General Mars
  Implications of Life

  Definition of Life
  Martian Meteorite

Data Analysis
  Thin Section Analysis
  Isotope Analysis
  Gas Chromatograph Mass Spectrometer
  Infrared Spectroscopy
  Alpha-Proton X-Ray Spectrometer
  Detection of Carbon Complexes
  Labeled Release
  Gas Exchange
  Pyrolytic Release
  Stimulus Response Experiments

Scientific Research and Design
Data Analysis -- Gas Exchange

The gas exchange experiment (GX) is based on the assumption that life consisted of heterotrophic microorganisms requiring the presence of or direct contact with organic substrates and possibly various organic growth factors for their metabolism, and that metabolism would involve the uptake or release of metabolic gases. 

Positive: Detection of metabolic gases (H2, Ne, N2, O2, Ar, or CO, NO, CH4, Kr, CO2, N2O, or H2S) after experimental procedure but none detected by the control. 

Negative: No such gases emitted by sample 

False-Positive: The presence of peroxides and superoxides in the soil could cause a false-positive. Upon contact with moisture, these compounds could produced O2 and are therefore not evidence of life. This will be avoided simply by judicious sample selection. 

mitCopyright © 2000 Massachusetts Institute of Technology
Comments and questions to Last updated: 10 December, 2000