2006 Annual Science Report
Indiana University, Bloomington Reporting | JUL 2005 – JUN 2006
Design and Assembly of a Cavity-Ring Down Spectrometer for Determination of Concentration and Isotopic Composition of Methane in Gases
Project Progress
T. C. Onstott recently published a paper (2006, Astrobiology Journal) concerning origins of Martian methane and advantages of utilizing a cavity-ring down spectrometer to characterize methane. J. Kessler, a postdoctoral research associate in the Onstott laboratory at Princeton University, is working on design and construction of a Cavity-Ring Down Spectrometer (CRDS) to make laboratory and field measurements of methane concentration ([CH4]) and distributions of stable isotopes (δ13C-CH4 and δ2H-CH4). The Princeton instrument is designed to analyze methane in gaseous, aqueous, and sedimentary medium in an automated fashion while achieving a precision comparable to standard laboratory-based techniques such as Isotope Ratio Mass Spectrometry [IRMS]. What sets this instrument apart from traditional IRMS is that 1) it will be field-portable, being the approximate size and weight of a standard travel suitcase, 2) it will make relatively rapid measurements (~1 measurement/sec), and 3) the total cost of the assembled parts will be approximately an order of magnitude less than purchasing a new IRMS. Kessler’s development efforts are focused on optimizing this instrument for terrestrial and extraterrestrial field research by 1) optimizing optical stability, sampling rate, precision, and sensitivity with respect to final instrument size and power requirements, 2) identifying the most reliable adsorption wavelength for CDH3 analyses, and 3) incorporating both near- and mid-IR semi-conductor lasers into the system as well as methane pre-concentrators and front-end methane samplers. All components for the Princeton CRDS have arrived and assembly is underway. The ultimate goal is to develop an instrument that is flight capable and can be proposed for the Astrobiology Field Laboratory mission. To this end, Onstott was Co-PI with Kevin K. Lehmann of the University of Virginia in a proposal submitted to the ASTID 2006 program for development of a Mars-landed mission CRDS.
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PROJECT INVESTIGATORS:
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PROJECT MEMBERS:
Kevin Lehmann
Co-Investigator
John Kessler
Postdoc
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RELATED OBJECTIVES:
Objective 2.1
Mars exploration
Objective 3.2
Origins and evolution of functional biomolecules
Objective 3.3
Origins of energy transduction
Objective 4.1
Earth's early biosphere
Objective 5.2
Co-evolution of microbial communities
Objective 5.3
Biochemical adaptation to extreme environments
Objective 6.2
Adaptation and evolution of life beyond Earth
Objective 7.1
Biosignatures to be sought in Solar System materials
Objective 7.2
Biosignatures to be sought in nearby planetary systems