{"id":63967,"date":"2024-10-01T09:34:36","date_gmt":"2024-10-01T09:34:36","guid":{"rendered":"http:\/\/6a12ec95-d884-45db-9e6a-e13c728e4c11"},"modified":"2024-10-01T10:39:44","modified_gmt":"2024-10-01T10:39:44","slug":"remember-the-dart-asteroid-impact-mission-this-month-esas-hera-spacecraft-will-launch-to-inspect-the-aftermath","status":"publish","type":"rss_feed","link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/rss_feed\/remember-the-dart-asteroid-impact-mission-this-month-esas-hera-spacecraft-will-launch-to-inspect-the-aftermath\/","title":{"rendered":"Remember the DART asteroid impact mission? This month ESA&#8217;s Hera spacecraft will launch to inspect the aftermath"},"content":{"rendered":"<p class=\"rssexcerpt\">The European Space Agency&#8217;s Hera and DART missions will attempt to impact a near-Earth object and alter its path. <\/p><p class=\"rssauthor\">By <\/p><p class=\"rssbyline\">Published: Tuesday, 01 October 2024 at 09:34 AM<\/p><hr class=\"no-tts wp-block-separator\"\/><?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?>\n<!DOCTYPE html PUBLIC \"-\/\/W3C\/\/DTD HTML 4.0 Transitional\/\/EN\" \"http:\/\/www.w3.org\/TR\/REC-html40\/loose.dtd\">\n<html><body><p>On 26 September 2022, 11 million kilometres (7 million miles) from Earth, a spacecraft weighing 610kg (1,345lb) hurtled through space at 6.1km per second (13,645mph) and crashed headlong into an asteroid called Dimorphos.<\/p><p>The plume of debris it sent up was like something from a science-fiction disaster movie, but it was far from that.<\/p><figure class=\"wp-block-image size-full\"><figcaption class=\"wp-element-caption\">Asteroid Didymos (top left) and moonlet Dimorphos, 2.5 minutes before the impact of NASA\u2019s DART spacecraft. Credit: NASA\/Johns Hopkins APL<\/figcaption><\/figure><p>This was the culmination of <a href=\"https:\/\/www.skyatnightmagazine.com\/space-missions\/nasa-dart-mission\">NASA\u2019s Double Asteroid Redirection Test<\/a> (DART), a mission designed to test Earth\u2019s ability to deflect an <a href=\"https:\/\/www.skyatnightmagazine.com\/space-science\/asteroids\">asteroid<\/a> using a kinetic impactor.<\/p><p>The collision shortened the orbit of Dimorphos, demonstrating for the first time that humanity can alter the orbit of a body in space and defend our planet from incoming asteroids.<\/p><p>In October 2024, the European Space Agency (ESA) plans to launch a follow-up mission to study the impact of this collision, known as Hera.<\/p><div class=\"wp-block-columns highlight-box is-layout-flex wp-container-core-columns-layout-4 wp-block-columns-is-layout-flex\"><div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\"><h3 class=\"wp-block-heading\" id=\"h-heading\"><strong>More on Earth impacts from space<\/strong><\/h3><ul><li><strong><em><a href=\"https:\/\/www.skyatnightmagazine.com\/space-science\/biggest-asteroid-threats\">NASA&#8217;s top 5 asteroid threats<\/a><\/em><\/strong><\/li><li><strong><em><a href=\"https:\/\/www.skyatnightmagazine.com\/space-science\/chelyabinsk-meteorite\">Chelyabinsk meteor<\/a><\/em><\/strong><\/li><li><strong><em><a href=\"https:\/\/www.skyatnightmagazine.com\/space-science\/famous-meteorites\">5 famous meteorites<\/a><\/em><\/strong><\/li><li><strong><em><a href=\"https:\/\/www.skyatnightmagazine.com\/space-science\/meteorite-ownership\">Can you own a meteorite?<\/a><\/em><\/strong><\/li><\/ul><\/div><div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\"><figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1200\" height=\"674\" src=\"https:\/\/c02.purpledshub.com\/uploads\/sites\/48\/2024\/06\/chances-asteroid-hitting-earth.jpg\" alt=\"What are the chances? Artist's illustration of an asteroid hitting Earth. Credit: Romolo Tavani \/ Getty Images\" class=\"wp-image-158164\"\/><figcaption class=\"wp-element-caption\">Credit: Romolo Tavani \/ Getty