QUOTE (Floyd @ Jul 17 2016, 10:25 AM)
I read a Science news story on electric fields in dust storms on Earth
LINK. A quick Google leads to NASA research on electric filed on dust devils on earth
LINK. Does anyone here know if researches ever considered placing a small instrument to measure electric and magnetic fields on a rover? If Spirit and Opportunity had such instruments, we would have gotten great data during near fatal dust storm and also all the cleaning events they experienced. I would be surprised if a combined magnetic and electric field monitor with data logger could not be built weighing significantly less than an ounce.
The lead author of the paper that triggered this story is Francesca Esposito, the PI of the DREAMS package on Schiaparelli, which includes the MicroARES electric field sensor.
The paper reports E-field measurements on dust in Morocco, allegedly supporting the idea that E-fields enhance dust lifting, although the theory that this would be the case was due to Kok and Renno (whose model results are reproduced in the paper)
I'm not sure the observations in this paper really establish cause vs effect, but certainly dustier circumstances correlate with stronger fields, and it will be interesting to see what the instrument yields at Mars.
QUOTE
Dust devils on earth create huge electric fields of up to 4,000 volts/meter and also contain magnetic fields. It would be good to ground truth this dust lifting phenomenon on Mars.
This is true (though I don't think I've seen any evidence of a static magnetic field, only UHF emissions detected with a coil. As for the E-field, indeed thousands of volts/m are typical in dust devils on Earth, but recall that the breakdown field on Earth is >10,000 V/m. The low surface pressure on Mars is near the minimum of the Paschen curve, and so breakdown may occur at a few hundred V/m, so I'd expect dust devils not to sustain fields much higher than that.