740 NUCLEAR SCNNCE ARSTRACTS © C3 alphe disintegration per second per square ceatimeter. The Presen.y of pologiwr-215 tr amounts that are close to aguilibriam tntirates a contirucus turnover rate of Ivear matertal st thie site of lees than 9! micrometer per yeer. The lack of feck a deposit at two other lunar sites euggests lower focal concentrations uranium there. (nutht 21818 DISCUSSION PAPER: RECOVERY OF DEUTERIUM IN THE ATMOSPRERE OF JUPITER, Wiockisy, R. B.; Reid, R.C ; Glaser, P_E, (Arthur D. Little, Inc.. Cambridge, Maes.), Aaa, N, ¥. Acad, Sci.: 163: 554-614 Sep 1969), A serious logistic problem ta tong space flights ia the necessity to carey a round-trip fuel supply or to obtain fuel efther at the ter- minus or at an Intermediate stop. Spacecraft in the future will probably be nuclear-powered and, hopefully, of a fusion-reaction type If the fusion type were realized, it would be imperative to provide and store deuterium. Several posalbilities for obtaining deuterium in the atmosphere of one of the gae-giant planets, such ae Jupiter, are explored. Most ''Earth'’ methods for preparing deuterium in # reasonably pure atate are rejected as being unaultable for application in space. To obtain deutertum from hydrogen present in the atmosphere of Jupiler, some method must be found to collect, liquefy, and seperate the hydrogen and deuterfum. Deuterium je probably present at a higher concentration than on Esrth, and values a4 high as 700 to 800 ppm have been suggested. One proposal is to orbit a vehicle in the stratosphere and collect the hydrogen (deuterium)—helium mixture by & ram action. The bydrogen would be liquefied and rectified to produce deuterium. Alao considered is location of the deuterium separation plant on one of Jupiter s moone, or on Saturn. The Galllean satellites of Jupiter would appear to be logical locations for large separation planta provided their atmospheres are found to be suitable, The concept of refueling a fusion device on Jupiter or some other gas giant doc. not appear to be imporsible (unless subsequent studies show no by drogen to be present} 2186 (RRB) NONEQUILIBRIUM RADIATION FROM PLANETARY ATMOSPHERES, Thompson. Samuel Lee, Lexington, Ky.; Univ, of Kentucky (19¢6). 1105p, Thesis, A possible sclution to the problem of ‘‘measured’’ atmospheric temperatures of Jupiter too high to be in equilibrium with the incident solar radiation ia studied. It is demonstrated that another tnterpretation of the measurements of the 8 to 14-1 ero‘asion is possible. The high radiation ‘temperature’ ia thus explicable by a cascade process of the molecules in Jupiter's atmosphere wherein & high energy photan ja received from the Sun and rerediated aa smailer quante. It ie also found that a possible explanation of the enhanced emigeton from the shadows of Jupiter's satellites is possible using the same idea. Nonequilibrium radiation and collisional deactivation processes in gases are studied. (TSS) (Dies. Abstr.) 21817 PROCEEDINGS OF THE LUNAR SCIENCE CONFER- ENCE HELD A‘ HOUSTON, TEXAS, FROM 5 TO 8 JANUARY. Science; 167: 447-7930 Jan 1970), (CONF -700106). Reralts of the firet systematic studies of the Apollo 1] armples by more than 500 actentists (rom nine countries are compiled, in ajl, 144 papere were submitted: separate abstracts were prepared for 50 {IWDM) For abstracts of imflicldual papers see: 20706-20711, 207°1— 20724, 20730-20739, and 2151 8~ 21547, 21518 AGE OF THE MOON: AN ISOTOPIC STUDY OF URANIUM-THORIUM-LEAD SYSTEMATICS OF LUNAR SAMPLES. Tatsumoto, Mitsunobu; Roashoit, John N. (Geological Survey, Denver). Sctenoe; 147: 461-3(30 Jan 1979), From Apotlo 11 Lunar Science Corderence, Houston, Tex. See CONF -700106, Concentrations of U, Th, and Pb in Apollo 11 samples studied are low (U, 0 16 t 0 47; Th, 0 $3 to 3.4, Pb, 0,25 to 1.7, In ppM) but the extremely radiogenic lerd in samples allows radiometric dating The fine dust and the breccia have a concordant age of 4 68 billion years on the basis of *Pbh/MPh, ppsty ppys my, and Pb/™Th ration. This age la comparable with the age of meteorites and with the age gecerally accepted for the Earth. Bix crystalline and vesicular semplee ere distlactly younger than the dust and breccia The "'u/"'Y ratte is the same as that in Earth rocks, and ™1 ts tp radioactive equilfprinz with parent 7y. (auth) “= ™ 2isi¢ AGES, IRRADIATION HISTORY, AND CHEMICAL COMPOSITION OF LUNAR ROCKS FROM THE SEA OF TRAN. QUICLITY, Albee, A, Lo; Burvett, D.5.; Chodos, A. Au: Eugster, O 3: Ponete, J, C.; Pananastaseion, D. Av: Podoerk, F. A. Ruas TG. 3 roa: Sana, KH. G.: Tera, FL; Waeserturg, G, J. fa'Worns Inat_ af Teob., Pasadena}. Science: 167 463-0130 Jan TH Vol. 4, Ne From Apolic 11 Leaner Science Cosfereece, Houston, Tex. See CONF . 