Orbital evolution of Jupiter's 8th satellite

The orbitai evolution of Pasiphae,the 8th satellite of Jupiter, has been investigated. Its osculating orbit for the epoch 29 October 1983 was numerically integrated over the interval of 20,000 years. Within the investigated time interval also the question of the Hill's stability has been studied. The Jacobian constant, generalized to the avegaged elliptic problem. calculated from position and velocities obtained by numerical integration, changes less then the order of 10 ^-8 The dominant pertubations by the Sun to the satellite allow us to use the intermediate orbit of the averaged elliptic three-body problem for investigation of the evolutionary change in the motion of the satellite. The mean motion of the agreement of perijove and the ascending node of the satellite are defined by analytical formulae, using the osculating non-Keplerian ellipse with moving node and perijove, and changing eccentricity. The results obtained according to this theory are comparable with those calculated from the numerical integration.