MOSCOW, June 30. /TASS/. The Tunguska space object was most likely a fragment of a comet’s icy nucleus, which turned into a cloud of water vapor at the moment of the blast, explaining the absence of solid fragments on the ground, Sergey Yazev, a leading researcher at the Institute of Solar-Terrestrial Physics of the Siberian Branch of the Russian Academy of Sciences and a professor at Irkutsk State University, told TASS in an interview on International Asteroid Day.

He noted that even today, debates continue over what happened on that day 118 years ago over the Siberian taiga near the Podkamennaya Tunguska River. Hundreds of hypotheses exist, though not all of them are scientifically sound.

"A detailed analysis showed that a tremendous explosion occurred at an altitude of 6-8 kilometers. The basic idea is that this resulted in the destruction of a fragment of the comet’s icy nucleus - it explosively turned into a cloud of water vapor, which is why no solid fragments fell to the ground," Yazev said, noting that he personally supports this theory.