Hi Brent, It is only a coincidence that the full moon/ lunar opposition happened so close to the equinox this year, AD 2010. It could happen any of the 14.5 days around the equinox, so roughly September 5 to October 5.
Last year the closest lunar opposition to the equinox was October 2 (or 3 depending on where you live). Ross > Date: Fri, 24 Sep 2010 11:46:50 -0700 > From: bren...@verizon.net > To: sundial@uni-koeln.de > Subject: Re: moon shadows > > > Hello, I am afraid that if you wanted to make the sort of > observations that you suggest to any accuracy then the gnomon set up > that you have used is incorrect. It should be set to point to true > north (not > > compass north) and be at an angle to the horizontal which is equal > to your latitude. The sun is due South at solar Noon and is not > (generally) at an altitude equal to your latitude at noon during an > equinox. > > Regards > > Patrick > > > > Hi patrick; > > I have seen the type of gnomon dial you refer to. > I think they call it an equatorial dial. > > Mine is the opposite, mine points due south since I am in the northern > hemisphere. And it does give me an accurate reading of my latitude. > I don't think it is coincidence. > When you point a gnomon at the sun at noon on the equinox the gnomon > is essentially in the same plane as the equatorial plane as the sun is > directly above the equator on equinox days. > So I think you can determine your latitude anywhere on earth by using > the same method. > > Correct me if I am wrong. > > As far as the moon shadows; I guess now if the moon was in the exact > same position as the sun was 12 hours earlier on an equinox that would > mean they are in the same plane and we would have had an eclipse. > However, I still find it fascinating that I had that big bright > harvest full moon so closely aligned with my pipe at solar midnight. > > brent > > --------------------------------------------------- > https://lists.uni-koeln.de/mailman/listinfo/sundial >
--------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
