In June, NASA’s Curiosity rover reported the highest burst of methane recorded yet, but neither ESA’s Mars Express nor the ExoMars Trace Gas Orbiter recorded any signs of the illusive gas, despite flying over the same location at a similar time.

New press release from ESA: http://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/Exploration/ExoMars/ESA_s_Mars_orbiters_did_not_see_latest_Curiosity_methane_burst