This was
your sky.

Clouds Over Tharsis on Mars

When and where do clouds form on Mars? The Mars Global Surveyor spacecraft, orbiting Mars, captured these clouds forming above Tharsis. Tharsis is a huge bulge on Mars, about 4,000 kilometers across and 7 kilometers high, containing several large volcanoes. These clouds temporarily disappeared as a large dust storm, the first tracked by an orbiting spacecraft, emerged from the South.