An unexplained phenomenon akin to a space-borne car wash has boosted the performance of one of the two U.S. rovers probing the surface of Mars, New Scientist magazine said on Tuesday. It said something -- or someone -- had regularly cleaned layers of dust from the solar panels of the Mars Opportunity vehicle while it was closed down during the Martian night. The cleaning had boosted the panels' power output close to their maximum 900 watt-hours per day after at one stage dropping to 500 watt-hours because of the heavy Martian dirt. By contrast, the power output of the solar...