17th December 2014 Sol 840

I am at the American Geophysical Union Conference in San Francisco.  The big MSL news here is the publication of our discovery of methane in the martian atmosphere.  This was done with the Tunable Laser Spectrometer in SAM.  Samples of the atmosphere were let in to the spectrometer over a 20  month period.  This spectrometer uses infrared lasers and mirrors to measure the absorption of light by atmospheric gases.  From this methane CH4 is identified, even in very small quantities.  Totals reached about 7 parts per billion atmospheric molecules, which is hundred of times less than the Earth’s atmosphere. However it raises one of the big questions of Mars exploration – if there is methane, is that a sign of past life?

You can read more about how the TLS works here:

http://ssed.gsfc.nasa.gov/sam/adventure/

My contribution with colleague Dr Susanne Schwenzer, to the methane work published in Science this week, is to check the composition of the rocks we drove over at the time of each methane analysis to see if there is any link to the methane releases.  There isnt so we have an unidentified source.

Methane can form in a variety of ways – one of them is the alteration of the mineral olivine.  I am talking about the alteration of the Gale rocks in one of the other AGU sessions. Its part of a paper that we have just got ‘in press’ at the Journal of Geophysical Research – the first UK-led paper on Mars Science Laboratory.  We show that a mixture of olivine and amorphous/glassy material altered as the sediments were buried and heated in a wet environment to form clay and magnetite – two of the minerals identified by CheMin.  This is helping to piece together how water interacted with the martian crust.