Images<\/figcaption><\/figure><\/div><\/div><figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1280\" height=\"427\" src=\"https:\/\/c02.purpledshub.com\/uploads\/sites\/48\/2022\/09\/nasa-dart-mission-hubble-sequence-aae4cf1.jpg\" alt=\"A series of images showing the effect of the DART spacecraft's impact into asteroid moonlet Dimorphus, as seen by the Hubble Space Telescope. The images were taken 22 minutes, 5 hours and 8.2 hours after impact. Credit: NASA, ESA, and STScI\" class=\"wp-image-112355\"\/><figcaption class=\"wp-element-caption\">A series of images showing the effect of the DART spacecraft&#8217;s impact into asteroid moonlet Dimorphus, as seen by the Hubble Space Telescope. The images were taken 22 minutes, 5 hours and 8.2 hours after impact. Credit: NASA, ESA, and STScI<\/figcaption><\/figure><h2 class=\"wp-block-heading\"><strong>Hera&#8217;s main objectives<\/strong><\/h2><p>Named Hera after the Greek goddess of marriage, the ESA mission will undertake a detailed and thorough investigation of the double asteroid system that Dimorphos is part of, its data forming an essential element of the plan to turn the successful DART experiment into a repeatable planetary defence strategy.<\/p><p>Hera will be the first mission to make a study of a binary asteroid.<\/p><p>The larger body of the pair, Didymos, is about 780 metres (half a mile) in diameter and spins once every 2.26 hours, putting it at the very limits of structural stability.<\/p><figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1200\" height=\"675\" src=\"https:\/\/c02.purpledshub.com\/uploads\/sites\/48\/2020\/06\/ESA-Hera-Dimorphos.jpg\" alt=\"Artist's impression of ESA's Hera mission for planetary defence approaching the boulder-strewn Dimorphos asteroid. Credit: ESA-Science Office\" class=\"wp-image-162658\"\/><figcaption class=\"wp-element-caption\">Artist&#8217;s impression of ESA&#8217;s Hera mission for planetary defence approaching the boulder-strewn Dimorphos asteroid. Credit: ESA-Science Office<\/figcaption><\/figure><p>The smaller \u2018moonlet\u2019, Dimorphos, is just 160 metres (525 feet) across. About 15% of all small asteroids are binary.<\/p><p>Selecting one to send DART to collide with meant mission control could measure the effect the impact had on Dimorphos\u2019s orbit as it transited Didymos after the impact.<\/p><p>It also helped that the Didymos system poses zero threat to Earth.<\/p><figure class=\"wp-block-image size-full has-lightbox\"><img loading=\"lazy\" decoding=\"async\" width=\"1200\" height=\"796\" src=\"https:\/\/c02.purpledshub.com\/uploads\/sites\/48\/2022\/11\/dart-asteroid-impact-diagram-468a479.jpg\" alt=\"An illustration showing the impact of the DART spacecraft on asteroid Didymos\" class=\"wp-image-113972\"\/><\/figure><h2 class=\"wp-block-heading\"><strong>What we know about the DART impact so far<\/strong><\/h2><p>Scientists have already been able to paint a broad picture of <a href=\"https:\/\/skyatnightmagazine.com\/space-missions\/nasa-dart-mission-success\">how successful DART was<\/a>, using ground observations and the <a href=\"https:\/\/www.skyatnightmagazine.com\/news\/webb-hubble-nasa-dart-images\">Hubble Space Telescope<\/a>.<\/p><p>For instance, the impact changed the shape of the moonlet.<\/p><p>Up until the mission, Dimorphos was a regular \u2018oblate spheroid\u2019, a squashed sphere wider around the equator and shorter pole to pole.<\/p><p>Now it\u2019s thought to be a \u2018triaxial ellipsoid\u2019, a 3D shape with three axes of different lengths (think an oblong watermelon).<\/p><figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1200\" height=\"800\" src=\"https:\/\/c02.purpledshub.com\/uploads\/sites\/48\/2022\/09\/nasa-dart-mission-webb-hubble-44d6c13.jpg\" alt=\"The impact of NASA's DART mission into asteroid moonlet Dimorphus, as seen by the James Webb Space Telescope (left) and the Hubble Space Telescope (right)\" class=\"wp-image-112352\"\/><figcaption class=\"wp-element-caption\">The impact of NASA&#8217;s DART mission into asteroid moonlet Dimorphus, as seen by the James Webb Space Telescope (left) and the Hubble Space Telescope (right). Credit: Image Credit: NASA, ESA, CSA, and STScI<\/figcaption><\/figure><p>The <a href=\"https:\/\/www.skyatnightmagazine.com\/space-science\/dart-impact-mission-could-deflect-earth-bound-asteroid\">impact also changed Dimorphos\u2019s orbit<\/a>.