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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Venus-- Correction
From: Frank Reed CT
Date: 2005 Dec 9, 02:55 EST
From: Frank Reed CT
Date: 2005 Dec 9, 02:55 EST
Bill you wrote: "...we could be looking at an errors up to 0.5'." By the way, the angular diameter of Venus is simply proportional to the planet's horizontal parallax, which you usually have direct access to in almanac data. For Venus, the angular diamater is just about twice the parallax. For Mars, it's roughly equal to the parallax. Incidentally, this also works for the Moon. The Moon's angular diameter is roughly half the Moon's parallax. Note that the ratios of those factors are nothing more than the ratios of the actual diameters (in miles, e.g.) of Venus, Mars, and the Moon. -FER 42.0N 87.7W, or 41.4N 72.1W. www.HistoricalAtlas.com/lunars