Wednesday 5th September Sol 29

We have been making initial analyses of the Mars atmosphere using SAM (Surface Analysis at Mars) which includes a mass spectrometer with gas chromatography.  This instrument is hoped to provide us with the most accurate analysis of the Mars atmosphere so far achieved.  Parts of SAM can also analyse solid samples for organic compounds but for the time being we are concentrating on the atmospheric analyses. 

But why is this important?  The Mars atmosphere has not been protected by a magnetic field since the Mars magnetic field dipole stopped about 4 billion years ago.  However, the heavy noble gases like xenon and krypton have been less affected by the atmospheric loss processes that have stripped Mars of much of its atmosphere since the planet’s magnetic field stopped.  So, one reason the SAM analyses are important is that when we look at the ratios of the heavy noble gases and their different isotopes we are in effect studying the ancient atmosphere of Mars when the planet’s climate was very different from todays.