Meteor Crater

Meteor Crater is a meteorite impact crater approximately 37 miles (60 km) east of Flagstaff and 18 miles (29 km) west of Winslow in the northern Arizona desert of the United States. The site had several earlier names, and fragments of the meteorite are officially called the Canyon Diablo Meteorite, after the adjacent Cañon Diablo.[2] Some sources refer to the crater as Barringer Crater because Daniel M. Barringer was one of the first people to suggest that it was produced by meteorite impact, and because the Barringer family filed mining claims on the crater and purchased the crater and its surroundings in the early 20th century.[3][4] Despite historic attempts to make the crater a public landmark, the crater remains privately owned by the Barringer family to the present day.[5] Because the United States Board on Geographic Names recognizes names of natural features derived from the nearest post office, the feature acquired the name of "Meteor Crater" from the nearby post office named Meteor.[6]

For meteorite-created craters in general, see Impact crater.
"Barringer Crater" redirects here. For the crater on the Moon, see Barringer (lunar crater).
Meteor Crater
Barringer Crater
Meteor Crater, also known as Barringer Crater
Impact crater/structure
ConfidenceConfirmed[1]
Diameter0.737 miles (1.186 km)
Depth560 feet (170 m)
Rise148 feet (45 m)
Impactor diameter160 feet (50 m)
Age50,000 years
ExposedYes
DrilledYes
Bolide typeIron meteorite
Location
LocationCoconino County, Arizona
Coordinates35°1′38″N 111°1′21″W
CountryUnited States
StateArizona
Meteor Crater
Location of Meteor Crater in Arizona
AccessInterstate 40
DesignatedNovember 1967
The Holsinger meteorite is the largest discovered fragment of the meteorite that created Meteor Crater and it is exhibited in the crater visitor center.

Meteor Crater lies at an elevation of 5,640 ft (1,719 m) above sea level.[7] It is about 3,900 ft (1,200 m) in diameter, some 560 ft (170 m) deep, and is surrounded by a rim that rises 148 ft (45 m) above the surrounding plains. The center of the crater is filled with 690–790 ft (210–240 m) of rubble lying above crater bedrock.[1] One of the interesting 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.[8]

The crater is privately owned by the Barringer family through their Barringer Crater Company, which proclaims it to be the "best preserved meteorite crater on Earth".[9][10] Since the crater is privately owned, it is not protected as a national monument, a status that would require federal ownership. It was designated a National Natural Landmark in November 1967.[11]

Formation

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.[12][13] The area was an open grassland dotted with woodlands inhabited by mammoths and giant ground sloths.[14][15]

The object that excavated the crater was a nickel-iron meteorite about 160 feet (50 meters) across. The speed of the impact has been a subject of some debate. Modeling initially suggested that the meteorite struck at up to 45,000 mph (20 km/s) but more recent research suggests the impact was substantially slower, at 29,000 mph (12.8 km/s). It is believed that about half of the impactor's bulk was vaporized during its descent through the atmosphere.[16] Impact energy has been estimated at about 10 megatons TNTe. The meteorite was mostly vaporized upon impact, leaving few remains in the crater.[17]

Since the crater's formation, the rim is thought to have lost 50–65 ft (15–20 m) of height at the rim crest as a result of natural erosion. Similarly, the basin of the crater is thought to have approximately 100 ft (30 m) of additional post-impact sedimentation from lake sediments and of alluvium.[18] These erosion processes are the reason that very few remaining craters are visible on Earth, since many have been erased by these geological processes. The relatively young age of Meteor Crater, paired with the dry Arizona climate, have allowed this crater to remain almost unchanged since its formation. The lack of erosion that preserved the crater's shape helped lead to this crater being the first crater recognized as an impact crater from a natural celestial body.[19]

