Various numbers have been given representing how many official reports there are of Lunar Transient Phenomena. Since 1783 numerous observers have occasionally witnessed 'mysterious happenings' on the Moon. We are aware of about 1500 sightings of what are now called 'lunar transient phenomena' (LTPs) that have been reported, but any observer wishing to search for such events will soon find that it is an exacting and problematical undertaking. Phenomena reported include local hazes, temporary color variations (sometimes red), localized brightness changes (glows), temporary obscurations of surface formations, etc. The reliability of many of these reports is questionable, for the eye, working under extreme conditions, is easily deceived. Other LTP observations seem to be authentic, especially when they have been confirmed by other experienced observers. One of these was Kozyrev's 1958 observation of a gaseous emission from the central peak of the crater Alphonsus, for which he obtained spectrographic evidence. It was once reported that there were no LTPs reported by the Apollo lunar astronauts. However, we have been advised by David O. Darling, LTP Recorder for ALPO, that this is not so. It appears that these events are confined to certain regions; for example, about 300 LTPs have been observed in the environs of the crater Aristarchus, over 70 near the crater Plato, and 25 in and around Alphonsus. Some phenomena have been seen in the peripheral areas of the maria. On-the-spot evidence comes from the results of an Apollo experiment in which sensitive instruments detected the emission of the radioactive gas radon in the neighborhood of the crater Aristarchus and along the edges of the circular maria.
The causes of the lunar transient phenomena are unknown, but although lunar volcanism ceased in the remote past and the present seismic activity is negligible, one must conclude that the Moon is not a completely dead world. If parts of the Moon's interior are still in a molten state, it would seem reasonable to expect the occasional escape of gases, or mixtures of gas and dust, from fissures near the surface. Could these be events that produce the transient lunar obscurations of surface detail? Here, then, is a field of study that demands much time, perseverance, dedication, a thorough knowledge of the lunar surface, and, from the practical point of view, a large, well-mounted, high-quality telescope.
Almost all of the LTPs were observed, then drawn by hand, the stories of the discoveries recanted. The time has come and the technology is here. What we need is live television pictures of the Moon and recorded instances of LTPs. If we accomplished nothing more, the Project would be worth it.