text: Some people, however, were not convinced. "Perhaps, said skeptics, alien markings were hidden by a haze." People believed the clouds had blocked the view of "alien markings". In 2001, on a "cloudless summer day". Mars Global Surveyor got another look. The photo was taken in maxium resolution. "Each pixels in the 2001 images spans 1.56 meters, compared to 43 meters per pixel in the best 1976 Viking photo."