The "Microscopic Imager" - Sol 9 (Approximate True Colors; credits: NASA/JPL-Caltech)

Caption NASA originale:"The Microscopic Imager (circular device in center) is in clear view above the surface at Meridiani Planum, Mars, in this approximate true-color image taken by the panoramic camera on the Mars Exploration Rover Opportunity. The image was taken on the 9th Sol of the Rover's journey.
The microscopic imager is located on the Rover's instrument deployment device, or arm. The arrow is pointing to the lens of the instrument. Note the dust cover, which flips out to the left of the lens, is open. This approximated color image was created using the camera's violet and infrared filters as blue and red".