One of the few areas of study for the amateur lunar specialist that remains of genuine scientific use is the highly controversial one of Transient Lunar Phenomena (TLP – Americans use the term Lunar Transient Phenomena, LTP). The reason for the controversy is that since the 1950s many people have made quite ridiculous claims of frequent weird happenings on the Moon's surface. The credibility of the subject has suffered greatly from the fanaticism of these people. Now, many people dismiss the whole subject out of hand. Some go as far as to deride all who would study the phenomena.

Most of the serious, long-term, students of the Moon – both amateur and professional – are wisely cautious about supposed transient lunar phenomena but accept that there is some evidence to support the view that there is, at the very least, something worthy of investigation. In this chapter I present some of the evidence and explain how you might take part in this study yourself.

THE MYSTERY UNFOLDS

Observers, most significantly regular observers, of the Moon report occasional odd appearances, including short-lived glows (sometimes coloured) and mist-like obscurations, involving small areas of the Moon's surface. This is not a new phenomenon. Indeed, reports go back centuries but by the twentieth century, when it was established that the Moon has essentially no atmosphere, most astronomers were of the opinion that all the observed oddities could be explained as mere tricks of the eye.