This image from NASA's Curiosity rover shows the cover on an inlet that will receive powdered rock and soil samples for analysis. It was taken by Curiosity's Mars Hand Lens Imager (MAHLI) on Curiosity's 36th Martian day, or sol, of operations on Mars (Sept. 11, 2012). MAHLI was about 8 inches (20 centimeters) away from the Chemistry and Mineralogy (CheMin) sample inlet when it took the picture. When the cover is open, Curiosity will be able to drop samples into the inlet so scientists can identify and quantify the minerals in the samples. The cover has a diameter of 2.67 inches (6.77 centimeters).
The image also shows sand and angular and rounded pebbles that were deposited on the rover deck when it landed.
Engineers and scientists have been using images like these to check out instruments since Curiosity landed on Mars on Aug. 5, 2012 PDT (Aug. 6, 2012 EDT).