Strewn Field Simulations and Field Searchs of a Few Latest Bolides Over Hungary - Connection with the Fragmentation Height

Abstract

nspired by several unsuccessful field searches on the probable fall locations, we reanal-ised a few most recently observed blowing bolides ap-peared over Hungary on: 18:47:33 UTC 8 April, 2018; 17:31:01 UTC April 06, 2015 (so-called "Easter Bo-lide"); and 19:02:08 UTC August 24, 2013. This study is based on careful recalibration of all available obser-vational materials, and both the visual orbit calculation and dark flight integration were done with codes de-veloped by us. For atmospheric model we used the International Standard Atmosphere (ISA1975), while the concrete meteorological parameters of the given dates were taken from ECMWF tables. We simulated the 'theoretical' strewnfields, showed some example on the logged real field searches and gave some com-ments. Finally we present a simple comparison of the structure and sizes of the calculated strewn fields to the well-studied historical strewnfields. Some conse-quences are deduced for the present and next field searches. A typical freefall starts about 25 km height or even higher, where the final desintegrations happen usually. Under this initial parameter the fragments are thrown along a longer strip, which makes the field searches to exhibit very low effectivity. Only some lucky circumstances (like the fortunate geometry of meteor path), better quality professional camera input data and additional technics (radar or accurate seismic detection) can help to find new fell meteorites.