ИСТИНА

Magnetic reconnection is a physical process in which magnetic field changes its topology, converting magnetic energy to the thermal energy and bulk flow energy of the accelarated charged particle flows. This process has a significant impact on the interaction between magnetized planets and the solar wind. It depends on the efficiency of reconnection, whether the interplanetary magnetic field (IMF) can penetrate the magnetosphere. In the present work we consider the case of Saturn. We test two models of the Saturn's magnetosphere. The first one is "open", in which the IMF penetrates the magnetosphere and reconnection is relatively efficient. The second one is the "partially clossed" model, in which the IMF does not cross the magnetopause. It is important, that the second model only is partially closed, because magnetospheric magnetic field lines connect with the IMF lines in the distant tail. We use magnetometer data from the Cassini spacecraft, ultraviolet images of Saturn's aurora from the Hubble Space Telescope and the paraboloid model of Saturn's magnetospheric magnetic field to examine which of these cases has been realized in nature. We show, that the efficiency of reconnection at Saturn depends on the orientation of the IMF, with reconnection at the two neutral points in the cusp regions for the case of the strong southward IMF is probably being the mostly efficient.