The Tunguska Event

I remember watching something related to this before on the Discovery Channel. I think in the end they concluded that the object was a meteor. They said that after the explosion from impact massive swathes of forest were flattened, curiously enough in a butterfly-like shape, or something like that. Some scientists did some lab experiments and found that at a certain angle of approach the resulting blast would've produced a similiar shape. Despite the lab's results an expedition to what should've been the impact site did not yield any physical evidence of such an meteorite, but the scientists there did find some strange mutations in the local wildlife. Although they found no sources of radiation.

Of course this is based off of what I can remember from the program I saw like 4 years ago and my memory is kind of fuzzy and blurred so don't quote me on any of this.

Jam it back in, in the dark.