Now, researchers led by Victor Kvasnytsya at the Institute of Geochemistry, Mineralogy and Ore Formation of the National Academy of Science of Ukraine in Kiev say that they have found a smoking gun. In what Kvasnytsya describes as the most detailed analysis yet of any candidate sample from the Tunguska event, the researchers conclude that their fragments of rock — each less than 1 millimetre wide — came from the iron-rich meteor that caused the blast. The study was published late last month in Planetary and Space Science.
“If these are Tunguska fragments, it could end any doubt that it was an asteroid impact,” says Gareth Collins, an Earth-impact researcher at Imperial College London. “We would have convincing proof that this was an extraterrestrial event, and it would rule out a comet.”
