Quote:
Originally Posted by Veeger
The physics of an airburst can be very difficult to determine for an object hurling 10's of thousand of miles an hour into the atmosphere, as can be expected by an asteroid or cometary fragment.
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As you hinted, an atmospheric burst from an asteroid or comet is totally different than that from a nuclear weapon. For the former, the total energy released is equivalent to 1/2*m*v
2. For the latter, it's in terms of kt-equivalents of TNT.
Furthermore, the rate at which the energy is released will determine the nature and the extent of the damage. Nuclear weapons release their energy far more rapidly than do meteors or comets.
If Tunguska was a comet, the effect probably involved the breakup of loosely aggregated ice and dust. The effect would be similar to tossing a bucket of water onto a beach ball, although the scales are somewhat different... The point is that the energy released probably occurred over many seconds, and all booms, bangs, and shattered windows were merely the result of the initial atmospheric entry shockwaves.
By contrast, had the same mass hit the planet, intact, we'd probably have had another event similar to the
K/T extinction event.