Click on image for full size (144K GIF) Image Courtesy of NASA

The uniquely red global surface of Mars is marked by many interesting features - some like those on the Earth and others strangely different. The reddish color is caused by rust (iron oxide) in the soil.

Some of these features are; volcanoes, canyon systems, river beds, cratered terrain, and dune fields.

Of these features, the most interesting includes the apparently dead volcano Olympus Mons, which rises 23 km (~75,000 ft) above the surrounding plains and is the highest known peak in the Solar System. Valles Marineris is a giant canyon system that runs about 2,500 miles across the surface of the planet and reaches depths of 6 km or 4 miles (for comparison, the Grand Canyon is not more than 1 mile deep).