Lunar ephemeris and selenographic coordinates of the earth and sun for 1977 and 1978
Ephemeris data are presented in sections for each month for 1977 and 1978 to provide a time history of lunar coordinates and related geometric information. A NASA Manned Spacecraft Center modification of an ephmeris tape was used to calculate and plot coordinates of the earth, moon, and sun. The ephemeris is referenced to the mean vernal equinox at the nearest beginning of a Besselian year. Therefore, the reference equinox changes from one year to the next between June 30 and July 1. The apparent discontinuity in the data is not noticeable in the graphical presentation, but can be observed in the digital output. The mean equator of epoch is used in all cases. The computer program used to compute and plot the ephemeris data is described in the appendix.