Sandia supercomputers offer new explanation of Tunguska disaster
ALBUQUERQUE, N.M. — The stunning amount of forest devastation at Tunguska a century ago in Siberia may have been caused by an asteroid only a fraction as large as previously published estimates, Sandia National Laboratories supercomputer simulations suggest.
“The asteroid that caused the extensive damage was much smaller than we had thought,” says Sandia principal investigator Mark Boslough of the impact that occurred June 30, 1908. “That such a small object can do this kind of destruction suggests that smaller asteroids are something to consider. Their smaller size indicates such collisions are not as improbable as we had believed.”
In Search of the Tunguska Meteorite
...The scientists from the University of Bologna hypothesize that the cosmic body made a “soft crash” in the marsh terrain, splashing on the soft, swampy soil and melting the underlying permafrost layer, releasing carbon dioxide, water vapor and methane. This broadened the hole caused by the crash, and explains the shape and size of Lake Cheko's basin, which is unusual for an impact crater. So far, this is the only hypothesis that accounts for the unique, funnel-like morphology of the lake’s basin. According to the Italian team, only the topmost, one-meter-deep layer of debris actually came from the inflowing river. The deeper sediments predate 1908 and they were the target over which the impact took place, meaning Lake Cheko is only one century old...
I will never look at the news the same way again 
It is disturbing that after all of these years researchers have not found much in the way of meteoric debris, if my memory serves.
Moscow - Russian police were combing the northern Siberian city of Krasnoyarsk on Friday for a three-ton meteorite that has disappeared from under the nose of its keepers.
The giant rock was stolen from the yard of the Tunguska Space Event foundation, whose director said it was the part of meteor that caused a massive explosion in Siberia in 1908, news agency Interfax reported.
"It winds up that it disappeared back in June, when the foundation was moving out of its old building," a police spokesperson told the agency
Shaidurov has used a detailed analysis of the mean temperature change by year for the last 140 years and explains that there was a slight decrease in temperature until the early twentieth century. This flies in the face of current global warming theories that blame a rise in temperature on rising carbon dioxide emissions since the start of the industrial revolution. Shaidurov, however, suggests that the rise, which began between 1906 and 1909, could have had a very different cause, which he believes was the massive Tunguska Event, which rocked a remote part of Siberia, northwest of Lake Baikal on the 30th June 1908.
