Ras Tanura (meteorite)
Coordinates: 26 ° 40'0 " N , 50 ° 9'0 " O Ras Tanura is a meteorite that was found in 1961 on the site of an oil loading terminal in Ra's Tanura in eastern Saudi Arabia .
history
In the early afternoon of February 23, 1961, after a bang in the sky near the town of Ra's Tanura, a particularly bright meteorite, a so-called bolide , was seen flying from south to north. In the cloudless sky, the bolide left a dense white cloud with a diameter of about 2 ° and a jagged glowing trail. The glowing trail disappeared about ten minutes after the bolide had passed, and the cloud could be seen for about 30 minutes. During this time the cloud moved about 15 ° to the east and was at about 60 ° altitude. The flight of the bolide was accompanied by a booming noise, like a drawn-out thunder that turned into a rumble. This description comes from an eyewitness from Dharan , about 40 kilometers south of the impact site. Another eyewitness testified that the meteorite was dug out of the ground about 12 minutes after the rumble had subsided. At that time it was 11:42 am GMT , which is 2:42 pm local time in Saudi Arabia.
The find took place on the South Pier , an oil loading terminal, the oil refinery of the Arabian-American Oil Company . Another eyewitness reported that he saw a fountain of water in the sea shortly after the explosion, so it can be assumed that the bulk of the meteorite fell into the Arabian Gulf .
The stone found was sent by ARAMCO as an unidentified flying object to Wright-Patterson Air Force Base and from there to the Smithsonian Astrophysical Observatory and from there to the research department of the meteorite collection of the National Museum of Natural History . There the stone has the catalog number USNM # 2171.
Appearance and classification
It concerns with the found object to a stony-iron - chondrite Class H6 weighing 6.1 grams with the appearance of a crusty stone. It is the only piece that has been found from the meteorite.
In an article by Brian Harold Mason in Smithsonian Contributions to the Earth Sciences # 19 from 1977, olivine and orthopyroxene are named as the main minerals of the meteorite , with other components that occur in smaller quantities, such as plagioclase and troilite as well as chromite and whitlockite .
The orthopyroxenes have a calcium oxide content of 0.75% and <0.1% sodium oxide , 0.10% titanium (IV) oxide and 0.14% chromium (III) oxide . Associated with orthopyroxenes, Diopside was found to have a proportion of 0.53% sodium oxide, 0.31% titanium (IV) oxide and 0.73% chromium (III) oxide.
In the section you can see many slightly rusty metal inclusions in a pale gray environment with no visible chondrons (silicate spheres). In a fine section, the asteroid shows an allotriomorphic-granular structure.
Web links
- Ras Tanura in the Meteorological Bulletin Database
Individual evidence
- ^ Report by John A. Wood (Cambridge, United States) in a letter to Evgeni Leonidowitsch Krinow dated March 30, 1961 (English; PDF , 151kB)
- ^ A b c Brian Mason: The RAS Tanura, Saudi Arabia, chondrite . Article in Smithsonian Contributions to the Earth Sciences, no.19, 1977, p .83