This paper reports some preliminary results from the Suprathermal Ion Detectors deployed on the lunar surface by the Apollo 12 and 14 astronauts. Salient features of these results include: the possible observation of sporadic venting of gas from the lunar surface; evidence for a prompt ionization and acceleration mechanism operating in the lunar exosphere; and a preliminary measurement yielding approximately 1 month for the e-folding decay time for the heavier components of the exhaust gases from the Apollo lunar landing systems. Prominent phenomena from which these results have been derived are: (1) ion bursts of low to moderate energy seen in conjunction with lunar sunrise and sunset; (2) solar wind energy ions detected on the night side of the Moon; (3) ions of several keV energy seen during the lunar sunset to midnight quadrant of the Moon's orbit; (4) magnetosheath ion flux enhancements; (5) ion bursts generated by the lunar impact of the Apollo 13 Saturn upper stage and other man-made objects; and (6) geomagnetic storm associated ion flux variations in the Earth's magnetotail. © 1972.
Freeman, J. W., Fenner, M. A., Hills, H. K., Lindeman, R. A., Medrano, R., & Meister, J. (1972). Suprathermal ions near the Moon. Icarus, 16(2), 328–338. https://doi.org/10.1016/0019-1035(72)90080-2