Additional information
by National Aeronautics and Administration (Author)
Solar eclipse canons have traditionally been publications offering maps of past and future eclipse paths using the best ephemerides of their day for calculating the positions of the Sun and Moon. The first major work of this kind was Theodor von Oppolzer's 1887 Canon der Finsternisse (Translated as Canon of Eclipses, Gingerich, 1962). It stands as one of the greatest achievements in computational astronomy of the 19th century and contains the elements of all 8,000 solar eclipses (and 5,200 lunar eclipses) occurring between the years -1207 and +2161 (1208 BCE and 2161 CE, respectively), together with maps showing the approximate positions of the central lines. The recently published Five Millennium Canon of Solar Eclipses: -1999 to +3000 (Espenak and Meeus, 2007) con¬tains individual maps for each of the 11,898 solar eclipses occurring over this period. The following points highlight the features and characteristics of this work. Based on modern theories of the Sun and the Moon constructed at the Bureau des Longitudes of Paris rather than the older Newcomb and Brown ephemerides; Ephemerides and eclipse predictions performed in Terrestrial Dynamical Time; Covers historical period of eclipses, as well as one millennium into the future; Global maps for each eclipse depict the actual northern and southern limits of the Moon's penumbral and umbral or antumbral shadows, as well as the sunrise and sunset curves; Maps include curve of eclipse magnitude 0.5; Maps include continental outlines with contemporary political boundaries and are large enough to identify geographic regions of eclipse visibility; Maps are based on the most current determination of the historical values of DELTA T; Estimates of eclipse path accuracy based on the uncertainty in the value of DELTA T (i.e., standard error in DELTA T) A primary goal of this work is to assist historians and archeologists in the identification and dating of eclipses found in references and records from antiquity. This is no easy task because there are usually several possible candidates. Accurate maps using the best available values of DELTA T coupled with estimates in the standard error of DELTA T, are critical in discriminating among potential eclipse candidates. Ultimately, historical eclipse identification can lead to improved chronologies in the timeline of a particular culture.