<\/p><p>Until 26 September 2022, it took 11 hours and 55 minutes to orbit Didymos; now it orbits in just 11 hours and 23 minutes.<\/p><p>By hitting the moonlet in the opposite direction to its orbit, DART shortened the orbit by 33 minutes and 15 seconds \u2013 far surpassing the mission\u2019s objective of shaving 73 seconds off the orbit time.<\/p><p>This success is partly thought to be due to the debris ejected from the explosion acting like a thruster.\u00a0<\/p><p>The impact turned Dimorphos into an \u2018active asteroid\u2019, one that exhibits a coma or tail, more like a <a href=\"https:\/\/www.skyatnightmagazine.com\/space-science\/a-guide-to-comets\">comet<\/a>.<\/p><p>In July 2023, Hubble imaged a swarm of 37 boulders drifting from the crash site.<\/p><p>Ranging in size from 1 to 6.7 metres (3.2 to 22ft) across, their total mass is about 0.1% the mass of Dimorphos.<\/p><p>But ground observations carry a 10% uncertainty, which Hera will remove when it arrives at the double asteroid, providing rock-solid observations.<\/p><figure class=\"wp-block-image size-full has-lightbox\"><img loading=\"lazy\" decoding=\"async\" width=\"1200\" height=\"675\" src=\"https:\/\/c02.purpledshub.com\/uploads\/sites\/48\/2020\/06\/esa-hera-mission-timeline.jpg\" alt=\"Infographic showing the timeline of ESA's Hera mission. Credit: ESA \u2013 Science Office\" class=\"wp-image-162659\"\/><figcaption class=\"wp-element-caption\">Infographic showing the timeline of ESA&#8217;s Hera mission. Credit: ESA \u2013 Science Office<\/figcaption><\/figure><h2 class=\"wp-block-heading\"><strong>What will the ESA Hera mission do?<\/strong><\/h2><p>It will be the ESA Hera mission\u2019s task to investigate the crash scene and submit a full report.<\/p><p>Launching from Cape Canaveral aboard a Falcon 9 rocket, Hera will take two years to reach Didymos.<\/p><p>This space cruise will include a sequence of deep-space manoeuvres, including a fly-by of Mars to gain extra velocity, passing just 6,000km (3,728 miles) from the Red Planet\u2019s surface.<\/p><p>It will use the opportunity to train its science instruments on Deimos, the smaller, more distant of <a href=\"https:\/\/www.skyatnightmagazine.com\/space-science\/the-moons-of-mars\">Mars\u2019s two moons<\/a>, from 1,000km (621 miles) away.<\/p><p>Here, Hera will calibrate its instruments on an object that astronomers think is an asteroid that Mars captured into its orbit, along with its larger moon, Phobos.<\/p><figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"940\" height=\"529\" src=\"https:\/\/c02.purpledshub.com\/uploads\/sites\/48\/2019\/04\/Mars-Moons-aa6460a.jpg\" alt=\"Two separate images of Mars's moons Deimos (left) and Phobos (right) captured by NASA's Mars Reconnaissance Orbiter. Image Credit: NASA\/JPL-caltech\/University of Arizona\" class=\"wp-image-27996\"\/><figcaption class=\"wp-element-caption\">Two separate images of Mars&#8217;s moons Deimos (left) and Phobos (right) captured by NASA&#8217;s Mars Reconnaissance Orbiter. Image Credit: NASA\/JPL-caltech\/University of Arizona<\/figcaption><\/figure><p>The ESA Hera spacecraft is due to reach the Didymos double system on 28 December 2026 and will carry out a six-month investigation.<\/p><p>It will measure the asteroid\u2019s mass to determine the efficiency with which DART\u2019s impact transferred its momentum.<\/p><p>Hera will also study the crater left by the collision in detail, to verify whether it\u2019s the strength of the impact or gravity which is the most important for crater formation, furthering our understanding of the cratering process in low gravity.