Sample Processing and Handling–Collection

The Rocknest aeolian deposit is similar to aeolian features analyzed by the Mars Exploration Rovers (MERs) Spirit and Opportunity. The fraction of sand <150 micrometers in size contains ~55 % crystalline material consistent with a basaltic heritage and ~45 % x-ray amorphous material. The amorphous component of Rocknest is iron-rich and silicon-poor and is the host of the volatiles (water, oxygen, sulfur dioxide, carbon dioxide, and chlorine) detected by the Sample Analysis at Mars instrument and of the fine-grained nanophase oxide component first described from basaltic soils analyzed by MERs. The similarity between soils and aeolian materials analyzed at Gusev Crater, Meridiani Planum, and Gale Crater implies locally sourced, globally similar basaltic materials or globally and regionally sourced basaltic components deposited locally at all three locations. The Mars Science Laboratory (MSL) roverCuriosity began exploring the surface ofMars on 6 August 2012 (universal time co-ordinated); until 13 September 2012, it conducted an initial engineering checkout of its mobility sys-tem, arm, and science instruments. Curiosity spent sols 57 to 100 (1) at a location named Rocknest, collecting and processing five scoops of loose, un-consolidated materials extracted from an aeolian sand shadow (2). Five scoops of material from the Rocknest sand shadow were individually collected and sieved (<150 mm) by the Sample Acquisition