The ExoMars Trace Gas Orbiter’s Atmospheric Chemistry Suite, ACS, made test measurements of the martian atmosphere between 28 February and 7 March 2017.
An example spectra is shown in the plot, made at thermal-infrared wavelengths. The deep and wide spectral band at the left of the plot is due to carbon dioxide, the main component of the martian atmosphere. Information held in the centre of this band corresponds to the temperature of the upper layers of the atmosphere, while the ‘wings’ correspond to the lower layers.
Information like this will enable scientists to compute the temperature profile of the atmosphere, which in turn will contribute to computer models of global atmosphere circulation.