Discovery and investigation

The crater came to the attention of scientists after American settlers encountered it in the 19th century. The crater was given several early names including "Coon Mountain," "Coon Butte," "Crater Mountain," "Meteor Mountain," and "Meteor Crater."[20][21][22] Meteorites from the area were called Cañon Diablo meteorites, after Canyon Diablo, Arizona, which was the closest community to the crater in the late 19th century. The canyon also crosses the strewn field where meteorites from the crater-forming event were found. The crater had initially been ascribed to the actions of a volcanic steam explosion, because the San Francisco volcanic field lies only about 40 miles (64 km) to the west.[23]

Albert E. Foote

In 1891, the mineralogist Albert E. Foote presented the first scientific paper about the meteorites of Northern Arizona.[24] Several years earlier, Foote had received an iron rock for analysis from a railroad executive. Foote immediately recognized the rock as a meteorite and led an expedition to search and retrieve additional meteorite samples. The team collected samples ranging from small fragments to over 600 lb (270 kg). Foote identified several minerals in the meteorites, including diamond, albeit of little commercial value. His paper to the Association for the Advancement of Science provided the first geological description of the crater to a scientific community.[25]

Grove Karl Gilbert

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.[25] Gilbert had assumed that if it were an impact crater then the volume of the crater, as well as meteoritic material, should be extant in the rim. Gilbert also assumed a large portion of the meteorite should be buried in the crater and that this would generate a large magnetic anomaly. Gilbert's calculations showed that the volume of the crater and the debris on the rim were roughly equivalent, so that the mass of the hypothetical impactor was missing, nor were there any magnetic anomalies; he argued that the meteorite fragments found on the rim were coincidental. Gilbert publicized his conclusions in a series of lectures.[26] In 1892, however, Gilbert would be among the first to propose that the Moon's craters were caused by impact rather than volcanism.</ref>[27]

Daniel M. Barringer


Looking into the crater from the north rim. The rust colored area on the far (south) rim is where the last drilling for the meteorite occurred, in 1929. This is where Daniel M. Barringer believed the bulk of the meteorite was buried. Rock around the south rim is uplifted.

In 1903, mining engineer and businessman Daniel M. Barringer suggested that the crater had been produced by the impact of a large iron-metallic meteorite. Barringer's company, the Standard Iron Company, staked a mining claim to the land and received a land patent signed by Theodore Roosevelt for 640 acres (one square mile, or 2.6 km2) around the center of the crater in 1903.[28][29][4] The claim was divided into four quadrants coming from the center clockwise from north-west named Venus, Mars, Jupiter and Saturn. In 1906, Roosevelt authorized the establishment of a newly named Meteor, Arizona, post office (the closest post office before was 30 miles (48 km) away in Winslow, Arizona).[30] This new post office was located at Sunshine, a stop on the Atchison, Topeka and Santa Fe Railway six miles north of the crater.[31]

Closeup of old mine shaft at the bottom of the crater. The Barringer Crater Company has attached an astronaut cutout and flag to the fence (inset)          full size image

Standard Iron Company conducted research on the crater's origins between 1903 and 1905. It concluded that the crater had indeed been caused by an impact. Barringer and his partner, the mathematician and physicist Benjamin Chew Tilghman, documented evidence for the impact theory in papers presented to the U.S. Geological Survey in 1906 and published in the Proceedings of the Academy of Natural Sciences in Philadelphia.[32]

Barringer's arguments were met with skepticism, as there was a reluctance at the time to consider the role of meteorites in terrestrial geology. He persisted and sought to bolster his theory by locating the remains of the meteorite. At the time of discovery, the surrounding plains were covered with about 30 tons of large oxidized iron meteorite fragments. This led Barringer to believe that the bulk of the impactor could still be found under the crater floor. Impact physics was poorly understood at the time and Barringer was unaware that most of the meteorite vaporized on impact. He spent 27 years trying to locate a large deposit of meteoric iron, and drilled to a depth of 1,375 ft (419 m) but no significant deposit was ever found.[33]

