Premium
Particle‐size dependent bipolar charging of Martian regolith simulant
Author(s) -
Forward Keith M.,
Lacks Daniel J.,
Sankaran R. Mohan
Publication year - 2009
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2009gl038589
Subject(s) - martian , triboelectric effect , mars exploration program , regolith , astrobiology , particle (ecology) , polarity (international relations) , dust storm , atmosphere of mars , martian soil , electric field , planet , charged particle , physics , geophysics , environmental science , chemical physics , storm , geology , martian surface , astronomy , chemistry , meteorology , ion , biochemistry , oceanography , quantum mechanics , cell
The intense dust devils and dust storms on Mars are believed to generate large electrostatic fields that significantly alter geophysical and geochemical processes on the planet. The existence of such fields must be related to a mechanism by which charged dust separates by polarity; it has been widely hypothesized that this separation originates from a particle‐size dependence of the charge polarity, but this effect has never been demonstrated. To address this issue, we carry out experiments on the triboelectric charging of Martian regolith simulant (JSC‐1 Mars), using a fluid flow apparatus wherein only particle‐particle interactions occur, as is the case in Martian dust events. Our experiments show direct evidence that smaller particles tend to charge negatively and larger particles tend to charge positively, which provides a mechanism for the charge separation that creates electric fields in Martian dust events.