Fundamental Ephemeris

Fundamental ephemeris is a precise mathematical model that predicts the positions of celestial bodies, such as planets or spacecraft, over time. It uses detailed data about their orbits and motions, derived from observations and physics, to generate accurate, time-specific information about their location in the sky. Essentially, it acts as a reliable "calendar" and "map" for astronomers and space missions, enabling them to know where a celestial object will be at any given moment with high accuracy.