Free Astronomy Magazine November-December 2014

SMALL BODIES ings, which, besides being full of informa- tion on the composi- tion of the falling ma- terial, suggested the presence, in the cloud of firing debris, of at least eight fragments with final masses (on the ground) in the order of hundreds of grams and up to 1-2 kg for the larger size piece. Unfortunately, in the ‘90s there was still the belief that the explosion of bolides produced only a few comparatively large fragments and a lot of dust. The idea that also many intermediate size fragments could be formed did not convince and con- sequently the places of the fall were calcu- lated −starting from images taken by as many stations as possible, far from each other− based on the deceleration exerted by the atmosphere on the supposedly great- er mass pieces. On that basis, repeated searches for the fragments of the Benešov meteorite were made in an ominous wood- ed area with a very rugged terrain, in part subject to the felling of trees and refor- estation, and where various types of plant processes and animals were constantly al- tering the soil surface. In those circum- stances, after many years from the fall, the appearance of a meteorite undergoes sub- stantial modifications, such as the total de- terioration of the fusion crust, becoming in fact no longer distinguishable from or- dinary terrestrial rocks, except using re- search techniques completely impractical T he location on the territory of the Ond ř ejov, Tel č e and P ř imda stations, with re- spect to some of the best-known places of the Czech Republic such as Prague. The arrow indi- cates the track and direction of the bolide. [Spurný et al.] Below, Pavel Spurný hunting for meteorites in the woods, with on the right Ji ř í Borovi č ka during a conference.