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The Tunable Laser Spectrometer (TLS) includes a new kind of semiconductor laser, the interband cascade laser, which was developed at MDL specifically for methane detection. The Tunable Laser Spectrometer (TLS) includes a new kind of semiconductor laser, the interband cascade laser, which was developed at MDL specifically for methane detection.
ABOVE: Low-angle self-portrait of NASA's Curiosity Mars rover shows the vehicle at the site from which it reached down to drill into a rock target called "Buckskin" on lower Mount Sharp.

MDL News & Trends

MDL-Developed Interband Cascade Laser for the TLS has Measured a Tenfold Spike in Methane

NASA's Mars Curiosity rover has measured a tenfold spike in methane, an organic chemical, in the atmosphere around it and detected other organic molecules in a rock-powder sample collected by the robotic laboratory's drill. This temporary increase in methane -- sharply up and then back down indicates there must be some relatively localized source. There are many possible sources, biological or non-biological, such as interaction of water and rock.

Researchers used Curiosity's onboard Tunable Laser Spectrometer in the Sample Analysis at Mars (SAM) laboratory a dozen times in a 20-month period to sniff methane in the atmosphere. During two of those months, in late 2013 and early 2014, four measurements averaged seven parts per billion. Before and after that, readings averaged only one-tenth that level.

Curiosity also detected different Martian organic chemicals in powder drilled from a rock dubbed Cumberland, the first definitive detection of organics in surface materials of Mars. These Martian organics could either have formed on Mars or been delivered to Mars by meteorites.

NASA's Mars rover Curiosity drilled into this rock target, "Cumberland," during the 279th Martian day, or sol, of the rover's work on Mars (May 19, 2013) and collected a powdered sample of material from the rock's interior. NASA's Mars rover Curiosity drilled into this rock target, "Cumberland," during the 279th Martian day, or sol, of the rover's work on Mars (May 19, 2013) and collected a powdered sample of material from the rock's interior.

Organic molecules, which contain carbon and usually hydrogen, are chemical building blocks of life, although they can exist without the presence of life. Curiosity's findings from analyzing samples of atmosphere and rock powder do not reveal whether Mars has ever harbored living microbes, but the findings do shed light on a chemically active modern Mars and on favorable conditions for life on ancient Mars.

"This first confirmation of organic carbon in a rock on Mars holds much promise," said Curiosity Participating Scientist Roger Summons of the Massachusetts Institute of Technology in Cambridge. "Organics are important because they can tell us about the chemical pathways by which they were formed and preserved. In turn, this is informative about Earth-Mars differences and whether or not particular environments represented by Gale Crater sedimentary rocks were more or less favorable for accumulation of organic materials. The challenge now is to find other rocks on Mount Sharp that might have different and more extensive inventories of organic compounds."

More information can be found online at:
http://www.jpl.nasa.gov/news/news.php?feature=4413

Analyses of findings were featured in the January issue of Science magazine in 2015:
“Mars methane detection and variability at Gale crater”, C. R. Webster, et al. Science 23 January 2015: Vol. 347 no. 6220 pp. 415-417