{"id":8888,"date":"2021-11-01T09:29:35","date_gmt":"2021-11-01T12:29:35","guid":{"rendered":"https:\/\/www.fie.undef.edu.ar\/ceptm\/?p=8888"},"modified":"2021-11-01T09:30:48","modified_gmt":"2021-11-01T12:30:48","slug":"cuarenta-y-dos-asteroides-vistos-como-nunca-antes","status":"publish","type":"post","link":"https:\/\/www.fie.undef.edu.ar\/ceptm\/?p=8888","title":{"rendered":"Cuarenta y dos asteroides vistos como nunca antes"},"content":{"rendered":"

Utilizando uno de los mayores telescopios del mundo (el VLT en Chile), se han tomado im\u00e1genes de muy alta calidad de 42 de los mayores asteroides situados en el cintur\u00f3n entre Marte y J\u00fapiter. Estas im\u00e1genes permiten estudiar c\u00f3mo se crearon los diferentes cuerpos del sistema solar. Hace unos cuatro a\u00f1os que Pierre Vernaza, del Laboratorio de Astrof\u00edsica de Marsella, comenz\u00f3 a coordinar un equipo que ha ido tomando im\u00e1genes precisas de algunos de los mayores asteroides utilizando un potente telescopio: uno de los cuatro Very Large Telescope (VLT) que el Observatorio Europeo Austral (ESO) \u00a0tiene instalados en el desierto de Atacama (Chile). Hasta el momento, el equipo ha tomado im\u00e1genes de 42 asteroides. La mayor\u00eda de estos objetos, tienen un tama\u00f1o superior a 100 km. Los dos objetos m\u00e1s grandes que el equipo sonde\u00f3 fueron Ceres y Vesta,<\/a>\u00a0que tienen alrededor de 940 y 520 kil\u00f3metros de di\u00e1metro, mientras que los dos asteroides m\u00e1s peque\u00f1os son\u00a0Urania y Ausonia,<\/a>\u00a0cada uno de solo unos 90 kil\u00f3metros.<\/p>\n

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Using the European Southern Observatory\u2019s Very Large Telescope (ESO\u2019s VLT) in Chile, astronomers have imaged 42 of the largest objects in the asteroid belt, located between Mars and Jupiter. Never before had such a large group of asteroids been imaged so sharply. The observations reveal a wide range of peculiar shapes, from spherical to dog-bone, and are helping astronomers trace the origins of the asteroids in our Solar System.<\/p>\n

The detailed images of these 42 objects are a leap forward in exploring asteroids, made possible thanks to ground-based telescopes, and contribute to answering the ultimate question of life, the Universe, and everything\u00a0[1]<\/a>.<\/p>\n

\u201cOnly three large main belt asteroids, Ceres, Vesta and Lutetia, have been imaged with a high level of detail so far, as they were visited by the space missions Dawn and Rosetta of NASA and the European Space Agency, respectively,<\/em>\u201d explains Pierre Vernazza, from the Laboratoire d\u2019Astrophysique de Marseille in France, who led the asteroid study published today in\u00a0Astronomy & Astrophysics<\/em>. “Our ESO observations have provided sharp images for many more targets, 42 in total.<\/em>“<\/p>\n

The previously small number of detailed observations of asteroids meant that, until now, key characteristics such as their 3D shape or density had remained largely unknown. Between 2017 and 2019, Vernazza and his team set out to fill this gap by conducting a thorough survey of the major bodies in the asteroid belt.<\/p>\n

Most of the\u00a042 objects<\/a>\u00a0in their sample are larger than 100 km in size; in particular, the team imaged nearly all of the belt asteroids larger than 200 kilometres, 20 out of 23. The two biggest objects the team probed were\u00a0Ceres and Vesta<\/a>, which are around 940 and 520 kilometres in diameter, whereas the two smallest asteroids are\u00a0Urania and Ausonia<\/a>, each only about 90 kilometres.<\/p>\n

By reconstructing the objects\u2019 shapes, the team realised that the observed asteroids are mainly divided into two families. Some are almost perfectly spherical, such as\u00a0Hygiea<\/a>\u00a0and Ceres, while others have a more peculiar, \u201celongated\u201d shape, their undisputed queen being the\u00a0\u201cdog-bone\u201d asteroid Kleopatra<\/a>.<\/p>\n

