Dear colleagues, on Saturday May 6, some minutes before 14 hours of European continental summertime, a very bright fireball appeared over south-western Poland and Silesia. It was visible from whole Poland, Czechia and Slovakia. Tens of thousands of people saw the magnificient spectacle. To be able to compute its atmospheric visible trajectory, enough accurate data for triangulation are needed. Just a tiny proportion of observers is able to reconstruct the event and to measure the needed pairs of angles for some points of the trajectory: their azimuths (geographic ones, measured from the north, preferably) and angular heights (elevations over a horizontal plane) -- angular heights are usually measurable just if some trees or buildings appeared close to the path. The data we have up to now are sparse: just the last part of the trajectory observed from the Observatory of the Comenius University near Modra (Little Carpathians), Observatory in Rimavska Sobota and my measurements made with help of one witness from Brno and one from a village south from it. The result is that the final blast and fragmentation took place probably some thirty kilometres over the Moravian-Silesian Beskides (longitude 18.4 degrees, latitude 49.5 degrees). The beginning of the visible trajectory is still very uncertain, it could have been two to three hundred kilometres northwards, in azimuth of some 340 degrees from the end of the fireball, perhaps near Poznan. The trajectory was rather horizontal. Further observations from places near to the path could yield much more accurate knowledge. Especially observers from the meteorological stations could be able to report (perhaps after a reconstruction) positions of some points on the (linear) trajectory, preferably including estimates of their uncertainties. People close to the path could have witnessed even some sounds, either simultaneous (electrophonic) or arriving some minutes (up to ten minutes) later. Accurate timings of those sounds would be most welcome. You see, dazzling daytime meteors are extremely rare over densely inhabited areas, and the investigation of this central European one is a tremendous opportunity to understand them better. Please, give this appeal to those people, who in the needed time (saturday 6. May 2000, 13:50 to 14:00 CEST) watched the sky, or may have heard the subsequent sounds. (More information could appear provisionaly at http://svetlo.astro.cz) Yours sincerely, Jenik Hollan -------------------------------------------------------------------------- Jan Hollan N. Copernicus Observatory and Planetarium in Brno Kraví hora 2, CZ - 616 00 Brno +420 (5) 41 32 12 87 home: Lipová 19, 602 00 Brno 43 23 90 96 member of the Society for Sustainable Living and volunteer of the Ecological counselling Veronica Panská 9, 602 00 Brno, Czechia fax: +420 (5) 42 21 05 61 e-mail: hollan@ped.muni.cz http://astro.sci.muni.cz/pub/hollan --------------------------------------------------------------------------