<\/p><p>It will also investigate changes in the moonlet\u2019s orbit, spin and libration (wobble), as well as surveying the surface and interior composition of Dimorphos.<\/p><h2 class=\"wp-block-heading\"><strong>ESA Hera instruments and Cubesats<\/strong><\/h2><p>The Hera spacecraft itself will have two asteroid-facing cameras (AFC) on board, a thermal infrared instrument (TIRI) and a HyperScout H hyperspectral imager to identify the asteroid\u2019s mineral makeup beyond the limits of visible light.<\/p><p>A laser range-finding instrument, the Planetary Altimeter (PALT), will be used for both navigation and science.<\/p><p>The ESA Hera spacecraft won\u2019t be alone in its task. Hera will also carry two CubeSats, Juventas and Milani, each the size of a shoebox, weighing around 12kg (26lb).<\/p><p>These will be released once Hera reaches the asteroids.<\/p><figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1200\" height=\"742\" src=\"https:\/\/c02.purpledshub.com\/uploads\/sites\/48\/2020\/06\/Milani-CubeSat.jpg\" alt=\"The Milani CubeSat, built at Tyvak International in Turin, Italy for ESA's Hera asteroid mission for planetary defence. Credit: Tyvak International\" class=\"wp-image-162660\"\/><figcaption class=\"wp-element-caption\">The Milani CubeSat, built at Tyvak International in Turin, Italy for ESA&#8217;s Hera asteroid mission for planetary defence. Credit: Tyvak International<\/figcaption><\/figure><p>Milani (named after Andrea Milani, the Italian mathematician and astronomer) will map Didymos and Dimorphos, and take images with its ASPECT spectrometer.<\/p><p>This will mean scientists can identify both bodies\u2019 mineral composition, tell the characteristics of any dust left over from the impact and pick out individual surface boulders.\u00a0<\/p><p>The two CubeSats and Hera will be linked by an inter-satellite system so that small changes in their positions relative to one another, due to the gravitational interaction of the asteroids, will help to assess their masses and gravitational fields.<\/p><p>The fleet of three craft will also pioneer autonomous navigation in deep space.<\/p><p>Both CubeSats and Hera carry visible-light cameras, lidar and star trackers so that they can autonomously navigate in the asteroids\u2019 combined gravity field, which is 40,000 times weaker than on Earth.<\/p><p>Once the core mission is complete, the new technology will be put through its paces, steering itself through the system like a self-driving car.<\/p><p>Meanwhile, CubeSat Juventas (the Roman name for Hera\u2019s daughter, Hebe) will carry the smallest radar ever flown in space, using it to carry out the first radar probe within an asteroid to determine whether Dimorphos is solid rock or a loose rubble pile.<\/p><p>Understanding its composition will help determine how to deal with asteroids that threaten Earth in the future.<\/p><figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1200\" height=\"674\" src=\"https:\/\/c02.purpledshub.com\/uploads\/sites\/48\/2024\/06\/impact-craters-solar-system.jpg\" alt=\"Artist's impression of an impact on Earth. Credit: ANDRZEJ WOJCICKI \/ Getty Images\" class=\"wp-image-158415\"\/><figcaption class=\"wp-element-caption\">Artist&#8217;s impression of an impact on Earth. Credit: ANDRZEJ WOJCICKI \/ Getty Images<\/figcaption><\/figure><h2 class=\"wp-block-heading\"><strong>Dealing with Earth-threatening asteroids<\/strong><\/h2><p>There are two basic methods of dealing with asteroid threats to our planet: fragmentation and deflection.<\/p><p>Many asteroids are loose rubble piles, so fragmentation by exploding a nuclear device above, or on, the surface is a possibility.<\/p><p>Drilling into an asteroid and planting a nuclear explosive to break up the asteroid and scatter the pieces was the solution depicted in the 1998 film <em>Armageddon<\/em>, but it\u2019s a risky one.<\/p><p>Before any explosive is planted, you need a detailed knowledge of the asteroid\u2019s composition, as any fragments larger than 35 metres (115ft) across would still pose a threat to Earth.