Organic molecules revealed in Mars’s Bagnold Dunes by Curiosity’s derivatization experiment

Abstract : The wet chemistry experiments on the Sample Analysis at Mars instrument on NASA’s Curiosity rover were designed to facilitate gas chromatography mass spectrometry analyses of polar molecules such as amino acids and carboxylic acids. Here we present the results of such a successful wet chemistry experiment on Mars on sand scooped from the Bagnold Dunes with the N-methyl-N-(tert-butyldimethylsilyl) trifluoroacetamide derivatization agent. No amino-acid derivatives were detected. However, chemically derivatized benzoic acid and ammonia were detected. Mass spectra matching derivatized phosphoric acid and phenol were present, as were several nitrogen-bearing molecules and as yet unidentified high-molecular-weight compounds. The origin of these compounds, including those that may be internal to the Sample Analysis at Mars background, is examined. This derivatization experiment on Mars has expanded the inventory of molecules present in Martian samples and demonstrated a powerful tool to further enable the search for polar organic molecules of biotic or prebiotic relevance.