Jul 022008
 

On Monday just gone, science remembered the centenary of of the largest impact on land of an object from space. Known today as the Tunguska Event, there remains no conclusive answer to the question of just what did enter the planet’s atmosphere over the Siberian tundra to annihilate at high altitude with more energy released than 150 Hiroshima bombs.

The area of Siberia where the detonation took place is desolate. Frozen ground in winter, sodden swamp in summer. Expeditions into the region take place almost every year now, yet little of viable scientific evidence pointing to exactly what occurred has surfaced. From an out-of-control alien spacecraft to a geophysical event, the explanations remain rife. Some say asteroid, some claim a comet core. The most frustrating part of the research into the event must surely be the complete lack of evidence of just what did enter and vaporise. No impact crater, no believable remains, no molten extra-terrestrial rock. Only the recorded written memories of those who witnessed the event and felt it’s consequences.

Flattened trees radiating out for hundreds of square kilometres from the epicentre are still seen today lying in the morass and hilliny forested terrain, evidence of the power of the occasion. At ground zero, tree trunks bereft of all branches still stand upright, charred and dead, indicative of the air burst immediately overhead. The only real measure human science has for the event is the atomic aftermath at Hiroshima and Nagasaki. Apparently these Earth-meets-space events – if indeed Tunguska was a space object meeting – occur around once every 300 years, according to recorded history. Amusingly, recorded history in the grand scheme of our planet’s history is so damn short on an astronomical time scale as to be irrelevant.

In the modern age, we’ll be well informed of the next event, and there will be a next event, of that we can be certain. Courtesy of the NASA Near Earth Object research program, supposedly our current astronomical science will be able to tell us well in advance of any approaching armageddon. Well … maybe. All I’ve ever seen in the news are the near misses. After the fact. Better to live in ignorance and die in a flash, I reckon.

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