Lunar transient phenomena (LTP): Manifestations,site distribution,correlations and possible causes

The author has been compiling a catalog of LTP reports (temporary changes observed on the moon). More than 1,400 of these observations, of which 1,353 have ancillary data, were analyzed in an attempt to determine the possible causes of LTP. There were 201 sites reported at least once; about $\text{1}\text{2}$ had two or more reports. One dozen sites contain 70% of all observations, and one site, Aristarchus, provides 30%. Of the dozen most reported sites, $\text{1}\text{2}$ are rayed and $\text{1}\text{2}$ are dark flat-floored craters. The distribution of sites strongly favors the borders of both the terra and marial sides of the maria. Many are within the maria, and a very few are inland; yet most of these are associated with dark flat areas.The phenomena manifest themselves in five categories, viz., Brightenings, or Darkenings, or as Gaseous, Reddish and Bluish events. Among the hypotheses proposed for their causes are tidal, low-illumination/thermoluminescence, magnetic-tail and solar-flare effects. Analyses were conducted to see if different phenomena had different causes. There is some suggestion that they do. As concerns the tidal effects. the strongest peaks are at 0.5 (apogee) for Gaseous and Darkenings phenomena, 0.6 for Reddish events, and 0.7 for Brightenings. Reddish LTP have the strongest correlation with sunrise, while Aristarchus, Plato, Ross D area, and Bluish phenomena have the strongest correlations with solar-flare activity that produced magnetic storms on earth. “All” observations, the ones labeled “Best” (probable true anomalies), and Aristarchus, showed minima in the first half and maxima in the last half of the anomalistic (tidal) period. Histograms of several individual sites, including neighboring ones, behave differently, e.g. Aristarchus and Herodotus. When observed data are compared with expected observations (assumed to be evenly distributed) there were various correlations. For the Best data, 12 and 10% of the LTP fall close to perigee and apogee, respectively, and 10% would be expected for each. Seventeen percent occur within one day after sunrise when 3% would be expected; 20% occur while the moon is in the earth's magnetopause where 14% would be expected, and 12% occurred the same day the earth had a magnetic storm where 3% would be expected.Charts of albedo vs. age of several points for ten features were constructed. From these the normal behavior of the features throughout a lunation period was obtained. Measures that depart 2 or more full steps in Elger's albedo scale, are considered to be anomalies. Several cases of anomalous measures show up; e.g., for points on the south wall of Eimmart an albedo of 3.5 was reported once at age 10 days while for age 9 days the average albedo was 8, as it was afterward at age 11 days. The 3.5 may have been an anomalous darkening but unnoticed by the observer. Most of the features remained stable. A few exceptions were found, with Dawes showing the most anomalies. These amounted to 12% by nights or 2% by individual measures. Thus, monitoring the moon may yield an LTP once in ten nights, or 50 observations.All hypotheses show correlations with some categories and some features. Sunrise correlation is the most frequent correlation. Few correlations involve as many as 50% of the observations. The distribution of all LTP sites is different from and unique compared with deep- and shallow-focus moonquake epicenters. Routine albedo measures reveal unobserved variations which amount to about 10% in nights of observation bu 2% of individual albedo measures.