Organic compounds in meteorites—III. Distribution and identification of aliphatic hydrocarbons produced by open flow Fischer-Tropsch processes

Abstract

The possible abiotic synthesis of the aliphatic hydrocarbons in extraterrestrial samples was investigated, using as a model, the Fischer-Tropsch reaction between hydrogen and carbon monoxide. Iron of meteoritic origin, as well as commercial nickel and nickel-iron alloys, were used as the catalyst. This type of synthesis produced small amounts of saturated and unsaturated hydrocarbons ranging from C 8 to about C 26. The saturated hydrocarbons were found to be predominantly n-paraffins plus smaller amounts of methyl branched isomers (7-, 6-, 5-, 4-, 3-, 2-methyl alkanes). The individual concentrations of these synthetic hydrocarbons decrease continuously with molecular weight. Although n-alkanes and their monomethyl branched isomers have been detected by gas chromatographic-mass spectrometric techniques among the products of more than 60 experiments, no traces of isoprenoid hydrocarbons were found.