Barringer, who in 1894 was one of the investors who made US$15 million in the Commonwealth silver mine in Pearce, Cochise County, Arizona, had ambitious plans for the iron ore.[34] He estimated from the size of the crater that the meteorite had a mass of 100 million tons.[26] Iron ore of the type found at 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.[34] "By 1928, Barringer had sunk the majority of his fortune into the crater — $500,000, or roughly $7 million in [2017] dollars."[35]

In 1929, astronomer F.R. Moulton was employed by the Barringer Crater Company to investigate the physics of the impact event. Moulton concluded that the impactor likely weighed as little as 300,000 tonnes, and that the impact of such a body would have generated enough heat to vaporize the impactor instantly.[36][37][38] Daniel M. Barringer died just ten days after the publication of Moulton's second report.

By this time, "the great weight of scientific opinion had swung around to the accuracy of the impact hypothesis...Apparently an idea, too radical and new for acceptance in 1905, no matter how logical, had gradually grown respectable during the intervening twenty years."[39]

Harvey H. Nininger
Fragment of the Cañon Diablo Meteorite

Harvey Harlow Nininger was an American meteoriticist and educator, and although he was self-taught, he revived interest in scientific study of meteorites in the 1930s and assembled the largest personal collection of meteorites up to that time. While based in Denver, Colorado, Nininger published the first edition of a pamphlet titled A Comet Strikes the Earth, which described how Meteor Crater formed when an asteroid impacted the Earth.[40] In 1942, Harvey Nininger moved his home and business from Denver, Colorado, to the Meteor Crater Observatory, located near the turn-off for Meteor Crater on Route 66.[41] He re-named the building the "American Meteorite Museum" and published a number of meteorite and Meteor Crater-related books from the location. 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 features still unique to the crater, such as half-melted slugs of meteoric iron mixed with melted target rock. Nininger's discoveries were compiled and published in a seminal work, Arizona's Meteorite Crater (1956).[42] 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 via the impact of an asteroid.[43]

Harvey Nininger believed that the crater should be nationalized, and, in 1948, successfully petitioned the American Astronomical Society to pass a motion in support. The Barringer family promptly terminated his exploration rights and ability to conduct further fieldwork at the crater.[44] To this day, Nininger is omitted from any display or reference at the privately-owned museum located on the crater rim.

Postcard from the American Meteorite Museum, near Meteor Crater, Arizona

Eugene M. Shoemaker
Meteor Crater from the southeast; the uplift around the rim can be seen.

Later research by Eugene Merle Shoemaker confirmed that the crater had formed due to a significant asteroid impact. 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. It cannot be created by volcanic action; the only known mechanisms of creating it are naturally through an impact event, or artificially through a nuclear explosion.[28][45] In 1960, Edward C. T. Chao and Shoemaker identified coesite at Meteor Crater, adding to the growing body of evidence that the crater was formed from an impact generating extremely high temperatures and pressures. The impact would have vaporized much of the main body of iron mass, while the pieces of Canyon Diablo meteorite found scattered around the site, had broken away from the main body before impact.[46]

Geologists used the nuclear detonation that created the Sedan crater, and other such craters from the era of atmospheric nuclear testing, to establish upper and lower limits on the potential energy of the meteor impactor.[47]

Geology

The impact created an inverted stratigraphy, so that the layers immediately exterior to the rim are stacked in the reverse order to which they normally occur; the impact overturned and inverted the layers to a distance of one to two kilometers outward from the crater's edge.[48][49] Specifically, climbing the rim of the crater from outside, one finds:

Soils around the crater are brown, slightly to moderately alkaline gravelly or stony loam of the Winona series; on the crater rim and in the crater itself the Winona is mapped in a complex association with Rock Outcrop.[50]

Panoramic view from upper deck


Recent history
Meteor Crater, 2010

During the 1960s and 1970s, NASA astronauts trained in the crater to prepare for the Apollo missions to the Moon.[51][52]

Meteor Crater from 36,000 ft (11,000 m)

