On the night of Friday, May 28, 2004, I observed a previously
unreported lunar light ray in Montes Riphaeus, a 150 kilometer long
mountain range that lies south of the crater Lansberg. I noticed the
ray initially sometime around 9:30 EDT (01:30 UT 2004/5/29) while
scanning the terminator at 159x with the 12.5" f/6.5 Cave Newtonian at
the Astronomical Society of Harrisburg's Naylor Observatory (position:
40.1° N, 76.9° W; elevation: 190 meters), which is located 2 miles
northwest of Lewisberry, Pennsylvania. A bit later I verified my
sighting with the ASH 17" f/15 classical Cassegrain, employing
magnifications of 162, 202, and 259x. What I saw was a thin shaft of
light running westward to the terminator, just south of an arc-shaped
region in the Riphaeus Mountains. The ray was positioned roughly at
6.25° south, 27.5° west.

At 10:45 EDT (02:45 UT), just prior to leaving the observatory, I
noted that the ray had widened somewhat.

My friend Tony Donnangelo was observing from his home that night and
was able to confirm my sighting.

For more on lunar light rays see
http://www.lunar-occultations.com/rlo/rays/rays.htm

Dave Mitsky