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The deficiency of siderophiles in the crust of the Earth is customarily attributed to leaching by metallic nickel-iron, which eventually sank to form the core. A similar deficiency exists in the Moon, which has, at best, a very much smaller core. Hence it is logical to consider the hypothesis that the Moon formed from the mantle of the Earth, after the siderophiles had been removed. It is shown that the non-hydrostatic figure of the Moon, and the requirement that the mascons must be supported, together with the high heat-flow, imply that the metal of the Moon is collected in the core. It probably amounts to less than 1 % of the Moon’s mass. Calculations show that if the core is in chemical equilibrium with the lunar silicates, then the nickel has been removed from the Moon as a whole to an extent which is greater than can be explained by theories of direct formation from a nebula. The only salvation for the idea of direct formation from a nebula appears to be an efficient process of extraction of the siderophiles by successive passage of small amounts of reduced metal through the silicate portion of the Moon. Since natural processes do not usually operate with the required efficiency, it can be concluded that the formation of the Moon by the fission of the Earth is geochemically plausible.

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 and quantitatively 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 complet biochemical compounds are low temperature homogenous reactions occurring in an aqueous environment.

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.

The following statements have been supplied to the Bulletin by some of this country's most distinguished scientists. Albert Einstein, the worlds most famous theoretical physicist, has been a U.S. citizen since 1933. He is a member of the Institute for Advanced Study at Princeton. Hans A. Bethe is professor of physics at Cornell University. Harold C. Urey, Nobel Prizewinner, is Distinguished Service Professor in the Department of Chemistry and the Institute for Nuclear Studies, University of Chicago. James Franck, Nobel Prizewinner in physics, is professor of physical chemistry at the University of Chicago. Samuel A. Goudsmit is senior scientist at Brookhaven National Laboratory. Cyril S. Smith is director of the Institute for the Study of Metals at the University of Chicago. Arthur H. Compton, another Nobel Prizewinner in physics, is chancellor of Washington University in St. Louis, Missouri. Dr. William P. Murphy, Nobel Prizewinner in medicine, is the co- discoverer of liver treatment for pernicious anemia.

Considerable evidence of diverse kinds has accumulated during the last 6 years indicating that some or possibly most of the stone meteorites come from the moon. Included in these may well be the carbonaceous chondrites of the Orgueil type and this indicates that contamination of the moon with terrestrial water has occurred. This statement does not depend on the carbonaceous matter being of biotic origin. Models for the origin of the moon are consistent with the hypothesis that some contamination of this kind occurred. This conclusion is possible regardless of whether the meteorites come from the moon or not.

The Ranger VII, VIII, and IX pictures of the moon show certain features quite unequivocally about the lunar surface. 1. It appears that a very considerable amount of erosion and fragmentation of the surface by micro- and macrometeorite bombardment and probably other processes has taken place. It would seem that the evidence indicates that this layer is some 10 or 20 m deep as a minimum. 2. There is considerable evidence for slump features on the moon. This probably includes the dimple craters as well as certain crevasses that are seen in all these pictures but particularly in the Alphonsus pictures. The volcanic activity indicated in the Ranger IX pictures is of a very mild type and the craters do not resemble any terrestrial volcanic features at all. They are very broad and apparently have been produced by the escape of gases from the lunar interior. It would appear that they might have been produced initially by collisions which were then modified by gas escaping, though one of these craters has an elliptical shape, arguing against this interpretation. 3. Various lines of evidence indicate that the material of the maria floors and especially of the Alphonsus floor consist of fragmented material to a very considerable depth, with substantial crevasses below the surface. It is not possible to decide whether such crevasses are the result of lava flows or the evaporation of massive amounts of water from beneath the surface. It is, however, the author’s opinion that the water interpretation is the more likely of the two. 4. The mountainous areas in the neighbourhood of Alphonsus are remarkably smooth as compared with the crater floor. This indicates that the crater rim consists of different material from the crater floor. 5. Secondaries are a prominent feature of all these Ranger pictures. Objects of more than a million tons have been thrown from Tycho to Mare Cognitum, a distance of 1000 km . It appears probable that the curious rays of Tycho which missed the craters may indeed be due to particles that have travelled completely around the Moon, and it seems likely that objects of meteoritic size have been thrown off the Moon and have arrived at the Earth. It seems to me that it would be well to be rather conservative in regard to the interpretation of these pictures. The maria of the Moon may consist of lava flows. They may be fragmented material. They may have been subjected to water at some time in their history. But the evidence of pictures alone is not sufficient to make a firm decision in regard to these conclusions.

From the standpoint of chemistry, the following properties of life appear to be important. Living things maintain metabolic processes, that is, chemical reactions in which compounds of one kind are absorbed by living things and compounds of another kind excreted. Animals absorb compounds containing high free energy and excrete those with low free energy. Plants absorb certain compounds of low free energy, i.e., carbon dioxide, excrete compounds of high free energy, oxygen plus carbohydrates, for example, and at the same time maintain a complex metabolism in which high energy compounds are used for living processes. This dynamic metabolic process is an exceedingly important characteristic of living things. In the second place, living organisms are distinguishable from their surroundings. We would not consider an ocean in which chemical reactions of a general type such as that mentioned above were taking place as a living organism. A living organism has form and structure, and this is of a very complicated and intricate kind in the case of modern organisms. The possibility of maintaining these exceedingly complicated and highly organized bodies can only be done in the face of the degenerating processes that are predicted on the basis of natural accidents by very special arrangements. Inevitably a single living organism will degenerate or be destroyed by accident. Hence the persistence of living things in the face of this degenerative tendency can only be maintained by some other mechanism, and that mechanism is the replicative characteristic. Living organisms are able to produce additional living organisms of a fairly perfect or at least operative kind and hence make allowance for the destruction of organisms that have been damaged or degenerated. The replicative function is a necessity. The free energy for this process which enables the living organism to overcome the requirements of an increase of entropy in all processes is, of course, free energy from the sun.

