Sikhote Alin Meteorite

Above: The front of the specimen card. The Sikhote Alin meteorite is classified as an iron meteorite in the IIAB group. This group has the lowest concentration of nickel in iron meteorites and is formed from the metallic core of a celestial body. The age of this group has been estimated using a radiometric dating process involving Rhenium-osmium isotopes, putting their formation at over 4 billion years ago. Above: Sikhote Alin specimens. This specimen is a complete Sikhote Alin meteorite. The specimen is housed in an acrylic jar that is encased within a glass-topped riker display box. The box measures 4 1/2" x 3 1/2". A small information card is also included, which serves as the certificate of authenticity. Please Note: The specimens vary in size and shape. Weight varies between 0.1 and 0.5 grams depending on the thickness of the piece. Specimens are selected for visible surface area and the product images are representative samples. About the Sikhote Alin Meteorite   "I saw blue flame sparkling in the sky because the meteorite was burning, and there were little fires trailing behind the main body. The windows of the bakery where I was working with my mother and brother trembled. A metal door of the oven flew open, and several hot charcoals fell out onto the floor." ~ Korney Shvets, an eyewitness of the descent.   Above: The sky after the meteor's descent was captured by artist Pyotr Medvedev. Medvedev had been preparing to paint a landscape when the arrival of an unexpected meteorite took him by surprise. He was able to record this moment with a painting of the massive smoke trail in the sky over the mountains. 10 years later, the Soviet Union would issue a stamp with a reprinting of Medvedev’s painting to commemorate the anniversary of the impact. Late in the morning on February 12th, 1947, a ball of light as bright as the sun-streaked over the Sikhote Alin Mountains in the Soviet Union. In homes below this meteorite’s path, walls shook, windows shattered, and doors flew open. As it descended, the object broke apart in a mid-air explosion. This airburst caused momentary blindness and the appearance of secondary shadows of objects within its light. The final impact emitted a booming explosion that was heard and felt for nearly 200 miles. Estimated to have a pre atmospheric mass of 220,000 pounds (100,000 kg) and a post atmospheric mass of 51,000 pounds (23,000 kg), the Sikhote Alin meteorite is one of the largest meteorite falls observed in recorded history. As it traveled at over 8 miles a second (14 km/s), the meteorite left a trail of smoke in its wake approximately 20 miles long (32 km) that remained in the sky for hours after impact. About three miles above the ground, the meteorite shattered in a powerful airburst explosion, causing a rain of debris. The area covered by this shower, or strewn field, is estimated to have had an area of half a mile. Fragments from this explosion were driven into trees and in one case created an impact crater 85 feet (26 m) across and 20 feet (6 m) deep. Above: Macro image of Sikhote Alin Specimens of the Sikhote Alin Meteorite come in two varieties: the smooth regmaglypts and the fragmented shrapnels. The regmaglypts show a glossy fusion crust and a thumbprint-like ablation pattern formed from the intense heat and pressure of atmospheric entry. The shrapnel specimens are sharp pieces of metal that were likely torn off from the meteorite during the airburst or on impact with the ground. Further Reading Fantucci, R., Mario Di Martino, and Romano Serra. "Tree-Ring Dating of Meteorite Fall in Sikhote-Alin, Eastern Siberia - Russia." International Journal of Astrobiology, vol. 11, no. 1, 2012, pp. 37-42.  Fisher, David E. “‘Ages’ of the Sikhote Alin Iron Meteorite.” Science, vol. 139, no. 3556, 1963, pp. 752–753. Smoliar, M.I., Walker, R.J., Morgan, J.W. “Re-Os Isotopic Constraints on the Crystallizations History of IIAB Iron Meteorites.” Lunar and Planetary Science, vol. 28. 1997.   Above: The back of the specimen card.