By Drog, Section News Posted on Thu Nov 21, 2002 at 03:40:09 AM PST
SpaceRef.com reports (along with just about everyone else) that the odds of a major asteroid impact is approximately 3x less likely than had been previously thought. In a paper submitted to Nature, Peter Brown, Canada Research Chair in Meteor Science and Assistant Professor in the Department of Physics & Astronomy at Western University, has revised the odds based on the study of 8 years worth of data collected from the United States Department of Defense and Department of Energy satellites, which were scanning the Earth for evidence of nuclear explosions.
In those eight years, nearly 300 optical flashes were detected, caused by small asteroids (one to 10 metres in size) exploding in the upper atmosphere. The revised estimate suggests Earth's upper atmosphere is hit about once a year by asteroids that release energy equivalent to 5 kilotons of TNT. Larger impacts, like the 10-megaton event that leveled 2000 square metres of forest in Tunguska, Siberia in 1908 (which would level New York City), should occur once every 1000 years. This is better than the old ground-based estimate of 300 years.
Well I'll sleep better tonight, let me tell you. How much would anyone like to wager, though, that as a result of this study, it will now be even more difficult to convince government officials to spend any money on devising asteroid defence systems?
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