On August 8, 1964, a pair of commercial pilots in a Cessna 150 flew low over the crater. After crossing the rim, they could not maintain level flight. The pilot attempted to circle in the crater to climb over the rim. During the attempted climb out, the aircraft stalled, crashed and caught fire. It is commonly reported that the plane ran out of fuel, but this is incorrect. Both occupants were severely injured but survived their ordeal.[53] A small portion of the wreckage not removed from the crash site remains visible.[54]

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."[55][56]

Tourist attraction

Meteor Crater is a popular tourist attraction privately owned by the Barringer family through the Barringer Crater Company, with an admission fee charged to see the crater. The Meteor Crater Visitor Center on the north rim features interactive exhibits and displays about meteorites and asteroids, space, the Solar System, and comets. It features the American Astronaut Wall of Fame and such artifacts on display as an Apollo boilerplate command module (BP-29), a 1,406-pound (638 kg) meteorite found in the area, and meteorite specimens from Meteor Crater that can be touched. Formerly known as the Museum of Astrogeology, the Visitor Center includes a movie theater, a gift shop, and observation areas with views inside the rim of the crater. Guided tours of the rim are offered daily, weather permitting.[57]

See also

Notes
  1. "Barringer". Earth Impact Database. Planetary and Space Science Centre University of New Brunswick Fredericton. Retrieved 2008-12-30.
  2. La Pas, L. (1943). "Remarks on four notes recently published by C. C. Wylie", Popular Astronomy, vol. 51, p. 341
  3. Grieve, R.A.F. (1990) "Impact Cratering on the Earth", Scientific American, 262 (4), 66–73.
  4. Barringer, B. (December 1964). "Daniel Moreau Barringer (1860–1929) and His Crater (the beginning of the Crater Branch of Meteoritics)". Meteoritics. Meteoritical Society. 2 (3): 186. Bibcode:1964Metic...2..183B. doi:10.1111/j.1945-5100.1964.tb01428.x.
  5. Plotkin, H.; Roy S. Clarke Jr. (2010). "Harvey Nininger's 1948 attempt to nationalize Meteor Crater". Meteoritics & Planetary Science. 43 (10): 1741–1756. doi:10.1111/j.1945-5100.2008.tb00640.x.
  6. "J. P. Barringer's acceptance speech." Meteoritics, vol. 28, p. 9 (1993). Retrieved on the SAO/NASA Astrophysics Data System.
  7. Images of America: Meteor Crater (p. 107), Neal F. Davis, Arcadia Publishing, 2016. ISBN 978-1-4671-1618-3.
  8. Shoemaker, Eugene M.; Susan W. Kieffer (1979). Guidebook to the Geology of Meteor Crater, Arizona. Tempe, Arizona: Center for Meteorite Studies, Arizona State University. p. 45.
  9. "Barringer Meteorite Crater * Meteorites Craters and Impacts". Barringercrater.com. Retrieved 2010-03-16.
  10. "Meteor Crater". Meteor Crater. Retrieved 2012-11-24.
  11. "Barringer Meteor Crater". US Dept of Interior, National Park Service. Retrieved 19 February 2013.
  12. Roddy, D. J.; E. M. Shoemaker (1995). "Meteor Crater (Barringer Meteorite Crater), Arizona: summary of impact conditions". Meteoritics. 30 (5): 567. Bibcode:1995Metic..30Q.567R.
  13. Nishiizumi, K.; Kohl, C.P.; Shoemaker, E.M.; Arnold, J.R.; Klein, J.; Fink, D.; Middleton, R. (1991). "In situ 10Be-26Al exposure ages at Meteor Crater, Arizona". Geochimica et Cosmochimica Acta. 55 (9): 2699–2703. Bibcode:1991GeCoA..55.2699N. doi:10.1016/0016-7037(91)90388-L.
