1. A table or set of data showing the predicted positions of celestial bodies (such as planets, stars, or the Moon) at specific times.
Usage: astronomy; plural: ephemerides or ephemerides
2. A publication containing such astronomical data, typically issued annually.
Usage: astronomy

Examples

• Astronomers use an ephemeris to predict the exact location of Jupiter on any given night.
• The Nautical Almanac is a well-known ephemeris used by sailors for navigation.
• Modern spacecraft rely on ephemerides to calculate precise orbital trajectories.
• She consulted the ephemeris to determine when the comet would be visible from Earth.
• The ephemeris data showed that the Moon would pass directly in front of the Sun during the eclipse.
• Telescope operators reference the ephemeris before observing distant planets.