A search for gaseous emissions from the moon

A study of 19 months of data shows that relative variations in the dayside lunar ionosphere are predictable from solar wind flux and solar extreme ultraviolet variations. Discrepancies in the absolute magnitudes exist, however. One significant discrepancy in the predicted and observed ion flux magnitudes probably arises from sputtered surface gases during and following an extended period of anomalously high solar wind flux. A second minor enhancement of the observed flux over the predicted flux may be due to endogenous lunar gas associated with an interval of high lunar seismic activity. However, considerable restraint is necessary in this interpretation since the enhancement is not strong and the interval follows within a few months after the Apollo-17 mission.