MIT Technology Review reports:
The Tunguska impact event is one of the great mysteries of modern history. The basic facts are well known. On 30 June 1908, a vast and powerful explosion engulfed an isolated region of Siberia near the Podkamennaya Tunguska River. [...]
That changes today with the extraordinary announcement by Andrei Zlobin from the Russian Academy of Sciences that he has found three rocks from the Tunguska region with the telltale characteristics of meteorites. If he is right, these rocks could finally help solve once and for all what kind of object struck Earth all those years ago.
The catch: Zlobin collected the samples in 1988, and waited 20 years to analyze them, casting some uncertainty on his research.