The "ring of fire" seen by satellite cameras around the polar caps (picture below) is probably created by electrons leaking from the tail's plasma sheet, whose magnetic field lines form a somewhat imperfect trap. ... One possible explanation involves the close association between auroral arcs and electric currents which flow along field lines between the ionosphere and distant space ( Birkeland currents ). ... That produces an extra resistance to the flow of current. ...

... Future seminars . P a s t seminars . ... Radiation-driven winds from stars and Active Galactic Nucle" . ... It is now clearly understood that the problem of mass loss is crucially important both from the point of view of it’s influence on the evolution of stars and for the explanation of physical processes and observational data in active galactic nuclei (AGN). ... Absorption of the radiation by continuum opacity is responsible for such an evolutionary significant mass loss in cold massive stars. ...

Luna and Io - A Comparison Study . ... They will construct paper scale models of Io , Luna , Earth and Jupiter and use these models to explain the differences between the two moons. ... Explain to the students that the picture is not to scale, but that it represents Jupiter and one of its moons. ... Have the students divide into groups of three or four and construct scale models of the Earth/Luna system, and the Jupiter/Io system, using the facts on the data sheets. ... Jupiter, Io, Earth, and Luna . ...

Cosmic Research, Vol. 42, No. 5, 2004, pp. 435­488. Translated from Kosmicheskie Issledovaniya, Vol. 42, No. 5, 2004, pp. 453­508. Original Russian Text Copyright © 2004 by Veselovsky, Panasyuk, Avdyushin, Bazilevskaya, Belov, Bogachev, Bogod, Bogomolov, Bothmer, Boyarchuk, Vashenyuk, Vlasov, Gnezdilov, Gorgutsa, Grechnev, Denisov, Dmitriev, Dryer, Yermolaev, Eroshenko, Zherebtsov, Zhitnik, Zhukov, Zastenker, Zelenyi, Zeldovich, Ivanov-Kholodnyi, Ignat'ev, Ishkov, Kolomiytsev, Krasheninnikov, Kudela,