A two-week scientific expedition to Tunguska (Central Siberia) is being organized by the Department of Physics of the University of Bologna, in cooperation with the Turin Astronomical Observatory (prof. M. Di Martino) and the Institute of Marine Geology of the National Research Council (CNR) of Bologna (prof. E. Bonatti). Owing to its scientific and social importance, the expedition has been sponsored mainly by Fondazione Cassa di Risparmio in Bologna.
To perform their tasks, the scientists have to build a camp in the taiga at some hundred kilometers from centers connected by roads. Local support will be provided by personnel and researchers of Tomsk University (Russia), lead by the Academician N.V. Vasilyev and by prof. G.V. Andreev. About 20 persons will take part in the expedition that is planned for the second half of July 1999. The expedition will be coordinate by prof. Giuseppe Longo (University of Bologna), who took part, together with prof. M. Galli, dott. S. Cecchini and dott. R. Serra, to the 1991 Italian expedition.
The aim of the new expedition is to carry out a systematic exploration of the site where the so-called "Tunguska event" took place, to establish the nature of the body that devastated about 2,150 square kilometers of Siberian taiga on 30 June 1908, felling more than 60 million trees. The explosion epicenter has been localized at 60° 53' 09'' N and 101° 53' 40'' E, near the river Stony Tunguska.
Subsequent studies showed that the explosion occurred at 0h 14' 28'' (Greenwich time) at a height of 5-10 km, releasing an energy between 10 and 20 million tons of TNT (Megaton), that corresponds to about one thousand Hiroshima's bombs.
During previous expeditions, neither macroscopic remnants of the body, nor a typical impact crater were observed. Nevertheless, it is the cosmic body that caused the greatest damages during historical times. The nature and composition of the Tunguska Cosmic Body is still unclear. Some data were acquired by the first Italian 1991 expedition, but a new expedition is required, in order to through light on the Tunguska event, and to give a valuable contributions to the international research programs aiming at the study of cosmic body impacts on the Earth surface.