Clouds Over Tharsis on Mars.

When and where do clouds form on Mars ? The Mars Global Surveyor spacecraft currently orbiting Mars is finding out. Photographs released last week showed clouds forming above Tharsis , a huge bulge on Mars about 4000 kilometers across and 7 kilometers high containing several large volcanoes . These clouds temporarily disappeared as a large dust storm emerged from the South , the first developing dust storm to be tracked by an orbiting spacecraft. Mars Global Surveyor continues to aerobrake during on its ongoing mission to survey the planet Mars.