Beschreibung:

Dunite, Chassignite North West Africa – Morocco When asteroids strike the surface of the Moon or Mars, portions of these planetary bodies are jettisoned into space in much the same manner as when a child dives onto a bed and dust is launched into the air. There are no meteorites from Venus and the likelihood is rather remote given the high escape velocity necessary for such objects to overcome the thick Venusian atmosphere and gravitational field. The determination of the Martian origin of a meteorite is the result of research conducted by hundreds of scientists. To date the Meteoritical Bulletin has published findings on 43 distinct Martian meteorites—referred to in scientific literature as SNCs (for Shergotty, Nakla and Chassigny—the names of what were determined to be Martian meteorites seen to fall, respectively, in India, Egypt and France). Only 2 of the 43 Martian meteorites are Chassignites. One, of course, is Chassigny itself and the other is NWA 2737 (the 2,737th meteorite classified following recovery from a designated grid of the Sahara Desert in North West Africa)—from which a specimen is now offered. As would be expected, samples of the planet Mars possess a highly specific chemical signature. Martian meteorites possess water-bearing minerals (thereby eliminating the asteroid belt as a point of origin—the point of origin for 99.8% of known meteorites). Martian meteorites also reveal evidence of having crystallized fairly recently in a planetary-sized gravitational field (but smaller than Earth’s) with levels of cosmic radiation consistent with inner solar system origin. In 1995, The New York Times and Science magazine confirmed that a small sample of gas trapped in tiny glass-like bubbles within a suspected Martian meteorite perfectly matched the atmospheric composition of Mars (as determined by the unmanned Viking lander in 1976). More recently, the abundances of argon, krypton, xenon and heavy nitrogen found in other Martian meteorites also comport with the character of the Martian atmosphere. NWA 2737 is a fresh, highly shocked meteorite. It is rich in olivine and its dark coloration is a result of the shocking that occurred approximately 175 million years ago. The complete slice offered here also contains a new mineral never before seen. Pyroxene and carbonates are also present. The total known weight of NWA 2737 is barely more than one pound. More than twenty scientific abstracts have been published concerning NWA 2737. A bibliography of these abstracts and the first abstract that cites NWA 2737 in the Meteoritical Bulletin is included in this extremely noteworthy offering. For meteorite cognoscenti, an exotic specimen of the planet Mars that can only grace a handful of collections. Weighs 0.9 grams; Measures 1 x 1/2in