Thursday, November 07, 2013
A new, DEVASTATING Chelyabinsk METEOR STRIKE: '7x as likely' as thought
"If you look at the number of impacts detected by US government sensors over the past few decades you find the impact rate of kiloton-class objects is greater than would be indicated by the telescopic surveys," said Bill Cooke, meteoroid environment office lead at NASA’s Marshall Space Flight Center at a press conference on Wednesday.
"Over the past few decades we've seen an impact rate about seven times greater than the current state of the telescopic surveys would indicate."
Cooke said that as the current state of asteroid surveys was expanded he expected we would find more meteorites in the vicinity to account for these impacts, but also that the amount of damage they caused was being reassessed.
The nuclear model used to estimate the amount of explosive force such incidents could cause had, in fact, been over estimating the blast impacts of such air-bursting meteors, he explained. But the amount of heat they generate, and the damage caused by the shockwave of air they push before them as they come down through the atmosphere, was significantly underestimated.
The Chelyabinsk meteor is the largest foreign body to come down to Earth since the Tunguska event in 1908, where a comet or meteor devastated 2,150 square kilometers of Siberia with an airburst, according to Lindley Johnson, NEO program executive of NASA's planetary science division. Read More