October 15, 2014 <\/p>\n
Image Caption: Image of the Beneov bolide, taken by the fish-eye guided camera at Ondejov Observatory. Its apparent magnitude was -22 (6000 times brighter than the -12.6 apparent magnitude of the full Moon) <\/p>\n
Provided by Dr. Jennifer Martin, Astronomy & Astrophysics <\/p>\n
Astronomy & Astrophysics is publishing the spectacular discovery of meteorite fragments 20 years after the corresponding bolide was seen in the skies of the Czech Republic. This discovery was made possible by reanalyzing the trajectory, which moved the impact line by 330 meters. Interestingly, the meteorites found on the ground are of different types, pointing to a parent asteroid of heterogeneous composition. <\/p>\n
Collisions of meter-sized meteoroids with the Earths atmosphere are relatively rare, occurring about 40 times a year. They cause very spectacular events, known as superbolides. One of the best known such events, the Beneov bolide, occurred on 7 May 1991 at 23h 03m 46s UT over the Czech Republic. It was recorded during systematic photographic observations by the European Fireball Network and certainly ended in a multiple meteorite fall, but no meteorite was found in the weeks and years after the fall, despite many attempts. <\/p>\n
In February 2011, nearly 20 years after the event, P. Spurn and his colleagues [1] measured the records again and analyzed the data with improved methods. This led to a new picture of the whole event with a revised atmospheric trajectory and a new impact location. This allowed the team to recover the Beneov meteorites, 20 years after the fall, exactly in the newly predicted area. It is the first time a meteorite is found so long after the bolide observation. The team found four small, highly-weathered meteorites with a total mass of 12 g. The probability that these four fragments come from different meteoroids and were found by chance at the same place is estimated to be 1 in 100,000 or less. Even more interestingly, these four meteorites are of three different mineralogical types. This means that the Beneov meteoroid was heterogeneous and contained at least three different types of material. After the Almahata Sitta fall, this is the second time that such a heterogeneous composition has been found. It raises the possibility that a significant fraction of all asteroids are heterogeneous and that they were strongly reprocessed by collisions with other asteroids in the main belt. <\/p>\n
Reanalysis of the Beneov bolide and recovery of polymict breccia meteorites old mystery solved after 20 years, by P. Spurn, J. Haloda, J. Borovika, L. Shrben, and P. Halodov <\/p>\n
Published in Astronomy & Astrophysics, 2014, 570, A39 <\/p>\n
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Discovery Of Benesov Meteorites 20 Years After The Bolide Event<\/a><\/p>\n","protected":false},"excerpt":{"rendered":" October 15, 2014 Image Caption: Image of the Beneov bolide, taken by the fish-eye guided camera at Ondejov Observatory. Its apparent magnitude was -22 (6000 times brighter than the -12.6 apparent magnitude of the full Moon) Provided by Dr. Jennifer Martin, Astronomy & Astrophysics Astronomy & Astrophysics is publishing the spectacular discovery of meteorite fragments 20 years after the corresponding bolide was seen in the skies of the Czech Republic. Continue reading