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. ...

... Hiorter and Celsius note that the polar aurora is accompanied by a disturbance of the magnetic needle. ... Richard Carrington in England observes a violent and rapid eruption near a sunspot; 17 hours later a large magnetic storm begins. ... Using it he observes a solar flare and confirms the connection between flares and magnetic storms. ... Explorer 1, launched by the US January 31, observes the radiation belt; Explorer 3, launched in March, comes up with the first clear evidence for its existence....

... Launch Date/Time: 1966-12-21 at 10:19:00 UTC . ... The Luna 13 spacecraft was launched toward the Moon from an earth-orbiting platform and accomplished a soft landing on December 24, 1966, in the region of Oceanus Procellarum. ... The spacecraft was equipped with a mechanical soil-measuring penetrometer, a dynamograph, and a radiation densitometer for obtaining data on the mechanical and physical properties and the cosmic-ray reflectivity of the lunar surface. ...