These events occur when the sun, at a low lunar altitude, projects a ray or spike of light, through a broken wall feature of a crater. Although many of these events may be visible on the surface of the moon, these are a listing of the more common ray events which have been reported in astronomical magazines, publications, or from observers who may have detected a ray for the first time, and reported it. Although not of any scientific value, the allusiveness of these events, coupled with the short time frame they are visible, make these real challenges for the avid lunar observer!
If you observe any of these events, and would like to have your observations placed in the reports, or if you think you have discovered another notable ray events, let me know and I will get it published here.
All the past predictions were generated using Harry Jamieson's "Lunar Toolkit" Program. Starting with the new 2015-2025 predictions, Jim Mosher's Lunar Terminator Visualization Tool (LTVT) was used. LTVT uses the JPL DE405 Ephemeris. Searching Jamieson's ToolKit program, it did not specify what ephemeris was being used to genereate the predictions of future events. One will notice if comparing times of the events, they are usually within minutes of each other. Since these events can occur over the span of several hours, the predicted times generated with LTVT should suffice. Also I noticed that using the date and solar altitude over a particular crater, that the solar altitude varied somewhat, but not too far off from the original ToolKit predictions. The difference I felt was also negligible. I also generated these predictions using a geocentric observer, rather than a specific set of terrestial longitude and latitude. When considering observing one of these events, the observer must first determine whether or not the moon will be visible in the sky for their part of the world. Not all events will be visible to everyone on the specifed date. It is also advisable to starting looking an hour or two before/after event time. It is not unusual for an event to occur before or after the predicted time frame.
Over the years I have received many reports of new rays and observation reports on existing events. These were on a hard drive that crashed years ago. Fortunately I was recently able to retrieve those reports, thanks to a friend who revived the information I needed. I will be processing those reports over the next several weeks, and posting them to the appropriate sections. I do not want anyone to think that I have just let these slide by. I look forward to any new events or reports, and will post them as I get them.
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Dave Mitsky's Observer's Calender
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