{"id":24298,"date":"2021-09-09T08:00:11","date_gmt":"2021-09-09T12:00:11","guid":{"rendered":"https:\/\/hobbyspace.com\/Blog\/?p=24298"},"modified":"2021-09-08T15:13:40","modified_gmt":"2021-09-08T19:13:40","slug":"eso-vlt-captures-sharpest-images-yet-of-a-dog-bone-asteroid","status":"publish","type":"post","link":"https:\/\/hobbyspace.com\/Blog\/?p=24298","title":{"rendered":"ESO: VLT captures sharpest images yet of a “dog-bone” asteroid"},"content":{"rendered":"

A new report from the European Southern Observatory (ESO<\/a>):<\/p>\n

ESO captures best images yet of peculiar \u201cdog-bone\u201d asteroid<\/a><\/strong><\/p>\n

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These eleven images are of the asteroid Kleopatra, viewed at different angles as it rotates. The images were taken at different times between 2017 and 2019 with the Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) instrument on ESO\u2019s VLT.\u00a0 Kleopatra orbits the Sun in the Asteroid Belt between Mars and Jupiter. Astronomers have called it a \u201cdog-bone asteroid\u201d ever since radar observations around 20 years ago revealed it has two lobes connected by a thick \u201cneck\u201d.<\/figcaption><\/figure>\n

Using the European Southern Observatory\u2019s Very Large Telescope (ESO\u2019s VLT), a team of astronomers have obtained the sharpest and most detailed images yet of the asteroid Kleopatra. The observations have allowed the team to constrain the 3D shape and mass of this peculiar asteroid, which resembles a dog bone, to a higher accuracy than ever before. Their research provides clues as to how this asteroid and the two moons that orbit it formed.<\/p>\n

\u201cKleopatra is truly a unique body in our Solar System,<\/em>\u201d<\/p>\n

says Franck Marchis, an astronomer at the SETI Institute in Mountain View, USA and at the Laboratoire d’Astrophysique de Marseille, France, who led a study on the asteroid \u2014 which has moons and an unusual shape \u2014 published today in Astronomy & Astrophysics<\/em>.<\/p>\n

\u201cScience makes a lot of progress thanks to the study of weird outliers. I think Kleopatra is one of those and understanding this complex, multiple asteroid system can help us learn more about our Solar System.<\/em>\u201d<\/p>\n

Kleopatra orbits the Sun in the Asteroid Belt between Mars and Jupiter. Astronomers have called it a \u201cdog-bone asteroid<\/em>\u201d ever since radar observations around 20 years ago revealed it has two lobes connected by a thick \u201cneck<\/em>\u201d. In 2008, Marchis and his colleagues discovered that Kleopatra is orbited by two moons, named AlexHelios and CleoSelene, after the Egyptian queen\u2019s children.<\/p>\n

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This image provides a size comparison of the asteroid Kleopatra with northern Italy.\u00a0 The top half of the image shows a computer model of Kleopatra, a \u201cdog-bone\u201d shaped asteroid which orbits the Sun in the Asteroid Belt between Mars and Jupiter. End to end, Kleopatra is 270 kilometres long.\u00a0 The bottom half of the image gives an aerial view of northern Italy, with the footprint Kleopatra would have if it were hovering above it.<\/figcaption><\/figure>\n

To find out more about Kleopatra, Marchis and his team used snapshots of the asteroid taken at different times between 2017 and 2019 with the Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE<\/a>) instrument on ESO\u2019s VLT<\/a>. As the asteroid was rotating, they were able to view it from different angles and to create the most accurate 3D models of its shape to date. They constrained the asteroid\u2019s dog-bone shape and its volume, finding one of the lobes to be larger than the other, and determined the length of the asteroid to be about 270 kilometres or about half the length of the English Channel.<\/p>\n

In a second study, also published in Astronomy & Astrophysics<\/em> and led by Miroslav Bro\u017e of Charles University in Prague, Czech Republic, the team reported how they used the SPHERE<\/a> observations to find the correct orbits of Kleopatra\u2019s two moons. Previous studies had estimated the orbits, but the new observations with ESO\u2019s VLT<\/a> showed that the moons were not where the older data predicted them to be.<\/p>\n

\u201cThis had to be resolved,<\/em>\u201d says Bro\u017e. \u201cBecause if the moons\u2019 orbits were wrong, everything was wrong, including the mass of Kleopatra<\/em>.\u201d<\/p>\n

Thanks to the new observations and sophisticated modelling, the team managed to precisely describe how Kleopatra\u2019s gravity influences the moons\u2019 movements and to determine the complex orbits of AlexHelios and CleoSelene. This allowed them to calculate the asteroid\u2019s mass, finding it to be 35% lower than previous estimates.<\/p>\n