  14. Kring, David (1997). "Air blast produced by the Meteor Crater impact event and a reconstruction of the affected environment". Meteoritics and Planetary Science. 32 (4): 517–30. Bibcode:1997M&PS...32..517K. doi:10.1111/j.1945-5100.1997.tb01297.x.
  15. Kring, David. "Barringer Meteor Crater and Its Environment". Lunar and Planetary Institute. Retrieved 2014-02-12.
  16. Melosh HJ; Collins GS (2005). "Planetary science: Meteor Crater formed by low-velocity impact". Nature. 434 (7030): 157. Bibcode:2005Natur.434..157M. doi:10.1038/434157a. PMID 15758988. S2CID 2126679.
  17. Schaber, Gerald G. "The U.S. Geological Survey, Branch of Astrogeology—A Chronology of Activities from Conception through the End of Project Apollo (1960–1973)", 2005, U.S. Geological Survey Open-File Report 2005-1190. (PDF)
  18. Poelchau, Michael; Kenkmann, Thomas; Kring, David (2009). "Rim uplift and crater shape in Meteor Crater: Effects of target heterogeneities and trajectory obliquity". Journal of Geophysical Research. AGU. 114 (E1): E01006. Bibcode:2009JGRE..114.1006P. doi:10.1029/2008JE003235.
  19. "Meteorite Crater – The shape of the land, Forces and changes, Spotlight on famous forms, For More Information". scienceclarified.com.
  20. Farrington, O. C. (1906). "Analysis of "iron shale" from Coon Mountain, Arizona". American Journal of Science. 22 (130): 303–309. Bibcode:1906AmJS...22..303I. doi:10.2475/ajs.s4-22.130.303.
  21. Guild, Frank Nelson (1910). The Mineralogy of Arizona. The Chemical Publishing Co. – via Google Books.
  22. Fairchild, Herman L. (1907). "Origin of meteor crater (Coon butte), Arizona". GSA Bulletin. 18 (1): 493–504. Bibcode:1907GSAB...18..493F. doi:10.1130/GSAB-18-493.
  23. McCall, Gerald Joseph Home; Bowden, A. J.; Howarth, Richard John (17 August 2017). The History of Meteoritics and Key Meteorite Collections: Fireballs, Falls and Finds. Geological Society of London. ISBN 9781862391949 – via Google Books.
  24. Foote, A. E. (1891). "A new locality for meteoric iron with a preliminary notice of the discovery of diamonds in the iron". American Journal of Science. 42 (251): 413–417. Bibcode:1891AmJS...42..413F. doi:10.2475/ajs.s3-42.251.413. S2CID 131090443.
  25. Kring, David (2007). Guidebook to the Geology of Barringer Meteorite Crater. Houston, Texas: Lunar and Planetary Institute.
  26. "Crater History: Investigating a Mystery". The Barringer Crater Company. Archived from the original on 31 December 2017. Retrieved 19 February 2013.
  27. Burke, John G. (1986). Cosmic Debris: Meteorites in History. Berkeley: University of California Press. p. 276. ISBN 0520056515.
  28. Oldroyd, David Roger, ed. (2002). The Earth Inside and Out: Some Major Contributions to Geology in the Twentieth Century. Geological Society. pp. 28–32. ISBN 1-86239-096-7.
  29. McCall, G.J.H.; Bowden, A.J.; Howarth, R.J., eds. (2006). The History of Meteoritics and Key Meteorite Collections. Geological Society. p. 61. ISBN 978-1-86239-194-9.
  30. Hoyt, W. G. (1983). "1983Metic..18..159H Page 162". Meteoritics. 18 (2): 159. Bibcode:1983Metic..18..159H. doi:10.1111/j.1945-5100.1983.tb00586.x.
  31. Hoyt, William Graves (1987). Coon Mountain Controversies: Meteor Crater and the Development of Impact Theory. University of Arizona Press. ISBN 9780816509683.
