Ion microprobe isotopic measurements of individual interplanetary dust particles

摘要: Ion microprobe measurements of D/H ratios in individual fragments eight stratospheric dust particles give δD values ranging from −386 to +2534‰ relative SMOW. The five far exceed those terrestrial samples and prove that the are interplanetary (IDPs). hydrogen isotopic composition is heterogeneous on a scale few microns demonstrating unequilibrated. Measurements conjunction with elemental molecular ion signals different IDPs show carbonaceous phase, not water, carrier D enrichments. Previous infrared transmission have shown fall into three main spectral classes. Particles two IR classes large ratios. Two studied third class do not. However, one these contains solar flare tracks extraterrestrial. Thus, most, but all, contain non-terrestrial composition. Carbon similar largely uniform for given particle. Small, significant, differences δ13C ~40‰ between seen. No correlations carbon compositions observed. The magnesium silicon found be normal within measurement errors.