An ephemeris (plural: ephemerides; from the Greek word "daily")'s a table of values that gives the positions of astronomical objects in the sky at a given time or times. Different kinds are used for astronomy and astrology. Even though this was also one of the first applications of mechanical computers, an ephemeris will still often be a simple printed table. The position's given to astronomers in a spherical polar coordinate system of right ascension and declination or to astrologer in longitud… (More on Ephemeris)