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The Siberian Shake-Up of 1908
The Solar System > Imagine getting up one fine June morning in the middle of a forested wilderness, taking a deep breath, letting out a long sigh, and enjoying the beautiful morning sky. Then suddenly the sky splits in two with a bright flash, only to turn into a blinding fireball so hot you feel you might burst into flames. Thunderous booming sounds overcome your pleasant surrounds and shake the earth. Your quiet, noneventful world has literally been rocked.
That would be an eye-opener, eh?
That's what happened 100 years ago on the 30th of June, 1908, over a remote area in Russia's Siberia, specifically near the Podkamennaya Tunguska River. It is an area so remote that few people lived there then, probably fewer on the outside even knew of it.
The Tunguska Event, as it is understatedly known in the scientific community, was real, to be sure. But a real what?
Understand that at the time, in the early 1900's, there were no satellites, phones, worldwide tracking stations, email, texts, and the like. If some monstrous event took place in the middle of Siberia back then, the news would travel slowly, and any response in getting to this forsaken place would be slower.
In fact, it wasn't until the 1920's that a Russian scientist, Leonid Kulik, curious about local accounts of a Brobdingnagian explosion that happened decades before, made some expeditions there.
Although he deduced that the explosion was from a meteorite impact, his findings - and the findings of all the subsequent expeditions there - discovered hundreds of square miles of felled and scorched trees. But there was no impact crater in the middle of the mayhem!
What on earth was this Tunguska Event, a phenomenon that knocked over more than 50 million trees and exploded with a force 1000 times greater than the Hiroshima atomic bomb, but left no crater?
Dunno!
Believe it or not, the jury is still out on this one. The prime suspects are extraterrestrial, as expected. But as to whether it was a comet or asteroid…? Go there and expect a fine argument.
A small comet is suspect because it is so weakly put together that it would be expected to blow to smithereens when impacting our dense atmosphere, unleashing a truckload of energy but leaving in essence nothing but dust and water vapor.
But a comet just tens of meters across would have ripped apart higher in the atmosphere, and the trace chemical evidence found on the ground imply an asteroid, not a comet.
Exactly one hundred years later there is still no consensus as to what it was. But there is plenty of agreement on what these intruders - asteroids or comets - can do when they hit.
The Tunguska beast was just a small impactor traveling at just tens of kilometers per second that fell over an unpopulated area full of nothing but trees and bunnies.
If the Tunguska rock had struck just hours later, Europe would have been in deep do-do.
A blast like that could easily have leveled a populated city like St Petersburg or London and all its inhabitants. Bigger rocks, on the order of hundreds of meters across or even a kilometer or two, can spell doom to entire continents of life.
We should be thankful that although blasts like Tunguska happen about once every several centuries or so, that most of our planet is still pretty much uninhabited. Nevertheless, a pinpoint strike can kill - big time. Just a little heads up!
Until next time, clear - and safe - skies!
Posted by Mark Ritter at 2008.06.29 08:29 PM | Comments (0)
