Putting the Russian meteorite in perspective

Friday morning, a large meteor entered the atmosphere over the southern Ural area of Russia, detonating with enough force to shatter windows in nearby towns and injure over 1000 people.  Preliminary estimates suggest an impactor traveling at 15 to 20 km/s, and weighing 8000 to 10,000 tons, exploding at an altitude of 20-30 km with the force of a nuclear weapon. These are hard numbers to wrap