- Jan 7, 2002
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Take a look on the left side of the animation. See those three aligned blue spots, with the one blue spot to the lower right? Those are called orographic clouds, formed when moist air is lifted up over an obstacle; the air cools and the moisture condenses, forming clouds. What kind of obstacle on the Martian surface could do that?
Volcanoes. Yes, volcanoes: in the animation, you can actually see clouds that have formed as the Martian atmosphere moves up the banks of the enormous volcanoes on the Tharsis shield, a massive uplift feature on Mars. The fourth cloud to the lower right is actually marking the spot of Olympus Mons, the largest volcano in the solar system.