By Matthew Polacek Methane on Mars Mars Methane

By Matthew Polacek Methane on Mars: Mars Methane Detection and Variability at Gale Crater

Methane Production �Atmospheric CH 4 on Earth �Biological sources Methanogens �Abiotic sources UV degradation Geothermal Production Etc. ,

Detection of Methane on Mars �Early Measurements Canada-France-Hawaii telescope NASA IRTF PFS MEX TES �Indications of global averages and localized plumes of methane

Modeling Methane on Mars �Plume findings are questionable Variability in measurements Lack of supporting evidence

Tunable Laser Spectrometer �Increased accuracy of the TLS at SAM on the Curiosity Rover �Two channel tunable laser spectrometer Channel 1, 2. 78 microns Channel 2, 3. 27 microns

Observations �Note: 1 -sol=24 hours 37. 5 minutes �Data from 605 sols � 11 direct ingest measurements and 2 methane enrichment experiments �Three groups Low-methane direct ingest Low-methane enrichment runs High-methane direct ingest

Analysis �Exogenous organics IDP and comets �Modeling UV/CH 4 conversion rate 2. 2 ppbv model vs. . 7 ppbv actual �High-methane results No quantitative correlation

Source: �Mars methane detection and variability at Gale crater Christopher R. Webster et al. Science 347, 415 (2015); DOI: 10. 1126/science. 1261713