{"id":8486,"date":"2022-07-12T02:19:18","date_gmt":"2022-07-12T06:19:18","guid":{"rendered":"https:\/\/spaceandplanetarynewswire.com\/?p=8486"},"modified":"2022-07-12T02:19:18","modified_gmt":"2022-07-12T06:19:18","slug":"hopping-space-dust-makes-asteroids-look-rougher","status":"publish","type":"post","link":"https:\/\/spaceandplanetarynewswire.com\/?p=8486","title":{"rendered":"Hopping Space Dust Makes Asteroids Look Rougher"},"content":{"rendered":"<div class=\"flex-video widescreen youtube\"><iframe title=\"Hopping dust\" width=\"500\" height=\"375\" data-src=\"https:\/\/www.youtube.com\/embed\/np28tr9mtxM?feature=oembed&#038;showinfo=0&#038;rel=0&#038;modestbranding=1&#038;iv_load_policy=3&#038;playsinline=1&#038;enablejsapi=1\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" class=\"lazyload\" data-load-mode=\"0\"><\/iframe><\/div>\n<p>Like corn kernels popping in a frying pan, tiny grains of dust may hop around on the surface of asteroids, according to a new study from physicists at the University of Colorado Boulder.&nbsp;<\/p>\n<p>That popcorn-like effect may even help to tidy up smaller asteroids, causing them to lose dust and look rough and craggy from space.&nbsp;<\/p>\n<p>The researchers&nbsp;<a href=\"https:\/\/www.nature.com\/articles\/s41550-022-01717-9\">published their results July 11<\/a>&nbsp;in the journal&nbsp;<em>Nature Astronomy<\/em>. Their findings may help scientists better understand how asteroids change shape over time\u2014and how these bodies migrate through space, sometimes bringing them dangerously close to Earth, said Hsiang-Wen (Sean) Hsu, lead author of the study.<\/p>\n<p>\u201cThe more fine-grained material, or regolith, these asteroids lose, the faster they migrate,\u201d said Hsu, a research associate at the&nbsp;<a href=\"https:\/\/lasp.colorado.edu\/home\/\">Laboratory for Atmospheric and Space Physics<\/a>&nbsp;(LASP) at CU Boulder.<\/p>\n<figure style=\"width: 1500px\" class=\"wp-caption alignnone\"><img decoding=\"async\" class=\"size-medium lazyload\" data-src=\"https:\/\/colorado.edu\/today\/sites\/default\/files\/styles\/hero\/public\/article-image\/dust_art.jpg?itok=ZHSaq2lt\" width=\"1500\" height=\"441\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 1500px; --smush-placeholder-aspect-ratio: 1500\/441;\"><figcaption class=\"wp-caption-text\">Artist&#8217;s depiction of the surface of an asteroid evolving over time as dust leaps into space through &#8220;electrostatic lofting.&#8221; (Credit: Hannah Arebalos)<\/figcaption><\/figure>\n<p>The research began with a few curious photos.<\/p>\n<p>In 2020, a&nbsp;<a href=\"https:\/\/colorado.edu\/today\/2018\/12\/03\/taking-measure-asteroid\">NASA spacecraft named OSIRIS-REx<\/a>&nbsp;traveled more than 1 billion miles to rendezvous with the asteroid (191055) Bennu, which is about as tall as the Empire State Building. But when the spacecraft arrived, scientists didn\u2019t find what they were expecting: The asteroid\u2019s surface looked like rough sandpaper, not smooth and dusty like researchers had predicted. There were even large boulders scattered over its exterior.<\/p>\n<p>Now, Hsu and his colleagues have drawn on computer simulations, or models, and laboratory experiments to explore that puzzle. He said that forces akin to static electricity may be kicking the smallest grains of dust, some no bigger than a single bacterium, off the asteroid and into space\u2014leaving only larger rocks behind.&nbsp;<\/p>\n<p>Bennu isn\u2019t alone, said study co-author Mih\u00e1ly Hor\u00e1nyi.<\/p>\n<p>\u201cWe\u2019re realizing that these same physics are occurring on other airless bodies like the moon and even the rings of Saturn,\u201d said Hor\u00e1nyi, a researcher at LASP and professor of physics at CU Boulder.<\/p>\n<figure style=\"width: 1500px\" class=\"wp-caption alignnone\"><img decoding=\"async\" class=\"size-medium lazyload\" data-src=\"https:\/\/colorado.edu\/today\/sites\/default\/files\/styles\/large\/public\/article-image\/timelapse_stacked_images_cropped_large.png?itok=lPtuDczW\" width=\"1500\" height=\"851\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 1500px; --smush-placeholder-aspect-ratio: 1500\/851;\"><figcaption class=\"wp-caption-text\">Timelapse image of grains of dust undergoing &#8220;electrostatic lofting&#8221; in a vacuum chamber.<\/figcaption><\/figure>\n<figure style=\"width: 750px\" class=\"wp-caption alignnone\"><img decoding=\"async\" class=\"size-medium lazyload\" data-src=\"https:\/\/colorado.edu\/today\/sites\/default\/files\/styles\/medium\/public\/article-image\/ryugu_boulders.jpeg?itok=vLEF9Mpg\" width=\"750\" height=\"561\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 750px; --smush-placeholder-aspect-ratio: 750\/561;\"><figcaption class=\"wp-caption-text\">Boulders on the surface of the asteroid Ryugu as seen by Japan&#8217;s Hayabusa2 spacecraft. (Credit: JAXA)<\/figcaption><\/figure>\n<figure style=\"width: 750px\" class=\"wp-caption alignnone\"><img decoding=\"async\" class=\"size-medium lazyload\" data-src=\"https:\/\/colorado.edu\/today\/sites\/default\/files\/styles\/medium\/public\/article-image\/454_eros_main.jpeg?itok=JuPGYiPy\" width=\"750\" height=\"506\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 750px; --smush-placeholder-aspect-ratio: 750\/506;\"><figcaption class=\"wp-caption-text\">The relatively smooth surface of the large asteroid Eros. (Credit: JPL\/NASA)<\/figcaption><\/figure>\n<p><strong>Bennu and Ryugu<\/strong><\/p>\n<p>Asteroids might look like they\u2019re frozen in time, but these bodies evolve throughout their lifetimes.