Magnetic reconnection in comets

Today many of the traditionally puzzling phenomena in the cometary plasma-tail environment can plausibly be linked to magnetic reconnection occurring in several regions of a comet (Niedner and Brandt, 1978 and 1980). The turn-on of these various reconnection sites appears to follow a cyclic pattern in which the plasma-tail disconnection event is the primary feature, and the periodic sector structure of the solar wind is the external driver. The purpose of this review is to discuss these different classes of cometary activity, to state the justifications for linking them to reconnection, to discuss proposed alternate (nonreconnection) models, and to suggest future tests of the hypotheses presented.