Accession Number:

AD0435703

Title:

MINERALOGY OF THE OXIDATION PRODUCTS OF THE SPUTNIK 4 FRAGMENT AND OF IRON METEORITES

Descriptive Note:

Corporate Author:

SMITHSONIAN ASTROPHYSICAL OBSERVATORY CAMBRIDGE MA

Personal Author(s):

Report Date:

1963-05-22

Pagination or Media Count:

12.0

Abstract:

The melted and oxidized products on the Sputnik 4 fragment make up 10 to 15 of the total mass and consist of droplets of alpha iron, coated with the iron oxides wustite magnetite and akaganeite and the magnesium oxide periclase. This assemblage of minerals reflects nonequilibrium conditions of rapid cooling from above 1535 C, the melting point of iron to below 80 C, the temperature region in which akaganeite can form as a metastable variety of iron oxyhydroxide. A reexamination of the crust during the fifth month after recovery showed that the akaganeite and some of the wustite had been oxidized to hematite. Wustite and akaganeite are metastable at surface temperatures and are therefore virtually unknown in terrestrial rocks and in meteorites. Their discovery of the Sputnik 4 fragment, however, led to the investigation, by X-ray diffraction procedures, of the crusts of numerous iron meteorites. Wustite was identified in association with magnetite in the fusion crust of the Bogou iron that fell in Upper Volta in August 1962, and of several older irons including the Braunau, Czechoslovakia, hexahedrite that fell in 1847. Akaganeite was found among the alteration products of weathered iron meteorites.

Subject Categories:

  • Astronautics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE