Editing Wabar craters (section)

==The expeditions==
[[File:Harry St. John Bridger Philby.jpg|upright|thumb|[[St John Philby]] in Riyadh]]

===1932 Philby===
The vast desert wasteland of southern Saudi Arabia known as the Empty Quarter, or ''[[Rub' al Khali]]'' in Arabic, is one of the most desolate places on Earth. In 1932, Harry St John "Jack" Philby was hunting for a city named [[Iram of the Pillars|Ubar]], that the [[Quran]] describes as having been destroyed by God for defying the Prophet [[Hud (prophet)|Hud]]. Philby transliterated the name of the city as Wabar.

Philby had heard of [[Bedouin]] legends of an area called ''Al Hadida'' ("place of iron" in Arabic) with ruins of ancient habitations, and also an area where a piece of iron the size of a camel had been found, and so organized an expedition to visit the site.  After a month's journey through wastes so harsh that even some of the camels died, on 2 February 1932 Philby arrived at a patch of ground about {{Convert|1/2|km2|mi2|spell=in}} in size, littered with chunks of white [[sandstone]], black [[glass]], and chunks of [[iron meteorite]]. Philby identified two large circular depressions partially filled with sand, and three other features that he identified as possible "submerged craters".  He also mapped the area where the large iron block was reputed to have been found.  Philby thought that the area was a volcano, and it was only after bringing back samples to the UK that the site was identified as that of a meteorite impact by [[Leonard James Spencer]] of the [[British Museum]].<ref>Philby (1933), pp 1-26</ref><ref>{{cite journal |url=http://rruff.geo.arizona.edu/doclib/MinMag/Volume_23/23-142-387.pdf |title=Meteoric Iron and Silica-Glass from the Meteorite Craters of Henbury (Central Australia) and Wabar (Arabia) |author=L. J. Spencer |journal=Mineralogical Magazine |volume=23 |issue=142 |date=September 1933 |pages=387–404 |doi=10.1180/minmag.1933.023.142.01|bibcode=1933MinM...23..387S }}</ref><ref>{{cite journal |url=http://rruff.geo.arizona.edu/doclib/MinMag/Volume_29/29-211-256.pdf |title=L. J. Spencer's work at the British Museum |author=W. Campbell Smith |journal=Mineralogical Magazine |volume=29 |issue=211 |date=December 1950 |issn=0026-461X |page=269 |doi=10.1180/minmag.1950.029.211.02|bibcode=1950MinM...29..256C }}</ref>

<blockquote>A volcano in the midst of the Rub' al Khali!  And below me, as I stood on that hill-top transfixed, lay the twin craters, whose black walls stood up gauntly above the encroaching sand like the battlements and bastions of some great castle.  These craters were respectively about 100 and 50 yards in diameter, sunken in the middle but half choked with sand, while inside and outside their walls lay what I took to be lava in great circles where it seemed to have flowed out from the fiery furnace. Further examination revealed the fact that there were three similar craters close by, though these were surmounted by hills of sand and recognizable only by reason of the fringe of blackened slag round their edges.<ref>Philby (1933), p. 13</ref></blockquote>

Amongst the samples of iron, cindery material, and silica glass that Philby brought back from the site was a {{Convert|25|lb|adj=on}} chunk of iron. Analysis showed it to be about 90% iron and 5% nickel, with the rest consisting of various elements, including copper, cobalt, and an unusually high concentration of [[iridium]], at 6 [[Parts-per notation#Parts-per expressions|ppm]]. This [[Goldschmidt classification#Siderophile elements|siderophile]] element implied that the Wabar site was a [[meteorite]] impact area.

===1937 Aramco===
In 1937, [[Saudi Aramco|Aramco]] geologists T. F. Harriss and Walton Hoag, Jr., also investigated the site, but, like Philby, were unable to locate the large block of iron.<ref name="aramco">{{cite journal | journal=Saudi Aramco World | issue=6 | first1=Z | last1=Bilkadi | url=http://www.saudiaramcoworld.com/issue/198606/the.wabar.meteorite.htm | title=The Wabar Meteorite | year=1986 | volume=37 | pages=26–33 | access-date=2008-07-19 | archive-date=2013-03-30 | archive-url=https://web.archive.org/web/20130330140110/http://www.saudiaramcoworld.com/issue/198606/the.wabar.meteorite.htm | url-status=dead }}</ref>

===1966 National Geographic and Aramco===
In 1966, reports came that the sands had shifted and the large iron block was again visible. ''[[National Geographic (magazine)|National Geographic]]'' journalist [[Thomas J. Abercrombie]] visited the site and found the large meteorite: "rumor has become a reality; the biggest iron meteorite ever found in Arabia lay at our feet&nbsp;... shaped roughly like a saucer, it measured about four feet in diameter and two feet thick at center. A little quick geometry puts its weight at almost two and a half tons."<ref name=thomas>Thomas J. Abercrombie, 1966, "Beyond the Sands of Mecca" ''National Geographic Magazine'', January 1966.</ref>

Later in October 1966, a group headed by Aramco employee James Mandaville visited the site with heavy lifting equipment. They found two large uncovered meteorites. The largest, weighing {{Convert|2045|kg}}, had a pitted, but roughly level, top surface about {{Convert|1|m|spell=in}} in diameter with one end formed into a cone shape when the meteorite penetrated the atmosphere like a bullet; it was embedded in sand, which had drifted over the top. It was photographed ''in situ'', then overturned by a bulldozer and lifted on board a trailer where it and another, smaller meteorite were taken to [[Dhahran]].<ref name=aramco/>

===1982 Aramco===
Mandaville visited the site twice after his 1966 visit.  On his last visit, in 1982, he noted that the desert winds and resultant movement of the dune system were covering the site: "instead of two thirds of the crater rim (visible as before [in 1966, 16 years earlier]), less than a quarter of it showed."<ref name=aramco/>

===1994–1995 Zahid Tractors===
In 1994 and 1995, a total of three expeditions were undertaken, sponsored by the Zahid Tractor Corporation. A [[United States Geological Survey]] scientist, [[Jeffrey C. Wynn]], joined all three expeditions, and astronomer and geologist [[Eugene Merle Shoemaker|Gene Shoemaker]] joined at least one.<ref>{{cite journal | first1=J.C. | last1=Wynn | url=http://volcanoes.usgs.gov/jwynn/1998SciAm-Wabar.pdf | title=The Day the Sands Caught Fire | last2=Shoemaker | first2=E.M. | journal=Scientific American | year=1998 | volume=279 | issue=5 | pages=36–45| doi=10.1038/scientificamerican1198-64 | bibcode=1998SciAm.279e..64W }}</ref>  These expeditions were made with modern off-road vehicles, but even with modern technology, the trips were difficult ones. Not only were conditions harsh, but the Wabar site was tricky to find, as it sits in the midst of an enormous dune field that has no fixed landmarks.