The JPL Planetary and Lunar Ephemerides DE440 and DE441

The planetary and lunar ephemerides called DE440 and DE441 have been generated by fittingnumerically integrated orbits to ground-based and space-based observations. Compared to theprevious general-purpose ephemerides DE430, seven years of new data have been added tocompute DE440 and DE441, with improved dynamical models and data calibration. The orbit ofJupiter has improved substantially by fitting to the Juno radio range and Very Long Baseline Array(VLBA) data of the Juno spacecraft. The orbit of Saturn has been improved by radio range andVLBA data of the Cassini spacecraft, with improved estimation of the spacecraft orbit. The orbitof Pluto has been improved from use of stellar occultation data reduced against the GAIA starcatalog. The ephemerides DE440 and DE441 are fitted to the same data set, but DE441 assumesno damping between lunar liquid core and solid mantle, which avoids a divergence when integratedbackwards in time. Therefore, DE441 is less accurate than DE440 for the current century, butcovers a much longer duration of years –13,200 to +17,191, compared to DE440 covering years1550 to 2650.