Tonight (9-25-2007) and coinciding with the first full Moon nearest the autumnal equinox, we have entered a harvest full moon window with an unusual 100 hours where there will always be light. Either the Sun or the Moon will illuminate the sky through the Moon reaching perigee on the 28th and continuing through the 30th. These near full Moon nights also will be unusually bright, as the Moon is near perigree. This unusual timing effect is the result of the rapid change in the length of the day near the equinox combined with the Moon's precession of about 50 minutes per night. This period of 100 hours of light also marks the beginning of the fall lunar imaging and observing season. Throughout the summer the Moon only has a few days each month at which it is at a high altitude above the local horizon in the northern hemisphere - usually near the third quarter phase in the early morning hours. The autumnal equinox marks the beginning of the fall lunar imaging season, where the Moon will more frequently rise at high altitudes favorable for astrophotography. Coincidentally, Venus also reached its greatest brillance in the early morning on Sept. 25th.
From my op, the number of hours that the Sun will be below the horizon and the Moon will be at an altitude higher than 50 degrees suitable for imaging are:
2007 10 52 11 61 12 64 2008 1 54 2 42 3 32 - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net