Visible in the above pictures are the north polar cap , made of water ice and dry ice , clouds including an unusual cyclone , and huge volcanoes leftover from ancient times. The Mars Global Surveyor satellite orbiting Mars continues to scan the surface for good places to land future robot explorers . Contrasting colors trace changing elevations in this new high-resolution topographic map of Mars . Likely the result of an asteroid impact, Mars' deepest basin is about 1300 miles across making it one of the largest impact features in the Solar System. Explorations of MOLA's rich topographic database are expected to produce insights into water flows and the geologic history of Mars.
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