Meteorite explodes above Ural Mountains
Astronomy News – It was a typically slow Friday morning for workers in the Russian industrial city of Chelyabinsk just east of the Ural Mountains. Just after 9 a.m. Russian time, the Sun was hanging just above the horizon to the southeast. The air was cold and still and the sky clear; accept for a few high clouds, and contrails from passing jets.
The quiet morning would explode with the arrival of an unexpected guest. A significant lightening of the sky toward the rising sun was the first hint something was different. Seconds later light exploded in a blinding flash that moved across the sky from right to left. The ground seemed to rumble and rotate in time with naked shadows of buildings, cars, and lampposts.
The blinding glare from the smoking object started to subside as its smoke trail broke into two parallel smokers moving across the southern sky. The sky flared twice more in blinding flashes of intense light, before the objects disappeared over the southwestern horizon.
Shockwave impacts the ground
Three to four minutes after the blinding flash came streaking across the sky, a colossal tremor hit the region shattering windows and causing car alarms to blare and humans to cry and exclaim. Incredibly, no loss of human life would result from the event, although over 1,000 people were treated for related injuries.
Watch this YouTube video on the resultant shockwave after the passage of the Chelyabinsk meteorite https://www.youtube.com/watch?v=tq02C_3FvFo.
Superbolide by the numbers
NASA has coined the term “superbolide”, for the dazzling bolide that resulted from the passage of a meteorite through the Earth’s atmosphere on February 15, 2013. The meteorite travelled through the atmosphere at a shallow 7 degree descending angle from east to west that passed about 12 miles (20 km) south of Chelyabinsk, Russia. The superbolide occurred when the meteorite was at an altitude of around 76,400 feet (23,300 meters) and moving at a speed of 11.6 miles per second (18.6 km/s).
Force of friction between the atmosphere and meteorite slowed and heated it. The fast movement of the meteorite through the atmosphere also compressed the air in front of it, creating the colossal tremor that shattered windows on the ground. The compression also ionized atoms and molecules, which emitted the blinding flash seen in the Russian sky, when they recombined with the electrons that were stripped from them. This energy also broke up the meteorite and ultimately caused it to explode when the increasing internal pressure exceeded the object’s internal strength.
Watch this YouTube video of the passage of the Chelyabinsk meteorite https://www.youtube.com/watch?v=SMnZr5DDRlA.
Watch this NASA video on the aftermath of the Chelyabinsk meteorite https://www.youtube.com/watch?v=Q9KwK0izt5c.