\u00a0<\/p><p>Deflection by impact, using kinetic impactors like DART or nuclear explosives, can work quickly and at short notice against a solid asteroid.<\/p><p>To be effective, they would need to delay or advance the approaching asteroid\u2019s orbit by about seven minutes, giving our planet time to move one Earth diameter along its orbit, out of the way.<\/p><p>But direct methods may not work against a loose rubble-pile asteroid; indirect methods could be better.<\/p><p>These include attaching rockets to the asteroid, thrusting it out of the way, or using a theoretical \u2018gravity tractor\u2019 that would deflect the asteroid with its own gravitational field.<\/p><p>When Hera ends its mission with a planned landing on Dimorphos, and its CubeSats come to rest on Didymos, it and DART will have paved the way for a planetary defence strategy that could save life on Earth from such an extinction event in the future.<\/p><p><strong><em>Are you excited by the ESA Hera mission? Let us know your thoughts by emailing <a href=\"mailto:contactus@skyatnightmagazine.com\" target=\"_blank\" rel=\"noreferrer noopener\">contactus@skyatnightmagazine.com<\/a>.<\/em><\/strong><\/p><p><strong><em>This article appeared in the October 2024 issue of BBC Sky at Night Magazine<\/em><\/strong><\/p> <\/body><\/html>\n<hr class=\"no-tts wp-block-separator\"\/>","protected":false},"excerpt":{"rendered":"<p>The European Space Agency&#8217;s Hera and DART missions will attempt to impact a near-Earth object and alter its path. <\/p>\n","protected":false},"author":24,"featured_media":63968,"template":"","categories":[1],"acf":{"readingTimeMinutes":"8"},"uagb_featured_image_src":{"full":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2024\/10\/remember-the-dart-asteroid-impact-mission-this-month-esas-hera-spacecraft-will-launch-to-inspect-the-aftermath.jpg",1200,800,false],"thumbnail":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2024\/10\/remember-the-dart-asteroid-impact-mission-this-month-esas-hera-spacecraft-will-launch-to-inspect-the-aftermath-150x150.jpg",150,150,true],"medium":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2024\/10\/remember-the-dart-asteroid-impact-mission-this-month-esas-hera-spacecraft-will-launch-to-inspect-the-aftermath-300x200.jpg",300,200,true],"medium_large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2024\/10\/remember-the-dart-asteroid-impact-mission-this-month-esas-hera-spacecraft-will-launch-to-inspect-the-aftermath-768x512.jpg",768,512,true],"large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2024\/10\/remember-the-dart-asteroid-impact-mission-this-month-esas-hera-spacecraft-will-launch-to-inspect-the-aftermath-1024x683.jpg",800,534,true],"1536x1536":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2024\/10\/remember-the-dart-asteroid-impact-mission-this-month-esas-hera-spacecraft-will-launch-to-inspect-the-aftermath.jpg",1200,800,false],"2048x2048":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2024\/10\/remember-the-dart-asteroid-impact-mission-this-month-esas-hera-spacecraft-will-launch-to-inspect-the-aftermath.jpg",1200,800,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 European Space Agency's Hera and DART missions will attempt to impact a near-Earth object and alter its path.","_links":{"self":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/rss_feed\/63967"}],"collection":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/rss_feed"}],"about":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/types\/rss_feed"}],"author":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/users\/24"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media\/63968"}],"wp:attachment":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media?parent=63967"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/categories?post=63967"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}