The Pathfinder spacecraft , now the Sagan Memorial Station, has ended the primary mission phase after returning a scientific bonanza from the surface of Mars . The Sojourner robot rolled hundreds of feet on the martian surface, circumnavigated the lander, and produced a wealth of data and images . As Mars rotates, most of its surface becomes visible. During Earth 's recent pass between Mars and the Sun , the Hubble Space Telescope was able to capture the most detailed time-lapse pictures ever from the Earth . Dark and light sand and gravel create an unusual blotted appearance for the red planet .
Winds cause sand-tinted features on the Martian surface to shift over time.
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.