This image shows fine sand from Mars that was filtered by NASA's Curiosity rover as part of its first "decontamination" exercise. These particles passed through a sample-processing sieve that is porous only to particles less than 0.006 inches (150 microns) across. The view from the rover's Mast Camera looks into the portion box and "throat" of the Collection and Handling for In-Situ Martian Rock Analysis (CHIMRA) tool on the end of the rover's arm.
The decontamination exercise involved scooping some soil, shaking it thoroughly inside the sample-processing chambers to scrub the internal surfaces, putting it through a sieve, dividing it into the appropriate portions, then discarding the sample. This image is downstream of the sieve. The portion box will meter out a portion about the volume of half a baby aspirin so that the instruments receiving the sample will not choke on a sample that is too big.
The decontamination procedure will be repeated three times. The rinse-and-discard cycles serve a quality-assurance purpose similar to a common practice in geochemical laboratory analysis on Earth.
This image was taken by Curiosity's right Mast Camera (Mastcam-100) on Oct. 10, 2012, the 64th sol, or Martian day, of operations. Scientists white-balanced the color in this view to show the Martian scene as it would appear under the lighting conditions we have on Earth.
Image credit: NASA/JPL-Caltech/MSSS