Feb 152013
 

According to JPL:

The meteor entered the atmosphere at about 40,000 mph (18 kilometers per second). … The size of the object before hitting the atmosphere was about 49 feet (15 meters) and had a mass of about 7,000 tons.

Plugging in the mass and velocity, we get a kinetic energy of 1134000000000000 joules. This works out to the equivalent of 271 kilotons.

There are a number of “bomb effects calculators” online that will show you what sort of damage you can expect from what sort of yield. Here’s one, putting a 271 kiloton blast in default New York City (apparently the Gold Standard in places to blow up):

newk york

Note that it puts an overpressure of 0.25 psi – what will blow out most windows – at a distance of 12 miles, much greater than the 50 km or so distances for such damage in Russia. Of course the Russian blast was at much greater altitude… that would certainly play into the effects. Exactly *how,* I’m a little unclear on.

The old-school Nuclear Bomb Effects Computer gives roughly equivalent results… for a 271 kton air blast, range to .25 psi is about 14 miles.

It should, I hope, concern everyone that a chunk of space debris massing 7,000 tons – more than a Los Angeles class attack sub – and about 15 meters across apparently managed to completely evade detection until it hit the atmosphere.

 Posted by at 4:00 pm