Observer: Tony Donnangelo
Date/time of observation: 2002/12/17 01:15 UT
Location of site: Hummelstown RD 3, PA, USA (40.26° N., 76.75° W.) 
Site Elevation: 479 feet (146 meters)
Site classification: Suburban
Sky darkness: Moon was 93% illuminated with a fair, clear sky.
Instrument: Takahashi FS-102
Magnification: 91x(9mm NaglerT6), 102.5x(8mm Vixon LSW), 234x(3.5mm Vixon LSW), 
               158x;315x;394x(Pentax 5.2LX with 2x Barlow & 2.5x Powermate)
Object: Crater G  (Northwest and adjacent to crater Lacroix), Rukl Chart #61
Lunar Light Ray s Coordinates: 36.5°S, 59.0°W.

I noticed this ray between observations of the Babbage Lunar Sunrise Ray. The floor of the crater was in total darkness, and the ray was extremely narrow and dim early on. It ran the width of the crater east and west, almost bisecting it. I wasn t positive at first if this was really a ray. I increased the magnification from 158x to 394x for clarification. It became brighter and slightly wider as time went on, which made it more easily evident that it was a ray even at lower magnifications. I alerted Dave Mitsky, and he came to observe with me. By the time he arrived at ~02:00 UT, the northern half of the floor had become partially illuminated. I observed it until the northern half became almost totally illuminated, while the southern half stayed in shadow. Even at this time, the ray was bright enough to be seen along the terminator on the floor of the crater. It was shorter in length by this time.

Starting Date = 2002/12/17 at 01:15 U.T.

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

Feature = lacroix
Feature Longitude: = -59.000
Feature  Latitude: = -37.900

Reproducing Lighting For: 2002/12/17 at 01:15 U.T.

Desired Solar Altitude =  +2.049(Rising),  Azimuth = +88.929
Average Co-longitude =  61.597
In the Time column, D=Daylight, T=Twilight

                      ---- Moon's ----    -- Earth's --
                        Topocentric        Topocentric      -------- Sun's --------
   UT Date    Time     Alt°   Semi-Diam''  Long°   Lat°     Colong°     Lat°    Azim°

 2002/12/17  01:15   +59.035    907.37    -2.183  +2.226    061.275   -0.414  +88.929

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