The official name of the latest rover we've sent to Mars is not Curiosity. It's Mars Science Laboratory. And one of the mobile lab's primary jobs -- besides photography and interplanetary telegraphy and being, generally, spunky -- is to do the very scientific job of assessing the soil on Mars. Curiosity has made its mission mainly to see what Mars is made of (and how its soil varies, and whether that soil could have once supported life).
Curiosity, having settled into life on Mars, has now begun the geological analysis aspect of its mission. Earlier this week, the rover took three small scoops of soil from a patch of dusty sand known as "Rocknest." It then sieved the sample to rid the dust of excess rocks. On Wednesday, finally, Curiosity fed a tiny bit of that sample -- a baby aspirin-sized bit -- into the inlet of its Chemistry and Mineralogy (CheMin) instrument. The CheMin will now use X-ray diffraction -- a mineral identification method never before employed on Mars -- to analyze the samples. (You can watch more about that process in the NASA-produced video here.)