Chemical Composition of the Lunar Surface in Sinus Medii

Franzgrote, Ernest J.; Patterson, J. Herbert; Turkevich, A.; Economou, T.; Sowinski, Kenneth P.

doi:10.1126/science.167.3917.376

Cited by 35 publications

(2 citation statements)

References 14 publications

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“…Some 50 particles from a radioactive source (this time the transuranium nuclide 242Cm) and measurement of the energy distribution of these particles by means of solid-state detectors after they had been scattered by the target atoms through angles close to 180 ø (therefore the term "backscattered"). They designed instruments that flew on three Surveyor missions (Surveyor V, VI, and VII) in the years 1967 and 1968 and yielded the first complete and accurate chemical analysis of lunar soils [Turkevich et al, 1969;Franzgrote et al, 1970;Patterson et al, 1970]. In addition to the measurement of backscattered alpha particles, these instruments already contained detectors to measure the energy distribution of protons, generated by (a, p) reactions on certain medium-heavy elements (F, Na, Mg, A1, Si, S, and C1), thus enhancing their resolution capability for these elements.…”

Section: Introductionmentioning

confidence: 99%

Determination of the chemical composition of Martian soil and rocks: The alpha proton X ray spectrometer

Rieder¹,

Wänke²,

Economou³

et al. 1997

J. Geophys. Res.

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Abstract. The alpha proton X ray spectrometer (APXS) for the Mars Pathfinder mission is designed to provide a complete and detailed analysis of chemical elements in Martian soil and rocks near the landing site. The APXS instrument is carried on the Pathfinder Microrover, which will provide transportation to places of interest on the Martian surface. It consists of a complex sensor head, mounted on a simple but sophisticated APXS deployment mechanism (ADM) outside the warm electronics box (WEB) of the Microrover, and the instrument electronics, mounted inside the WEB. The ADM permits the instrument sensor head to be placed against soil and rock samples in arbitrary positions, ranging from horizontal to vertical, in order to perform in situ analysis. The possibility to transport the APXS to an arbitrary location, preselected on Earth, and to perform in situ analysis there, constitutes one of the most exciting aspects of the Pathfinder mission. The principle of the APXS technique is based on three interactions of alpha particles from a radioisotope source with matter: simple Rutherford backscattering, production of protons from (c•, p) reactions on light elements, and generation of characteristic X rays upon recombination of atomic shell vacancies created by c• bombardment. Measurement of the intensities and energy distributions of these three components yields information on the abundance of chemical elements in the sample. In terms of sensitivity and selectivity, data are partly redundant and partly complementary: alpha backscattering is superior for light elements (C, O), while proton emission is mainly sensitive to Na, Mg, A1, Si, S, and X ray emission is more sensitive to heavier elements (Na to Fe and beyond). A combination of all three measurements enables determination of all elements (with the exception of H and He) present at concentration levels above typically a fraction of 1%.

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Section: Introductionmentioning

confidence: 99%

Determination of the chemical composition of Martian soil and rocks: The alpha proton X ray spectrometer

Rieder¹,

Wänke²,

Economou³

et al. 1997

J. Geophys. Res.

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“…Together with the total frequency distribution graphs the mean chemical compositions of the lunar surface at the Surveyor 5, 6 and 7 sites (Turkevich et al, 1969;Franzgrote et al, 1970;Patterson et al, 1970, respectively) are also indicated. From Surveyor data it can be seen that the Surveyor 7 site near the crater Tycho is composed of a typical terra-like material, while the Surveyor 5 and 6 sites represent mare-type sites.…”

Section: Selenochemistry Area By Areamentioning

confidence: 99%

Bulk components in lunar rocks

Raitala¹

1980

Bull Geol Soc Finland

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The deviations of principal lunar rock oxides collected from periodicals are presented in the form of frequency distribution graphs. The geochemical characteristics of rock types from different landing sites are briefly discussed. Of the major lunar rock components AI2O3, FeO, CaO and MnO are most indicative of terra-mare contrary. Terra rock classification is not unambiguous but mare basalts can be divided into highand low-titanium basalts with several subgroups. Since lunar missions are few in number and are directed at restricted areas there are evidently still many unsampled lunar rock types.

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Chemistry of the moon

Wänke

Topics in Current Chemistry Fortschritte Der Chemischen Forschung

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Chemical Composition of the Lunar Surface in Sinus Medii

Cited by 35 publications

References 14 publications

Determination of the chemical composition of Martian soil and rocks: The alpha proton X ray spectrometer

Determination of the chemical composition of Martian soil and rocks: The alpha proton X ray spectrometer

Bulk components in lunar rocks

Chemistry of the moon

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