Thanks for the Scrub
This image from Curiosity's Mast Camera shows NASA's Curiosity rover just after discarding a soil sample as part of its first "decontamination" exercise. A small amount of remnant material is visible inside the delivery tube, which is magnified in the blow-up at lower right. The Collection and Handling for In-Situ Martian Rock Analysis (CHIMRA) tool on the end of the rover's arm had just finished shaking some scooped-up soil thoroughly inside the sample-processing chambers to scrub the internal surfaces, putting it through a sieve and dividing it into the appropriate portions.
When the decontamination process has been performed three times and actual sample distribution is ready to occur, the samples will be delivered to the Chemistry and Mineralogy and the Sample Analysis at Mars instruments.
The amount being discarded here was about the volume of half a baby aspirin.
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.
JPL manages the Mars Science Laboratory/Curiosity for NASA's Science Mission Directorate in Washington. The rover was designed, developed and assembled at JPL, a division of the California Institute of Technology in Pasadena.