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Urey, H. C.

Publications and source records attributed to Urey, H. C..

At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1977

The deficiency of siderophile elements in the moon

An attempt is made to reconcile a plausible origin of the moon with the observed deficiency of siderophile elements in the moon. A numerical analysis is performed which indicates that at least 1% metal was needed to extract nickel successfully from the moon and that the deficiency of lunar siderophiles can be explained on the basis of a fission hypothesis. It is suggested that leaching by liquid metallic iron caused the lunar deficiency and that the leaching took place in the protoearth from which the moon subsequently formed by fission.

Okeefe, J. A.↗
NASA NTRS1976

Origin of organic compounds on the primitive earth and in meteorites

The paper examines the role and relative contributions of different forms of energy to the synthesis of amino acids and other organic compounds on the primitive earth and in the solar nebula. Attention is directed mainly to the activation steps and formation of reactive intermediate compounds. Electric discharges appear to be not only the most efficient energy for amino acid synthesis but also yield a mixture of amino acids that is qualitatively and quantitatively the same as that found in the Murchison carbonaceous chondrite. Ultraviolet light is likely to have played a major role in prebiotic synthesis. The reaction of CO plus H2 plus NH3 on the surface of a Fischer-Tropsch catalyst produces reactive intermediates which lead to amino acids and other organic compounds in a much less efficient way than electric discharges.

Miller, S. L.↗
NASA NTRS1972

Abundances of the elements.

An elemental abundance table along the lines used by Suess and Urey (1956) is presented. Since this early work, other studies have been made, and improvement in the abundance tables has been made as more reliable data have become available. Some changes in the original tables have been made, but the original abundances and their variations with mass numbers remain remarkably similar. The solar abundance of iron for many years appeared to be very much less relative to silicon than would be indicated by the data from the meteorites.

Urey, H. C.↗
NASA NTRS1972

Mass spectrometric analysis of organic compounds, water and volatile constituents in the atmosphere and surface of Mars - The Viking Mars Lander.

An experiment centering around a mass spectrometer is described, which is aimed at the identification of organic substances present in the top 10 cm of the surface of Mars and an analysis of the atmosphere for major and minor constituents as well as isotopic abundances. In addition, an indication of the abundance of water in the surface and some information concerning the mineralogy can be obtained by monitoring the gases produced upon heating the soil sample. The organic material will simply be expelled by heating to 150, 300, and 500 C into the carrier gas stream of a gas chromatograph interfaced to the mass spectrometer or by slowly heating the sample in direct communication with the spectrometer. It is planned to analyze a total of up to nine soil samples in order to study diurnal and seasonal variations. The system is designed to give useful data even for minor constituents if the total of organics should be as low as 5 ppm. The spectrometer covers the mass range of 12-200 with adequate resolution.

Anderson, D. M.↗
NASA NTRS1972

The origin of the moon and solar system.

The Rb-87/Sr-87 ages of many of the lunar rocks suggest that the fundamental differentiation took place 4.5 b.y. ago and that remelting occurred without exchange of the rubidium and strontium with the surroundings. The Apollo A rocks are an exception to this. They appear to have acquired rubidium without all of the Sr-87 produced during the first aeon. Also in the remelting about half of the radiogenic leads were lost to the surroundings by a vaporization process. We interpret these results to mean that remelting occured in a system that was nearly closed to the surroundings and that the high early concentrations of radioactive elements in highly insulating surroundings made this possible.

Urey, H. C.↗
NASA NTRS1971

Model history of the lunar surface

Lunar surface history model, discussing mascons, chemical composition, isochron ages and seismic and electrical properties of samples

Hawkins, J. W.↗
NASA NTRS1969

Origin and history of the moon

Lunar origin and history, discussing evolution temperature, large and small craters and association with solar system evolution

Urey, H. C.↗