Observer: Tony Donnangelo
Date/time of observation: 2003/01/13 02:56 U.T.
Site location: Hummelstown RD 3, PA, USA (40.26° N., 76.75° W.) 
Site elevation: 479 feet (146 meters)
Site classification: Suburban
Moon's age: 10d 06:32, 73% illuminated 
Instrument: Takahashi FS-102
Magnification: 158x(Pentax 5.2mm XL), 234x(3.5mm Vixen SW) 
Object: Campanus (crater)
Lunar ray coordinates:  28.0°S., 28.0°W.
Rukl chart #: 53

I began my observing session four hours prior to seeing this light ray. It was bitter cold out. I spent almost as much time inside warming up than actually observing. I had just gone outside from one of my warming-up periods, and the ray was visible at that time. It couldn t have been visible much sooner than that.

When I first observed the ray, it was extremely dim and hard to see. This may have been due to it being extremely narrow and sky conditions that weren t very transparent. It was also very short. It emanated from the illuminated peak of the central mountain and stretched to the western wall. I tried to increase the magnification, but poor sky conditions degraded the view too much. I was skeptical at first and wanted to verify what I was looking at.

After 25 minutes, the ray widened slightly to more of a cone shape and brightened significantly. The central mountain now cast a very narrow shadow in the ray, dissecting it along its total length. I last looked at it at 05:00 U.T. The sky became almost totally cloudy, but I could still see the ray through a thin cloud layer. It widened to a pie-shaped wedge and was very bright. It now started slightly east of the central mountain, and the mountain s shadow was offset in the ray. The floor of the crater remained dark, except for the ray, during the whole observing session.

Site Longitude = +40.260
Site Latitude = +76.750
Site Elevation = +146.000

Feature = campanus
Feature Longitude: = -27.800
Feature  Latitude: = -28.000

Reproducing Lighting For: 2003/1/13 at 02:56 U.T.

Desired Solar Altitude =  +2.856(Rising),  Azimuth = +89.721
Average Co-longitude =  31.035

Crater size: Dimension: 48x48Km / 29x29Mi, Height: 2080m / 6300ft, Height/Wide ratio: 0.0433 Description: This crater has some steep slopes, particularly to the north. It also has pretty high walls that are terraced. The flat floor is filled with lava and has a central mountain and a few craterlets. (Tony Donnangelo)(