SAM measurement of krypton and xenon on Mars

Because of their importance to our understanding of planetary and atmospheric evolution, the abundances and isotopic ratios of the noble gases are an important measurement objective of the Sample Analysis at Mars (SAM) investigation on the Mars Science Laboratory mission. SAM has conducted atmospheric enrichment experiments in which the abundances and isotopic ratios of Ar, N2,/sub>, and Kr have been measured and we have detected and computed upper limits on the abundance of Xe as well. In this report, we focus on the Kr and Xe experiments. Viking measured the martian atmosphere, including Kr and Xe. The Viking experiments were conducted using dynamic mass spectrometry with chemical scrubbing to minimize CO and CO2 and variable numbers of enrichment cycles to obtain the values shown in Table 1. Also shown are one SAM data set as well as values obtained from analysis of the shergottite EET (A) 79001 Lith. C—the shock melt component