Historic Event in Astronomy

Today, Friday 15th February 2013.  Russia’s Ural mountains.  A fireball streaks through the clear morning sky.  Loud bangs follow.  A meteor crashes in Russia about 1,500 kilometres (930 miles) east of Moscow.  As the shockwave blows out windows and rocks buildings, it injures at least 950 people, the BBC News reports.  Most of those hurt from the Chelyabinsk region where the meteor fell, suffered cuts and bruises.

10 Tonne Hot Rod Above Russian Skies

The Russian Academy of Sciences estimates that the meteor weighed about 10 tonnes and entered the Earth’s atmosphere at a speed of at least 54,000 kilometres per hour (33,000 miles per hour).  It would have shattered about 30-50 kilometres (18-32 miles) above ground, with most of the meteor burning up.  Although the meteoroid appears to have burst in mid-air rather than hit the Earth’s surface, this event is still referred to as an impact. 

Tunguska Impact, 1908

The Tunguska event is the largest impact event on or near Earth in recorded history.  The shock wave of the resulting explosion is estimated to have measured 5.0 on the Richter scale.

Estimates of the energy of the blast are thought to be equivalent to a 10–15 megatons TNT explosion.  About 1,000 times more powerful than the atomic bomb dropped on Hiroshima, Japan!

By comparison, today’s impact event was relatively small…