[1] One of the features of the crater is its squared-off outline, believed to be caused by existing regional jointing (cracks) in the strata at the impact site.

[9] 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.

[10][11] The area was an open grassland dotted with woodlands inhabited by mammoths and giant ground sloths.

[26][27] Several years earlier, Foote had received an iron rock for analysis from a railroad executive.

His paper to the Association for the Advancement of Science provided the first geological description of Meteor Crater to a scientific community.

[28] In November 1891, Grove Karl Gilbert, chief geologist for the U.S. Geological Survey, investigated the crater and concluded that it was the result of a volcanic steam explosion.

Gilbert's calculations showed that the volume of the crater and the debris on the rim were roughly equivalent, which meant that the mass of the hypothetical impactor was missing.

[30] Mining engineer and businessman Daniel M. Barringer suspected that the crater had been produced by the impact of a large iron meteorite.

Barringer had amassed a small fortune as an investor in the successful Commonwealth Mine in Pearce, Cochise County, Arizona.

[29] The metal content of the iron meteorites found around the crater was valued at the time at US$125/ton, so Barringer was searching for a lode he believed to be worth more than a billion 1903 dollars.

He received a land patent signed by Theodore Roosevelt for 640 acres (1 sq mi, 260 ha) around the center of the crater in 1903.

[35][36][22] In 1906, at his request, President Roosevelt also authorized the establishment of a post office unconventionally named "Meteor", located at Sunshine, a stop on the Atchison, Topeka and Santa Fe Railway, 6 miles (9.7 km) north of the crater.

Moulton was employed by the Barringer Crater Company to investigate the physics of the impact event.

Apparently an idea, too radical and new for acceptance in 1905, no matter how logical, had gradually grown respectable during the intervening 20 years.

He also conducted a wide range of research at the crater, discovering impactite, iron-nickel spherules related to the impact and vaporization of the asteroid, and the presence of many other features, such as half-melted slugs of meteoric iron mixed with melted target rock.

[44] Nininger's extensive sampling and fieldwork in the 1930s and 40s contributed significantly to the scientific community's acceptance of the idea that Meteor Crater formed by the impact of an asteroid.

Nininger hoped that a public museum could be built on the crater's rim, and that the project might lead to the founding of a federal institute of meteorite research.

A key discovery was the presence in the crater of the minerals coesite and stishovite, rare forms of silica found only where quartz-bearing rocks have been severely shocked by an instantaneous overpressure.

The pieces of Canyon Diablo meteorite found scattered around the site broke away from the main body before and during the impact.

[48] Shoemaker published his conclusions in his 1974 book, the Guidebook to the geology of Meteor Crater, Arizona.

[60] In 2006, a project called METCRAX (for METeor CRAter eXperiment) investigated "the diurnal buildup and breakdown of basin temperature inversions or cold-air pools and the associated physical and dynamical processes accounting for their evolving structure and morphology.