Origin of organic compounds on the primitive earth and in meteorites.

The role and relative contributions of different forms of energy to the synthesis of amino acids and other organic compounds on the primitive earth, in the parent bodies or carbonaceous chondrites, and in the solar nebula are examined. A single source of energy or a single process would not account for all the organic compounds synthesized in the solar system. Electric discharges appear to produce amino acids more efficiently than other sources of energy and the composition of the synthesized amino acids is qualitatively similar to those found in the Murchison meteorite. Ultraviolet light is also likely to have played a major role in prebiotic synthesis. Although the energy in the sun's spectrum that can be absorbed by the major constituents of the primitive atmosphere is not large, reactive trace components such as H2S and formaldehyde absorb at longer wavelengths where greater amounts of energy are available and produce amino acids by reactions involving hot hydrogen atoms. The thermal reaction of CO + H2 + NH3 on Fischer-Tropsch catalysts generates intermediates that lead to amino acids and other organic compounds that have been found in meteorites. However, this synthesis appears to be less efficient than electric discharges and to require a special set of reaction conditions. It should be emphasized that after the reactive organic intermediates are generated by the above processes, the subsequent reactions which produce the more complete biochemical compounds are low temperature homogenous reactions occurring in an aqueous environment.

A new theory of lunar magnetism.

In the hypothesis advanced here it is supposed that the field, in which rocks at the lunar surface acquired the remanent magnetization found through the Apollo project, arose from permanent magnetization of the deep interior of the moon. This theory involves the assumption that the moon, apart from a surface shell, accreted cold and remained below the Curie point of iron until sometime later than 3 x 10(9) years ago. The magnetization was acquired as the moon formed in a gas sphere in the strong magnetic field of the early sun.

Carbon compounds in Apollo 11 lunar samples.

Are they entrapped solar wind particles, meteoritic or cometary contributions, remnants of a primordial atmosphere or products of the degassing of the Moon ?

Organic compounds in lunar samples: pyrolysis products, hydrocarbons, amino acids.

Lunar fines and a chip from inside a rock pyrolyzed in helium at 700 degrees C gave methane, other gases, and aromatic hydrocarbons. Benzene/methanol extracts of fines yielded traces of high molecular weight alkanes and sulfur. Traces of glycine, alanine, ethanolamine, and urea were found in aqueous extracts. Biological controls and a terrestrial rock, dunite, subjected to exhaust from the lunar module descent engine showed a different amino acid distribution. Interpretation of the origin of the carbon compounds requires extreme care, because of possible contamination acquired during initial sample processing.

Solar wind gases, cosmic ray spallation products, and the irradiation history.

The isotopic abundances of the rare gases in the fines are found to be similar to those previously reported for gas-rich meteorites. Relative to the heavy gases, neon and helium are depleted by factors of 2.5 and 10 respectively. Accurate krypton-krypton ages for rocks 10017, 10047, 10057, and 10071 were obtained covering a range of from 47 to 509 x 10(6) years. Varying relative production rates of the krypton and xenon isotopes in these rocks suggest different irradiation conditions and a complex history for at least some of the rocks.

A review of evidence for biological material in meteorites.

The first carbonaceous chondrite fell in France in 1806, and in the years following analyses for organic matter were made which showed this material to be similar to material of biological origin. But the analyses were not conclusive. Within the last few years, additional work has been done which has proved to be very interesting and somewhat controversial. The composition of the inorganic fraction of these objects is very similar to that of other meteorites, showing that no sorting by sedimentary processes has occurred. For this reason, students of meteorites have believed that the material could not be biological. However, the soluble constituents are similar to those to be expected in a primitive ocean of the earth. Some of the assumed fossils have been shown to be contaminants but others appear to be indigenous. After mineral matters are removed from them they still show evidence of containing carbonaceous material. Micro-paleontologists have also reported material which they believe to be similar to terrestrial fossils. Fatty acids, porphyrins, and nucleic acid bases have been reported and a small optical activity as well. The immense difficulty that students of meteorites have in understanding this situation may be alleviated if it should be proved that some of our stone meteorites, including the carbonaceous ones, are coming from the moon. There seems to be some possibility that this could be true.