WABAR

A massive meteoric aerial burst equal to ~12 kilotons lit up the sky over desert sands in the Empty Quarter of the Rub' al Khali, Saudi Arabia, at a site known as Wabar. This name is a transliteration of Ubar, but is not the actual site of the legendary lost city that was rediscovered in 1992, 400 km south of the Wabar site. The Wabar impact site was known to the local Bedouins for generations but remained undescribed until visited by the British explorer H. Philby in 1932, and later surveyed by E. Shoemaker and J. Wynn in 1994–95.

Found dispersed in and around three impact craters situated on 125 acres of desert sands was black glass, white impactite rock containing coesite, and remnants of iron-nickel that were spalled off of the impacting body. The largest mass, which was recovered 400 m south-southwest of the largest crater, is a shield-shaped, aerodynamically-oriented, fusion-crusted, 2.43-ton mass known as the Camel's Hump. Several other multi-kg masses, as well as numerous small, twisted fragments, such as the 14.1 g specimen pictured above, have been found on the surface. Additional meteorite remnants uncovered below the sand have been completely weathered to shale. Wabar is a member of the IIIAB group of irons and displays a medium Thomson (Widmanstätten) structure.

Black glass splattered from the impact surrounds the crater rims, and tiny glass droplets like the one pictured below were found about a half mile northwest of the crater, indicating that a wind was blowing from the southeast at the time of the fall. This is consistent with the prevailing wind conditions during the early evening hours in early Spring. These glass droplets, known as "pearls", are composed of 90% local sand and 10% microscopic particles of iron-nickel.

It is estimated that the original mass weighed at least 3,500 tons and the largest impacting fragment was ~9 m in diameter. The impactite distribution pattern indicates that the object arrived from the northwest at a shallow angle. From measurements of the rate of infilling of the craters by sand, as well as through TL studies, it is estimated that the fall occurred between 235 and 416 years ago, or an average of 289 (±46) years ago. While there is some testimony that the fall could be associated with a witnessed event that occurred in 1863, current evidence suggests an earlier fall. Notably, two historical poems written by separate authors have been found which describe the fall of a fireball over Tarim, a town located ~600 km southwest of the Wabar site (H. Basurah, MAPS 38, No. 7, Suppl., 2003). In these poems, the authors specify that the fall occurred on a Saturday night, September 1, 1704 (in equality with the Islamic calendar), which is ~300 years ago, in excellent accord with the TL data. Of the nearly two hundred craters discovered on Earth, the Wabar Crater is one of only seventeen to contain remnants of the original impacting object.

An iron pendant known as 'Qarabawi's Charm', which had been hung around a camel's neck by the Egyptian Ababda nomadic tribe to ward off evil, was sent by the Geological Museum in Cairo to the Smithsonian Institution in 1977 (Mayne et al., 2010). Careful studies verified its meteoritic origin having a Ni content of 6.8%. An extensive comparitive search of all middle-east irons revealed that Wabar has an identical Ni content, and may be the source material of the Camel Charm.

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