Don't Look Up

On this day in history thirteen years ago a meteor entered the atmosphere above Chelyabinsk Oblast in the southern Ural region of Russia.  It exploded with the force estimated to be more than thirty times that of the nuclear device used on Hiroshima.  

Likely originating from the asteroid belt located between Mars and Jupiter it was estimated to be approximately 60 feet in diameter and 9100 tons.  Its approach to earth was a shallow trajectory with an estimated speed of 43,000 miles per hour.  The blinding light was visible up to 60 miles distant and exploded in an air burst at an altitude of about 18 miles (97,000 feet).  Remarkably, nobody saw it coming as its radiant (direction of approach) was from the sun.  

Even more remarkable, there were no deaths; although, almost 1,500 individuals sought medical treatment for injuries mostly from indirect injuries (broken glass) as a consequence of the shock waves from the blast.  7,200 buildings in six cities across the region were damaged. 

In the aftermath of the air burst a significant number of small meteorites fell in areas west of Chelyabinsk; described as gravel falling from the sky. In 2013 Russian scientists identified a two foot sized chunk buried in the muddy bottom of Lake Chebarkul.  It was recovered, broke the scales used to weigh it and split into three pieces.  

This meteor event is the largest known object to have entered the atmosphere since the Tunguska event in 1908 which destroyed a large forested area in a remote part of Siberia.