ИСТИНА

N. A. Solovaya (Sternberg State Astronomical Institute, Lomonosov Moscow Univerzity, Moscow, Russia); E. M. Pittich (Astronomical Institute, Slovak Academy of Sciences, Bratislava, Slovak Republic). The motion of the argument of perijove of the 8th satellite of Jupiter has been investigated. The dominant perturbations by the Sun to the satellite allow us to use the intermediate orbit, obtained by approximated solution of differential equations before transformation by the Zeipel’s method. The orbit is non-Keplerian ellipse. The secular motion of the ascending node, argument of perijove, and essential periodic perturbations were taken into account. The retrograde motion demonstrates an interesting geometry of the satellite’s orbit. Using our theory we show that can be cases when the inclination and eccentricity have such values by which the circular motion of the argument of perijove becomes librating around 90 or 270 deg. Therefore it is not possible to speak about the mean motion of the argument of perijove. Taking into account the results of our previous work and results of other authors we can give following conclusions. The mean motion of the ascending node is similar in all works. But the mean motion of the argument of perijove is different. We suppose that it is not possible to speak about the mean motion of the argument of perijove of Pasiphae.