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Thermal and Evolved Gas Analyzer (TEGA)

NSSDCA ID: 2007-034A-04

Mission Name: Phoenix Mars Lander
Principal Investigator:Dr. William V. Boynton


The Thermal and Evolved Gas Analyzer (TEGA) is designed to analyze ice and soil samples to determine the isotopic ratios of hydrogen, oxygen, carbon, and nitrogen. TEGA consists of a set of eight miniature high-temperature furnaces and a mass spectrometer. Each furnace can be used only once. A sample is delivered by the robotic arm to an oven, which is sealed. Scanning calorimetry, where the temperature is increased slowly and the energy usage is carefully monitored, is done to determine when phase changes of the different components occur. As ices and other volatiles are vaporized, the evolved gases are delivered to the mass spectrometer to determine their elemental and molecular composition. The mass spectrometer is sensitive to concentrations as small as 10 parts per billion.

Alternate Names

  • PhoenixMarsLander/TEGA
  • TEGA
  • urn:nasa:pds:context:instrument:tega.phx

Funding Agency

  • NASA-Office of Space Science Applications (United States)


  • Planetary Science: Geology and Geophysics

Additional Information

Questions and comments about this experiment can be directed to: Dr. David R. Williams



NameRoleOriginal AffiliationE-mail
Dr. Heather L. EnosExperiment ManagerUniversity of
Dr. William V. BoyntonLead InvestigatorUniversity of

Selected References

  • Boynton, W. V., et al., Evidence for Calcium Carbonate at the Mars Phoenix Landing Site, Science, 325, No. 5936, 61-64, doi:10.1126/science.1172768, July 2009.
  • Sutter, B., et al., The detection of carbonate in the martian soil at the Phoenix Landing site: A laboratory investigation and comparison with the Thermal and Evolved Gas Analyzer (TEGA) data, Icarus, 218, No. 1, p. 290-296, doi:10.1016/j.icarus.2011.12.002, Mar. 2009.
  • Hoffman, J. H., et al., Phoenix Mars Mission-The Thermal Evolved Gas Analyzer, J. Am. Soc. Mass. Spectrom. Sci., 19, No. 10, 1377-1383,doi:10.1016/j.jasms.2008.07.015, Oct. 2008.
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