{"id":2734,"date":"2019-03-29T01:59:17","date_gmt":"2019-03-28T22:59:17","guid":{"rendered":"http:\/\/energyholding.world\/?p=2734"},"modified":"2019-04-08T17:07:35","modified_gmt":"2019-04-08T14:07:35","slug":"hubble-watches-spun-up-asteroid-coming-apart","status":"publish","type":"post","link":"http:\/\/energyholding.world\/?p=2734","title":{"rendered":"Hubble Watches Spun-Up Asteroid Coming Apart"},"content":{"rendered":"\n
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This Hubble Space Telescope image reveals the gradual self-destruction of an asteroid, whose ejected dusty material has formed two long, thin, comet-like tails. The longer tail stretches more than 500,000 miles (800,000 kilometers) and is roughly 3,000 miles (4,800 kilometers) wide. The shorter tail is about a quarter as long. The streamers will eventually disperse into space.
Credits: NASA, ESA, K. Meech and J. Kleyna (University of Hawaii), and O. Hainaut (European Southern Observatory) <\/figcaption><\/figure><\/div>\n\n\n\n

\u201cWe didn\u2019t have to go to Gault,\u201d explained Olivier Hainaut of the \nEuropean Southern Observatory in Germany, a member of the Gault \nobserving team. \u201cWe just had to look at the image of the streamers, and \nwe can see all of the dust grains well-sorted by size. All the large \ngrains (about the size of sand particles) are close to the object and \nthe smallest grains (about the size of flour grains) are the farthest \naway because they are being pushed fastest by pressure from sunlight.\u201d  <\/p>\n\n\n\n

Gault is only the second asteroid whose disintegration has been \nstrongly linked to a process known as a YORP effect. (YORP stands for \n\u201cYarkovsky\u2013O’Keefe\u2013Radzievskii\u2013Paddack,\u201d the names of four scientists \nwho contributed to the concept.) When sunlight heats an asteroid, \ninfrared radiation escaping from its warmed surface carries off angular \nmomentum as well as heat. This process creates a tiny torque that can \ncause the asteroid to continually spin faster. When the resulting \ncentrifugal force starts to overcome gravity, the asteroid\u2019s surface \nbecomes unstable, and landslides may send dust and rubble drifting into \nspace at a couple miles per hour, or the speed of a strolling human. The\n researchers estimate that Gault could have been slowly spinning up for \nmore than 100 million years.<\/p>\n\n\n\n

Piecing together Gault\u2019s recent activity is an astronomical forensics\n investigation involving telescopes and astronomers around the world. \nAll-sky surveys, ground-based telescopes, and space-based facilities \nlike the Hubble Space Telescope pooled their efforts to make this \ndiscovery possible.<\/p>\n\n\n\n

The initial clue was the fortuitous detection of the first debris \ntail, observed on Jan. 5, 2019, by the NASA-funded Asteroid \nTerrestrial-Impact Last Alert System (ATLAS) telescope in Hawaii. The \ntail also turned up in archival data from December 2018 from ATLAS and \nthe Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) \ntelescopes in Hawaii. In mid-January, a second shorter tail was spied by\n the Canada\u2013France\u2013Hawaii Telescope in Hawaii and the Isaac Newton \nTelescope in Spain, as well as by other observers. An analysis of both \ntails suggests the two dust events occurred around Oct. 28 and Dec. 30, \n2018. <\/p>\n\n\n\n

Follow-up observations with the William Herschel Telescope and ESA\u2019s \n(European Space Agency) Optical Ground Station in La Palma and Tenerife,\n Spain, and the Himalayan Chandra Telescope in India measured a two-hour\n rotation period for the object, close to the critical speed at which a \nloose \u201crubble-pile\u201d asteroid begins to break up.<\/p>\n\n\n\n

\u201cGault is the best \u2018smoking gun\u2019 example of a fast rotator right at \nthe two-hour limit,\u201d said team member Jan Kleyna of the University of \nHawaii in Honolulu.<\/p>\n\n\n\n

An analysis of the asteroid\u2019s surrounding environment by Hubble \nrevealed no signs of more widely distributed debris, which rules out the\n possibility of a collision with another asteroid causing the \noutbursts. <\/p>\n\n\n\n

The asteroid\u2019s narrow streamers suggest that the dust was released in\n short bursts, lasting anywhere from a few hours to a few days. These \nsudden events puffed away enough debris to make a \u201cdirt ball\u201d \napproximately 500 feet (150 meters) across if compacted together. The \ntails will begin fading away in a few months as the dust disperses into \ninterplanetary space. <\/p>\n\n\n\n

Based on observations by the Canada\u2013France\u2013Hawaii Telescope, the \nastronomers estimate that the longer tail stretches over half a million \nmiles (800,000 kilometers) and is roughly 3,000 miles (4,800 kilometers)\n wide. The shorter tail is about a quarter as long.<\/p>\n\n\n\n

Only a couple of dozen active asteroids have been found so far. \nAstronomers may now have the capability to detect many more of them \nbecause of the enhanced survey capabilities of observatories such as \nPan-STARRS and ATLAS, which scan the entire sky. \u201cAsteroids such as \nGault cannot escape detection anymore,\u201d Hainaut said. \u201cThat means that \nall these asteroids that start misbehaving get caught.\u201d<\/p>\n\n\n\n

The researchers hope to monitor Gault for more dust events.<\/p>\n\n\n\n

The team\u2019s results have been accepted for publication by The Astrophysical Journal Letters.<\/p>\n\n\n\n

The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington, D.C. <\/p>\n\n\n\n

https:\/\/nasa.gov<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

\u201cWe didn\u2019t have to go to Gault,\u201d explained Olivier Hainaut of the European Southern Observatory in Germany, a member of the Gault observing team. \u201cWe just had to look at the image of the streamers, and we can see all of the dust grains well-sorted by size. All the large grains (about the size of […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[18],"tags":[],"_links":{"self":[{"href":"http:\/\/energyholding.world\/index.php?rest_route=\/wp\/v2\/posts\/2734"}],"collection":[{"href":"http:\/\/energyholding.world\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/energyholding.world\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/energyholding.world\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/energyholding.world\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2734"}],"version-history":[{"count":2,"href":"http:\/\/energyholding.world\/index.php?rest_route=\/wp\/v2\/posts\/2734\/revisions"}],"predecessor-version":[{"id":2842,"href":"http:\/\/energyholding.world\/index.php?rest_route=\/wp\/v2\/posts\/2734\/revisions\/2842"}],"wp:attachment":[{"href":"http:\/\/energyholding.world\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2734"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/energyholding.world\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2734"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/energyholding.world\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2734"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}