Open AccessCharged dust dynamics above the surface of a comet far from the Sun
Author(s) -
Juhász A.,
Szegő K.
Publication year - 1998
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/97ja02991
Subject(s) - physics , comet , photoelectric effect , solar wind , charged particle , radiation pressure , electron , comet tail , radiation , comet nucleus , van allen radiation belt , atomic physics , plasma , astrobiology , astronomy , magnetosphere , ion , optics , nuclear physics , quantum mechanics
We investigate the dynamics of small dust particles ejected from the sunlit side of the nucleus of a comet far from the Sun. The motion of these particles is determined by gravity, electromagnetic forces, and solar radiation pressure. The nucleus is not shielded from either the solar wind or the solar UV radiation; therefore the surface of the nucleus absorbs electrons and protons and emits photoelectrons. As a result, the surface gets positively charged. Above the nuclear surface a photoelectron plasma sheath forms in which the ejected dust grains collect electrostatic charges and become responsive to the electric field in the sheath. We show that most of the dust cloud created by an impact (e.g., a lander) will settle after a few (∼4) hours elsewhere and not in the close vicinity of the impact site (i.e., on the lander itself).