<P> Other factors that affect solar power output include the opacity of the Martian atmosphere and Martian seasonal changes, however this does not account for the unexplained and complete removal of dust from intricate surfaces as can be observed in the images above; for example, the chassis and sundial are not photo - voltaic in nature . </P> <P> The Materials Adherence Experiment had a glass plate that allowed the dust to be cleared off and protected a Gallium arsenide photo - cell . It was part of the Mars Pathfinder program in the 1990s . This allowed the rate at which dust accumulated to be measured </P> <Ul> <Li> In early 2014 cleaning events boosted power levels on the Opportunity (MER - B) rover by 70% . A particularly strong cleaning event occurred in March 2014 while the rover was at Endeavour crater </Li> </Ul> <Li> In early 2014 cleaning events boosted power levels on the Opportunity (MER - B) rover by 70% . A particularly strong cleaning event occurred in March 2014 while the rover was at Endeavour crater </Li>

Who is cleaning the nasa mars rover curiosity