Ron Macnaughton

How the Ancients Predicted Eclipses

This talk will describe Moon-Earth-Sun patterns, in particular the Saros cycle. Babylonian astrologers kept records for centuries on clay tablets, which let them make rough predictions from observed cycles. Greek epicycle models for lunar motion improved accuracy. By the mid-17th century, mathematical models by Kepler and others allowed astronomers to make eclipse maps, which showed areas with predicted totality.


Ron MacnaughtonA retired physics teacher, Ron Macnaughton has given many astronomy presentations to different groups, including the 2016 GA in London, about the celestial navigation techniques used by explorer David Thompson to establish latitude and longitude. Ron has been a RASC member for decades, serving as chair of the National Education Committee, and coordinating the design and production of the Star Finders for the International Year of Astronomy.