Possible Detection of Perchlorates by Evolved Gas Analysis of Rocknest Soils: Global Implication

The Sample Analysis at Mars (SAM) instrument suite on board the Mars Science Laboratory (MSL) recently ran four samples from an aeolian bedform named Rocknest. Rocknest was selected as the source of the first samples analyzed because it is representative of both windblown material in Gale crater as well as the globally-distributed dust. The four samples analyzed by SAM were portioned from the fifth scoop at this location. The material delivered to SAM passed through a 150 m sieve and should have been well mixed during the sample acquisition/ preparation/handoff process. Rocknest samples were heated to ~835 C at a 35 C/minute ramp rate with a He carrier gas flow rate of ~1.5 standard cubic centimeters per minute and at an oven pressure of ~30 mbar. Evolved gases were detected by a quadrupole mass spectrometer (QMS).