Elemental abundances in interplanetary dust

The paper reports on measurements taken of elemental abundances in two interplanetary dust grains. Meteoroidal residue found inside micrometeoritic craters was discovered by optically scanning the 800 sq cm aluminum surface of the S-228 transuranic cosmic-ray experiment exposed to space for 67d during the Skylab-IV mission. Crater analyses for two randomly sampled meteoroids showed a composition consistent with troilite in the 9 micron-minute particle. Chondritic abundances were found in the 30 micron-minute particle. Particles of similar size and chemistry were common in carbonaceous chondrite meteorites. The inferred grain sizes within the 30 micron-minute particle provided evidence for the similarity to carbonaceous chondrites rather than to other meteorite types.