View Full Version : Total lunar eclipse 10 December 2011

2011-Dec-04, 06:56 PM
The last eclipse of the year


2011-Dec-05, 02:19 PM
The same day U.S. property taxes are due. Coincidence? I don't think so. :shifty:

2011-Dec-05, 08:56 PM
On November 29 I initiated a thread for this topic which still exists on the front page of this same forum: http://www.bautforum.com/showthread.php/124849-Total-Lunar-Eclipse-December-10 . Please feel free to join us.

The panorama graphic and timetable that I created can be found at: www.CurtRenz.com/moon . Itís drawn in horizontal coordinates as seen from San Francisco (UT-8), but the timings will be the same for anyone experiencing nighttime if adjusted for time zone. This method accounts for the effects of the Earth's rotation, unlike the more typical diagrams drawn in equatorial coordinates with the Moon appearing to move in a straight line.

Unlike many eclipse prognosticators, rather than the somewhat nonsensical method traditionally used for determining shadow sizes, I employ the so-called French Rule. Then I go a step further by not considering the shadows to be perfectly circular, and instead adjust for the oblate shape of the Earth.

As a practical matter my efforts may be overdone, since the shadow edges are not sharp, and the theoretical increase in shadow size is a fudge factor. I bow to those considerations by posting timings with a precision in minutes rather than seconds (or tenths of a second, egads!)