700166, The "Xb~-"Sr internal leockrone for five rocks yield an age of 3.65 2 €.05 « 10° years which presemably dates the formation of the Sea of Tranquilitty. Potassium - argon ages are consistent with this reewit. The soll hes a model age of 4.5 « 10’ years, which ia best regarded as the time of initial differentiation of the hi ar crest. A peculiar rock fragment from the eoll gave a model age of 4.44 * 10° yeare. Relative sbundasces of alhalia do not sugyeet differentia) volatilization, The irradiation history of lunar rocks {a inferred from tactopic measurements of gadolinizm, vanadium, and cogmogenic rare gases. Spallation xenon spectra exhibit a high and variable ™'Xe/!*Xe ratio. No evidence for "1 waa found. The tsotoptc composition of aolar-wind xenon Is dlatinct from that of the atmosphere and of the average for carbonaceous chondrites, but the krypton composition appears similar to average carbonaceous chondrite krypton. (auth) 21828 @ar/"ar DATING OF LUNAR ROCK SAMPLES, Turner, Grenville 466-8130 Jan 1979), (Univ, of Sheffield, Eng). analyzed tn detail by means of the *#Ar—Ar dating technique. The extent of radiogenic argon loss in these samples ranges from 7 to 248%, Potassium-argon ages, correctet for the effects of this lous, cluater relatively closely around the vaiue of 3.7 « 10° yeara. Most of the vulcanism associated with the formation of the Mare Tranquillitatis presumably occurred around 3.7 * 10° years ago. A major cause of the escape of gas from lunar rock is probably the impact event which ejected the rock from its place of origin to its place of discovery. Upper limita for the times at which these impact events occurred have been estimated. (auth) 21821 URANIUM-THORIUM-LEAD ISOTOPE RELATIONS IN LUNAR MATERIALS. Silver, Leon T. (California Inst. of Tech., Pasadena). Science; 167; 468-71(30 Jan 1970), From Apollo 11 Lunar Setence Conference, Houston. Tex. See CONF-700106. The lead isotopic compositions and uranium, thorium, and lead concentrations were measured on aix samples of material from the Sea of Tranquillity. The leads are moderately to very radio~ gentc; the Initial lead concentrations are very low; the uranium and thortum levels are 6,26 to 0.88 and 0.87 to 3.35 parts per million, respectively The Th/U ratiog cluater about 236 value Apparent agee calculated for four rocks are 4.1 to 4.2 x 10° years. Dust and breccia yield apparent ages of 4 60 to 4.63 « 10" years The uranium ~ lead ages are concordant, or nearly so, in alt cases The lunar surface is an anctent region with an extended record of events in the early history of the solar syatem The discrepancy between the rock ages and dust ages poses a fundamental question about Tock genesis on the Moon. (auth) 21822 RUBIDIUM-STRONTIUM, URANIUM, AND THORIUM- LEAD DATING OF LUNAR MATERIAL, Gopalan, K.; Kaushal, S.; Lee-Hu, C.; Wetherill, GW. (Univ. of Calffornla, Los Ap-~ Beles). Science; 167: 471-3(30 Jan 1970). From Apollo 11 Lunar Sctence Conferenoe, Houston, Tex. See CONF -700106. Rubidium and strontium concentrations and strontium {eotopic compositions were measured on whole rock samples and density fractlons of microgabbro. Density fractions on two rocks define taochrone of 3400 and 4500 milion yeare with large uncertaintles owing to low enrichmentof radiogeni¢ atrontium Lead from fine surface material te highly radiogenic. An age of 4750 million yeare was calculated from the ratio of "Pb/?*Pb. The concen- trations of uranium, thorium, and lead isotopes are consistent with the evolution of lead in 4 4700-million-year-old closed syetem characterired by the ratios of uranium to lead and of thorium to lead In thie surface material. (euth) 21623 RUBIDIUM-STRONTIUM RELATIONS IN TRANQUILLITY BASE SAMPLES, Hurley, P. M.; Pinson, W, H. Jr. (Maseachusetts Inst. of Tooh., Cambridge), Science; 167: 473~ 4(90 Jan 1070). From Apollo 11 Lunar Science Confersuce, Houston, Tax, See CONF-700106, Pretiminary tote! rook analyses diacloeed a greatly differeat Rb depletion between two groups of these (gneous rocks, and ratios of « Br/*6r indicate that the Rb depletion in these materials must have cocurred during or shortly after the accretion of the terrestrial planets. (exth 218246 RUBIDIUM-STRONTIUM AGE AND ELEMENTAI AND TROTOPIC ABUNDANCES OF SOME TRACE ELEMENTS IN LU. NAR SAMPLES ddurthy, V. Rama apalls); Schmitt, R. A.; May, P. « . Pes a eeern Science; 167: From Apollo 11 Lunar Sciences Conference, Houston, Tex See CONF -700106, Seven crystalline rock samples returned by Apolio 3) were (Univ of Minnesote, Minne Sotemoe; 167: 4769/90 Jan 1979). he r.