A collection of > 800 reports of lunar transient phenomena (LTP) etsntained 771 positive and 112 negative observations with sufficient ancillary data. to be analyzed for five hypotheses of causes. Greater than one third of these reports involve Aristarchus, divided almost equally between two observing g;rsups, One homogeneous group involved one observer, Bartlett, and the other, heterogeneous group comprised all other observers. These two groups plus their ~=ombiaaation were each separately analyzed for each hypothesis for Aristarchus ., The observations seemed to form four categories, viz. (1) gaseous, (2) reddislh, ( 3 ) bluish, and (4) colorless brightenings and were analyzed under each category for each hypothesis and group, as well a s the total Aristarchus and total of a.l.1 sites which were analyzed for each hypothesis. Each and all were compared. The five hypotheses involved the effects of (1) tides, (2) sunrise, (3) low-angle i8lumiwtion, (4) earth's magnetic tail, and (5) solar particles.The analytical results for Aristarchus suggest the following: (1) ga.sesus phenomena of Bartlett differed in analytical behavior from those of all. others; (2) Bartlett's reddish phenomena differed from all others, being seen at times when gaseous phenomena were not present, suggesting he saw ground color in iii the absence of events of an obscuring medium. All othersr reddish phenomena were probably lunar events; (3) Bartlettls bluish phenomena correlated similarly to all others brightenings (and their bluish), suggesting that similar phenomena were observed by the two groups, but that Bartlett may be blue-sensitive, seeing color when others do not. Absence of reports of reddish, orange or pink phenomena by Bartlett (his reddish were browns, coppers and yellow-browns) imply lower sens:iltivity to red for him a s well as greater blue sensitivity; (4) behavior of each separate site considered was capricious with few similarities between near neighk~ors .For all sites the following a r e deduced from the analyses: (1) Nearly all categories, in&,vidual sites, and the totality of observations correlated most strongly with sunrise. Selection effects probably do not account for all of this correlation, implying that sunrise conditions a r e favorable to the observation of phenomena;(2) High co~rrelation was also found for magnetic tail effects; (3) Tidal effects correlated ~tlrnost exclusively with perigee only, being less than expected for apogee, but even perigee correlations declined with increased numbers of observations, re:julting in only a slight excess over expected percentages even at perigee, The correlation is somewhat stronger a t times of greater orbital eccentricity than at the lesser eccentricities; (4) A tidal correlation though, is weakened by the similar correlation (instead of the expected opposite) of the Absent phel~omena, and the progression around the lunar anomalistic orbit of dates of the Onset of phenomena; (5) The correlation for direct solar bombardment frown solar flares is weak but appea...

Several more or less unsatisfactory theories have been proposed for the origin of lunar sinuous rills such as Schröter's Valley. This paper presents a new explanation of the formation of these rills, namely, that they are valleys eroded by nuées ardentes. Characteristics of the rills, including form and association, are cited in support of this theory. Supporting evidence is found in the similarity of the rills to furrows eroded by nuées ardentes on the earth.

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Orbiter photographs of the wall of a large circular formation on the moon show that the wall is a convex body resembling a flow of viscous lava. The slopes are less than the angle of repose of dry rock; hence an explanation in terms of mass wastage is hard to support. The viscosity is approximately 10(13) centimeter-gram- second units, indicating an acid lava.

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