The largest meteorite crater in the world — evidence of fortunate circumstances, scientists say. The disaster, which led to its formation 50,000 years ago could have been much more serious. Jay Melosh (Jay Melosh) from the University of Arizona, and Gareth Collins (Gareth Collins), from Imperial College London in the journal Nature article, which revolutionized the course of a meteorite collision with the planet.
The collision and explosion occurred on the territory of the State of Arizona in the United States, with a crater diameter of 1.2 km and a depth of 150 meters. It was believed that the meteorite entered the Earth's atmosphere at a speed of about 20 kilometers per second — much faster than today's spaceships are displayed on the orbit. Ballistic analyzes in the middle of the last century showed that the culprit accident — a 20-meter outer body.
In this scenario, the meteorite would have melted and the melt rocks of the crater and surrounding area, but significant traces of this was found. The computer model, which was built Melosh and Collins, describes the fall of the heavier, slower and more "cold" meteorite. Because of the resistance of the atmosphere cosmic body begins to break down in the air, and its fragments are dispersed by the shock wave. The model was based on data from several expeditions discovered a fragment of a meteorite crater far abroad.
Scientists believe that 50,000 years ago the Earth was lucky encounter with a large space body (new estimate of the diameter — 40 meters, and weight — 300 tons) over a relatively "small" explosion capacity of 2.5 megatons. The site of the University of Arizona researchers presented a program that allows visitors to pick up on your own parameters to assess the impact of a meteorite and its fall.
Battery News, 14.03.2005 17:33