What is Meteor Crater in Arizona?
Meteor Crater, also called Barringer Crater, is a bowl about 1.2 km wide and 170 m deep in the Arizona desert, blasted out around 50,000 years ago by an iron asteroid perhaps 50 m across.
In the dry plains of northern Arizona, east of Flagstaff, lies one of the best-preserved impact craters on Earth. Meteor Crater is a nearly circular bowl about 1.2 km across and around 170 m deep, with a rim that rises some 45 m above the surrounding land. Because the climate is dry and the crater is young, erosion has barely softened it.
It formed roughly 50,000 years ago, when an iron asteroid, perhaps 50 m across, struck at high speed. Most of the impactor was vaporised or melted in the explosion, but thousands of fragments were scattered across the surrounding desert. These are known as the Canyon Diablo meteorites, after a nearby canyon, and they are among the most widely collected iron meteorites in the world. The impact also overturned the layers of rock at the rim, so that older rocks now lie on top of younger ones.
The crater's origin was fiercely debated. In the early 1900s the mining engineer Daniel Moreau Barringer argued that it was made by an impact and spent years drilling in search of a huge buried iron mass that he hoped to mine. He never found it, because most of the impactor had not survived. Proof came in 1960, when the geologist Eugene Shoemaker and colleagues identified coesite, a form of silica created only at enormous pressures, in the crater's rocks. This was one of the first clear mineral signatures of an impact, and it helped found the modern science of impact cratering.
The crater is still owned by the Barringer family and is a popular visitor attraction with a museum. Apollo astronauts trained there before going to the Moon. Collecting meteorites on the site is not permitted, so enjoy them in the museum instead.