Iron abundances on the lunar surface as measured by the Lunar Prospector gamma‐ray and neutron spectrometers

作者：D. J. Lawrence, W. C. Feldman, R. C. Elphic, Robert Little, T. H. Prettyman, S. Maurice, P. G. Lucey, A. B. Binder · 发表于：Journal of Geophysical Research Atmospheres · 年份：2002 · DOI：10.1029/2001je001530 · 被引用次数：295 · 研究领域：Planetary Science and Exploration、Astro and Planetary Science、Isotope Analysis in Ecology

Global measurements of iron abundances on the lunar surface are presented using data from the Lunar Prospector (LP) Gamma‐Ray Spectrometer (GRS) and Neutron Spectrometer (NS). In this study, we derive relative iron abundances from the low‐altitude, high spatial resolution (∼(45 km) 2 ) LP data using the 7.6 MeV neutron capture gamma‐ray doublet. As part of the LP‐GRS analysis, we demonstrate the importance of accounting for variations in neutron number density across the lunar surface by measuring neutron fluxes using LP‐NS data. In a first step of comparing the LP‐GRS data with previously published iron abundances inferred from Clementine Spectral Reflectance (CSR) data, we show that the existing CSR FeO data are nonlinear with respect to the LP relative iron abundances. We use the LP data to linearize the relationship between the CSR and the relative iron values then recalibrate the CSR data to iron abundance using returned soil abundances. We then correlate the CSR data, except for major anomalies, with the LP relative iron measurements to convert the LP data to absolute iron abundances. When we compare the LP‐GRS and revised CSR data sets, we find a very good correspondence. There are two locations (Mare Tranquillitatis and South Pole‐Aitken (SPA) basin) that show major discrepancies, suggesting that the CSR data are locally overestimating iron abundances. In both these regions, the discrepancies identified by the LP‐GRS/CSR comparison are possibly explained by mineralogi...