One of the reasons the Maurolycus ray caught my eye was the unusual position of the ray within the crater. The break in the wall is actually on the WESTERN (setting sun) side of the crater. In addition, the ray does not project from this break onto the immediately adjacent crater floor towards the central peak, as normally seen for many rays. Instead, the ray appeared to begin around the same region as the bright central peak of the crater (skipping the dark region between the break in the western wall and the peak). From the region of the central peak, the ray then extended further from the center of the crater towards the opposite EASTERN wall. Most of the crater floor was still dark, except for the central peak and this ray of light located between the central peak and extending to the east. This is what gave the whole scene the dramatic "ray from a lighthouse" appearance, rather than a "ray from the wall" appearance. This sort of effect could be created by the high walls of Maurolycus (one of the deeper craters on the moon), and a complex topology of the floor. The whole north western floor of the crater floor appears to be battered lower than the eastern part (best seen in Lunar Orbiter Consolidated Atlas shot http://www.lpi.usra.edu/research/lunar_orbiter/img/4-95H2.jpg ). As a result, a ray of light coming through the western wall could skip the western half of the crater, catch the central peak and the eastern half of the crater floor, and appear to project like a lighthouse beacon from the central peak in an otherwise dark ocean.

Do you know of any older observations of this effect? I drew a sketch the night I saw it an would be interested to compare to older observations, sketches, or photographs.