Interesting article at thunderbolts.info. "Unexplained" Forces Keep Mars Rovers Moving:
The rovers have provided continuous surprises since the outset. When their missions began, their solar cells were providing 900 watt-hours of electricity per day. Over the months that followed Spirit's output dropped to 400 watt-hours daily, while Opportunity dropped to about 500 watt-hours. A primary reason for the drop was the accumulation of dust on the panels. But then, to the amazement of mission scientists, Opportunity's power began to INCREASE, and kept on increasing until the power peaked at just over 900 watt-hours.A simple, logical, scientific explanation rejected by pre-existing scientific dogma. But wait, there's more:
As reported by Newscientist.com, the Mars rover Opportunity "stumbled into something akin to a carwash," which somehow 'cleaned' its solar panels. Jim Erickson of NASA's Jet Propulsion Laboratory admitted that the cause of this surprise 'cleaning' could not be explained. 'These exciting and unexplained cleaning events have kept Opportunity in really great shape,' Erickson said."
The remarkable cleaning occurred in spurts during the Martian night. The team managing the rover reported that on at least four occasions over a six-month period, the rover's power output suddenly increased by up to 5% in a single night. Some suggested that the Martian winds might have swept the dust off the panels. Others wondered if frost could have caused the dust to clump, exposing more of the panels. And some even suggested that the tilting of the rover while climbing hills might have caused a portion of the dust to drop off. Such "explanations" only add to the exasperation of those who understand very well what has occurred. Does dust fall off the top of your car when you drive uphill? Does the speed of your car on the highway clean the dust off? Is your car cleaner after a windy day?
While the rovers' cleanings and endurance is unexplained by NASA, a clue to the puzzle is provided by the agency's own news release dated July 14, 2005: "When humans visit Mars, they'll have to watch out for towering electrified dust devils." With these words, NASA gave official sanction to an idea that had already been percolating from separately funded research projects in recent years. This research has explored the electrical component to dust devils in the Arizona desert -- investigators were surprised to find that these vortices are electrically charged. According to the recent news item "Electric Sand Findings Could Lead to Better Climate Models," one investigator speculates that "electric fields get so large on the Red Planet they produce ground-level sparks."
But since it is verboten within official science to speak of planets as charged bodies, the investigators can only envision the electric fields associated with dust devils as an effect of particles bouncing and rubbing against each other -- ignoring the larger electrical condition required to generate the vortex in the first place. NASA suggests, "Dust devils get their charge from grains of sand and dust rubbing together in the whirlwind. When certain pairs of unlike materials rub together, one material gives up some of its electrons (negative charges) to the other material. Smaller dust particles tend to charge negative, taking away electrons from the larger sand grains." In this view, the rising central column of hot air that powers the dust devil carries the negatively charged dust upward and leaves the heavier positively charged sand swirling near the base. In this way, the charges get separated, creating an electric field.
But regardless of what causes the electric fields associated with Martian "dust devils" and dust storms, NASA still seems unwilling to consider their relevance to the rovers anomalies. From the electrical perspective, the robots' seemingly unfathomable endurance is easily explained as an effect of repeated electrostatic cleanings. On Mars, because of the atmosphere's thinness, dust particles charge more easily and will thus stick more "stubbornly" to a surface. Thus, the notion of repeated cleanings absent the electric force becomes all the more preposterous.
Ironically, a number of researchers have posited that the best cleaning method for removal of dust from power-systems on Mars will involve electrostatic applications. At the 2002 Photovoltaic Specialists Conference, G.A. Landis and P.P Jenkins stated in their paper "Dust mitigation for Mars solar arrays": "The environment of Mars is expected to be an ideal one for use of electrostatic dust-removal techniques."Heh.