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Reanalysis of the Benesov bolide and recovery of polymict breccia meteorites - old mystery solved after 20 years
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SYSNO ASEP 0434829 Druh ASEP J - Článek v odborném periodiku Zařazení RIV J - Článek v odborném periodiku Poddruh J Článek ve WOS Název Reanalysis of the Benesov bolide and recovery of polymict breccia meteorites - old mystery solved after 20 years Tvůrce(i) Spurný, Pavel (ASU-R) ORCID, RID
Haloda, J. (CZ)
Borovička, Jiří (ASU-R) RID, ORCID
Shrbený, Lukáš (ASU-R) RID, ORCID
Halodová, P. (CZ)Zdroj.dok. Astronomy & Astrophysics. - : EDP Sciences - ISSN 0004-6361
Roč. 570, October (2014), A39/1-A39/14Poč.str. 14 s. Forma vydání Tištěná - P Jazyk dok. eng - angličtina Země vyd. FR - Francie Klíč. slova meteorites ; meteors ; meteoroids Vědní obor RIV BN - Astronomie a nebeská mechanika, astrofyzika CEP GA205/08/0411 GA ČR - Grantová agentura ČR GAP209/11/1382 GA ČR - Grantová agentura ČR Institucionální podpora ASU-R - RVO:67985815 UT WOS 000344158500098 DOI https://doi.org/10.1051/0004-6361/201424308 Anotace The main motivation for this work was to explain and solve the old mystery connected with the detailed instrumental observation of the Benešov superbolide on 7 May 1991 over the central part of the Czech Republic. In spring 2011, we remeasured all available records and reanalyzed the data. We used slightly different methods and new approaches, which we gradually developed to analyze several recent instrumentally observed meteorite falls. We assembled a new consistent picture of the Benešov event, which resulted in a slightly revised impact location and suggested a new strategy that might lead to a recovery of Benešov meteorites after 20 years. The reality completely confirmed all our assumptions and surpassed our expectations. We found four small highly weathered fragments with a total mass of 11.63 g (1.54 g (H5), 7.72 g (with achondritic clast), 1.99 g, 0.38 g (all LL3.5)). They were recovered exactly in the predicted impact area for corresponding masses, namely within 40 m from the highest probability line. Although all fragments are very small and their weathering grade is high (W3 for all pieces), their interior was preserved enough for reliable analysis (except for the smallest one). The meteorite is classified as a polymict breccia containing three recognized lithologies with different texture, chemical, and mineralogical composition. This result is pioneering in many aspects. We proved that in some special cases it is still possible to predict and find meteorites a long time after the fall. The most important result, however, is the heterogeneity of the recovered meteorites. This case clearly shows that larger meteoroids can be compositionally very complicated bodies. We discovered that the Benešov meteoroid consisted of at least three different types of material – LL3.5, H5, and primitive achondrite. This case also implies that it is very useful to study as many fragments as possible from one fall because there can be significant differences among them. Pracoviště Astronomický ústav Kontakt Anežka Melichárková, bibl@asu.cas.cz, Tel.: 323 620 326 Rok sběru 2015
Počet záznamů: 1