Roberto Gorelli points our attention at a recently published meteor related paper:

Computation of a possible Tunguska’s strewn field

This article has been submitted for publication by Albino Carbognani, Mario Di Martino, and Giovanna Stirpe.

Abstract: On June 30, 1908 at about 0h 14.5m UTC the Tunguska Event (TE) occurred, most likely caused by the fall of a small stony asteroid of about 50-60 meters in diameter over the basin of the Tunguska River (Central Siberia). Unfortunately the first expedition was made by Leonid Kulik 19 years after the event and macroscopic meteorites have never been found around epicenter. In this paper we want to establish whether macroscopic fragments, about 1 m in diameter, could have survived the airburst of TCB (Tunguska Cosmic Body) and where they might have fallen. For this purpose we have implemented a fall model for the description of the mass ablation, pancake expansion with final airburst and fragment dark flight. The fragments have a higher mean strength than the main body due to Weibull’s law. The results, for a TCB kinetic energy of 15 Mt, atmospheric speed in the range 11-20 km/s, trajectory inclination of 35° and average strength in the range 10-50 MPa, tell us that for a macroscopic fragment with a mean strength between 20-70 MPa would be possible to survive the hight temperature airburst and reach the ground. The falling speed of the fragments is in the range 0.8-0.5 km/s and this favored their burial in the permafrost. The range of mean strength values for the TCB’s fragment appear physically plausible if we consider the falls of the F1 fragment in the case of Chelyabinsk in 2013 and Carancas in 2007. So our possible strewn field, computed for a typical atmospheric speed of 15 km/s, is located from 11 to 20 km North-West from the epicenter, depending by the high (35°) or low inclination (15°) trajectory being considered. Finally Cheko Lake, which by some authors is considered an impact crater, falls several km outside the strewn fields and, based on our results, it is unlikely that it could be a real impact crater: only if the TCB’s trajectory had an azimuth of about 150° −180° would be in the strewn field area, but it is not consistent with the most likely trajectory.


You can download this paper for free: (19 pages).


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