Abundances of Volatile - Bearing Species from Evolved Gas Analysis of Samples from the Rocknest Aeolian Bedform in Gale Crater

Abstract

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. SAM detected the evolution of H2O, CO2, O2, and SO2, indicative of the presence of multiple volatile bearing species (Fig 1). The Rocknest bedform is a windblown deposit selected as representative of both the windblown material in Gale crater as well as the globally-distributed martian dust. Four samples of Rocknest material were analyzed by SAM, all from the fifth scoop taken at this location. The material delivered to SAM passed through a 150 m sieve and is assumed to have been well mixed during the sample acquisition/preparation/handoff process. SAM heated the Rocknest samples to approx.835 C at a ramp rate of 35 C/min with a He carrier gas flow rate of apprx.1.5 standard cubic centimeters per minute and at an oven pressure of ~30 mbar [1]. Evolved gases were detected by a quadrupole mass spectrometer (QMS). This abstract presents the molar abundances of H2O, CO2, O2, and SO2 as well as their concentration in rocknest samples using an estimated sample mass