The Rb87-Sr87ages of many of the lunar rocks suggest that the fundamental differentiation took place 4.5 × 109yr 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 Sr87produced during the first aeon. Also in the remelting about half of the radiogenic leads were lost to the surroundings probably the soil by a vaporization process. We interpret these results to mean that remelting occurred 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.

“No one has the right to withdraw from the world of action at a time when civilization faces its supreme test.”

A survey of the abundances of elements in the ocean and sedimentary rocks as compared to their abundances in the weathered igneous rocks shows that carbon, nitrogen, oxygen as water, chlorine, bromine and boron are highly concentrated in the surface materials and that thicknesses of from 17 to 89 km of the outer part of the earth would be required to produce these elements if all of them now present in the igneous rocks were removed. A study of the available information indicates that many other elements would be concentrated at the earth’s surface if chlorine, bromine and boron were concentrated there by a high-temperature volatilization process either from volcanoes or in an original high-temperature atmosphere of the earth . It is concluded that the removal of these elements from the outer parts of the earth occurred through solution in water at low or moderate temperatures ( ~ 100°C or less), since they are soluble and other elements are not. Iodine should belong to this group, but its position is uncertain because of doubtful analytical data. Sulphur may belong in some degree with the volatiles, i.e. carbon as methane or carbon dioxide, nitrogen as ammonia or molecular nitrogen, and water. It is shown that the low abundances of mercury and arsenic in the sediments are inconsistent with a temperature of formation of the earth’s surface regions higher than a few hundred degrees centigrade. The presence of appreciable quantities of nitrogen in the igneous rocks indicates that this element was present in condensed phases during the earth ’s formation, and a survey of the conditions of stability of such compounds indicates temperatures of about 200°C or less. It has not been possible to decide whether liquid water was present on the primitive earth .

None saw more quickly than the scientists that atomic energy would demand new techniques of political control. No one has followed the discussion of these techniques with greater concern of mind and heart than Dr. Urey who now discusses not the ideal, but the practical, solution. Dr. Urey, a Nobel Prize Winner and a recently elected member of the Royal Society of London, is Distinguished Service Professor of Chemistry and a member of the Institute for Nuclear Studies at the University of Chicago.

Carbon compounds in Apollo 12 lunar fines and core samples, using pyrolysis, mass spectrometry, ion exchange chromatography and optical and electron microscopy

Life-Forms in Meteorites: Origin of Life-like Forms in Carbonaceous Chondrites Introduction

Electron probe x-ray microanalysis of organized elements in the orgueil carbonaceous meteorite

As a result of the Apollo expeditions, Dr. Urey has changed some of the ideas about the Moon he held in 1969. Major questions remain. However, the author still believes that the Moon originated as a separate body and was captured by the Earth. This post-Apollo view of the Moon is based in part on Dr. Urey's address last spring to the American Chemical Society on the occasion of receiving its highest award, the Priestley Medal. Portions of the address reproduced here are reprinted by permission of the copyright owner, the American Chemical Society, from its periodical, Chemical & Engineering News, 51 (April 16, 1973), 13–16.Dr. Urey is emeritus professor of chemistry at large at University of California, San Diego.

On the afternoon of May 18, 1973, members of his family, colleagues and friends gathered in a flower-banked chamber of the Smithsonian Institution in Washington, D.C. to pay tribute to Eugene Rabinowitch. The beautiful memorial service was illuminated by a series of eulogies, spoken by close associates of the Bulletin's editor-in-chief. They heightened the realization of loss in the passing of one of the great scientist-humanists of the twentieth century.Herewith we publish excerpts from some of the eulogies which describe the life and work of Eugene Rabinowitch and which reflect his philosophy. These remarks are followed by messages from members of the world scientific community which Eugene Rabinowitch served as a powerful voice of conscience.

In the October issue of the BULLETIN, the editors presented an article entitled “Freedom Demands Responsibility” by Cuthbert Daniel and Arthur M. Squires, accompanied by comments from Eric Ashby, A...

IN a recent communication1, Dr. Kohman suggests that tektites are meteorites which originate in interstellar space and collide with the solar system. I should like to direct attention again to the various facts that must be explained by any acceptable postulated history of these objects. (1) Tektites have chemical compositions remarkably similar to those of the more acid sedimentary rocks. This is true for the major and minor constituents. (I have been privileged to see analyses as yet unpublished on these minor constituents.) Such a chemical composition is not produced by any other naturally occurring chemical processes that we know of, except perhaps in very rare and special circumstances. (2) Tektites obviously have been melted, and this means that a temperature of some 1,500° C. or more was supplied by some means. In fact some appear to have been reheated to the melting point by passage through gas or by a blast of gas over the object. No terrestrial source of heat is known which could produce such high temperatures. (3) They are distributed thinly over areas of hundreds and thousands of kilometres in linear dimensions. (4) They are reported to contain aluminium-26 and beryllium-10. This observation is due to Dr. Kohman and Dr. Ehmann.

Chemical composition of moon from Surveyor results, noting resemblance to terrestrial basalt

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.

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

To find a process for successful photochemical separation of isotopes several conditions have to be fulfilled. First, the different isotopes have to show some differences in the spectrum. Secondly, and equally important, this difference must be capable of being exploited in a photochemical process. Parts A and B outline the physical and chemical conditions, and the extent to which one might expect to find them fulfilled. Part C deals with the applicability of the process.