Here's one report on research on static electricity that might occur in Martian soil:

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Title: Electrical Properties of Martian Regolith Simulant Particles.
Authors: Calle, C. I.; Kim, H. S.
Affiliation: AA(Sweet Briar College), AB(NASA/Kennedy Space Center)
Journal: American Astronomical Society Meeting #193, #96.07
Publication Date: 12/1998
Origin: AAS
Abstract Copyright: (c) 1998: American Astronomical Society
Bibliographic Code: 1998AAS...193.9607C

Abstract
Hubble Space Telescope observations of Mars from Earth as well as spacecraft
measurements from orbit around Mars and from the Martian surface itself have
shown that suspended dust is a significant component of the Martian atmosphere.
Dust clouds have been observed extending over areas as large as a few million
square kilometers. Hubble has also photographed planet-wide dust storms lasting
for over one month. These conditions, coupled with the absence of any
significant amounts of water in the Martian atmosphere, may create electrostatic
potentials that could be hazardous for astronauts and equipment in future
missions. The electrical properties of the Martian soil have been determined
directly only by radio occultation from spacecraft in orbit about Mars, by
earth-based radar, and by microwave radiometry. For the present work,
experiments were designed to determine the electrical properties of a Martian
regolith simulant prepared from Andesitic rocks by NASA Johnson Space Center
that has been shown to be a good spectral analog to the soil in the bright
regions of Mars. The volume electrical conductivity of the simulant was measured
to be intermediate between that of a good conductor and that of a good
insulator. Thus, the simulant particles were expected to exhibit fairly high
surface electrostatic charging and polarizability. Experiments to determine
polarization and electrostatic charging of the simulant particles under several
conditions were conducted.
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IF it is static electricity that is causing the stickiness then to get samples to be delivered to the Mars Phoenix instruments we might try to take the samples when the moisture in the air is highest.
The Mars MER rovers found there was frost deposited at night that burned off in early morning. This time would likely be when the humidity was highest at those sites.
The Mars Phoenix site is in a polar region during Martian northern summer where the Sun is always above the horizon so strickly speaking there won't be *night-time* frost deposition. Still there is great air temperature variation from -30C to -80C so there will likely be a diurnal time frame when the frost deposition is highest and also an optimal time frame where this frost will burn off as the temperature rises. Note also that orbital observations show that atmospheric water vapor is highest in the Mars polar regions so such frost deposition at the Phoenix site might be signicantly higher than for the equatorial MER rovers.
However, it is not certain that static electricity due to low air moisture is the problem here. Conceivably it might be the exact opposite where residual *liquid* water in the soil contributes to the stickiness of the soil. If this is the case then we will actually want to take the samples when the himidity in the air is lowest. Both scenarios should be tried.
Still another possibility is the magnetite particles that have been seen at the other landing sites is the cause of the stickiness. If this is the case I doubt that humidity variations will have an effect on the stickiness. I don't have a solution in this case. Perhaps experiments with Mars similants containing such magnetic particles would provide a solution about how best to deliver samples to the lander experiments.


Bob Clark