Upper limits to gas emission from lunar transient phenomena sites

Lunar transient phenomena have been attributed to the release of gases from within the moon. The failure of the Apollo surface experiments to detect significant atmospheric enhancements can be used to establish upper limits to the amount of gases now being released from the various sites associated with lunar transient phenomena. An analysis of the sensitivity of the network of Apollo Suprathermal Ion Detector Experiments (deployed initially in 1969 and still operating) indicates that they would have detected any contemporary gas release greater than 6,500 kg from Alphonsus, 28,000 kg from Aristarchus, and similar quantities from other craters. The quantity of gas required to cause such phenomena as obscurations or glow discharge is probably much greater than these values. Consequently, if transient phenomena are real lunar surface events, they must originate from a mechanism other than simple gas emission.