By combining the asteroids\u2019 shapes with information on their masses, the team found that the densities change significantly across the sample. The four least dense asteroids studied, including\u00a0Lamberta and Sylvia<\/a>, have densities of about 1.3 grams per cubic centimetre, approximately the density of coal. The highest,\u00a0Psyche and Kalliope<\/a>, have densities of 3.9 and 4.4 grammes per cubic centimetre, respectively, which is higher than the density of diamond (3.5 grammes per cubic centimetre).<\/p>\n

This large difference in density suggests the asteroids\u2019 composition varies significantly, giving astronomers important clues about their origin. \u201cOur observations provide strong support for substantial migration of these bodies since their formation. In short, such tremendous variety in their composition can only be understood if the bodies originated across distinct regions in the Solar System,<\/em>\u201d explains Josef Hanu\u0161 of the Charles University, Prague, Czech Republic, one of the authors of the study. In particular, the results support the theory that the least dense asteroids formed in the remote regions beyond the orbit of Neptune and migrated to their current location.<\/p>\n

These findings were made possible thanks to the sensitivity of the Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE<\/a>) instrument mounted on ESO\u2019s\u00a0VLT<\/a>\u00a0[2]<\/a>.\u00a0\u201cWith the improved capabilities of SPHERE, along with the fact that little was known regarding the shape of the largest main belt asteroids, we were able to make substantial progress in this field,\u201d<\/em>\u00a0says co-author Laurent Jorda, also of the Laboratoire d’Astrophysique de Marseille.<\/p>\n

Astronomers will be able to image even more asteroids in fine detail with ESO\u2019s upcoming Extremely Large Telescope (ELT<\/a>), currently under construction in Chile and set to start operations later this decade. \u201cELT observations of main-belt asteroids will allow us to study objects with diameters down to 35 to 80 kilometres, depending on their location in the belt, and craters down to approximately 10 to 25 kilometres in size,<\/em>\u201d says Vernazza. \u201cHaving a SPHERE-like instrument at the ELT would even allow us to image a similar sample of objects in the distant\u00a0Kuiper Belt<\/a>. This means we\u2019ll be able to characterise the geological history of a much larger sample of small bodies from the ground.<\/em>\u201d<\/p>\n

Notes<\/strong><\/p>\n

<\/a>[1] In\u00a0The Hitchhiker’s Guide to the Galaxy<\/a>\u00a0by Douglas Adams, the number 42 is the answer to the “Ultimate Question of Life, the Universe, and Everything.” Today, 12 October 2021, is the 42nd<\/sup>\u00a0anniversary of the publication of the book.<\/p>\n

<\/a>[2] All observations were conducted with the Zurich IMaging POLarimeter (ZIMPOL), an imaging polarimeter subsystem of the SPHERE instrument that operates at visible wavelengths.<\/p>\n

Fuente:<\/strong> https:\/\/www.eso.org<\/em><\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

Utilizando uno de los mayores telescopios del mundo (el VLT en Chile), se han tomado im\u00e1genes de muy alta calidad de 42 de los mayores… <\/p>\n","protected":false},"author":1,"featured_media":8889,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[35],"tags":[],"_links":{"self":[{"href":"https:\/\/www.fie.undef.edu.ar\/ceptm\/index.php?rest_route=\/wp\/v2\/posts\/8888"}],"collection":[{"href":"https:\/\/www.fie.undef.edu.ar\/ceptm\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.fie.undef.edu.ar\/ceptm\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.fie.undef.edu.ar\/ceptm\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.fie.undef.edu.ar\/ceptm\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=8888"}],"version-history":[{"count":3,"href":"https:\/\/www.fie.undef.edu.ar\/ceptm\/index.php?rest_route=\/wp\/v2\/posts\/8888\/revisions"}],"predecessor-version":[{"id":8892,"href":"https:\/\/www.fie.undef.edu.ar\/ceptm\/index.php?rest_route=\/wp\/v2\/posts\/8888\/revisions\/8892"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.fie.undef.edu.ar\/ceptm\/index.php?rest_route=\/wp\/v2\/media\/8889"}],"wp:attachment":[{"href":"https:\/\/www.fie.undef.edu.ar\/ceptm\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=8888"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.fie.undef.edu.ar\/ceptm\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=8888"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.fie.undef.edu.ar\/ceptm\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=8888"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}