Criteria for identification of ablation debris from primitive meteoric bodies

Abstract

Samples of ablated materials are analyzed to determine properties expected to be characteristic of particulates generated by the ablation of primitive meteoric bodies. Analyses of carbonaceous chondrite fusion crusts and samples artificially ablated in the laboratory indicate that the majority of meteor ablation debris should consist of assemblages of silicate minerals, principally olivine, and micron-sized magnetite grains. It is expected that ablation debris of >10 μm should have abundances of Fe, Mg, Si, Ca, and Ni similar to those found in chondritic meteorites. Volatile species such as S, H2O, and Cl are lost during ablation and normally should not be found in ablated material. The major findings of this study are supported by the analysis of spherules collected in the atmosphere which are thought, on separate grounds, to be genuine meteor ablation products. The majority of meteoric bodies probably have cometary origins, and it is hoped that the ability to collect and reliably identify meteor ablation debris from terrestrial contaminants will provide an opportunity to do laboratory analysis on cometary matter.