  32. Barringer, D.M. (1906). "Coon Mountain and its Crater." Proceedings of the Academy of Natural Science of Philadelphia, 57:861–86. PDF
  33. Smith, Dean (1964). The Meteor Crater Story. Meteor Crater Enterprises, Inc. pp. 17–25. Bibcode:1964mcs..book.....F.
  34. Southgate, Nancy; Barringer, Felicity (2002). A Grand Obsession: Daniel Moreau and His Crater. Barringer Crater Co.
  35. "How Meteor Crater swallowed a fortune and strengthened a family". October 25, 1917. Retrieved 2020-02-02.
  36. Moulton, F. R. (August 24, 1929). Report on the Meteor Crater - I. Philadelphia: Barringer Crater Company.
  37. Moulton, F. R. (November 20, 1929). Report on the Meteor Crater - II. Philadelphia: Barringer Crater Company.
  38. Crowson, Henry L. (1971). "A method for determining the residual meteoritical mass in the Barringer Meteor Crater". Pure and Applied Geophysics. 85 (1): 38–68. Bibcode:1971PApGe..85...38C. doi:10.1007/bf00875398. S2CID 140725009.
  39. Barringer, Brandon (1964). "Daniel Moreau Barringer (1860-1929) and His Crater". Meteoritics. 2 (3): 183–200. Bibcode:1964Metic...2..183B. doi:10.1111/j.1945-5100.1964.tb01428.x.
  40. Nininger, Harvey Harlow (1942). A Comet Strikes the Earth. El Centro, California: Desert Magazine Press. ASIN B001O84HN8.
  41. Nininger, Harvey Harlow (1972). Find a falling star. New York: P.S. Eriksson. ISBN 0-8397-2229-X. OCLC 570546.
  42. Nininger, Harvey Harlow (1956). Arizona's Meteorite Crater. Sedona, Arizona: American Meteorite Laboratory. ISBN 978-0910096027.
  43. Artemieva N.; Pierazzo E (2010). "The Canyon Diablo impact event: Projectile motion through the atmosphere". Meteoritics & Planetary Science. 44 (1): 25-42. doi:10.1111/j.1945-5100.2009.tb00715.x.
  44. Plotkin, H.; Roy S. Clarke Jr. (2010). "Harvey Nininger's 1948 attempt to nationalize Meteor Crater". Meteoritics & Planetary Science. 43 (10): 1741–1756. doi:10.1111/j.1945-5100.2008.tb00640.x.
  45. Shoemaker, Eugene M. (1987). "Meteor Crater, Arizona", Geological Society of America Centennial Field Guide – Rocky Mountain Section.
  46. Levy, David (2002). Shoemaker by Levy: The man who made an impact. Princeton: Princeton University Press. pp. 69, 74–75, 78–79, 81–85, 99–100. ISBN 9780691113258.
  47. "Keyah Math – Numerical Solutions for Culturally Diverse Geology". keyah.asu.edu.
  48. Kring, David (2007). Guidebook to the Geology of Barringer Meteorite Crater, Arizona. Houston, Texas: Lunar and Planetary Institute.
  49. "Basic Stratigraphy of Barringer Meteor Crater". Department of Planetary Science, University of Arizona. Retrieved 19 February 2013.
  50. https://websoilsurvey.sc.egov.usda.gov/App/WebSoilSurvey.aspx
  51. "Apollo Lunar Training". nau.edu.
  52. Phinney, William (2015). Science Training History of the Apollo Astronauts. NASA SP -2015-626. p. 180,187,193,220,222,224,233–234,238,245.
  53. Harro Ranter. "ASN Aircraft accident 08-AUG-1964 Cessna 150 N6050T". aviation-safety.net.
  54. Plane Crash At Meteor Crater Revisited, September 1, 2008 Meteorite-times.com
  55. "University of Utah METCRAX page". Archived from the original on 2012-04-23.
  56. "METCRAX". utah.edu.
  57. "admissions - Meteor Crater". Meteor Crater. Retrieved 2018-01-16.
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