Meteor Crater General Information
Size of the crater: 1.2 km
Age: 50 000 years
Site: Arizona, USA; 35º1´38´´N 111º1´21´´W
Size of the body: 50 m
Velocity: 13 km/sec

Investigation History
As I have already stressed in my project, impact cratering is a very modern science field. It has been developing really fast during only the last century. The first link between a sizable terrestrial structure and a meteorite impact was established by D. M. Barringer in 1902, when he was trying to prove that Canyon Diablo Crater, Arizona, was of an impact origin. But investigation of the crater origin dates back to 1891, when G. K. Gilbert, a scientist who was one of the scientist to accept the impact origin of Lunar craters, tried to find any evidence of an extraterrestrial body in the crater. But though numerous fragments of meteoritic iron was found everywhere around the crater, Gilbert failed to find any body large enough to produce a crater.
Barringer’s interest in the crater began as a mining venture. Actually, as he has heard of the iron meteorites, young engineer proposed that a body to excavate the crater of 1.2 km in diameter should be approximately the same size. Barringer did believe that it is buried deep under the crater. So he hoped to excavate the body and get an enormous source of iron. Shafts of up to 419 m deep were excavated to find the body. For over 27 years Barringer had invested much money and dedication in his project. During that time span, several papers were published by Barringer and his colleagues, Tilghman and Moulton. Tilghman, along with Barringer, supposed in his paper in 1906 that though the body would possesses an extremely high speed (around 20 km/sec as estimated by Tilghman), it would still not carry enough energy to destroy completely after the impact. The most progress was made in 1929 by Moulton, who had discovered, that the crater could have been produced by a much smaller body than estimated firstly (about 70 times smaller). He had also realized that most of the meteorite iron would be vaporized as the result of the impact, not buried underneath the crater. Barringer, who didn’t want to agree that all his studies were a complete failure, started long and furious debated with Moulton, climaxed in Barringer’s death from heart failure. The engineer couldn’t stand the loss of his genuine project. Unfortunately, Moulton's theory didn’t gain much respect either, and was never published. But the first step was made.
By the time of his death, Barringer along with his co-researches has already proved to many scientists all over the world that crater formation can be not only due to volcanic activity, but also of impact origin. Debates on the subject continued up to 1950s, producing many works and researches on the subject, giving the strongest impetus to impact cratering. Though Barringer didn’t succeed in his investigation, scientists all over the world still do remember his name as of the scientist who started the impact cratering work. His name is now commemorated in the name of the crater, which was changed from Coon Mountain crater to Barringer Meteor crater.

Reconstruction of the impact
The crater was created about 50,000 years ago during the Pleistocene epoch when the local climate on the Colorado Plateau was much cooler and damper. At the time, the area was an open grassland dotted with woodlands inhabited giant woolly animals. It was uninhabited by humans, the first of whom are thought to have reached North America only around 13,000 years ago.
The object which excavated the crater was a nickel-iron meteorite about 50 meters across, which impacted the plain at a speed of 13-15 kilometers per second. The speed of the impact has been a subject of some debate. Modeling initially suggested that the meteorite struck at a speed of up to 20 kilometers per second, but more recent research suggests the impact was substantially slower, at probably of about 14 km/s because of substantial deceleration in atmosphere. It is believed that about half of the body’s 300,000 tons bulk was vaporized during its descent, before it hit the ground.
A lot of small (m-sized) fragments landed separately from the main body and could be found a few miles away from the crater as iron meteorites. The impact produced a massive explosion equivalent to at least 2.5 megatons of TNT – equivalent to a large thermonuclear explosion. The blast dug out 175 million tons of rock. Much more impact energy, equivalent to an estimated 6.5 megatons, was released into the atmosphere and generated a devastating above-ground shockwave. For a meteorite of its size, the impact melted surprisingly little rock, though it produced high enough temperatures and pressures to transform carbon minerals into diamonds. Debris from the impact has been found over an area of 260 km². The shock of the impact would have produced a localized earthquake of magnitude 5.5 or higher.

Ecological effect
The blast and thermal energy released by the impact would certainly have been lethal to living creatures within a wide area (certainly not as lethal as Chicxulub – all effects are LOCAL). All life within a radius of three to four kilometers would have been killed immediately. The impact produced a fireball hot enough to cause severe flash burns at a range of up to 10 km (7 miles). A shock wave moving out at 2,000 km/h (1,200 mph) leveled everything within a radius of 14-22 km (8.5-13.5 miles), dissipating to hurricane-force winds that persisted to a radius of 40 km (25 miles).Despite this destruction, the Barringer impact did not throw up enough dust to seriously affect the Earth's climate. The area was likely recolonized by the local flora and fauna within a century. This did not much affect the crater itself; its preservation was aided by the local climate's shift to its present-day arid conditions.

Cultural effect
There is clearly no need to repeat, that the discovery of impact origin of this very crater was the beginning of impact cratering as a whole. The new science was born. And still the contribution of the crater research to modern science is enormous. Numerous works on numerical modeling of the impact are conducted. It is quite important to mention, that this crater is a perfect and almost untouched example of a meteoritic crater on the Earth, so it was used as an example to many other impact crater models.
Another important fact to mention that during the “Cold War” just before the beginning of NASA Lunar program, Meteor crater was used as a training place for the astronauts. They practiced landing, walking and research work on the Moon at the crater, as the crater itself, rocks within the crater (subjected to high pressures during the impact) , and the desert around it are pretty much similar to one’s of the Moon. Many nowadays students interesting in impact cratering start their career in this crater as well.
Despite its importance as a geological site, it is not protected as a national monument, as it is still owned by the members of Barringer’s family.Meteor Crater is today a popular tourist attraction. Tours around the crater gain the enormous popularity. Examples of meteoritic iron can be purchased. So every person in the world interested in space can start his education here - in the birthplace of impact cratering.