New modelling of Mars’s most striking cloud

This split view shows the Arsia Mons Elongated Cloud, or AMEC, on Mars: a white wisp of water ice that emerges downwind of the 20-km-tall Arsia Mons volcano every day in martian spring and summer. Researchers now think that exotic physics might be behind this cloud’s formation – physics related to how water vapour turns into icy cloud particles.

The view at the top shows actual observations of the cloud made by the European Space Agency’s Mars Express mission (with the spacecraft’s Visual Monitoring Camera). This video was previously released by ESA in 2021.

The simulation below shows how the cloud emerges in new modelling by scientists using Mars Express to explore how the cloud springs to life (using a regional atmospheric model).

As time continues, indicated to the top left, the AMEC can be seen emerging in both views. Some differences can be seen between the two views (timing, duration, length), but this still represents a big success for the model, as we do not know nearly as much about Mars’s atmospheric state as we do about Earth’s.

The full story

[Image description: GIF with two panels. The top panel is titled 'Observations' and shows a satellite view of Mars. A dark area moves from right to left, revealing Mars's surface, and with it, a white cloud emanating from a volcano. The bottom panel is titled 'Simulation'. Like in the 'Observations' panel above, a dark area moves from right to left, revealing Mars's surface and a white cloud coming from the volcano. The size, shape and movement of the white cloud are very similar in the observations and the simulation.]