John S. Lewis was so concerned about the threat from the skies that he wrote a book about it. Not nuclear weapons, no, the big threat, the threat of the Earth getting hit by a giant meteor. We all know about the one that took out the dinosaurs, right? But that only happens every several millions years. Though it’s probably kind of random. In any case, the Earth — or, rather, the Earth’s atmosphere — is being smacked into by pretty good-sized rocks on a regular basis. The atom bomb that decimated Hiroshima was 15 kilotons; Nagasaki was 20. If a meteor hit the surface of the planet with that force, it would be intense.
The Defense Support Program (DSP-647) satellites, which operate in geosynchronous orbit thirty-five thousand kilometers above the equator, carry infrared telescopes with sensitive imaging detectors designed to detect and track the heat from the engines of military ballistic missiles. … DSP satellites find that there are about a dozen ten- to twenty-kiloton explosions in the atmosphere per year … Between 1975 and 1992, the DSP system observed 136 large fireball entries [i.e., meteors], not one of which reached the surface of Earth intact. …
[A]nother American program for monitoring nuclear weapons tests has deployed ultrasensitive air-pressure sensors called microbarographs on the roofs of numerous American embassies and consulates around the world to detect the pressure waves of nuclear explosions. … [T]his network observed a major event on August 3, 1963, over the ocean between South Africa and Antarctica. This explosion, which reportedly had a yield of at least five hundred kilotons of TNT, was initially misidentified as a secret nuclear weapons test by South Africa or Israel; however, no radioactivity was deteced after the blast, and the nuclear explanation is clearly wrong.
And you thought atmospheres were just good for breathing — turns out one makes a damn good force field.
source:
Rain of Iron and Ice: the very real threat of comet and asteroid bombardment
by John S. Lewis
1996. Helix Books / Perseus Publishing
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