would be the most dangerous, scientists can calculate where the safest location to strike on the asteroid’s surface will be.<\/p>\n
“With these probability maps, we can push asteroids away while preventing them from returning on an impact trajectory, protecting the Earth in the long run,” said Makadia.<\/p>\n","protected":false},"excerpt":{"rendered":"Selecting the right spot to smash a spacecraft into the surface of a hazardous asteroid to deflect it…\n","protected":false},"author":2,"featured_media":14421,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23],"tags":[14454,85,46,141,145,14453],"class_list":["post-14420","post","type-post","status-publish","format-standard","has-post-thumbnail","category-space","tag-comets-and-meteors-astronomy-space-probes","tag-il","tag-israel","tag-science","tag-space","tag-sun-solar-flare-nasa-space-exploration-solar-system-asteroids"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/14420","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/comments?post=14420"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/14420\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media\/14421"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media?parent=14420"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/categories?post=14420"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/tags?post=14420"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}