A Search for Molecular and Isotopic Biomarkers on the Surface of Mars Using High-Resolution Mass Spectrometry, 15-9367Printer Friendly Version
Inclusive Dates: 09/22/02 - Current
Background - It is very unlikely that life (in the form of bacteria) currently exists on Mars, but is quite possible that it once did. Controversy over life on Mars began in earnest with the Voyager mission in the 1970s and heightened with the recent discovery of controversial evidence for relic biogenic activity in the Alan Hills 84001 meteorite, believed to be part of the ancient martian crust. What was unusual about Alan Hills 84001 was the presence of nonbiogenic organic material embedded in apparent fossil inclusions that suggested evidence of nanobacteria. To resolve the issue of Mars' habitability, NASA has embarked on a series of missions to study the atmosphere, surface, and subsurface of the planet.
Approach - Any search for pre-biotic or biotic materials on Mars must concentrate on chemical signatures of the necessary components of life. These center on identifying sources of water and the hydrological cycle; understanding the composition of surface minerals and elements, particularly C, N, O, P, and S from which complex molecules characteristic of life can be built; and isotopic markers characteristic of organic processes such as the 12C/13C ratio. One key approach to making these identifications is the technique of high-performance mass spectroscopy and associated chemical separation processes such as gas chromatography. Following initial studies, we have concluded that a reflectron time-of-flight mass spectrometer (RTOF/MS) offers the highest performance in resolution and dynamic range for the minimal resources (mass, power) that are available for Mars surface experiments. Our objectives are therefore to build a prototype of a state-of-the-art RTOF/MS capable of detection and quantitative analysis of less than 1 part per billion of pre-biotic and biogenic materials at mass resolutions of 10,000 or above. Technology developed in this project will be applicable to future exploration of Europa, Titan, and Triton which are other candidates for biogenic processes.
Accomplishments - Mathematical studies of the electro-optics of TOF mass spectrometers have confirmed our initial premise that RTOF/MS is capable of the necessary performance. A prototype instrument is nearing completion together with a test chamber. Two proposals have been submitted to NASA for studies with the University of Michigan, Jet Propulsion Laboratory, and the University of Hawaii that are expected to lead to funding for SwRI participation in Mars Surface Lander investigations scheduled for 2009 launch.