Lunar Gravity via Apollo 14 Doppler Radio Tracking

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Science  14 Jan 1972:
Vol. 175, Issue 4018, pp. 165-168
DOI: 10.1126/science.175.4018.165


Gravity measurements at high resolution were obtained over a 100-kilometer band from + 70° to -70° of longitude during the orbits of low periapsis altitude (approximately 16 kilometers). The line-of-sight accelerations are plotted on Aeronautical Chart and Information Center mercator charts (scale 1 : 1,000,000) as contours at 10-milligal intervals. Direct correlations between gravity variations and surface features are easily determined. Theophilus, Hipparchus, and Ptolemaeus are negative features, whereas Mare Nectaris is a large positive region. The acceleration profiles over Mare Nectaris are suggestive of a broad disk near the surface rather than a deeply buried spherical body. These data are in good agreement with the short arc of Apollo 12 lunar module descent data.