Radioactivity of the Lunar Surface

Kraner, H.W.; Schroeder, Gerald L.; Davidson, Gilbert; Carpenter, J. W.

doi:10.1126/science.152.3726.1235

Cited by 27 publications

(6 citation statements)

References 5 publications

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“…the production of the enormous Imbrium basin. These rocks proved to be mainly breccias with compositions closely allied to the Kreep type rocks described above 5 and coming quite possibly from deeper layers within the moon. This brings us to the Apollo 15 and 16 missions.…”

Section: Questions About the Moonsupporting

confidence: 52%

Lunar Composition from Apollo Orbital Measurements

Adler

Trombka

Yin

1973

Astrophysics and Space Science Library

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Section: Questions About the Moonsupporting

confidence: 52%

Lunar Composition from Apollo Orbital Measurements

Adler

Trombka

Yin

1973

Astrophysics and Space Science Library

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“…We assume that such "minimum" doses are also responsible for metamictizing dust grains on the lunar surface -and that the surface residence time of the grains in the radon atmosphere is about 1000 years. Then, by using the "efficient" radon diffusion model of Kraner et al (7) and a present Th/U ratio of about 4, we infer that the concentration of U in the moon should be at least 100 times higher than the highest values so far obtained for the Apollo 14 samples. Therefore, it seems unlikely that the a-decay of a radon atmosphere is responsible for the amorphous coatings on the grains.…”

mentioning

confidence: 62%

“…As these low-energy nuclei have very short penetrations in matter (about 1000 A in silicates), they might produce such superficial effects in the dust grains as (i) thin "vapordeposited" coatings resulting from solar wind sputtering (3,4) and (ii) superficial metamictized layers formed by the overlapping of the radiation-damaged islands produced along the path of the incident ions (5,6). Furthermore, these effects could be enhanced by a-decay products recoiling downward from a hypothetical lunar radon atmosphere (7,8), with energies comparable to those expected from very heavy solar wind ions. In this report we describe evidence for the existence of metamictized layers in the lunar dust grains and summarize various implications of this new phenomenon for cosmophysics.…”

mentioning

confidence: 99%

Ultrathin Amorphous Coatings on Lunar Dust Grains

Bibring¹,

Duraud²,

Durrieu³

et al. 1972

Science

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UItrathin amorphous coatings have been observed by high-voltage electron microscopy on micrometer-sized dust grains from the Apollo 11, Apollo 12, Apollo 14, and Luna 16 missions. Calibration experiments show that these coatings result from an "ancient" implantation of solar wind ions in the grains. This phenomenon has interdisciplinary applications concerning the past activity of the sun, the lunar albedo, the ancient lunar atmosphere and magnetic field, the carbon content of lunar soils, and lunar dynamic processes.

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“…Measuring characteristic‐energy alpha particles to map radon emanation from the lunar surface and the subsequent deposition of decay products was first suggested by Kraner et al [1966]. Alpha particles from the decay of radon and its daughter products appear as a distinct set of peaks on a background energy spectrum of interplanetary energetic alpha particles.…”

Section: Introductionmentioning

confidence: 99%

Recent outgassing from the lunar surface: The Lunar Prospector Alpha Particle Spectrometer

et al. 2005

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[1] The Lunar Prospector Alpha Particle Spectrometer (APS) was designed to detect characteristic-energy alpha particles from the decay of Rn-222, Po-218, and Po-210 and to therefore map sites of radon release on the lunar surface. These three nuclides are radioactive daughters from the decay of U-238; hence the background level of alpha particle activity is a function of the lunar crustal uranium distribution. Radon reaches the lunar surface either at areas of high soil porosity or where fissures release the trapped gases in which radon is entrained. Once released, the radon spreads out by ''bouncing'' across the surface on ballistic trajectories in a random-walk process. The half-life of Rn-222 allows the gas to spread out by several hundred kilometers before it decays (depositing approximately half of the Po-218 recoil nuclides on the lunar surface) and allows the APS to detect gas release events up to several days after they occur. The long residence time of the Pb-210 precursor to Po-210 allows the mapping of gas vents which have been active over the last approximately 60 years. The APS found only a faint indication of Po-218 alpha particles. However, the Rn-222 alpha particle map shows that radon gas was emanating from the vicinity of craters Aristarchus and Kepler at the time of Lunar Prospector. The Po-210 alpha particle distribution reveals a variability in time and space of lunar gas release events. Po-210 and Rn-222 detections are associated with both thorium enhancements and lunar pyroclastic deposits.

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Radioactivity of the Lunar Surface

Cited by 27 publications

References 5 publications

Lunar Composition from Apollo Orbital Measurements

Lunar Composition from Apollo Orbital Measurements

Ultrathin Amorphous Coatings on Lunar Dust Grains

Recent outgassing from the lunar surface: The Lunar Prospector Alpha Particle Spectrometer

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