Physical Properties of Meteorites

The surfaces of freshly fallen meteorites contain evidence of aerodynamic sculpturing during their passage through the atmosphere and of selective ablation of inclusions such as troilite nodules that may leave cavities on the surface of the specimen. Most stony meteorite specimens have a smooth surface that may be modified in some cases by being nodular, striated, ribbed, porous, or even scoriaceous (Mason 1962, p. 44-45). The surfaces of many iron meteorites contain shallow depressions resembling thumb prints 

The presence of a fusion crust, the color and shape of the surface, the presence of metallic grains, and the unusual densities, in most cases, permit meteorite specimens to be distinguished from terrestrial boulders. These criteria apply to meteorite specimens that occur not only in the cold desert of Antarctica, but also to those that are collected in the hot deserts of the world, and in all other places where meteorites can be found. Even though tens of thousands of meteorite specimens have been collected on the East Antarctic ice sheet, Antarctica is not receiving a higher flux of meteorites compared to other areas of the Earth. The apparent abundance of meteorites is caused primarily by their better preservation in the ice and by the dynamics of the East Antarctic ice sheet. 

The cardinal rule of meteorite collecting in Antarctica and elsewhere is When in doubt, collect it and let the experts decide whether it is a meteorite. However, the scientific value of meteorites can be compromised if they are not collected properly. Therefore, ANSMET has recommended a simple procedure for collection meteorites in Antarctica and for documenting the collecting site  

Place the specimen into a clean plastic bag by using a clean knife or scissors without touching it with bare or gloved hands. 

Identify the outside of the sample bag by a number and mark the collecting site and sample number on a map or aerial photograph. 

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