NASA Reference Publication 1216

Fred Espenak
Fifty Year Canon of Lunar Eclipses: 1986 - 2035

Fifty Year Canon of Lunar Eclipses: 1986 - 2035 has been designed to compliment Fifty Year Canon of Solar Eclipses: 1986 - 2035 (NASA RP 1178). Like its companion volume, its primary goal is to provide a five decade reference of moderately detailed eclipse predictions and maps for use by the astronomical community. During the past century, Canon of Eclipses [Oppolzer, 1887] has served as an invaluable guide to both solar and lunar eclipses. However, with the advent of high speed electronic computers and modern ephemerides, eclipse predictions of far greater accuracy are possible today. Although such predictions are published annually in the Astronomical Almanac by the Nautical Almanac Office, this publication only becomes available six to nine months before the beginning of each year. Canon of Lunar Eclipses: -2002 to +2526 [Meeus and Mucke, 1979] covers eclipses over an unprecedented 45 century interval. But due to the sheer number of eclipses covered in this work, the details for any one event must be rather brief. For instance, very little information is given concerning the visibility of an eclipse except for the geographic coordinates where the Moon appears at the zenith at greatest eclipse. While mathematical formulae are provided for calculating the Moon's altitude from any point on Earth, a map showing regions of visibility during each phase would convey a great deal of information at one glance.

Since Fifty Year Canon of Lunar Eclipses: 1986 - 2035 covers a much shorter time period, it's possible to include such maps in addition to diagrams showing the Moon's path through Earth's shadow. The graphical representation of this information provides the reader with an immediate appreciation of the geometry involved during each eclipse. Finally, data included with the figures and in the accompanying tables supplement the eclipse predictions.

Teachers, students, amateur astronomers and interested laymen should find this work useful as a general reference on eclipses during this century and the next. Lunar eclipses are one of the most dramatic and beautiful celestial phenomena visible to the naked eye. As such, they generate a great deal of interest among the general public and news media. Naturally, questions arise as to where a particular eclipse will be visible from, and when the next eclipse occurs. Unfortunately, there is very little information in print about the visibility of future eclipses and most references are obscure, not easily accessible and/or out of print. The eclipse path diagrams, world maps and detailed tables appearing in Fifty Year Canon of Lunar Eclipses: 1986 - 2035 should go far in addressing these issues.

The Fifty Year Canon of Lunar Eclipses: 1986 - 2035 is composed of three major sections and two appendices. Section 1 is a catalog which lists the general characteristics of every lunar eclipse from 1901 through 2100. Section 2 graphically illustrates the path of the Moon through Earth's shadow and the global visibility of every lunar eclipse from 1901 through 2100. Finally, section 3 consists of detailed eclipse path figures and predicted contact times along with cylindrical projection maps (including political boundaries) of the global visibility for every lunar eclipse from 1986 through 2035.

Appendix A provides some general background on lunar eclipses and covers eclipse geometry, eclipse frequency and recurrence, enlargement of Earth's shadow, crater timings during eclipses, eclipse brightness estimation and time determination. Appendix B is a listing of a very simple FORTRAN program which can be used to predict the occurrence and general characteristics of lunar eclipses. It makes use of many approximations while maintaining a reasonable level of accuracy and reliability. The program is based primarily on algorithms devised by Meeus [1982] and the ample comments should make the program self- explanatory.

Permission is freely granted to reproduce any portion of this NASA Reference Publication. All uses and/or publication of this material should be accompanied by an appropriate acknowledgment of the source.

The Fifty Year Canon of Lunar Eclipses: 1986 - 2035 has been reprinted by Sky Publishing Corporation and may be ordered from them.

2008 Mar 14