TGO watches evolution of dust storm on Mars
The ExoMars Trace Gas Orbiter's main science mission began at the end of April 2018, just a couple of months before the start of the global dust storm that engulfed the planet. TGO followed the onset and development of the storm and monitored how the increase in dust affected the water vapour in the atmosphere.
TGO made the first high-resolution solar occultation measurements with its two spectrometers ACS and NOMAD, by looking at the way sunlight is absorbed in the atmosphere to reveal the chemical fingerprints of its ingredients. This enabled the vertical distribution of water vapour and 'semi-heavy' water, to be plotted from close to the martian surface to above 80 km altitude – important for understanding the history of water at Mars over time. The new results track the influence of dust in the atmosphere on water, and provide further insight into the escape of hydrogen atoms into space. The instruments also recorded dust and ice clouds appearing at different altitudes, and a quick enhancement of water vapour in the atmosphere.