Discover the secrets of a giant cloud of Mars

2021/06/22 Elhuyar Zientzia Iturria: Elhuyar aldizkaria

Images of the special cloud described by the UPV/EHU Group of Planetary Sciences. ESA/GCP/UPV

On Mars a special cloud of water ice is created. It can reach 1,800 km in length and 150 km in width. It opens very quickly and in a few hours disappears again. But it repeats itself every morning, when spring reaches the south of Mate. The UPV-EHU Planetary Science team has unveiled the mystery of the giant cloud through new observations of the Mars Express probe that returns to the orbit of Mars since 203.

The giant cloud rises near the volcano Arsia Mons. The volcano, 20 km high, causes the cloud by obstruction to the wind. The air has to climb the slopes of the volcano and when carrying moisture it cools. This creates an orographic cloud: It is formed at 45 km of height, where the upper wind drags, very quickly, to 600 km/h. This generates the largest orographic cloud ever seen on Mars for two or three hours.

It is generated every day for several months, before dawn. However, at sunrise, the air temperature increases and disappears by evaporation. Jorge Hernández Bernal, researcher of Planetary Sciences, and professor Agustín Sánchez Lavega, consider that studying in depth the creation of the cloud will contribute to improve our knowledge about the climate systems of Mars and Earth. More information on the UPV website.