English: Swiss Cheese terrain on the south polar cap of Mars, as seen by Mars Global Surveyor. Largest mesas ~4 meters (13 feet) high; area of 3 x 3 kilometers (1.9 x 1.9 miles).
The NASA website hosts a large number of images from the Soviet/Russian space agency, and other non-American space agencies. These are not necessarily in the public domain.
The SOHO (ESA & NASA) joint project implies that all materials created by its probe are copyrighted and require permission for commercial non-educational use. [2]
Swiss Cheese terrain on the south polar cap of Mars, as seen by Mars Global Surveyor. Largest mesas ~4 meters (13 feet) high; area of 3 x 3 kilometers (1.9 x 1.9 miles).