Lunar orbital gamma ray measurements from Apollo 15 and Apollo 16.Examination of the data obtained by gamma-ray spectrometers on the Apollo 15 and Apollo 16 spacecraft has been carried out in part by summing up broad regions of the energy spectrum. The most instructive of these energy regions is 0.55 to 2.75 MeV, where the difference in count rates observed can be accounted for mainly by variations in the Th, U, and K content of the surface layers. The highest values are found in Mare Imbrium and Oceanus Procellarum, where a good deal of local variation is observed. By contrast, little increase is seen in the eastern maria surveyed compared with count rates in highland areas. The broad highland regions are low in radioactivity, but there is a measurable rise near the southernmost latitude on the far side. In addition to the radioactive lines, gamma-ray lines which can be ascribed to O, Si, Fe, Mg, and Al have been identified.
Document ID
19730056595
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Arnold, J. R.
Peterson, L. E.
Reedy, R. C. (California, University San Diego, Calif., United States)
Trombka, J. I. (NASA Goddard Space Flight Center Greenbelt, Md., United States)
Metzger, A. E. (California Institute of Technology, Jet Propulsion Laboratory, Pasadena Calif., United States)