&nbsp;<\/p>\n<p>Hsu explained that asteroids like Bennu are constantly spinning, which exposes their surfaces to sunlight, then shadow and sunlight again. That never-ending cycle of heating and cooling puts a strain on the largest rocks at the surface, until they inevitably crack.<\/p>\n<p>\u201cIt\u2019s happening every day, all the time,\u201d Hsu said. \u201cYou wind up eroding a big piece of rock into smaller pieces.\u201d<\/p>\n<p>Which is why, before scientists arrived at Bennu, many were expecting to find it covered in smooth sand\u2014a bit like how the moon looks today. Not long before, a Japanese space mission&nbsp;landed on a second small asteroid called Ryugu. The team found a similarly rough and craggy terrain.&nbsp;<\/p>\n<p>Hsu and his colleagues were suspicious.<\/p>\n<p>Since the 1990s, researchers at LASP have used vacuum chambers in the lab to&nbsp;<a href=\"https:\/\/www.colorado.edu\/today\/2020\/08\/31\/researchers-develop-dustbuster-moon\">investigate the strange properties of dust<\/a>&nbsp;in space, including a feat they call \u201celectrostatic lofting.\u201d Study co-lead author Xu Wang explained that as the sun\u2019s rays bathe small grains of dust, they begin to pick up negative charges. Those charges will build until, suddenly, the particles burst apart, like two magnets repelling each other.<\/p>\n<p>In some cases, those grains of dust can pop away at speeds of more than 20 miles per hour (or more than 8 meters per second).<\/p>\n<p>\u201cNo one had ever considered this process on the surface of an asteroid before,\u201d said Wang, a research associate at LASP.<\/p>\n<p><strong>Small asteroid, big asteroid<\/strong><\/p>\n<p>To do that, the researchers, including former CU Boulder undergraduate students Anthony Carroll and Noah Hood, ran a series of calculations examining the physics of regolith on two hypothetical asteroids. They tracked how dust might form, then hop around over hundreds of thousands of years. One of those faux asteroids was about a half-mile across (similar in size to Ryugu) and the second several miles wide (closer in diameter to big asteroids like Eros).&nbsp;<\/p>\n<p>The size made a difference. According to the team\u2019s estimates, when grains of dust jumped on the bigger asteroid, they couldn\u2019t gain enough speed to break free of its gravity. The same wasn\u2019t true on the smaller, Ryugu-like asteroid.<\/p>\n<p>\u201cThe gravity on the smaller asteroid is so weak that it can\u2019t hold back the escape,\u201d Hsu said. \u201cThe fine-grained regolith will be lost.\u201d<\/p>\n<p>That lost dust, in turn, will expose the surface of the asteroids to even more erosion, leading to a boulder-rich scenery like scientists found on Ryugu and Bennu. Within several million years, in fact, the smaller asteroid was almost completely swept clean of fine dust. The Eros-like asteroid, however, stayed dusty.&nbsp;<\/p>\n<p>Hsu noted that this scrubbing effect could help to give the orbits of small asteroids a nudge. He explained that asteroids migrate because the sun\u2019s radiation pushes on them slowly over time. Based on previous research by other scientists, he suspects that asteroids covered in boulders may move faster than those with a dustier appearance.<\/p>\n<p>He and his colleagues may soon get more proof to back up their calculations. In less than 3 months, a NASA mission called the&nbsp;<a href=\"https:\/\/www.nasa.gov\/planetarydefense\/dart\/dart-news\">Double Asteroid Redirection Test<\/a>&nbsp;(DART) will visit a pair of smaller asteroids\u2014and Hsu will be watching to see how dusty they are.&nbsp;<\/p>\n<p>\u201cWe will have new surface images to test our theory,\u201d he said. \u201cIt\u2019s nice for us, but also a little nerve-wracking.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Like corn kernels popping in a frying pan, tiny grains of dust may hop around on the surface of asteroids, according to a new study from physicists at the University of Colorado Boulder.&nbsp; That popcorn-like effect may even help to tidy up smaller asteroids, causing them to lose dust and look rough and craggy from&hellip;<\/p>\n","protected":false},"author":71,"featured_media":8489,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0,"fifu_image_url":"https:\/\/colorado.edu\/today\/sites\/default\/files\/styles\/hero\/public\/article-image\/dust_art.jpg?itok=ZHSaq2lt","fifu_image_alt":"Hopping Space Dust Makes Asteroids Look Rougher","footnotes":""},"categories":[216],"tags":[],"class_list":["post-8486","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-discovery"],"_links":{"self":[{"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=\/wp\/v2\/posts\/8486","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=\/wp\/v2\/users\/71"}],"replies":[{"embeddable":true,"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=8486"}],"version-history":[{"count":1,"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=\/wp\/v2\/posts\/8486\/revisions"}],"predecessor-version":[{"id":8488,"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=\/wp\/v2\/posts\/8486\/revisions\/8488"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=\/wp\/v2\/media\/8489"}],"wp:attachment":[{"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=8486"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=8486"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=8486"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}