The Tunguska Event

On June 30th of 1908 there was a gargantuan explosion above the Podkamennaya Tunguska river in Siberia. Either an asteroid or a comet entered the atmosphere and exploded in mid-air no less than 3 miles above the ground. Nevertheless, the event is considered an "impact" in the scientific field given the amount of physical force inherent in the aftermath and is, in fact, the single largest impact event in known history. The speculated energy attributed to the event varies but generally falls between 10-15 megatons, which is a great many times more than what was done to Hiroshima. Of all the places on the Earth, this explosion took place over the vast Russian hinterlands, populated primarily by trees. 80 million of those trees were stripped like telephone poles and knocked flat in huge arcs pointing away from the blast over an area of some 830 square miles. For the next few nights, the night skies were aglow over all of Europe and Asia. 

Insanely, scientific study of the event was minimal until nearly a decade later. To be fair, this must have had much to do with the isolation and difficulties of the area, not to mention the extreme possibility of destroyed or lost research during the many turbulent years ahead for Russia. Consider also that the epicenter could only be reached by traversing hundreds of miles of tree fall. Still, since the event there have been around 1'000 related reports written and they continue to the present day. The absence of any crater is of course the chief mystery here (though many believe that Lake Cheko in the region is possibly a crater formed by just a small chunk of whatever it was that burst.) The second big question mark is to whether or not this was an asteroid (most believed), a comet, or an alien death-tunnel (least believed.) Some even think it may have been a black hole flying though the earth or tectonic-based, However, this does not account for the tiny spheres of nickel and iron that were found in disproportionate abundance in the area, lending much credence to the meteoroid theory. 

Clearly, even taking Siberia's sparse population into account, a huge number of persons must have witnessed this event. But very few of these people told their story to anyone who wrote them down and compiled them. The details we have been able to sweep together since then tell us that some kind of inestimably bright light source suddenly appeared in the sky "like a second sun." The size, color and shape of this light vary, though many described it like a column or pillar. Following the explosion of light were literal explosions of force that came in at least three distinct "thumps." Coupled by the tremendous knocking sounds of giant stones falling, thunder claps or sound-barrier breaks. The wind and heat produced by these thumps scorched, stripped and knocked down trees, resulting in a further sound like heavy artillery fire. Millions of limbs and trunks all snapping at once. The air became unbearably hot, windows shattered and people ran screaming as if from the end times. Many people left their homes and belongings after the event and went to monasteries and holy shrines to fast and pray for forgiveness. Natives in the area had their own Gods to worry about during the event too, believing it to be the angry work of OGDY. Further, when the first expedition set out to find the epicenter of the blast, the native guides who led them there refused to enter the actual blast sight, saying they feared the "valleymen."
A similar explosion, though on a much much smaller scale also happened above Russia just earlier this year, killing many and receiving wide media coverage.