mt1955's Journal: Rover Solar Panels Cleaned

New Scientist reports that the Mars Rover Opportunity has had its solar panels cleaned on at least four seperate occasions and NASA doesn't know how it's happening.

The rovers landed on Mars in January with solar cells capable of providing more than 900 watt-hours of electricity per day. Spirit's output has dropped to about 400 watt-hours, partly because Martian dust has caked its solar panels. Opportunity's output also declined at first - to around 500 watt-hours - but over the past six months it has regained power (New Scientist, 30 October, p 6). Lately, its solar cells have been delivering just over 900 watt-hours.

Rover team leader Jim Erickson at NASA's Jet Propulsion Laboratory in Pasadena, California, told New Scientist that a process still not understood.