Observer: Jeff Burton Date/time of observation: 2003/03/13 01:50 UT Location: Paducah, KY, USA (37°02'41" N, 88°34'26" W) Altitude: 108.5 meters (356 feet) Bortle Scale: 8 - City Sky, Antoniadi Scale: III Instrument: 114mm f/8 Newtonian Magnification: 206x (11mm Tele Vue Plossl / 2.5x Barlow), 175x (13mm Tele Vue Plossl / 2.5x Barlow), 70x (13mm Tele Vue Plossl) Object: Mercator (Crater), Rukl Chart #53, Colongitude: 27°.9 Lunar Light Ray Coordinates: 29°.6 S, 26°.4 W. Started observing the ray at 01:05 UT, at this time it appeared as a very small triangle of light on the western crater rim just south of craterlet Mercator C and directly across from craterlet Mercator B, which lies on the eastern rim. The ray began to lengthen and extend towards the center of the crater over the course of the next twenty minutes. By 01:35 UT, the ray appeared to extend about forty percent of the distance to the crater’s center, which was the maximum extent of the ray’s length. By 01:50 UT, the base of the ray has widened and the ray was an obvious wedge-shaped light on the floor of the crater at lower magnification (70x). The base of the wedge shaped ray continued to widen and around 02:20 UT, the southern side of the crater began to fill with sunlight. Thirty minutes later, the crater floor was mostly bathed in bright sunlight.

MERCATOR LUNAR RAY

Observer: Dave Mitsky & Tony Donnangelo
Date/time of observation: 2003/03/13 01:25 U.T.
Site location: Hummelstown RD 3, PA, USA (40.26° N., 76.75° W.) 
Site elevation: 479 feet (146 meters)
Site classification: Suburban
Instrument: Takahashi FS-102
Magnification: 158x(5.2mm Pentax XL), 234x(3.5mm Orion Lanthinum SW)  

The observing session began an hour prior to the lunar ray prediction of 01:37 U.T. With no ray yet occurring, I began observing other features and noticed a new ray in crater Lubiniezky E. I called Dave Mitsky and reported my observation. Living only a few miles away, he arrived within fifteen minutes.

The edge of a cloud bank ran west to east at the zenith, making observing difficult. It was ~80 to 90% cloudy near the moon, totally cloudy to its south, and mostly clear to its north. I wouldn’t normally attempt observing under those conditions; however, I had never seen this particular ray.

A break in the clouds occurred just 12 minutes prior to the predicted time, and Dave noticed a very small patch of light on the western end of Mercator’s floor, which was otherwise totally shadowed. We increased magnification and resolved a short, somewhat narrow pie-shaped wedge of light ~9 Km. long. Our observation was as Jane Houston Jones had originally reported, confirming her sighting.

Dave and I were able to observe the ray again at 1:55 U.T. It now appeared slightly broader and longer. At 2:15 U.T., we made our last observation. It continued to grow broader and longer. The clouds now completely covered the moon, and we ended our observing session.