The Orbits of the Regular Jovian Satellites and the Orientation of Jupiter's Pole

In support of the Juno mission currently in orbit about Jupiter, we have updated our ephemerides for the Galilean and four inner Jovian satellites, Amalthea, Thebe, Adrastea, and Metis (Jacobson, 2014 European Planetary Science Congress, Vol. 9). For the update we expanded the data set to include astrometry through 2018, mutual events through 2021, eclipse timings from 1650 to 2016, stellar occultations, occultations of the Juno spaceccraft, and Juno tracking data through early 2024. Our model for the satellite orbits is a numerical integration of their equations of motion expanded to include effects of tides raised on Jupiter by the Galilean satellites and the tide raised on Io by Jupiter, and general relativistic effects due to the Sun and Jupiter including the Lense-Thirring effect. We account for the external perturbations from the Sun, Saturn, Uranus, and Neptune. The direct effects of the Moon, the inner planets, the dwarf planets, Ceres and Vesta, and the asteroids are ignored but the mass of the Sun is augmented with their masses to indirectly include their perturbations. We allow for the gravitational field of an oblate Jupiter and for the quadrupole gravitational fields of the Galilean satellites. The direction and precession of Jupiter's pole are needed to orient the Jupiter gravity field. The model for the motion of the pole is based on the rotational equations of motion for a rigid axially symmetric body. The applied torques are derived from the Sun, Saturn, Uranusand the Galilean satellites acting on Jupiter's figure. We numerically integrate the equations over a 400 year period and fit the integrated orientation angles with a Fourier series.In this paper we report on the results of our latest determination of the satellite orbits, the Jovian tidal parameters, and the Jupiter pole parameters. We find clear evidence that Io and Europa are spiraling inward while Ganymede is on an outward spiral. We also find that our pole model requires a Jupiter polar moment of inertia somewhat larger than most theoretical predictions.