Meteor Crater
Interesting facts
- The impact released energy estimated at about 10 megatons of TNT, and recent modelling puts the meteorite's speed at roughly 12.8 km per second.
- About half of the iron body is thought to have vaporised in the atmosphere before it ever reached the ground.
- The blast flipped the rock layers around the rim upside down, so the oldest strata now lie on top for up to two kilometres from the edge.
- Beneath the crater floor lies 210 to 240 metres of shattered rubble above the original bedrock.
- In 1891 the mineralogist Albert Foote found microscopic diamonds inside iron fragments collected around the crater.
- Daniel Barringer spent 27 years hunting for a buried iron mass he estimated at 10 million tons, drilling as deep as 419 metres.
- In 1929 the astronomer Forest Ray Moulton calculated that the impactor would have vaporised on contact; Barringer died ten days after Moulton's second report.
- G. K. Gilbert, who rejected an impact origin here, was in 1892 among the first scientists to argue that the Moon's craters were made by impacts.
- Scientists used craters left by atmospheric nuclear tests, such as Sedan, to set upper and lower limits on the energy of the impact.
Why it is worth it
Meteor Crater, also called Barringer Crater, is the best-preserved meteorite crater on Earth, a bowl about 1,200 metres across and 170 metres deep in the high desert of northern Arizona. Its rim rises some 45 metres above the surrounding plain, and its outline is curiously squared off, a result of the joints that already cracked the rock layers when the impact came. The crater was punched out about 50,000 years ago, when the Colorado Plateau was cooler and wetter, a grassland with woods where mammoths and giant ground sloths roamed. The impactor was a nickel-iron meteorite about 50 metres wide, and its fragments are known as the Canyon Diablo meteorite.
The crater's story is also a story of scientific argument. The geologist G. K. Gilbert concluded that it was not an impact crater, finding no buried mass of iron. The mining investor Barringer was convinced of an impact and spent much of his fortune drilling for the iron he believed lay under the floor; he never found it, because most of the meteorite had vaporised on impact. Proof came in the twentieth century, when Eugene Shoemaker identified shocked quartz minerals, coesite and stishovite, that form only under the instantaneous pressures of an impact. The crater became a model for understanding craters across the Solar System.
NASA astronauts trained in the crater in the 1960s and 1970s to prepare for the Apollo landings, and training continues. The crater is still owned by the Barringer family and was designated a National Natural Landmark in 1967. A visitor centre on the north rim has exhibits on meteorites and space, a boilerplate Apollo command module and a 1,406-pound meteorite found nearby, and meteorite fragments from the crater that can be touched.
Getting there
The crater lies just off Interstate 40, about 60 km east of Flagstaff and about 29 km west of Winslow. The nearest airport is Flagstaff Pulliam (FLG), about 60 km away.
On these lists
From the encyclopaedia
Meteor Crater, or Barringer Crater, is an impact crater about 37 mi (60 km) east of Flagstaff and 18 mi (29 km) west of Winslow in the desert of northern Arizona, United States. The site had several earlier names, and fragments of the meteorite are officially called the Canyon Diablo Meteorite, after the adjacent Canyon Diablo.
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