Comet-solar wind interactions: A dusty point of view

Abstract

Anticipating the new results from the space missions to Comet Halley and Comet Giacobini-Zinner, we make a brief review of recent theoretical and observational studies of dust-plasma environment. In order to relate different disciplines in cometary research in the context of comet-solar wind interaction, two separate issues: (a) surface processes and (b) plasma processes are considered to indicate how various kinds of observations of cometary dust comas and tails may be used to infer the conditions of solar wind - comet interaction and the corresponding plasma processes in the cometary ionospheres and ion tails (and vice-versa). In particular, it is suggested that the narrow sunward-pointing dust streamers emitted from the cometary nuclei could be related to the electrostatic transport of sub-micron dust over the nuclear surfaces at large heliocentric distances; and the striae sometimes observed in cometary dust tails at smaller heliocentric distances could be the consequence of electrostatic fragmentation of fluffy dust particles in the ion tails.