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And now the weather ... on Mars! 
Blinding dust storms can seriously ruin your plans for a landing on Mars. ESA is adapting the global climate models that we use to forecast our weather on Earth for the turbulent conditions that Mars offers its future visitors. You could hardly call the weather on Mars pleasant, and presently it is far from predictable. As well as having an average surface temperature of -63°C, and a thin, inhospitable atmosphere of mainly carbon dioxide, last year, a springtime dust storm smothered the entire planet for months. There are also dust devils, which are swirling columns of dust that can reach several kilometres in height that frequently race across the barren surface. Such severe and dusty weather conditions can interfere with the manoeuvres made by spacecraft as they enter an orbit around the planet. For a craft landing on the surface, scientific investigations would have to be put on hold until the weather got better.
Here on Earth, it is water that is the driving force behind our weather. On Mars, where there is only a tiny amount of water vapour from its north pole in summer, dust takes over the role, heating the atmosphere by absorbing sunlight. Since the atmosphere on Mars is so thin and there are no oceans on the surface to store the heat from the Sun, temperatures rise and fall more quickly and dramatically because of surface changes and atmospheric heating by the Sun.
Similarly to Earth's weather, hot air rising at the equator is replaced by cooler air, giving rise to trade winds which stir up the Martian dust, provoking the small storms that can merge to form the monster tempests.
A super-resolution camera will take more accurate and detailed images of the Martian atmosphere than ever before, imaging the entire planet in full colour, 3D, and at high resolution. Two other instruments will take vital measurements of the dust, atmospheric gases, and surface composition.
Over its four-year lifetime, Mars Express will be closely watching the clouds, fog, dust devils, and storms, looking for clues to explain the climate changes on Mars, now and in the past. The data it returns will help to check and refine the new Martian global climate models so that future missions make sure they arrive there during the high season.
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