PBS Nova - Meteor Strike (2013).
It was YouTube's single most watched online video event of all time. On the morning of February 15th 2013, car cameras and cellphones captured a blinding streak that flashed across the sky over Russia's Ural Mountains, followed by an explosion that injured some 1,500 people and damaged buildings in six cities. According to NASA, the Siberian meteor–the size of a small house and weighing around 10,000 tons–was the largest object to burst in the atmosphere since the massive Tunguska event of 1908. Within days, NOVA crews were in Chelyabinsk Russia following impact scientists as they hunted for debris from the explosion and clues to the meteor's origin. Besides this on-the-spot report, Siberian Fireball explores the evidence for far greater explosions in the past–from Tunguska to the asteroid that extinguished the dinosaurs 65 million years ago. With the U.S. spending an average of only about $3 million a year on asteroid detection, what are the chances that a massive impact will strike us without warning, as the Siberian meteor did?